My 2c between Mtb in wet and mucky Irish conditions and work (a large variety of food manufacturing and packaging equipment) both are equally disastrous to bearings. I’ve often had to replace bearings from machine manufacturers with “mtb spec” 2rs SS repacked so it’s not just bike manufacturers skimping. Slow moving Needle bearings (ntn similar sized to mtb pivots) are not sealed and impossible to repack, replaced with 2 tier 1 SS bearings repacked with waterproof grease (2 cartridge bearings same width as a single needle).
Simple Bearing strategy.
1. 2rs tier 1 manufacture (sks, fag, ntn, eye).
2. Pull the seals and fill with marine grease. Yes they don’t spin as well but they will be fine after 200m on the bike.
3. Re pack with grease every 3 years if they have failed at that point get SS versions. (Sks,fag,ntn etc)
4. Wash your bike after every ride, and re lube your chain. 5. 🤞🏻
I’m picking up a year old modern xc race bike with ceramic speed bb and pullies so I’m sure I’ll be replacing them with something stock and Chris king at some point. Find out later.
I'm not an engineer but after having to replace enduro .axx bearings every few months on mu mondraker foxy (terrible linkage design than bathes the bearings...
I'm not an engineer but after having to replace enduro .axx bearings every few months on mu mondraker foxy (terrible linkage design than bathes the bearings in mud and water with no drainage) I stared looking for a better option. I believe solid lubricated bearings for pivots makes sense. I think sks or ntn has a version. Incredibly hard to find though. My question is, are enduro maxx bearings actually any good? The tolerances of the balls and cages seems very loose.
Enduro bearings are cheap Chinese bearings with a great marketing team. Enduro maxxx bearings lasted under a year in my 2020 Occam and the NTN ones...
Enduro bearings are cheap Chinese bearings with a great marketing team. Enduro maxxx bearings lasted under a year in my 2020 Occam and the NTN ones I put in have been fine for over 3 years. I carefully removed the seals and packed them with green grease so I’m sure that helped.
My Mondraker uses 10pcs 15x24x7 3802 size bearings. The upper and lower linkages seem to eat bearings even though I've made a small additional mudcover. The original bearings can be found priced around 55 - 130 euros as a set but I'm not sure what's the quality.
I would like to buy and test some "premium" bearings but the 7mm version of the 15x24 bearing seems to be quite hard to find from any let's say premium bearing vendor like SKF. I've used couple of times a special tool to push the bearing full grease through the seals (Alantani bearing packer) but it doesn't seem to make much difference. I have also good tools from Bearingpro Tools UK that keep bearing work very easy.
The Enduro bearings don't seem to release any standards if they fulfil the DIN 628-3 or DIN 625-1 or actually anything. I'm not saying it would be mandatory but that would make them less bicycle-specific magic bearings.
Enduro bearings state also that the 3802 LLU MAX BO static load is 4310 N and for comparison in (for the example) www.kugellager-express.de/ sells china-bearings where similar bearings have at max to 1560N static load rating (3802-2RS-TN model) and the 63802-V-2RS circa 864 N. I wonder if this variable have any effect on anything or is the biggest reason just either poor frame design to protect in harsh (wet) riding conditions or bad bearing quality.
It would be interesting to know why Mondraker chose this very bicycle-specific bearing.
//corrected kugellager-express numbers to be static not dynamic as they were.
My 2c between Mtb in wet and mucky Irish conditions and work (a large variety of food manufacturing and packaging equipment) both are equally disastrous to...
My 2c between Mtb in wet and mucky Irish conditions and work (a large variety of food manufacturing and packaging equipment) both are equally disastrous to bearings. I’ve often had to replace bearings from machine manufacturers with “mtb spec” 2rs SS repacked so it’s not just bike manufacturers skimping. Slow moving Needle bearings (ntn similar sized to mtb pivots) are not sealed and impossible to repack, replaced with 2 tier 1 SS bearings repacked with waterproof grease (2 cartridge bearings same width as a single needle).
Simple Bearing strategy.
1. 2rs tier 1 manufacture (sks, fag, ntn, eye).
2. Pull the seals and fill with marine grease. Yes they don’t spin as well but they will be fine after 200m on the bike.
3. Re pack with grease every 3 years if they have failed at that point get SS versions. (Sks,fag,ntn etc)
4. Wash your bike after every ride, and re lube your chain. 5. 🤞🏻
I’m picking up a year old modern xc race bike with ceramic speed bb and pullies so I’m sure I’ll be replacing them with something stock and Chris king at some point. Find out later.
Pretty much what I wrote earlier. 👍
However, be careful with stainless steel bearings: they have a lower load capacity because stainless is softer than hardened bearing steel. If you fill your bearings with marine grease and maintain them regularly anyway, there are only disadvantages in going stainless.
Excellent topic once again!My Mondraker uses 10pcs 15x24x7 3802 size bearings. The upper and lower linkages seem to eat bearings even though I've made a small...
Excellent topic once again!
My Mondraker uses 10pcs 15x24x7 3802 size bearings. The upper and lower linkages seem to eat bearings even though I've made a small additional mudcover. The original bearings can be found priced around 55 - 130 euros as a set but I'm not sure what's the quality.
I would like to buy and test some "premium" bearings but the 7mm version of the 15x24 bearing seems to be quite hard to find from any let's say premium bearing vendor like SKF. I've used couple of times a special tool to push the bearing full grease through the seals (Alantani bearing packer) but it doesn't seem to make much difference. I have also good tools from Bearingpro Tools UK that keep bearing work very easy.
