MTB Tech Rumors and Innovation

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Poleczechy
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8/8/2023 10:42am
1llumA wrote:
Seems like Flight Attendant Sid shock and fork are in the works

Seems like Flight Attendant Sid shock and fork are in the works

365480551 618788116996397 5690022931556828730 n

I'm shocked Flight Attendant didn't originate on the SID and SIDLuxe considering remote lockouts are way more common in XC.

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dolface
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8/8/2023 1:53pm
gbcoke wrote:
Sram's new dh brake caliper looking production ready (courtesy of Bikerumor)...  

Sram's new dh brake caliper looking production ready (courtesy of Bikerumor)...

 

prototype-sram-brake-caliper-fort-william-world-champs-2023 0prototype-sram-brake-caliper-fort-william-world-champs-2023-pads-position 0

Are we gonna talk about the pads being bottom-loaded or is that not thing people care about?

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AndehM
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8/8/2023 2:05pm
gbcoke wrote:
Sram's new dh brake caliper looking production ready (courtesy of Bikerumor)...  

Sram's new dh brake caliper looking production ready (courtesy of Bikerumor)...

 

prototype-sram-brake-caliper-fort-william-world-champs-2023 0prototype-sram-brake-caliper-fort-william-world-champs-2023-pads-position 0

dolface wrote:

Are we gonna talk about the pads being bottom-loaded or is that not thing people care about?

It's less ideal, but I'd put it way down on my list of things I care about in brakes.  The main reason I sold my Codes and went to Hayes is how incredibly light and smooth the lever feel is.  I loved the ease of bleeding the Codes, availability of parts, contact point adjust, MatchMaker... but once I felt Dominion levers I had to have them.  It must be a lot due to the piston/seal friction and return spring stiffness, because Codes have a bearing mount too.

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C-LION
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8/8/2023 3:09pm

New Trek Slash could be released very soon, maybe as early as on Thursday…let’s see, but apparently in August.

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sharpy212
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8/8/2023 3:47pm

Seen the SRAM brakes on few bikes at Fort William at the weekend, Ronan Dunne was using them…. Pads looked like the loaded in from the bottom. 

SteveClimber
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8/8/2023 3:53pm
gbcoke wrote:
Sram's new dh brake caliper looking production ready (courtesy of Bikerumor)...  

Sram's new dh brake caliper looking production ready (courtesy of Bikerumor)...

 

prototype-sram-brake-caliper-fort-william-world-champs-2023 0prototype-sram-brake-caliper-fort-william-world-champs-2023-pads-position 0

dolface wrote:

Are we gonna talk about the pads being bottom-loaded or is that not thing people care about?

Is that an issue? when swapping pads you should re-surface the rotor a tiny bit anyway, so you have to remove the wheel anyway?

I've never thought about it, but i'd prefer a solid brake than the option of sliding in pads from the top

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8/8/2023 4:16pm
1llumA wrote:
Seems like Flight Attendant Sid shock and fork are in the works

Seems like Flight Attendant Sid shock and fork are in the works

365480551 618788116996397 5690022931556828730 n

Nino has been running the fork and shock (we couldn't see it) in the past two world cup races. 

8/8/2023 4:20pm

With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this. Maintaining good stiffness and accessing the post bolts fight each other when combined with all that. I’m not a fan of all the random standards, especially considering they aren’t well adhered to (iscg is the worst), but wider post mounts wouldn’t be the worst thing. 

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Onawalk
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8/8/2023 5:13pm
Primoz wrote:
As for patenting it, I think it could be argued it's not patentable (in the shape we assume it's in). Unless it's specifically the chainstay shape...

As for patenting it, I think it could be argued it's not patentable (in the shape we assume it's in). Unless it's specifically the chainstay shape and attachement of the linkage. You could argue the currently public demo uses the same layout - a horst link with a linkage driven shock where a pull link (the vertical one) actuates the shock.

kcy4130 wrote:
Yeah, I'm not sure it's patentable, it might be unique enough, not sure? The patent system can be are a minefield of clusterfucks sometimes, in the...

Yeah, I'm not sure it's patentable, it might be unique enough, not sure? The patent system can be are a minefield of clusterfucks sometimes, in the US anyhow. I'm just speculating as to why they've gone to such lengths to keep it under wraps. 

it just needs to be pending, not a patent granted, which would allow for years of development progress ahead of others.  By the time others were able capitalize, we would be on the 7 bar linkages, with low pivots....

