2020 MTB Tech Rumors and Innovation

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3/21/2020 9:21 PM

brash wrote:

Steve from Vorsprung was testing a very modified Lyrik when I spotted him in Queenstown at Skyline.

Looked like a giant air reservoir/piggyback at the base of the left leg.

I quizzed him about it, said secret squirrel stuff and commended me on my coil conversion. Wish I snuck a sneaky pic now.

MXBREWSK wrote:

Maybe the concept that Showa was using 4-5 years ago on their motocross bikes, triple air chambers.

brash wrote:

Exactly like that, I'd seen it on KXF motocross bikes a few years ago. This was on the bag of the leg however.

Brash here is the link explaining the triple air chamber Showa fork. https://www.dirtrider.com/features/showa-separate-function-triple-chamber-air-fork-explained/

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MXBREWSK

3/21/2020 11:50 PM

BOS had a piggyback fork back in 2008:
https://m.pinkbike.com/news/Bos-suspension-preview-2008.html

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3/21/2020 11:56 PM

Thats similar to the older 2004-ish white bros DH3 but both are an IFP on the damper side. The above is suggesting a 3rd air chamber in the air spring to adjust bottom out?


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3/22/2020 4:56 AM
Edited Date/Time: 3/22/2020 4:58 AM

If I understand the Showa fork correctly, they're not using the fork legs as the spring casing like we do in MTB. One thing to note here is that it's an upside-down fork, so an analogy with a standard MTB fork would mean you would need to flip the components upside down to get the same layout.

Anywho, they use a spring cartridge. The two valves on the top are used to fill the inside of the cartridge and the outside of the cartridge. The inner one is clear, but to put this system into a MTB fork, the main spring volume would be in the lower leg with a shaft running through the upper sliders. Then the sliders are also sealed against the cartridge (unlike what we do with cartridge dampers for example) and that volume is pumped with the low (~7 psi) pressure from the top.

The piggyback in the bottom i suppose pressurizes the negative spring inside the cartridge through the hollow shaft (I don't see another way how to do it otherwise). In MTB we have a timing port to equalize the pressure with the use of only one valve. A similar method to this piggyback (infinitely adjustable negative spring) was used by Rock Shox with their Dual Air products (separate valves for positive and negative springs).

Why use the third chamber in this way is a bit beyond me, I don't see a way how it would modify the spring curve significantly (you don't alter the progression ratio significantly, unless it has a completely different volume to the main chamber, but in that case you don't exhibit much force anyway). Maybe they just had to seal off the lower to prevent all of the oil from accumulating there and then added another valve and sold it as a feature? Given the low pressure in there, this seems like a logical train of thought and makes the third chamber more or less a gimmick.

EDIT: as for the BOS piggyback, yeah, it's on the damper side. This is normal for high end moto forks, at least on the road. Might be connected to the general layout of the fork though (no offset, spring and damper each in their own leg or doubled up, etc.)
https://image.isu.pub/190115094415-7349cf5a2952e00deff0792bf813facc/jpg/page_1.jpg

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3/23/2020 2:21 PM

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3/23/2020 3:02 PM

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3/23/2020 3:18 PM
Edited Date/Time: 3/23/2020 3:25 PM

metadave wrote:

Thats similar to the older 2004-ish white bros DH3 but both are an IFP on the damper side. The above is suggesting a 3rd air chamber in the air spring to adjust bottom out?


It was I who guessed bottom out. It seems on that Showa fork it is not. But hey MTB world let's make it happen. it seems obvious to me. But I'm not an "Engineer."

#MillionDollarIdea.

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3/23/2020 3:40 PM
Edited Date/Time: 3/23/2020 3:41 PM

Just add spacers and you're half way there...

There's a lot of work being done on making air springs more linear. This would directly negate that. The thing is, you want full travel as often as possible. A "third spring" would just make it harsh at the end. What you want is a speed sensitive bottom out resistance module. A hydraulic bottom out stop. The faster you hit it, the more resistance it gives you.

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3/23/2020 4:34 PM

Primoz wrote:

Just add spacers and you're half way there...