The Enduro bearings don't seem to release any standards if they fulfil the DIN 628-3 or DIN 625-1 or actually anything. I'm not saying it would be mandatory but that would make them less bicycle-specific magic bearings.
Enduro bearings state also that the 3802 LLU MAX BO static load is 4310 N and for comparison in (for the example) www.kugellager-express.de/ sells china-bearings where similar bearings have at max to 1560N static load rating (3802-2RS-TN model) and the 63802-V-2RS circa 864 N. I wonder if this variable have any effect on anything or is the biggest reason just either poor frame design to protect in harsh (wet) riding conditions or bad bearing quality.
It would be interesting to know why Mondraker chose this very bicycle-specific bearing.
//corrected kugellager-express numbers to be static not dynamic as they were.
The bearing you are looking for is a dual row angular contact ball bearing, Kugellager express has it. It's a 3802. Enduro also has them.
Notice the numbers you are comparing are static vs. dynamic loading which is not the same.
As for bushings, they are technically ideal for pivots, but require additional sealing (could be used for bearings to prolong the life as well, based on how often it is implemented it's science fiction for the bike industry...), a hardened axle to slide in the bearings, but the problem is they need clearance to operate and thus you will get knocking from your rear end.
A properly mounted (and executed design wise) ball bearing will be preloaded axially and thus will not have any slop and/or sliding upon start of rotation. Yes, bushings are technically more suitable for pivots, but everybody using them sooner or later goes back to ball bearings...
Regarding my experience, I normally run (ran) max fill Kugellager express bearings in a non-sealed Bird frame, switching to Enduros they lasted longer in the same frame. Don't have a long track record on that one though...
The bearing you are looking for is a dual row angular contact ball bearing, Kugellager express has it. It's a 3802. Enduro also has them. Notice the...
The bearing you are looking for is a dual row angular contact ball bearing, Kugellager express has it. It's a 3802. Enduro also has them.
Notice the numbers you are comparing are static vs. dynamic loading which is not the same.
As for bushings, they are technically ideal for pivots, but require additional sealing (could be used for bearings to prolong the life as well, based on how often it is implemented it's science fiction for the bike industry...), a hardened axle to slide in the bearings, but the problem is they need clearance to operate and thus you will get knocking from your rear end.
A properly mounted (and executed design wise) ball bearing will be preloaded axially and thus will not have any slop and/or sliding upon start of rotation. Yes, bushings are technically more suitable for pivots, but everybody using them sooner or later goes back to ball bearings...
Regarding my experience, I normally run (ran) max fill Kugellager express bearings in a non-sealed Bird frame, switching to Enduros they lasted longer in the same frame. Don't have a long track record on that one though...
Sorry my typo! I corrected to my post that the numbers were static load.
I'm not saying that it matters but I find it little interesting that Endurobearings exceeds most normal bearings static load rating like it's 4x what FAG has. I wonder what makes the difference?
From an industry perspective Enduro is almost ubiquitous for a few reasons: 1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively expensive) to source elsewhere. They are one of the few suppliers with a wide range of max complement small bearings. Max complement is a big improvement in load capacity for the specific use case of suspension pivots (high dynamic load, low rotation speeds).
2. They are well known and have lots of international support for people replacing bearings. Go try replacing all the bearings on a Pivot Firebird with NTN equivalents. You might be able to do this in Germany but in a lot of the world finding someone who can supply a dozen bearings of mixed sizes from NTN will be challenging and expensive.
Enduro are not perfect but they are not the total junk some people would have you believe. The seals are a bit weak, and they don't seem to use quality factory grease. However, IMO the primary causes of bearing failure are: 1. Poor frame alignment and bearing layout. This is honestly hard to get right depending on the suspension layout. A chainstay weldment with bearings in the chainstay will NEVER have the bearings within any sort of engineering concentricity tolerance. This is less critical if the bearings are significantly oversized. The other tolerance issue is bore circularity which from some manufacturers (and even between runs of a single mfg) will vary in quality significantly. In aluminium you need a reasonable interference fit and frequently I see bikes where the bearing can be pushed in/out by hand (especially after being worn in).
2. Undersized bearings from the OEM. No excuses on this one. I see it on at least 60% of bikes. It saves ~100g of weight and requires much more frequent bearing replacement. In other cases, it is done to ease packaging constraints but it's just bad design. You see companies specifying bearings based on average replacement lifespan (a season) rather than proper load rating.
3. Inadequate sealing. Depending on how much flex the bearing will see and where the bearing is located they need more than just the rubber seal. Bikes see a LOT of water and fine dirt particles. In places of high exposure, they should have some sort of bearing covers. Rocky Mountain did a good job on their main pivots with this. Deviate also has an excellent seal arrangement for their main pivot (although I am sure the friction is quite a bit higher).