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8/8/2023 5:14pm
With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this...

With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this. Maintaining good stiffness and accessing the post bolts fight each other when combined with all that. I’m not a fan of all the random standards, especially considering they aren’t well adhered to (iscg is the worst), but wider post mounts wouldn’t be the worst thing. 

yup, and ever since everyone settled on the post mount standard, brakes almost always use an adaptor anyway........so it wouldn't really be that big of a deal to make callipers with different bolt spacing.

 

As for bottom loading pads - I take the wheel out to clean the calliper and reset the pistons anyway, so it makes literally no difference. Even with top loading pads, if the old pads were slightly worn getting the new pads in was still a pain if you left the wheel in 

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Onawalk
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8/8/2023 5:14pm
1llumA wrote:
Seems like Flight Attendant Sid shock and fork are in the works

Seems like Flight Attendant Sid shock and fork are in the works

365480551 618788116996397 5690022931556828730 n

Poleczechy wrote:

I'm shocked Flight Attendant didn't originate on the SID and SIDLuxe considering remote lockouts are way more common in XC.

weight,

I think the rollout on long travel bikes made a tonne of sense, and likely the largest segment of new, premium bikes being sold

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Onawalk
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8/8/2023 5:19pm
With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this...

With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this. Maintaining good stiffness and accessing the post bolts fight each other when combined with all that. I’m not a fan of all the random standards, especially considering they aren’t well adhered to (iscg is the worst), but wider post mounts wouldn’t be the worst thing. 

yup, and ever since everyone settled on the post mount standard, brakes almost always use an adaptor anyway........so it wouldn't really be that big of a...

yup, and ever since everyone settled on the post mount standard, brakes almost always use an adaptor anyway........so it wouldn't really be that big of a deal to make callipers with different bolt spacing.

 

As for bottom loading pads - I take the wheel out to clean the calliper and reset the pistons anyway, so it makes literally no difference. Even with top loading pads, if the old pads were slightly worn getting the new pads in was still a pain if you left the wheel in 

I take the wheel out, but I still watch the work from the hole on the top, while mounted to the bike/fork,  are you flipping the bike over? removing the caliper?

Also makes micro setting adjustments easy to be able to see where things are centered

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TEAMROBOT
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8/8/2023 5:58pm

From the other site, interviewing the Norco design team on the new proto downhill bike. Thought I'd share this bit about a patent for a link that adjusts progression without affecting anything else? Don't get how this is possible, but they're smarter than me so who knows?

"We’ve filed two patents based on the suspension layout and kinematic adjustment designed into the new DH race bike... The second patent applies to the method of leverage curve progression adjustment we’ve designed into the bike which allows us to alter the level of support from the rear suspension in isolation without needing to alter shock tune, damper settings, spring rate or shock pressure."

I was scratching my head because I would assume a different leverage profile always necessitates a different shock tune, damper settings, spring rate, etc. Curious on your thoughts.

5
8/8/2023 6:23pm
TEAMROBOT wrote:
From the other site, interviewing the Norco design team on the new proto downhill bike. Thought I'd share this bit about a patent for a link...

From the other site, interviewing the Norco design team on the new proto downhill bike. Thought I'd share this bit about a patent for a link that adjusts progression without affecting anything else? Don't get how this is possible, but they're smarter than me so who knows?

"We’ve filed two patents based on the suspension layout and kinematic adjustment designed into the new DH race bike... The second patent applies to the method of leverage curve progression adjustment we’ve designed into the bike which allows us to alter the level of support from the rear suspension in isolation without needing to alter shock tune, damper settings, spring rate or shock pressure."

I was scratching my head because I would assume a different leverage profile always necessitates a different shock tune, damper settings, spring rate, etc. Curious on your thoughts.

Shocks are often tuned off of average leverage ratio so as long as travel remains the same then general tuning would still be accurate. If tune is done for a specific spot in travel then that's out the window as soon as leverage curve changes. Damping force as felt at the wheel is inversely proportional to leverage ratio squared for anyone who's curious.

