Charging the small clip-on AXS battery on the fly would be a little difficult while in use. This is why SRAM is proposing to mount the batteries on the small solar panels. They really don't want to deal with wires given the whole appeal of AXS is "wireless"
I've looked into making a longer battery AXS solution for a long distance XCM racer. I can use a cheap Amazon AXS battery and solder a wire to it. This would allow the rider to run a much larger battery inside their bike frame instead of the 2.2Wh battery. Similar to how Di2 is wired. This in-frame battery can then be wired to a dynamo/usb bank for constant top-up. Ideally it would be nice SRAM starts selling the wiring harness they use for their AXS equipped e-bikes but the use case is very niche and really only useful for 24hr+ racers, bike packers and ultra marathoners like tour divide.
It seems to me that the seat post would be the best place to generate electricity. Use the riders weight to generate power on the drop. It could charge the seat post battery as you use it. Then if you run out of shift battery, just switch the two.
Not sure why you're getting downvoted... you can probably jury rig a dynamo/USB bank combo to charge your AXS batteries on the road, and I bet...
Not sure why you're getting downvoted... you can probably jury rig a dynamo/USB bank combo to charge your AXS batteries on the road, and I bet bikepackers are doing just that, but a SRAM native, plug and play, sleek and integrated, trail rider friendly option seems like a no brainer.... but it'd have wires, which is off brand. I think that and the limited market for range anxiety paranoid type folks is your biggest obstacle to go to market. Everyone else can just carry an extra battery. Jockey wheel charging is far fetched... you don't need a ton of watts but you need more copper/EM flux to actually generate electricity.
Or stick to cables.
The downvotes on perfectly normal posts started back a few months ago when some idiot made some idiotic comments and got destroyed. He's been down voting everything he reads since then.
Ok here’s another crazy one, what if your Tuned Mass Damper also had a regeneration component, I think in theory this would also allow you to change the natural frequency on the fly, no?
Ok here’s another crazy one, what if your Tuned Mass Damper also had a regeneration component, I think in theory this would also allow you to...
Ok here’s another crazy one, what if your Tuned Mass Damper also had a regeneration component, I think in theory this would also allow you to change the natural frequency on the fly, no?
I don't want to REALLY derail this thread...but about 15 years ago I worked as an engineering consultant and ultimately spun off a small company to develop vibration based energy harvesters that were essentially tuned mass dampers. The damping was electromechanical, and tuned both with hardware and software. Our secret sauce and patent material was a mechanical means to decouple the frequency of the harvester from the input source...it could be very efficient with a wide range of input excitation frequencies. They never made much power, though...you could take a measurement or send a low power signal, but charging a battery was never the application. Supercap, yes, not a battery. We never made any money.
Not sure why you're getting downvoted... you can probably jury rig a dynamo/USB bank combo to charge your AXS batteries on the road, and I bet...
Not sure why you're getting downvoted... you can probably jury rig a dynamo/USB bank combo to charge your AXS batteries on the road, and I bet bikepackers are doing just that, but a SRAM native, plug and play, sleek and integrated, trail rider friendly option seems like a no brainer.... but it'd have wires, which is off brand. I think that and the limited market for range anxiety paranoid type folks is your biggest obstacle to go to market. Everyone else can just carry an extra battery. Jockey wheel charging is far fetched... you don't need a ton of watts but you need more copper/EM flux to actually generate electricity.
Or stick to cables.
Lithium batteries need a very narrow range of power input for charging, and a current that is "clean". Easier to do this with a PV panel than a dyno.
You can always convert the voltage (up or down) and smooth the current...
A friend of mine said years ago he's dumbfounded why Shimano didn't have a magnet in the crank spindle, a winding in the BB shell and a supercap in place of the battery to power the di2 system.
You can always convert the voltage (up or down) and smooth the current... A friend of mine said years ago he's dumbfounded why Shimano didn't have a...
You can always convert the voltage (up or down) and smooth the current...
A friend of mine said years ago he's dumbfounded why Shimano didn't have a magnet in the crank spindle, a winding in the BB shell and a supercap in place of the battery to power the di2 system.
To convert and clean up the power from a dynamo to charge something like a derailleur, you’d need a fairly complex setup including a bridge rectifier, a voltage regulator to ensure consistent output, and filtering components like capacitors and inductors to smooth out the current. Depending on the dynamo’s output, you might also need a DC-DC converter to step the voltage up or down. On top of this you'll need heat sinks to keep everything cool.
This would very quickly get too heavy and too bulky for a bike. The efficiency losses would also be significant. I doubt it would be worth the effort.
Honestly, it would be easier to "downgrade" the AXS/Transmission batteries to use NiMH, which are much more robust and easier/simpler to charge off a dyno. Many hybrid cars still use NiMH over lithium batteries because they are more temperature tolerant, require less complex load balancing, less housing protection, less complex charging requirements, etc despite having a far worse power to weight ratio.