4. Lack of preload. This is a huge one; deep groove ball bearings are designed to have a small amount of preload during dynamic loading (and especially dynamic radial loading). Not having this drastically reduces their lifespan. In many places, this can be very hard to achieve on bicycle pivots. I had previously designed a hub assembly for an open-wheel race car that had the hub machined incorrectly so that the preload bolt was not fully engaging. The car went through bearings in under an hour of operation. Once the issue was fixed and the preload nut properly tensioned between the inner and outer bearings the bearings were not replaced for another 3 years. The best example of this being done on bikes is the Orbea Rallon main pivot. The bearings are in the frame, the primary axle is tightened finger tight to preload them, and then the chainstay uses a pinch bolt onto the axle to lock the assembly down. Assuming the machining of the frame is done well those bearings will probably never need replacement. I attempted something similar on the Norco Range main pivot but due to the size of the threads, it is difficult to estimate the required preload. Lower bearing life on that bike was also quite poor for some people likely due to poor concentricity of the two bores (they were machined in separate operations). (edit: Apparently the Rallon ruined a perfect assembly by putting a spacer sleeve between the two bearings. This will prevent proper preload but it does allow someone to tighten the bolt down to 3 ugga duggas without destroying the bearings).
Bushings might sound like Engineering 101 for bicycle pivots but they are absolutely not the right option for a myriad of reasons. The friction increase will be very noticeable in suspension feel, bushings require extremely tight shaft and bore tolerances for proper operation, and bushings must be kept very clean. Bearings are more forgiving as they use integrated sealing and the shaft tolerance has a much wider range of function as the tightest tolerances are internal to the bearing assembly.
From an industry perspective Enduro is almost ubiquitous for a few reasons:1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively...
From an industry perspective Enduro is almost ubiquitous for a few reasons: 1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively expensive) to source elsewhere. They are one of the few suppliers with a wide range of max complement small bearings. Max complement is a big improvement in load capacity for the specific use case of suspension pivots (high dynamic load, low rotation speeds).
2. They are well known and have lots of international support for people replacing bearings. Go try replacing all the bearings on a Pivot Firebird with NTN equivalents. You might be able to do this in Germany but in a lot of the world finding someone who can supply a dozen bearings of mixed sizes from NTN will be challenging and expensive.
Enduro are not perfect but they are not the total junk some people would have you believe. The seals are a bit weak, and they don't seem to use quality factory grease. However, IMO the primary causes of bearing failure are: 1. Poor frame alignment and bearing layout. This is honestly hard to get right depending on the suspension layout. A chainstay weldment with bearings in the chainstay will NEVER have the bearings within any sort of engineering concentricity tolerance. This is less critical if the bearings are significantly oversized. The other tolerance issue is bore circularity which from some manufacturers (and even between runs of a single mfg) will vary in quality significantly. In aluminium you need a reasonable interference fit and frequently I see bikes where the bearing can be pushed in/out by hand (especially after being worn in).
2. Undersized bearings from the OEM. No excuses on this one. I see it on at least 60% of bikes. It saves ~100g of weight and requires much more frequent bearing replacement. In other cases, it is done to ease packaging constraints but it's just bad design. You see companies specifying bearings based on average replacement lifespan (a season) rather than proper load rating.
3. Inadequate sealing. Depending on how much flex the bearing will see and where the bearing is located they need more than just the rubber seal. Bikes see a LOT of water and fine dirt particles. In places of high exposure, they should have some sort of bearing covers. Rocky Mountain did a good job on their main pivots with this. Deviate also has an excellent seal arrangement for their main pivot (although I am sure the friction is quite a bit higher).
4. Lack of preload. This is a huge one; deep groove ball bearings are designed to have a small amount of preload during dynamic loading (and especially dynamic radial loading). Not having this drastically reduces their lifespan. In many places, this can be very hard to achieve on bicycle pivots. I had previously designed a hub assembly for an open-wheel race car that had the hub machined incorrectly so that the preload bolt was not fully engaging. The car went through bearings in under an hour of operation. Once the issue was fixed and the preload nut properly tensioned between the inner and outer bearings the bearings were not replaced for another 3 years. The best example of this being done on bikes is the Orbea Rallon main pivot. The bearings are in the frame, the primary axle is tightened finger tight to preload them, and then the chainstay uses a pinch bolt onto the axle to lock the assembly down. Assuming the machining of the frame is done well those bearings will probably never need replacement. I attempted something similar on the Norco Range main pivot but due to the size of the threads, it is difficult to estimate the required preload. Lower bearing life on that bike was also quite poor for some people likely due to poor concentricity of the two bores (they were machined in separate operations). (edit: Apparently the Rallon ruined a perfect assembly by putting a spacer sleeve between the two bearings. This will prevent proper preload but it does allow someone to tighten the bolt down to 3 ugga duggas without destroying the bearings).
Bushings might sound like Engineering 101 for bicycle pivots but they are absolutely not the right option for a myriad of reasons. The friction increase will be very noticeable in suspension feel, bushings require extremely tight shaft and bore tolerances for proper operation, and bushings must be kept very clean. Bearings are more forgiving as they use integrated sealing and the shaft tolerance has a much wider range of function as the tightest tolerances are internal to the bearing assembly.
Do you design bikes out of interest? You seem very knowledgeable on the minutiae of bike design.
What are your takeaways then of how to design a frame correctly from a bearing perspective?
Use larger bearings, accurate tolerances, and preloaded (is a collet style main pivot good for this?) seem like the big 3 from what you've said.
Obviously it's give and take with all the other aspects, but I do like designs like the RAAW Madonna with it's oversized main pivot bearings, and extra sealing, not sure if they're preloaded properly however?
FWIW, the spacer in orbea has logic to it. It's the same approach that is used in hubs - you achieve the bearing preload through the spacer width vs. Casing seat width. The problem is that you need tight tolerances to achieve the correct preload which might be hard to achieve. A lot of hubs use adjustable preload as it's just easier and cheaper.