There's a lot of work being done on making air springs more linear. This would directly negate that. The thing is, you want full travel as often as possible. A "third spring" would just make it harsh at the end. What you want is a speed sensitive bottom out resistance module. A hydraulic bottom out stop. The faster you hit it, the more resistance it gives you.

this is what the smashpot does.

Linear travel (it's a spring duh) with speed sensitive, shimmable hydraulic bottom out that works spectacularly.

The big catch, heavy AF but doesn't bother me.

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3/23/2020 5:46 PM

Wamp Rat wrote:

Well I'm intruigued...

https://forestal.com/en/products/siryon

That looks cleaaaaaaaaan. know its still unpopular, but i'm slowly being pushed towards the option of an ebike in my line up. My Jeep and friends trucks get beat to shit every year and maintenance costs and gas add up from riding at my local shuttle spot. It has an 9km fire road all the trails plus the same on the way back from two sides and someday's i'm just one or two people. The idea of getting a few more pedal laps in and be out longer with far less shuttle truck maintenance is really appealing to me. I've seen more than one F150 and even the odd Tacoma chewed up by that road after a few years.

That being said, This is only for fire road climbs and local alpine hiking trails that are regularly accessed with bikes as well and not trail riding or riding down under power. I feel like the cost of another bike would be offset by 2-3 years of vehicle maintenance and gas alone plus id at least be pedaling.

Hell, add on a tow road for your buddy and charge two tall cans a day for the lift access lol

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3/23/2020 6:44 PM

Wamp Rat wrote:

Well I'm intruigued...

https://forestal.com/en/products/siryon

metadave wrote:

That looks cleaaaaaaaaan. know its still unpopular, but i'm slowly being pushed towards the option of an ebike in my line up. My Jeep and friends trucks get beat to shit every year and maintenance costs and gas add up from riding at my local shuttle spot. It has an 9km fire road all the trails plus the same on the way back from two sides and someday's i'm just one or two people. The idea of getting a few more pedal laps in and be out longer with far less shuttle truck maintenance is really appealing to me. I've seen more than one F150 and even the odd Tacoma chewed up by that road after a few years.

That being said, This is only for fire road climbs and local alpine hiking trails that are regularly accessed with bikes as well and not trail riding or riding down under power. I feel like the cost of another bike would be offset by 2-3 years of vehicle maintenance and gas alone plus id at least be pedaling.

Hell, add on a tow road for your buddy and charge two tall cans a day for the lift access lol

I’m waiting for the e-bike that converts to a regular bike in 5 mins. Swap out the motor for a shell with normal cranks and bb, remove the battery and you’re good to go.

17.5kg for the forestal is pretty good anyway though.

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3/23/2020 6:57 PM

Primoz wrote:

Just add spacers and you're half way there...

There's a lot of work being done on making air springs more linear. This would directly negate that. The thing is, you want full travel as often as possible. A "third spring" would just make it harsh at the end. What you want is a speed sensitive bottom out resistance module. A hydraulic bottom out stop. The faster you hit it, the more resistance it gives you.

No, the third spring concept makes it even more linear than before. You effectively start with a low pressure, small volume air spring that is very sensitive but starts ramping up quickly (a typical air spring starts of firm but tapers off/reduces rate around 1/3rd stroke). Once that first chamber reaches the pressure of the second chamber, you start compressing both so its magically turned in to a large volume fork and you can reach the end of the stroke

You also don't need to reach full travel as often as possible, there is no good reason to do that. The best result is whatever travel the fork needs to absorb and dissipate the bump. If you are using full travel for the sake of it you won't actually be absorbing the bump properly and its more harsh than it needs to be.

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3/23/2020 9:41 PM

MXBREWSK wrote:

Maybe the concept that Showa was using 4-5 years ago on their motocross bikes, triple air chambers.

brash wrote:

Exactly like that, I'd seen it on KXF motocross bikes a few years ago. This was on the bag of the leg however.

MXBREWSK wrote:

Brash here is the link explaining the triple air chamber Showa fork. https://www.dirtrider.com/features/showa-separate-function-triple-chamber-air-fork-explained/

Manitou already have a similar 3 chamber system with IRT in the Dorado
It's just all inside the leg. There's the main chamber and negative like normal, and a 3rd small chamber that you run at a higher pressure to control ramp up and bottom out.