Ok here’s another crazy one, what if your Tuned Mass Damper also had a regeneration component, I think in theory this would also allow you to...
Ok here’s another crazy one, what if your Tuned Mass Damper also had a regeneration component, I think in theory this would also allow you to change the natural frequency on the fly, no?
I don't want to REALLY derail this thread...but about 15 years ago I worked as an engineering consultant and ultimately spun off a small company to...
I don't want to REALLY derail this thread...but about 15 years ago I worked as an engineering consultant and ultimately spun off a small company to develop vibration based energy harvesters that were essentially tuned mass dampers. The damping was electromechanical, and tuned both with hardware and software. Our secret sauce and patent material was a mechanical means to decouple the frequency of the harvester from the input source...it could be very efficient with a wide range of input excitation frequencies. They never made much power, though...you could take a measurement or send a low power signal, but charging a battery was never the application. Supercap, yes, not a battery. We never made any money.
Sorry, back to bikes.
This is an absolutely acceptable (for me anyway) derail of the thread.
I'd say we all appreciate the technical knowledge, and actual working experience in your post.
Its the "Shimano is the only good brake out there, screw all others" type of opinionated garbage that most arn't interested in.
You can always convert the voltage (up or down) and smooth the current... A friend of mine said years ago he's dumbfounded why Shimano didn't have a...
You can always convert the voltage (up or down) and smooth the current...
A friend of mine said years ago he's dumbfounded why Shimano didn't have a magnet in the crank spindle, a winding in the BB shell and a supercap in place of the battery to power the di2 system.
To convert and clean up the power from a dynamo to charge something like a derailleur, you’d need a fairly complex setup including a bridge rectifier...
To convert and clean up the power from a dynamo to charge something like a derailleur, you’d need a fairly complex setup including a bridge rectifier, a voltage regulator to ensure consistent output, and filtering components like capacitors and inductors to smooth out the current. Depending on the dynamo’s output, you might also need a DC-DC converter to step the voltage up or down. On top of this you'll need heat sinks to keep everything cool.
This would very quickly get too heavy and too bulky for a bike. The efficiency losses would also be significant. I doubt it would be worth the effort.
Honestly, it would be easier to "downgrade" the AXS/Transmission batteries to use NiMH, which are much more robust and easier/simpler to charge off a dyno. Many hybrid cars still use NiMH over lithium batteries because they are more temperature tolerant, require less complex load balancing, less housing protection, less complex charging requirements, etc despite having a far worse power to weight ratio.
I'd be willing to bet what you are describing is a 5x5 cm PCB with one chip (with everything integrated) and a few passive components with absolutely no heatsinks needed for it to work.
Electronics very very rarely need heatsinks unless there are tens of watts going through them.
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.Also, alloy Stumpy 15 release...
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.
Also, alloy Stumpy 15 release pushed back to spring/summer 2025.
The sentinel doesnt need the lower or slacker treatment... it 100% needs steeper & longer. best upgrade you can make to a sentinel is a 1deg headset to steepen the HTA.
I may be no enginologist, but I'm pretty sure that damping is the act of turning kinetic energy into thermal energy. That heat has to go...
I may be no enginologist, but I'm pretty sure that damping is the act of turning kinetic energy into thermal energy. That heat has to go somewhere and stuffing the shock into an enclosed space will limit both convection and radiation. Is cooling reduced enough to matter? Open question, but shocks for sure get hotter in this configuration. Do we think this configuration was cooked up in the quest of performance, or in order to make MTBs look more like road bikes?
Moi Moi mentioned the shock performance degrading very quickly on the wrapped tues he was riding at Thredbo. Said something along the lines of it turning...
Moi Moi mentioned the shock performance degrading very quickly on the wrapped tues he was riding at Thredbo. Said something along the lines of it turning into a pogo stick in a run.
Hmm has anyone ever done a proper test/analysis of shock performance to temperature change?As the biggest suspension geek I can think of @TheSuspensionLabNZ have you ever...
Hmm has anyone ever done a proper test/analysis of shock performance to temperature change? As the biggest suspension geek I can think of @TheSuspensionLabNZ have you ever run across any detailed tests rather than just the usual online forum subjective reckons?
Sorry for late reply (I don't take a look here too often), but I work for big suspension supplier in automotive sector and I had a few opportunities to measure mtb shocks. I've measured my friend's dhx2 '19, my own sdlx coil '20 and brand new Bomber CR.