As for suspension pivots, the way Santa Cruz does the lower link is actually really smart (and a correct application of a collet axle, unlike Bird for example). You screw the axle into the chainstay and preload the bearing with a step in the axle, but nothing holds the Chainstay on the NDS axially vs the axle. Expanding the collet axle finally fixes the NDS chainstay to the axle. With that you cover the tolerances in the chainstay assembly (you can have space between the inner face on the NDS and the bearing next to it) and can achieve the bearing preload needed.
From an industry perspective Enduro is almost ubiquitous for a few reasons:1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively...
From an industry perspective Enduro is almost ubiquitous for a few reasons: 1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively expensive) to source elsewhere. They are one of the few suppliers with a wide range of max complement small bearings. Max complement is a big improvement in load capacity for the specific use case of suspension pivots (high dynamic load, low rotation speeds).
2. They are well known and have lots of international support for people replacing bearings. Go try replacing all the bearings on a Pivot Firebird with NTN equivalents. You might be able to do this in Germany but in a lot of the world finding someone who can supply a dozen bearings of mixed sizes from NTN will be challenging and expensive.
Enduro are not perfect but they are not the total junk some people would have you believe. The seals are a bit weak, and they don't seem to use quality factory grease. However, IMO the primary causes of bearing failure are: 1. Poor frame alignment and bearing layout. This is honestly hard to get right depending on the suspension layout. A chainstay weldment with bearings in the chainstay will NEVER have the bearings within any sort of engineering concentricity tolerance. This is less critical if the bearings are significantly oversized. The other tolerance issue is bore circularity which from some manufacturers (and even between runs of a single mfg) will vary in quality significantly. In aluminium you need a reasonable interference fit and frequently I see bikes where the bearing can be pushed in/out by hand (especially after being worn in).
2. Undersized bearings from the OEM. No excuses on this one. I see it on at least 60% of bikes. It saves ~100g of weight and requires much more frequent bearing replacement. In other cases, it is done to ease packaging constraints but it's just bad design. You see companies specifying bearings based on average replacement lifespan (a season) rather than proper load rating.
3. Inadequate sealing. Depending on how much flex the bearing will see and where the bearing is located they need more than just the rubber seal. Bikes see a LOT of water and fine dirt particles. In places of high exposure, they should have some sort of bearing covers. Rocky Mountain did a good job on their main pivots with this. Deviate also has an excellent seal arrangement for their main pivot (although I am sure the friction is quite a bit higher).
4. Lack of preload. This is a huge one; deep groove ball bearings are designed to have a small amount of preload during dynamic loading (and especially dynamic radial loading). Not having this drastically reduces their lifespan. In many places, this can be very hard to achieve on bicycle pivots. I had previously designed a hub assembly for an open-wheel race car that had the hub machined incorrectly so that the preload bolt was not fully engaging. The car went through bearings in under an hour of operation. Once the issue was fixed and the preload nut properly tensioned between the inner and outer bearings the bearings were not replaced for another 3 years. The best example of this being done on bikes is the Orbea Rallon main pivot. The bearings are in the frame, the primary axle is tightened finger tight to preload them, and then the chainstay uses a pinch bolt onto the axle to lock the assembly down. Assuming the machining of the frame is done well those bearings will probably never need replacement. I attempted something similar on the Norco Range main pivot but due to the size of the threads, it is difficult to estimate the required preload. Lower bearing life on that bike was also quite poor for some people likely due to poor concentricity of the two bores (they were machined in separate operations). (edit: Apparently the Rallon ruined a perfect assembly by putting a spacer sleeve between the two bearings. This will prevent proper preload but it does allow someone to tighten the bolt down to 3 ugga duggas without destroying the bearings).
Bushings might sound like Engineering 101 for bicycle pivots but they are absolutely not the right option for a myriad of reasons. The friction increase will be very noticeable in suspension feel, bushings require extremely tight shaft and bore tolerances for proper operation, and bushings must be kept very clean. Bearings are more forgiving as they use integrated sealing and the shaft tolerance has a much wider range of function as the tightest tolerances are internal to the bearing assembly.
Do you design bikes out of interest? You seem very knowledgeable on the minutiae of bike design.What are your takeaways then of how to design a...
Do you design bikes out of interest? You seem very knowledgeable on the minutiae of bike design.
What are your takeaways then of how to design a frame correctly from a bearing perspective?
Use larger bearings, accurate tolerances, and preloaded (is a collet style main pivot good for this?) seem like the big 3 from what you've said.
Obviously it's give and take with all the other aspects, but I do like designs like the RAAW Madonna with it's oversized main pivot bearings, and extra sealing, not sure if they're preloaded properly however?
Designed for an OEM pre-covid so ancient history. Still do a bit of custom linkage work for various people. Using a split clamp chainstay like the Orbea Rallon (and many steel bikes) with the below bearing layout is pretty much perfect. The main axle would be torqued to basically finger tight and then locked using the split clamp.
Ideally the main frame bore would be bored from 1 side and then retaining rings used to seat the bearings. This ensures concentricity as cheaply as possible (very hard to do machining from two sides). You could also use a undercut endmill and conventional bearing seats.
The main problem with this approach is if you don't look at the manual and know what your are doing you will crank the axle down and crush the bearings together. I think this is the reason most OEM's go with the spacer between. A spacer application without VERY precise tolerances (which effectively won't happen in a frame application) you won't get consistent preload. Even in hub applications I doubt most companies are holding seat to seat tolerances (and the length tolerance on the spacer) accurately enough.
