MTB Tech Rumors and Innovation

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10/30/2024 12:01pm
Eae903 wrote:
So bikes were too linear and we needed to use air shocks to fix it, but now bikes are more progressive, so we need to increase...

So bikes were too linear and we needed to use air shocks to fix it, but now bikes are more progressive, so we need to increase the air volume in our shocks to make them more linear. Makes sense to me! 

the frame designers and shock makers are always going back and forth since time immemorial - originally the shocks were too progressive, which limited air shocks to short travel until 5th element brought out a large volume can which meant long travel bikes (130mm!) could use them. Volumes got bigger and travel increased so we started adding spacers to reduce that volume while running more sag, and now we seem to have a bit of both - I still get confused by Rockshox and their naming of air springs, which take in to account the volume of the negative chamber as well as the positive chamber. Large volumes overall are generally better most of the time - you can use lower pressure for the same spring rate and get less seal friction as well as accomodating a wider range of rider weights, even in higher leverage frames

7
overbiked
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10/30/2024 12:08pm
TEAMROBOT wrote:
That's one reason for the various air cans, and in a world where you can get a Starling with 0% progression or a Privateer with 44%...

That's one reason for the various air cans, and in a world where you can get a Starling with 0% progression or a Privateer with 44% progression, big brands like Rockshox and Fox need OEM options to fit a super wide range of suspension parameters. There are other benefits to more air volume though, like more mechanical leverage to overcome seal drag. In the coil vs. air battle, more volume is a pretty powerful tool to help air chase performance. That's what they did with the new Boxxer air spring: bigger volume, smaller piston size, more PSI ===> "coil like feel." The new SDLX can doesn't offer a smaller piston size, but it does offer the same piston size and more air volume, which accomplishes the same goal.

So is this Linear XL just the opposite of a MegNeg? I remeber a lot of people hating the MegNeg on a lot of bikes, but great on a couple. Will the Linear XL only be okay on something like the Stumpy 15?

TEAMROBOT
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10/30/2024 12:54pm
overbiked wrote:
So is this Linear XL just the opposite of a MegNeg? I remeber a lot of people hating the MegNeg on a lot of bikes, but...

So is this Linear XL just the opposite of a MegNeg? I remeber a lot of people hating the MegNeg on a lot of bikes, but great on a couple. Will the Linear XL only be okay on something like the Stumpy 15?

Great question. I don't know the size of the negative air chamber in the new Linear XL can, so I can't say. I would be surprised if it's "the opposite" of the MegNeg. I would wager it features a healthy-sized negative chamber in addition to the really really big positive chamber. I don't think RS or any of the manufacturers are going to go back to small negative chambers anytime soon. But I don't know.

2
10/30/2024 2:06pm
overbiked wrote:
So is this Linear XL just the opposite of a MegNeg? I remeber a lot of people hating the MegNeg on a lot of bikes, but...

So is this Linear XL just the opposite of a MegNeg? I remeber a lot of people hating the MegNeg on a lot of bikes, but great on a couple. Will the Linear XL only be okay on something like the Stumpy 15?

TEAMROBOT wrote:
Great question. I don't know the size of the negative air chamber in the new Linear XL can, so I can't say. I would be surprised...

Great question. I don't know the size of the negative air chamber in the new Linear XL can, so I can't say. I would be surprised if it's "the opposite" of the MegNeg. I would wager it features a healthy-sized negative chamber in addition to the really really big positive chamber. I don't think RS or any of the manufacturers are going to go back to small negative chambers anytime soon. But I don't know.

The standard air can for aftermarket shocks looks like the "linear" one which has a smaller negative chamber. This is the same company that shrunk fork air spring negative chambers again between B1 and C1 generation forks around 2021. Then re-increased negative volumes for 2023.....

"progressive" has a larger negative chamber (so actually a less variable spring rate but overall force characteristic will be higher/more supportive/'coil like' ie closest megneg equivalent) and linear XL increases positive and negative chamber volume which I assume has similar rate curve to the linear can but at lower pressures

So yeah I looked in to it and still find the naming suuuuuuuper confusing. THe Linear XL probably suits hyper progressive (as in rate of change, not just change in rate...) bikes like the Megatower or Enduro which used to not be very suitable for the megneg

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NoahColorado
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10/30/2024 2:14pm

Maybe this will help:

Screenshot 2024-10-30 at 3.11.21%E2%80%AFPM

(10 points to whoever can find the error in this graph)

 

11
Finkill
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10/30/2024 2:18pm Edited Date/Time 10/30/2024 2:19pm
Maybe this will help:(10 points to whoever can find the error in this graph) 

Maybe this will help:

Screenshot 2024-10-30 at 3.11.21%E2%80%AFPM

(10 points to whoever can find the error in this graph)

 

Lots happening at 70% travel! 