I did a few test runs of bomber. My very first run and the last one was on the same settings, and what caught my attention was damping forces drop of 400 Newtons at 0,5 m/s. I didn't measure temperature (from experience it was between 40-50 C degrees), and unfortunatelly I can't share files with data, but shock was 968-01-153
This is far more innovative than some battery BS and marginal gains with udh and new paint. I totally see the day that I’m old enough to be done with high speed riding and just want to go explore
Sorry for late reply (I don't take a look here too often), but I work for big suspension supplier in automotive sector and I had a...
Sorry for late reply (I don't take a look here too often), but I work for big suspension supplier in automotive sector and I had a few opportunities to measure mtb shocks. I've measured my friend's dhx2 '19, my own sdlx coil '20 and brand new Bomber CR.
I did a few test runs of bomber. My very first run and the last one was on the same settings, and what caught my attention was damping forces drop of 400 Newtons at 0,5 m/s. I didn't measure temperature (from experience it was between 40-50 C degrees), and unfortunatelly I can't share files with data, but shock was 968-01-153
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.Also, alloy Stumpy 15 release...
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.
Also, alloy Stumpy 15 release pushed back to spring/summer 2025.
I have heard the complete opposite from a geo perspective (steeper HTA). When the Sentinel came out, there was no Spire. Now there is the Spire so Transition can now make the Sentinel more of an "all mountain" bike and keep the Spire as their big enduro bike.
I'd be willing to bet what you are describing is a 5x5 cm PCB with one chip (with everything integrated) and a few passive components with...
I'd be willing to bet what you are describing is a 5x5 cm PCB with one chip (with everything integrated) and a few passive components with absolutely no heatsinks needed for it to work.
Electronics very very rarely need heatsinks unless there are tens of watts going through them.
Where near a wireless derailleur or rear axle are you going to put a 5x5 PCB with associated weatherproof housing?
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.Also, alloy Stumpy 15 release...
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.
Also, alloy Stumpy 15 release pushed back to spring/summer 2025.
The sentinel doesnt need the lower or slacker treatment... it 100% needs steeper & longer.best upgrade you can make to a sentinel is a 1deg headset...
The sentinel doesnt need the lower or slacker treatment... it 100% needs steeper & longer. best upgrade you can make to a sentinel is a 1deg headset to steepen the HTA.
You're living in 2026. We got more reach, we got steeper seat tubes, now stays are getting longer and occasionally proportional across sizes and stack heights are growing. Next step is to figure out that the crazy front centers slack head tubes, long forks and long reaches make weighting the front wheel really hard any time you're not pointed down something steep... moderate head angles let you ride a longer reach and have room to be dynamic on the bike without it turning into a bus. Geometron is already there on their latest bike, though it's still a pretty extreme take.
It seems like the new hot thing is to want steeper head tube angles. It seems like a counter culture thing but who knows lol. I guess I’m still living in the (recent) past. In highschool i rode a 2001 trek fuel that felt like it was actively trying to OTB and kill me. I still really like really slack trail bikes. Give me a 150mm bike with a 63° head tube angle and I’ll be happier than a pig in shit.
Foes big rig is looking pretty dialed. Calling it the FXR.
Charging the small clip-on AXS battery on the fly would be a little difficult while in use. This is why SRAM is proposing to mount the batteries on the small solar panels. They really don't want to deal with wires given the whole appeal of AXS is "wireless"
I've looked into making a longer battery AXS solution for a long distance XCM racer. I can use a cheap Amazon AXS battery and solder a wire to it. This would allow the rider to run a much larger battery inside their bike frame instead of the 2.2Wh battery. Similar to how Di2 is wired. This in-frame battery can then be wired to a dynamo/usb bank for constant top-up. Ideally it would be nice SRAM starts selling the wiring harness they use for their AXS equipped e-bikes but the use case is very niche and really only useful for 24hr+ racers, bike packers and ultra marathoners like tour divide.
It seems to me that the seat post would be the best place to generate electricity. Use the riders weight to generate power on the drop. It could charge the seat post battery as you use it. Then if you run out of shift battery, just switch the two.
The downvotes on perfectly normal posts started back a few months ago when some idiot made some idiotic comments and got destroyed. He's been down voting everything he reads since then.
Ok here’s another crazy one, what if your Tuned Mass Damper also had a regeneration component, I think in theory this would also allow you to change the natural frequency on the fly, no?
I don't want to REALLY derail this thread...but about 15 years ago I worked as an engineering consultant and ultimately spun off a small company to develop vibration based energy harvesters that were essentially tuned mass dampers. The damping was electromechanical, and tuned both with hardware and software. Our secret sauce and patent material was a mechanical means to decouple the frequency of the harvester from the input source...it could be very efficient with a wide range of input excitation frequencies. They never made much power, though...you could take a measurement or send a low power signal, but charging a battery was never the application. Supercap, yes, not a battery. We never made any money.
Sorry, back to bikes.
New Hightower.
Gotta be a new Hightower.