FWIW, the spacer in orbea has logic to it. It's the same approach that is used in hubs - you achieve the bearing preload through the...
FWIW, the spacer in orbea has logic to it. It's the same approach that is used in hubs - you achieve the bearing preload through the spacer width vs. Casing seat width. The problem is that you need tight tolerances to achieve the correct preload which might be hard to achieve. A lot of hubs use adjustable preload as it's just easier and cheaper.
As for suspension pivots, the way Santa Cruz does the lower link is actually really smart (and a correct application of a collet axle, unlike Bird for example). You screw the axle into the chainstay and preload the bearing with a step in the axle, but nothing holds the Chainstay on the NDS axially vs the axle. Expanding the collet axle finally fixes the NDS chainstay to the axle. With that you cover the tolerances in the chainstay assembly (you can have space between the inner face on the NDS and the bearing next to it) and can achieve the bearing preload needed.
I believe Santa Cruz use inner seat-to-seat spacers in most applications so no preload (or based on the link tolerance so unpredictable). Once thing that Santa Cruz does perfectly is using single seal bearings and a zerk fitting to pump grease in the back of the bearing and out the seal. So much better than manually trying to clean and regrease.
True on the spacer. It is possible to achieve preload with the correct length as we discussed, but yeah, not ideal. Still, it gives you a lot more freedom on the chainstay tolerance wise.
As for bearing seats, at some point Frameworks used the headset approach - had a straight bore and then aluminium cups inserted into the bore and bearings into it. Might make sense to do it that way...
From an industry perspective Enduro is almost ubiquitous for a few reasons:1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively...
From an industry perspective Enduro is almost ubiquitous for a few reasons: 1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively expensive) to source elsewhere. They are one of the few suppliers with a wide range of max complement small bearings. Max complement is a big improvement in load capacity for the specific use case of suspension pivots (high dynamic load, low rotation speeds).
2. They are well known and have lots of international support for people replacing bearings. Go try replacing all the bearings on a Pivot Firebird with NTN equivalents. You might be able to do this in Germany but in a lot of the world finding someone who can supply a dozen bearings of mixed sizes from NTN will be challenging and expensive.
Enduro are not perfect but they are not the total junk some people would have you believe. The seals are a bit weak, and they don't seem to use quality factory grease. However, IMO the primary causes of bearing failure are: 1. Poor frame alignment and bearing layout. This is honestly hard to get right depending on the suspension layout. A chainstay weldment with bearings in the chainstay will NEVER have the bearings within any sort of engineering concentricity tolerance. This is less critical if the bearings are significantly oversized. The other tolerance issue is bore circularity which from some manufacturers (and even between runs of a single mfg) will vary in quality significantly. In aluminium you need a reasonable interference fit and frequently I see bikes where the bearing can be pushed in/out by hand (especially after being worn in).
2. Undersized bearings from the OEM. No excuses on this one. I see it on at least 60% of bikes. It saves ~100g of weight and requires much more frequent bearing replacement. In other cases, it is done to ease packaging constraints but it's just bad design. You see companies specifying bearings based on average replacement lifespan (a season) rather than proper load rating.
3. Inadequate sealing. Depending on how much flex the bearing will see and where the bearing is located they need more than just the rubber seal. Bikes see a LOT of water and fine dirt particles. In places of high exposure, they should have some sort of bearing covers. Rocky Mountain did a good job on their main pivots with this. Deviate also has an excellent seal arrangement for their main pivot (although I am sure the friction is quite a bit higher).
4. Lack of preload. This is a huge one; deep groove ball bearings are designed to have a small amount of preload during dynamic loading (and especially dynamic radial loading). Not having this drastically reduces their lifespan. In many places, this can be very hard to achieve on bicycle pivots. I had previously designed a hub assembly for an open-wheel race car that had the hub machined incorrectly so that the preload bolt was not fully engaging. The car went through bearings in under an hour of operation. Once the issue was fixed and the preload nut properly tensioned between the inner and outer bearings the bearings were not replaced for another 3 years. The best example of this being done on bikes is the Orbea Rallon main pivot. The bearings are in the frame, the primary axle is tightened finger tight to preload them, and then the chainstay uses a pinch bolt onto the axle to lock the assembly down. Assuming the machining of the frame is done well those bearings will probably never need replacement. I attempted something similar on the Norco Range main pivot but due to the size of the threads, it is difficult to estimate the required preload. Lower bearing life on that bike was also quite poor for some people likely due to poor concentricity of the two bores (they were machined in separate operations). (edit: Apparently the Rallon ruined a perfect assembly by putting a spacer sleeve between the two bearings. This will prevent proper preload but it does allow someone to tighten the bolt down to 3 ugga duggas without destroying the bearings).
Bushings might sound like Engineering 101 for bicycle pivots but they are absolutely not the right option for a myriad of reasons. The friction increase will be very noticeable in suspension feel, bushings require extremely tight shaft and bore tolerances for proper operation, and bushings must be kept very clean. Bearings are more forgiving as they use integrated sealing and the shaft tolerance has a much wider range of function as the tightest tolerances are internal to the bearing assembly.
Do you design bikes out of interest? You seem very knowledgeable on the minutiae of bike design.What are your takeaways then of how to design a...
Do you design bikes out of interest? You seem very knowledgeable on the minutiae of bike design.