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3/23/2020 10:47 PM

Wamp Rat wrote:

Well I'm intruigued...

https://forestal.com/en/products/siryon

It looks like Specialized, Marin and Orange had intercourse.

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3/23/2020 10:53 PM

Wamp Rat wrote:

I’m waiting for the e-bike that converts to a regular bike in 5 mins. Swap out the motor for a shell with normal cranks and bb, remove the battery and you’re good to go.

17.5kg for the forestal is pretty good anyway though.

Here you go!: https://ebike-mtb.com/en/lapierre-ezesty-am-ltd-ultimate-2019-review/

That's the most underated e-bike platform out there. Such a great setup.
Can quickly remove the small motor and battery and boom, it's a normal MTB. The only problem with this system is that it's not massive wattage and range. However, it's pretty perfect otherwise. Would love to see more bikes like this. If brands did this, it would create a wave of e-bike purchases. The VAST majority of people can't afford two $5k+ mountain bikes so they're stuck with analog or e-bike. This design could change all of that.

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3/23/2020 11:11 PM

Wamp Rat wrote:

Well I'm intruigued...

https://forestal.com/en/products/siryon

metadave wrote:

That looks cleaaaaaaaaan. know its still unpopular, but i'm slowly being pushed towards the option of an ebike in my line up. My Jeep and friends trucks get beat to shit every year and maintenance costs and gas add up from riding at my local shuttle spot. It has an 9km fire road all the trails plus the same on the way back from two sides and someday's i'm just one or two people. The idea of getting a few more pedal laps in and be out longer with far less shuttle truck maintenance is really appealing to me. I've seen more than one F150 and even the odd Tacoma chewed up by that road after a few years.

That being said, This is only for fire road climbs and local alpine hiking trails that are regularly accessed with bikes as well and not trail riding or riding down under power. I feel like the cost of another bike would be offset by 2-3 years of vehicle maintenance and gas alone plus id at least be pedaling.

Hell, add on a tow road for your buddy and charge two tall cans a day for the lift access lol

Wamp Rat wrote:

I’m waiting for the e-bike that converts to a regular bike in 5 mins. Swap out the motor for a shell with normal cranks and bb, remove the battery and you’re good to go.

17.5kg for the forestal is pretty good anyway though.

I agree. A dummy shell for the Bosch/whatever motor when I don't want it and I'm in. Duel wielding. The Cannondale moterra SE with the 180 boxxer with that and I'm so in....

I want a Cannondale and an ebike... This is the end times

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3/24/2020 12:01 AM

Primoz wrote:

Just add spacers and you're half way there...

There's a lot of work being done on making air springs more linear. This would directly negate that. The thing is, you want full travel as often as possible. A "third spring" would just make it harsh at the end. What you want is a speed sensitive bottom out resistance module. A hydraulic bottom out stop. The faster you hit it, the more resistance it gives you.

TheSuspensionLabNZ wrote:

No, the third spring concept makes it even more linear than before. You effectively start with a low pressure, small volume air spring that is very sensitive but starts ramping up quickly (a typical air spring starts of firm but tapers off/reduces rate around 1/3rd stroke). Once that first chamber reaches the pressure of the second chamber, you start compressing both so its magically turned in to a large volume fork and you can reach the end of the stroke

You also don't need to reach full travel as often as possible, there is no good reason to do that. The best result is whatever travel the fork needs to absorb and dissipate the bump. If you are using full travel for the sake of it you won't actually be absorbing the bump properly and its more harsh than it needs to be.

What you're describing is DRCV. It's been done and has already been forgotten as well.

As for the third spring, Big Bird mentioned bottom out control. So the third spring is exactly what he was talking about and speaking about what he was talking about, it would make it harsh at the end of the stroke. I was specifically NOT talking about the DRCV or opening up the positive spring with an additional volume.

As fro full stroke, listen to Cannfields podcast if you don't believe me. He said that you should bottom out (clunk it!) the suspension every ride, a few times maybe even. It kinda makes sense, why ride around with unused travel that you only use 'for extreme cases when you need it', a few times a year, when you can just handle those extreme cases or slow down a bit.