14
monarchmason
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10/30/2024 2:29pm
Maybe this will help:(10 points to whoever can find the error in this graph) 

Maybe this will help:

Screenshot 2024-10-30 at 3.11.21%E2%80%AFPM

(10 points to whoever can find the error in this graph)

 

Finkill wrote:

Lots happening at 70% travel! 

And then when it hits 70% again, it goes up. But its still at 70%. Shit, this shock is literally bottomless if this graph is correct. 

9
10/30/2024 2:29pm
Maybe this will help:(10 points to whoever can find the error in this graph) 

Maybe this will help:

Screenshot 2024-10-30 at 3.11.21%E2%80%AFPM

(10 points to whoever can find the error in this graph)

 

Finkill wrote:

Lots happening at 70% travel! 

You can make any shock "bottomless" if the graph just never reaches 100%!

They also normalised all of the springs at sag, which isn't realistic - the linear can would probably have the least sag and the progressive one the most if you plotted what a rider would actually use. 

7
1
boozed
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10/30/2024 3:57pm
Maybe this will help:(10 points to whoever can find the error in this graph) 

Maybe this will help:

Screenshot 2024-10-30 at 3.11.21%E2%80%AFPM

(10 points to whoever can find the error in this graph)

 

Finkill wrote:

Lots happening at 70% travel! 

And then when it hits 70% again, it goes up. But its still at 70%. Shit, this shock is literally bottomless if this graph is correct. 

It's bottomless, but unfortunately the rate of change in the spring rate hits infinity at 70% travel.  You win some you lose some.

2
10/30/2024 5:50pm
Finkill wrote:

Lots happening at 70% travel! 

And then when it hits 70% again, it goes up. But its still at 70%. Shit, this shock is literally bottomless if this graph is correct. 

boozed wrote:

It's bottomless, but unfortunately the rate of change in the spring rate hits infinity at 70% travel.  You win some you lose some.

If my calculations are correct... 

70percent.jpg?VersionId=wM5aCGJo0kx.tqoxo65oWbpR.cOOwJ
41
10/30/2024 6:51pm

At 70% travel there is a singularity which allows your spring force to simultaneously be three different values. Some hypothesize that if you can push past 70% travel you will bridge spacetime and land in a parallel universe. 

40
Nobble
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10/30/2024 7:01pm
Maybe this will help:(10 points to whoever can find the error in this graph) 

Maybe this will help:

Screenshot 2024-10-30 at 3.11.21%E2%80%AFPM

(10 points to whoever can find the error in this graph)

 

Finkill wrote:

Lots happening at 70% travel! 

You can make any shock "bottomless" if the graph just never reaches 100%!They also normalised all of the springs at sag, which isn't realistic - the...

You can make any shock "bottomless" if the graph just never reaches 100%!

They also normalised all of the springs at sag, which isn't realistic - the linear can would probably have the least sag and the progressive one the most if you plotted what a rider would actually use. 

Can you elaborate on why this approach is incorrect?


Isn’t that the way a consumer would set up their bike?

4
ballz
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10/30/2024 8:32pm
At 70% travel there is a singularity which allows your spring force to simultaneously be three different values. Some hypothesize that if you can push past...

At 70% travel there is a singularity which allows your spring force to simultaneously be three different values. Some hypothesize that if you can push past 70% travel you will bridge spacetime and land in a parallel universe. 

And then, Craig calls you.

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sspomer
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10/31/2024 8:07am

got an email about this kickstarter for an in-tire pressure gauge that connects to a garmin device called Outrider. looks interesting.

https://www.kickstarter.com/projects/outride/outrider-a-tire-pressure-sensor-for-bikes

"A low-cost, real-time tire pressure sensor made to improve the safety and performance of your bike's only two contacts with the ground. It fits securely inside of your tubeless tires and gives real-time pressure readings and alerts to your Garmin device via wireless transmissions." 

20
Landjonz
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10/31/2024 8:29am
Bildschirmfoto 2024-10-31 um 16.22.49

New Sram Transmission coming early 2025!?  🤔 Maybe the cable actuated one?

10
bikelurker
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10/31/2024 9:34am
Landjonz wrote:
New Sram Transmission coming early 2025!?  🤔 Maybe the cable actuated one?
Bildschirmfoto 2024-10-31 um 16.22.49

New Sram Transmission coming early 2025!?  🤔 Maybe the cable actuated one?

I bet gx transmission mechanical "first ride impresions" are about to drop, big mtb media is hinting it already...