What are your takeaways then of how to design a frame correctly from a bearing perspective?
Use larger bearings, accurate tolerances, and preloaded (is a collet style main pivot good for this?) seem like the big 3 from what you've said.
Obviously it's give and take with all the other aspects, but I do like designs like the RAAW Madonna with it's oversized main pivot bearings, and extra sealing, not sure if they're preloaded properly however?
Designed for an OEM pre-covid so ancient history. Still do a bit of custom linkage work for various people. Using a split clamp chainstay like the...
Designed for an OEM pre-covid so ancient history. Still do a bit of custom linkage work for various people. Using a split clamp chainstay like the Orbea Rallon (and many steel bikes) with the below bearing layout is pretty much perfect. The main axle would be torqued to basically finger tight and then locked using the split clamp.
Ideally the main frame bore would be bored from 1 side and then retaining rings used to seat the bearings. This ensures concentricity as cheaply as possible (very hard to do machining from two sides). You could also use a undercut endmill and conventional bearing seats.
The main problem with this approach is if you don't look at the manual and know what your are doing you will crank the axle down and crush the bearings together. I think this is the reason most OEM's go with the spacer between. A spacer application without VERY precise tolerances (which effectively won't happen in a frame application) you won't get consistent preload. Even in hub applications I doubt most companies are holding seat to seat tolerances (and the length tolerance on the spacer) accurately enough.
These are all great points! Most people don't realise bearings need a minimum amount of preload on them in nearly all bicycle applications, as even if you can't feel play they will move under load which concentrates the force on a single point instead of across multiple balls. Hubs are an interesting one - DT and Hope have normally had decent tolerances, to the point if you fit generic Enduro bearings to them you will immediately get play but using the faactory bearings they run really smooth. It was the most common mistake I saw people make with CK hubs - they would only "nip up" the preload collar which would also create play straight way.
As for bushings in pivots - I had about 4 or 5 Turner DW 5spots and they all had wildly different tolerances - I think my 2010 or 11 bike had almost perfect tolerances, one of the early Fox RP23 shocks and a Marzocchi 55 RC3 Ti - it ran amazing! I think my last one in 2013 had super tight pivots which made for noticeably less sensitivity. I wondered if hardened steel shafts would be better, but the extra outward squish of aluminium helps take up clearances so that might have caused more play as well
Where are all the angular contact bearings at? I have 2 WheelsMFG angular contact BB sets with a couple hard seasons on them. One on my SS and the other on my enduro rig. Semi annual repack with grease and still running smooth, yet to wear one out. Went through multiple dual row BBs on the SS before the WheelsMFG.
Angular contact races are designed to take radial and axial loads simultaneously, which seems like a no brainer for most MTB applications, particularly main pivots in suspension. Am I missing something here? Cost, size other limitations?
Additional drag when preloaded to a suitable degree. Wheelhub bearings in cars are highly preloaded compared to what we run.
That and the need for external seals which takes up axial space. This is probably a big factor in all of it. Complexity in general compared to current setups.
Where are all the angular contact bearings at? I have 2 WheelsMFG angular contact BB sets with a couple hard seasons on them. One on my...
Where are all the angular contact bearings at? I have 2 WheelsMFG angular contact BB sets with a couple hard seasons on them. One on my SS and the other on my enduro rig. Semi annual repack with grease and still running smooth, yet to wear one out. Went through multiple dual row BBs on the SS before the WheelsMFG.
Angular contact races are designed to take radial and axial loads simultaneously, which seems like a no brainer for most MTB applications, particularly main pivots in suspension. Am I missing something here? Cost, size other limitations?
You can get sealed units from Enduro in a handful of good sizes like the 7001 2RS MAX. I actually have no idea why you don't see these more; they are almost without doubt a better option for high load suspension pivots like the main pivot. They really do need some preload mechanism though so that could be part of it.
My 2c between Mtb in wet and mucky Irish conditions and work (a large variety of food manufacturing and packaging equipment) both are equally disastrous to bearings. I’ve often had to replace bearings from machine manufacturers with “mtb spec” 2rs SS repacked so it’s not just bike manufacturers skimping.
Slow moving Needle bearings (ntn similar sized to mtb pivots) are not sealed and impossible to repack, replaced with 2 tier 1 SS bearings repacked with waterproof grease (2 cartridge bearings same width as a single needle).
Simple Bearing strategy.
1. 2rs tier 1 manufacture (sks, fag, ntn, eye).
2. Pull the seals and fill with marine grease. Yes they don’t spin as well but they will be fine after 200m on the bike.
3. Re pack with grease every 3 years if they have failed at that point get SS versions. (Sks,fag,ntn etc)
4. Wash your bike after every ride, and re lube your chain.
5. 🤞🏻
I’m picking up a year old modern xc race bike with ceramic speed bb and pullies so I’m sure I’ll be replacing them with something stock and Chris king at some point. Find out later.
This. 100%.
Excellent topic once again!
My Mondraker uses 10pcs 15x24x7 3802 size bearings. The upper and lower linkages seem to eat bearings even though I've made a small additional mudcover. The original bearings can be found priced around 55 - 130 euros as a set but I'm not sure what's the quality.
I would like to buy and test some "premium" bearings but the 7mm version of the 15x24 bearing seems to be quite hard to find from any let's say premium bearing vendor like SKF. I've used couple of times a special tool to push the bearing full grease through the seals (Alantani bearing packer) but it doesn't seem to make much difference. I have also good tools from Bearingpro Tools UK that keep bearing work very easy.