And why would using full travel be harsh? NOT using full travel is harsh because you get a lot more chatter as feedback. Force and equal but positive reaction and all. Riding over a bump and using more travel will dissipate the same energy over a longer stroke, which means lower force values. Less harsh. But maybe you're talking about the harshness coming from the fork being stuck in it's travel? That's not necessarily a spring's fault, but something damping should take care of. A harsh ride (fork being stuck down) is, for example, often caused by a rebound that's too slow.

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3/24/2020 12:06 AM

Metadave I don't exactly understand your situation, you have to drive up and down to the trailhead using a car? Or is it flat? If it's riding up, don't you have a trail to get back down?

9 km doesn't sound SO bad to have to pedal with a normal bike... My most often ride includes 11 km of tarmac and gravel roads (flat-ish) to get to the gravel road climb and get back home from the trail descent. And this is the closest option with other trails requiring even more flat tarmac/gravel transfers.

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3/24/2020 12:50 AM

Formula and Ohlins are already using the triple air chamber concept, and the Runt and MRP ramp control are essentially that as well although all have variations in execution and concept.

Regarding using full travel, in my opinion, you only want to be using ONLY as much travel as necessary to dissipate the force of the bump so that you can maintain geometry and ride height and hence handling more consistently.

Bottoming out in itself is not bad if it is necessary to absorb the bump, but if the travel required to absorb the bump is say 120mm and you have 160mm of travel, so you set it up to use all 160mm on the same bump, you are probably setting your suspension too soft and likely compromising your mid stroke support in doing so.

This is all however still subject to personal preference of how you like your suspension to feel at the end of the day. Some people prefer the same bump force to be absorbed more linearly over slightly longer travel while some prefer a more progressive or stiffer setup that would use less travel but cause the damper to work harder and create more heat etc.

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3/24/2020 1:07 AM

I never said 'use up your travel on a root'. I said use up your travel on your average ride, don't leave 1 or 2 cm of it left for 'just in case' situations.

As for ramp control, it's a volume changing module, just like tokens are. Only that it's toolless. The Formula DH fork does have 3 air chambers, but the AM one has 2 chambers (separate negative chamber). A more important thing is that Formula uses their foam 'tokens', that can compress and thus add variability in the volume reduction they provide depending on the surrounding air pressure. I would like to see how their bottom out control works though.

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3/24/2020 1:25 AM

The Formula DH fork is the only one that uses 3 completely separated air chambers all with their own valve, most of the others use interconnected chambers that adjust and/or equalize between them.

Using the Runt in say a cane creek helm fork (not sure they are compatible) would essentially create a 3 chamber fork, although I think most brands have decided that a self equalizing negative chamber is a better option and are playing with the volume rather than the pressure thereof.

The ramp control is kind of a speed sensitive interconnected air chamber token system. It’s actually quite a complicated little device in its concept.

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3/24/2020 3:40 AM

Primoz wrote:

Metadave I don't exactly understand your situation, you have to drive up and down to the trailhead using a car? Or is it flat? If it's riding up, don't you have a trail to get back down?

9 km doesn't sound SO bad to have to pedal with a normal bike... My most often ride includes 11 km of tarmac and gravel roads (flat-ish) to get to the gravel road climb and get back home from the trail descent. And this is the closest option with other trails requiring even more flat tarmac/gravel transfers.

To clarify, this is for our local DH trails near Calgary. It's a valley setting in the Alberta foothills (Moose Mountain) with two gravel fireroads with trails built off both sides and a low lying parking lot in the middle. 9-11km per lap up the first side from main parking with 500m up to the two top trails and 3-8km back on various terrain back to start from two sides of that hill and 3km/350m up the other side with 1-4km back to start on the other. For two popular trails involving the first climb it's 23km with 950m to get back to my truck for one lap. Even trying for a third or aiming to hit a different start trail adds a ton elevation, checking on a recording,another 23km ride one time was 1300m for the trails that day splitting between the two sides.