4
sspomer
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10/31/2024 11:21am Edited Date/Time 10/31/2024 11:22am

radness from manitou. we had one of the originals in the office at decline. i always thought it was the coolest looking bike even if it was probably poorly functioning.

DSC09509

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SteveClimber
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10/31/2024 12:57pm
sspomer wrote:
got an email about this kickstarter for an in-tire pressure gauge that connects to a garmin device called Outrider. looks interesting.https://www.kickstarter.com/projects/outride/outrider-a-tire-pressure-sensor-for-bikes"A low-cost, real-time tire...

got an email about this kickstarter for an in-tire pressure gauge that connects to a garmin device called Outrider. looks interesting.

https://www.kickstarter.com/projects/outride/outrider-a-tire-pressure-sensor-for-bikes

"A low-cost, real-time tire pressure sensor made to improve the safety and performance of your bike's only two contacts with the ground. It fits securely inside of your tubeless tires and gives real-time pressure readings and alerts to your Garmin device via wireless transmissions." 

This actually looks like a solid product. 

I wonder if it can graph the pressure in the tyre (i.e high speed sensor) to see how often you bottom out tyre into rim from impacts. 

1
Primoz
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10/31/2024 1:22pm

The pressure probably doesn't change enough to notice this.

veefour
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10/31/2024 2:22pm
Karabuka wrote:

What kind of crab is that?

I'm thinking it's a king crab 'cause it's got a crown.

19
10/31/2024 2:33pm
Primoz wrote:

The pressure probably doesn't change enough to notice this.

Yeah, the "spring" part of the tyre comes from the casing so there is very little pressure change, also a sharp impact will compress the tyre easier and have the least change in pressure too so it wouldn't be reliable. Cars use pressure monitoring to infer load on the tyre but they are almost always sitting on flat ground so would be a little bit more accurate.

 

Pressure sensors are cool though - I'm tempted to back it but does it only work with Garmin? I should read that a bit closer

2
10/31/2024 2:41pm
Finkill wrote:

Lots happening at 70% travel! 

You can make any shock "bottomless" if the graph just never reaches 100%!They also normalised all of the springs at sag, which isn't realistic - the...

You can make any shock "bottomless" if the graph just never reaches 100%!

They also normalised all of the springs at sag, which isn't realistic - the linear can would probably have the least sag and the progressive one the most if you plotted what a rider would actually use. 

Nobble wrote:

Can you elaborate on why this approach is incorrect?


Isn’t that the way a consumer would set up their bike?

Sag is a good starting point but in practise the "progressive" cans will run with more sag or else they build force too fast in the middle of the travel. Likewise coil shocks will have a different sag measurement again. I guess the graph does a good job of amplifying the differences between each option, by fixing that one variable but it might help if they included what pressure produced all of those curves too.

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SteveClimber
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10/31/2024 2:47pm
Primoz wrote:

The pressure probably doesn't change enough to notice this.

yeah i guess not, you only compress a a small portion of the tyre's total volume when slamming into a rock. Bummer.

3
Eae903
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10/31/2024 3:03pm Edited Date/Time 10/31/2024 3:04pm
sspomer wrote:
got an email about this kickstarter for an in-tire pressure gauge that connects to a garmin device called Outrider. looks interesting.https://www.kickstarter.com/projects/outride/outrider-a-tire-pressure-sensor-for-bikes"A low-cost, real-time tire...

got an email about this kickstarter for an in-tire pressure gauge that connects to a garmin device called Outrider. looks interesting.

https://www.kickstarter.com/projects/outride/outrider-a-tire-pressure-sensor-for-bikes

"A low-cost, real-time tire pressure sensor made to improve the safety and performance of your bike's only two contacts with the ground. It fits securely inside of your tubeless tires and gives real-time pressure readings and alerts to your Garmin device via wireless transmissions." 

Those are quite the accuracy claims for the cost. What do they know that Sram doesn't? And how would it work with a tire insert other than a tannus? 

1
brash
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10/31/2024 3:19pm Edited Date/Time 10/31/2024 3:22pm

in a far corner of my shitbox den lurks this beauty. One day her time will come again. 

 

you know those barnfinds with old porsches and mercedes gullwings in America, I'll be the Australian version of old 90's mtb. If I had hair I'd get it permed.

IMG 0792
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pacojo
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10/31/2024 3:24pm
Primoz wrote:

The pressure probably doesn't change enough to notice this.

yeah i guess not, you only compress a a small portion of the tyre's total volume when slamming into a rock. Bummer.

even if the pressure did change enough, I highly doubt they sample the pressure often enough to glean anything more than "tire flat" from the data. with a claimed 800+ hour battery life, I'd guess they aren't sampling at more than 1 Hz.

2

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