The Enduro bearings don't seem to release any standards if they fulfil the DIN 628-3 or DIN 625-1 or actually anything. I'm not saying it would be mandatory but that would make them less bicycle-specific magic bearings.
Enduro bearings state also that the 3802 LLU MAX BO static load is 4310 N and for comparison in (for the example) www.kugellager-express.de/ sells china-bearings where similar bearings have at max to 1560N static load rating (3802-2RS-TN model) and the 63802-V-2RS circa 864 N. I wonder if this variable have any effect on anything or is the biggest reason just either poor frame design to protect in harsh (wet) riding conditions or bad bearing quality.
It would be interesting to know why Mondraker chose this very bicycle-specific bearing.
//corrected kugellager-express numbers to be static not dynamic as they were.
Pretty much what I wrote earlier. 👍
However, be careful with stainless steel bearings: they have a lower load capacity because stainless is softer than hardened bearing steel. If you fill your bearings with marine grease and maintain them regularly anyway, there are only disadvantages in going stainless.
The bearing you are looking for is a dual row angular contact ball bearing, Kugellager express has it. It's a 3802. Enduro also has them.
Notice the numbers you are comparing are static vs. dynamic loading which is not the same.
As for bushings, they are technically ideal for pivots, but require additional sealing (could be used for bearings to prolong the life as well, based on how often it is implemented it's science fiction for the bike industry...), a hardened axle to slide in the bearings, but the problem is they need clearance to operate and thus you will get knocking from your rear end.
A properly mounted (and executed design wise) ball bearing will be preloaded axially and thus will not have any slop and/or sliding upon start of rotation. Yes, bushings are technically more suitable for pivots, but everybody using them sooner or later goes back to ball bearings...
Regarding my experience, I normally run (ran) max fill Kugellager express bearings in a non-sealed Bird frame, switching to Enduros they lasted longer in the same frame. Don't have a long track record on that one though...
Sorry my typo! I corrected to my post that the numbers were static load.
I'm not saying that it matters but I find it little interesting that Endurobearings exceeds most normal bearings static load rating like it's 4x what FAG has. I wonder what makes the difference?
Kugellager
Endurobearings
FAG 3802-B-2RSR-TVH-HLC
Looking at Kugellager Express 63802 (non MAX) has load values of 1250 N (static) and 2070 N (dynamic).
Looking at the 6902 (non MAX) at Kugellager, Enduro and SKF, static ratings are:
2250, 2483, 2240 N. Dynamic ratings are 4340 and 4360 for KE and SKF. Enduro doesn't show dynamic ratings.
From an industry perspective Enduro is almost ubiquitous for a few reasons:
1. They offer a lot of bicycle-specific sizes that can be very hard (and relatively expensive) to source elsewhere. They are one of the few suppliers with a wide range of max complement small bearings. Max complement is a big improvement in load capacity for the specific use case of suspension pivots (high dynamic load, low rotation speeds).
2. They are well known and have lots of international support for people replacing bearings. Go try replacing all the bearings on a Pivot Firebird with NTN equivalents. You might be able to do this in Germany but in a lot of the world finding someone who can supply a dozen bearings of mixed sizes from NTN will be challenging and expensive.
Enduro are not perfect but they are not the total junk some people would have you believe. The seals are a bit weak, and they don't seem to use quality factory grease. However, IMO the primary causes of bearing failure are:
1. Poor frame alignment and bearing layout. This is honestly hard to get right depending on the suspension layout. A chainstay weldment with bearings in the chainstay will NEVER have the bearings within any sort of engineering concentricity tolerance. This is less critical if the bearings are significantly oversized. The other tolerance issue is bore circularity which from some manufacturers (and even between runs of a single mfg) will vary in quality significantly. In aluminium you need a reasonable interference fit and frequently I see bikes where the bearing can be pushed in/out by hand (especially after being worn in).
2. Undersized bearings from the OEM. No excuses on this one. I see it on at least 60% of bikes. It saves ~100g of weight and requires much more frequent bearing replacement. In other cases, it is done to ease packaging constraints but it's just bad design. You see companies specifying bearings based on average replacement lifespan (a season) rather than proper load rating.
3. Inadequate sealing. Depending on how much flex the bearing will see and where the bearing is located they need more than just the rubber seal. Bikes see a LOT of water and fine dirt particles. In places of high exposure, they should have some sort of bearing covers. Rocky Mountain did a good job on their main pivots with this. Deviate also has an excellent seal arrangement for their main pivot (although I am sure the friction is quite a bit higher).
4. Lack of preload. This is a huge one; deep groove ball bearings are designed to have a small amount of preload during dynamic loading (and especially dynamic radial loading). Not having this drastically reduces their lifespan. In many places, this can be very hard to achieve on bicycle pivots. I had previously designed a hub assembly for an open-wheel race car that had the hub machined incorrectly so that the preload bolt was not fully engaging. The car went through bearings in under an hour of operation. Once the issue was fixed and the preload nut properly tensioned between the inner and outer bearings the bearings were not replaced for another 3 years. The best example of this being done on bikes is the Orbea Rallon main pivot. The bearings are in the frame, the primary axle is tightened finger tight to preload them, and then the chainstay uses a pinch bolt onto the axle to lock the assembly down. Assuming the machining of the frame is done well those bearings will probably never need replacement. I attempted something similar on the Norco Range main pivot but due to the size of the threads, it is difficult to estimate the required preload. Lower bearing life on that bike was also quite poor for some people likely due to poor concentricity of the two bores (they were machined in separate operations).