Lithium batteries need a very narrow range of power input for charging, and a current that is "clean". Easier to do this with a PV panel than a dyno.
You can always convert the voltage (up or down) and smooth the current...
A friend of mine said years ago he's dumbfounded why Shimano didn't have a magnet in the crank spindle, a winding in the BB shell and a supercap in place of the battery to power the di2 system.
To convert and clean up the power from a dynamo to charge something like a derailleur, you’d need a fairly complex setup including a bridge rectifier, a voltage regulator to ensure consistent output, and filtering components like capacitors and inductors to smooth out the current. Depending on the dynamo’s output, you might also need a DC-DC converter to step the voltage up or down. On top of this you'll need heat sinks to keep everything cool.
This would very quickly get too heavy and too bulky for a bike. The efficiency losses would also be significant. I doubt it would be worth the effort.
Honestly, it would be easier to "downgrade" the AXS/Transmission batteries to use NiMH, which are much more robust and easier/simpler to charge off a dyno. Many hybrid cars still use NiMH over lithium batteries because they are more temperature tolerant, require less complex load balancing, less housing protection, less complex charging requirements, etc despite having a far worse power to weight ratio.
for the people interested in fatbikes..... surly just dropped the moonlander v2. 24 x 6.2" tires (not a typo) and a pinion.
https://surlybikes.com/bikes/moonlander-v2
Is this an attempt to normalize the tire size so they can then pivot and sell hunting e-fat-bikes
they will certainly roll over the competition.
This is an absolutely acceptable (for me anyway) derail of the thread.
I'd say we all appreciate the technical knowledge, and actual working experience in your post.
Its the "Shimano is the only good brake out there, screw all others" type of opinionated garbage that most arn't interested in.
Thank You
I'd be willing to bet what you are describing is a 5x5 cm PCB with one chip (with everything integrated) and a few passive components with absolutely no heatsinks needed for it to work.
Electronics very very rarely need heatsinks unless there are tens of watts going through them.
Looked transitions website. The the scout and sentinel are both really on sale and don’t have New Years colors. New ones coming soon maybe?
I was at a dealer today, and they said that the new Sentinel was coming with internal storage and longer/lower/slacker treatment. Soonish.
Also, alloy Stumpy 15 release pushed back to spring/summer 2025.
The sentinel doesnt need the lower or slacker treatment... it 100% needs steeper & longer.
best upgrade you can make to a sentinel is a 1deg headset to steepen the HTA.
Sorry for late reply (I don't take a look here too often), but I work for big suspension supplier in automotive sector and I had a few opportunities to measure mtb shocks.
I've measured my friend's dhx2 '19, my own sdlx coil '20 and brand new Bomber CR.
I did a few test runs of bomber. My very first run and the last one was on the same settings, and what caught my attention was damping forces drop of 400 Newtons at 0,5 m/s.
I didn't measure temperature (from experience it was between 40-50 C degrees), and unfortunatelly I can't share files with data, but shock was 968-01-153
Dan Hanebrink would be proud!
This is far more innovative than some battery BS and marginal gains with udh and new paint. I totally see the day that I’m old enough to be done with high speed riding and just want to go explore
This would be the ultimate bike to show up on when you are meeting your friends for a trail ride without saying anything about it. 😆
So about 10% of change from cold to warm?
I have heard the complete opposite from a geo perspective (steeper HTA). When the Sentinel came out, there was no Spire. Now there is the Spire so Transition can now make the Sentinel more of an "all mountain" bike and keep the Spire as their big enduro bike.
Someone posted this guy before, which is a sick looking homemade bike.
My question is, isn't the off-the-shelf oval ring clocked incorrectly because of the idler? Its backwards, like the old 90s BioPace chainrings
Where near a wireless derailleur or rear axle are you going to put a 5x5 PCB with associated weatherproof housing?
You're living in 2026. We got more reach, we got steeper seat tubes, now stays are getting longer and occasionally proportional across sizes and stack heights are growing. Next step is to figure out that the crazy front centers slack head tubes, long forks and long reaches make weighting the front wheel really hard any time you're not pointed down something steep... moderate head angles let you ride a longer reach and have room to be dynamic on the bike without it turning into a bus. Geometron is already there on their latest bike, though it's still a pretty extreme take.
Haro's France IG page just released a pic of an upcoming carbon version of the Daley, 150/140 rig, she clean:
And they have some pics of a very tidy enduro rig as well, not sure what got in the water at Haro but I'm here for it.
It seems like the new hot thing is to want steeper head tube angles. It seems like a counter culture thing but who knows lol. I guess I’m still living in the (recent) past. In highschool i rode a 2001 trek fuel that felt like it was actively trying to OTB and kill me. I still really like really slack trail bikes. Give me a 150mm bike with a 63° head tube angle and I’ll be happier than a pig in shit.
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