As for spring rate or shock pressure, increasing progression while travel remains fixed generally results in a higher leverage ratio at the sag point. So to keep the same sag point you'd need to increase spring rate/pressure or you'd be sitting lower. If you say that leverage ratio at sag point remains the same, then increasing progression will decrease travel and then you'd be changing the average leverage ratio around which the shock is tuned. The one way around this would be set it up so that leverage ratio at the sag point is fixed and most the progression change comes from increasing the leverage ratio between sag and top of travel, but that would be a huge limitation in tunability. Also wouldn't be a limitation I would understand. Bottom out resistance is the sum of energy that goes into the spring and energy that is dissipated by the damper so increasing spring rate or damping is the only way to increase bottom out resistance. 

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SteveClimber
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8/8/2023 7:43pm

I dont really get what they are trying to say though?

You can increase support without change spring or damping settings? Yeah every frame you make more progressive via flip chip will do that. 

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Onawalk
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8/8/2023 7:49pm
I dont really get what they are trying to say though? You can increase support without change spring or damping settings? Yeah every frame you make...

I dont really get what they are trying to say though?

You can increase support without change spring or damping settings? Yeah every frame you make more progressive via flip chip will do that. 

Nope, if youre changing the progression, be ready to adjust settings for it....

1
8/8/2023 8:55pm

So the fuel EX gen6 with adjustable progression, If you go from linear to progressive, youd have to increase pressure?

8/8/2023 9:00pm

Generally more progressive for a given travel amount results in higher leverage ratio at the sag point so higher spring rate or pressure to be at that sag point. This is because wheel travel is the integral of leverage ratio. If you decrease it in one spot you have to increase it in another otherwise there is a travel reduction. 

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Primoz
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8/8/2023 10:30pm Edited Date/Time 8/8/2023 10:37pm
With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this...

With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this. Maintaining good stiffness and accessing the post bolts fight each other when combined with all that. I’m not a fan of all the random standards, especially considering they aren’t well adhered to (iscg is the worst), but wider post mounts wouldn’t be the worst thing. 

yup, and ever since everyone settled on the post mount standard, brakes almost always use an adaptor anyway........so it wouldn't really be that big of a...

yup, and ever since everyone settled on the post mount standard, brakes almost always use an adaptor anyway........so it wouldn't really be that big of a deal to make callipers with different bolt spacing.

 

As for bottom loading pads - I take the wheel out to clean the calliper and reset the pistons anyway, so it makes literally no difference. Even with top loading pads, if the old pads were slightly worn getting the new pads in was still a pain if you left the wheel in 

The marketing argument with top loaded pads was also that everything was cooled better as the air could blow through the caliper.

Anywho, most brakes do indeed use adaptors, except for stuff like Zebs where 200 mm rotors are direct mount. That does complicate things a bit. With forks having wider spacing shouldn't be an issue, but with rear brakes there might be some pushback considering there are flat mount MTB frames out there. And given all the marketing messaging how protected the caliper is inside the frame (mounted between the chain and seatstay, making adjustments a huge PITA), I could imagine some pushback on that idea to be honest.

It might be possible to make a wider post mount standard where an adaptor could be used to go to the old caliper? That would shaft people on old bikes that would want to run new brakes, but it's exactly the same situation Transmission has put the same people - you can either run the old stuff on your old bike or the old stuff or Transmission on your new, UDH bike.

Primoz
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8/8/2023 10:35pm

Regarding the Norco tidbit, my first reaction (after looking at the Pit Bits 2 days ago) is that they have multiple dogbone and swing links to drive the shock and can play around with that to alter the shape of the leverage ratio. The reaction came as I was looking at it the other day and wondering how high the forces in those small links must be and then instantly thinking this must be it for the patent. There could be something else, but as far as I saw, they are running an inverted horst link with an additional linkage to drive the shock. So kiiiiiinda what Specialized are doing with the Demo conceptually-wise.

1
8/8/2023 10:59pm
Primoz wrote:
Regarding the Norco tidbit, my first reaction (after looking at the Pit Bits 2 days ago) is that they have multiple dogbone and swing links to...

Regarding the Norco tidbit, my first reaction (after looking at the Pit Bits 2 days ago) is that they have multiple dogbone and swing links to drive the shock and can play around with that to alter the shape of the leverage ratio. The reaction came as I was looking at it the other day and wondering how high the forces in those small links must be and then instantly thinking this must be it for the patent. There could be something else, but as far as I saw, they are running an inverted horst link with an additional linkage to drive the shock. So kiiiiiinda what Specialized are doing with the Demo conceptually-wise.