(edit: Apparently the Rallon ruined a perfect assembly by putting a spacer sleeve between the two bearings. This will prevent proper preload but it does allow someone to tighten the bolt down to 3 ugga duggas without destroying the bearings).
Bushings might sound like Engineering 101 for bicycle pivots but they are absolutely not the right option for a myriad of reasons. The friction increase will be very noticeable in suspension feel, bushings require extremely tight shaft and bore tolerances for proper operation, and bushings must be kept very clean. Bearings are more forgiving as they use integrated sealing and the shaft tolerance has a much wider range of function as the tightest tolerances are internal to the bearing assembly.
Do you design bikes out of interest? You seem very knowledgeable on the minutiae of bike design.
What are your takeaways then of how to design a frame correctly from a bearing perspective?
Use larger bearings, accurate tolerances, and preloaded (is a collet style main pivot good for this?) seem like the big 3 from what you've said.
Obviously it's give and take with all the other aspects, but I do like designs like the RAAW Madonna with it's oversized main pivot bearings, and extra sealing, not sure if they're preloaded properly however?
FWIW, the spacer in orbea has logic to it. It's the same approach that is used in hubs - you achieve the bearing preload through the spacer width vs. Casing seat width. The problem is that you need tight tolerances to achieve the correct preload which might be hard to achieve. A lot of hubs use adjustable preload as it's just easier and cheaper.
As for suspension pivots, the way Santa Cruz does the lower link is actually really smart (and a correct application of a collet axle, unlike Bird for example). You screw the axle into the chainstay and preload the bearing with a step in the axle, but nothing holds the Chainstay on the NDS axially vs the axle. Expanding the collet axle finally fixes the NDS chainstay to the axle. With that you cover the tolerances in the chainstay assembly (you can have space between the inner face on the NDS and the bearing next to it) and can achieve the bearing preload needed.
Designed for an OEM pre-covid so ancient history. Still do a bit of custom linkage work for various people. Using a split clamp chainstay like the Orbea Rallon (and many steel bikes) with the below bearing layout is pretty much perfect. The main axle would be torqued to basically finger tight and then locked using the split clamp.
Ideally the main frame bore would be bored from 1 side and then retaining rings used to seat the bearings. This ensures concentricity as cheaply as possible (very hard to do machining from two sides). You could also use a undercut endmill and conventional bearing seats.
The main problem with this approach is if you don't look at the manual and know what your are doing you will crank the axle down and crush the bearings together. I think this is the reason most OEM's go with the spacer between. A spacer application without VERY precise tolerances (which effectively won't happen in a frame application) you won't get consistent preload. Even in hub applications I doubt most companies are holding seat to seat tolerances (and the length tolerance on the spacer) accurately enough.
I believe Santa Cruz use inner seat-to-seat spacers in most applications so no preload (or based on the link tolerance so unpredictable). Once thing that Santa Cruz does perfectly is using single seal bearings and a zerk fitting to pump grease in the back of the bearing and out the seal. So much better than manually trying to clean and regrease.
True on the spacer. It is possible to achieve preload with the correct length as we discussed, but yeah, not ideal. Still, it gives you a lot more freedom on the chainstay tolerance wise.
As for bearing seats, at some point Frameworks used the headset approach - had a straight bore and then aluminium cups inserted into the bore and bearings into it. Might make sense to do it that way...
These are all great points! Most people don't realise bearings need a minimum amount of preload on them in nearly all bicycle applications, as even if you can't feel play they will move under load which concentrates the force on a single point instead of across multiple balls. Hubs are an interesting one - DT and Hope have normally had decent tolerances, to the point if you fit generic Enduro bearings to them you will immediately get play but using the faactory bearings they run really smooth. It was the most common mistake I saw people make with CK hubs - they would only "nip up" the preload collar which would also create play straight way.
As for bushings in pivots - I had about 4 or 5 Turner DW 5spots and they all had wildly different tolerances - I think my 2010 or 11 bike had almost perfect tolerances, one of the early Fox RP23 shocks and a Marzocchi 55 RC3 Ti - it ran amazing! I think my last one in 2013 had super tight pivots which made for noticeably less sensitivity. I wondered if hardened steel shafts would be better, but the extra outward squish of aluminium helps take up clearances so that might have caused more play as well
Where are all the angular contact bearings at? I have 2 WheelsMFG angular contact BB sets with a couple hard seasons on them. One on my SS and the other on my enduro rig. Semi annual repack with grease and still running smooth, yet to wear one out. Went through multiple dual row BBs on the SS before the WheelsMFG.
Angular contact races are designed to take radial and axial loads simultaneously, which seems like a no brainer for most MTB applications, particularly main pivots in suspension. Am I missing something here? Cost, size other limitations?
Additional drag when preloaded to a suitable degree. Wheelhub bearings in cars are highly preloaded compared to what we run.
That and the need for external seals which takes up axial space. This is probably a big factor in all of it. Complexity in general compared to current setups.
You can get sealed units from Enduro in a handful of good sizes like the 7001 2RS MAX. I actually have no idea why you don't see these more; they are almost without doubt a better option for high load suspension pivots like the main pivot. They really do need some preload mechanism though so that could be part of it.
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