Forgive my terrible illustration, but more or less this. I’m guessing in making that lower link much smaller than on the Range they had to get creative to make leverage curve work out and ended up with the linkage driven solution that then had the benefit of more miscellaneous adjustments to play with.IMG 3097

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8/8/2023 11:45pm
With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this...

With the existing post mount standard, brakes are at a point where more line pressure and or bigger pistons and pads will necessitate things like this. Maintaining good stiffness and accessing the post bolts fight each other when combined with all that. I’m not a fan of all the random standards, especially considering they aren’t well adhered to (iscg is the worst), but wider post mounts wouldn’t be the worst thing. 

Sounds like a move to a radial mount (ala Hope's 2016 proto bike) would help get around/improve that issue? And make rotor size changes easier too.

Primoz
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8/9/2023 12:27am

No. This has been discussed in the past (not sure if here or not), but bike brakes are mounted with a lot more support than radial mount brakes on motorbikes. The caliper being offset means the caliper isn't only pulled perpendicularly to the bolts, but is actually pushed onto the fork/frame/adapter axially as well. This takes a lot of the load off the bolts and the mounting interface and we can thus run smaller bolts than what would be needed with radial mounting. Plus changing rotor sizes might become a lot more limited (running a 200 or a 220 mm rotor on a 160 mm radial mount would make for some LOOOOOOOOOONG bolts) as you don't want the bolts to be too long.

There is some logic to the madness that is the current post mount standard. What does need to die a painful, but quick death is the 203 mm rotor standard. In a world of 200 mm direct mount interfaces, standardised 20 mm jumps between rotor sizes, 220 mm rotors becoming the norm, etc. how in the hell can we still have 203 mm rotors that are so widespread (is there anyone else besides Sram making 200 mm rotors at all?)?? And then you have 220 and 223 mm rotors, there are some proto 246 mm rotors out there (Neko), etc. It's a clear 'fuck logic, that's why' situation. If 185 mm rotors were able to be done away with, why is the 203 option so persistent?

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8/9/2023 1:12am
Primoz wrote:
Regarding the Norco tidbit, my first reaction (after looking at the Pit Bits 2 days ago) is that they have multiple dogbone and swing links to...

Regarding the Norco tidbit, my first reaction (after looking at the Pit Bits 2 days ago) is that they have multiple dogbone and swing links to drive the shock and can play around with that to alter the shape of the leverage ratio. The reaction came as I was looking at it the other day and wondering how high the forces in those small links must be and then instantly thinking this must be it for the patent. There could be something else, but as far as I saw, they are running an inverted horst link with an additional linkage to drive the shock. So kiiiiiinda what Specialized are doing with the Demo conceptually-wise.

Forgive my terrible illustration, but more or less this. I’m guessing in making that lower link much smaller than on the Range they had to get...

Forgive my terrible illustration, but more or less this. I’m guessing in making that lower link much smaller than on the Range they had to get creative to make leverage curve work out and ended up with the linkage driven solution that then had the benefit of more miscellaneous adjustments to play with.IMG 3097

I would also guess the lack of a need for a dropper post on a dedicated DH frame allowed them to use more of the seat tube for the additional linkage. I'm seconding @Primoz's concern about the high forces going into those dogbone pivots - the upper one in particular has a lot of leverage over the shock link, and I hope they have any potential durability problems sorted if it ever carries over to a production model.

Also, I can't say how accurate this is (to my eyes it seems close, even using a photo for reference, but it's hard to tell), but the linkage could theoretically result in some pretty interesting leverage curves with two inflection points (the only thing similar is the newer Focus JAM/Thron). I highlighted the different 'phases' you could distinguish in the wheel force gradient:

Yellow = soft small-bump, Green = consistent mid-stroke support at/after sag point, Blue = slight reduction for medium/large hit absorption, Magenta = end-stroke/bottom-out support. Overall they might be too subtle to really notice in this implementation (it could just feel pretty linear until the end), but this sort of 'quad-phase' design accounting for medium/large compressions could be pretty interesting compared to the usual 'triple-phase' stuff you hear all the time (small-bump compliance/mid-stroke support/bottom-out prevention) from Canyon, Marin and others.

Screenshot 2023-08-09 005305v2

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