The longer road is shuttle-able, the shorter is not. I think in this case or similar an assisted bike would be a huge advantage to get more laps in and not have to run the truck at all. I don't mind the pedaling all day but I'm limited in the amount of no truck assist big lap days per week even at mid/end of summer fitness and having the option of not using the truck at all to get the same amount of laps I usually do on a shuttle day more than once a week would be pretty great to spend pedaling instead. Even if it's assisted. And again, no vehicle maintenance which per year adds up to about 1000-1500$ before gas and regular maintenance after beating trucks up that road from May to October.

Not smashing up through the woods at 60km an hour in a gas guzzler is also appealing to me in this case. Again, I don't think for most people assisted bikes have a place when simply trail riding, I see full suspension Enduro ebikes taking over the stuff I usually ride my hardtail on which is a bit much, but I am starting to see a place for them and it's replacing shuttle trucks.

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3/24/2020 3:57 AM

Because even setting the correct pressure in one valve is a challenge for a lot of riders, that's why interconnected chambers are used. Imagine all the moaning of 'my fork doesn't extend all the way' when people would put too much air pressure in the negative chamber and the image that would produce amongst the public.

The Runt is another variable volume adjustment system, where instead of the foam inserts an adjustable air chamber is used (changing the chamber air pressure changes the way the main positive spring volume changes, the higher the pressure in the Runt, the less volume change there is). The Runt is again different to the Showa fork (the two air chambers of the Showa are still paralel, the Runt is serial).

I've just found the Ohlins system, it's the same as the Runt. The only difference is that the 'third chamber' valve is at the bottom of the fork, not at the top, since it's not a replacement cartridge.

So we're talking about variable chamber volume systems here, the only unknown at the moment is then the Formula. And still, none of these systems is a bottom out control and all of them try to achieve a more linear force-stroke characteristic, which is the complete opposite of bottom out ramp-up, a standard air spring is the best for that by itself due to the inherent ramp-up.

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3/24/2020 4:35 AM

So, I've found a video explaining the Formula system. It's the same as everything else, serially mounted air springs to vary the volume of the (main) positive chamber through the stroke and to vary it 'toollessly'. A more finely tuneable version of their foam spacers (which, interestingly, can still be used with the fork... To add another layer of complexity then?).



So yeah, all these systems are designed and used to LOWER the ramp-up at the end of the stroke, not to increase it. If you look at the runt and the graphs:
https://images.squarespace-cdn.com/content/v1/5705bbaaf699bb254be1fc78/1501017983055-7WSX5CVKGW5LBBRBT407/ke17ZwdGBToddI8pDm48kF3t0Chi_9Z_8TNxaXn1uwgUqsxRUqqbr1mOJYKfIPR7LoDQ9mXPOjoJoqy81S2I8N_N4V1vUb5AoIIIbLZhVYxCRW4BPu10St3TBAUQYVKcvRJXkUZN7YT_o_Ls8DiWkzQNGSI9f83yykTNFqoLd2hGT-L8Rh0p_Gbs0Sg_dAtO/image-asset.png?format=1000w

Without a variable third spring chamber size, in effect lowering the rate of volume change of the main chamber, the shape of the graph would be similar to all other lines, but would just be much higher.

And don't get me wrong, I've never said any of this is bad or anything. Maybe it's not needed (or not as simple) for the average rider, it's for the tinkerer who knows what he's doing, but giving you these options is a good thing (if you know what do to with them). All I'm saying is that neither of these systems is nothing along the lines of bottom out control (regardless of the marketing behind it), it's not hydraulic bottom out control (except for the smashpot, apparently, though I haven't looked into detail regarding it) and it's not like what the Showa MX fork is, if I understood that correctly (that used two parallel positive chamber airsprings, but I still think it was added because it was cheap and had added marketing value, not necessarily because of the performance gains, which would be supported by the very low pressures running inside the chamber).
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3/24/2020 4:38 AM

For some reason I can't edit my posts... Anywho, I just wanted to add, Formula is saying the third chamber adds progresivity to the fork when you add pressure. That is correct. But the catch is you're not adding progressivity compared to a 'normal 2 chamber fork', you're getting closer to said fork. The triple chamber spring design, to start off, REMOVES progresivity. That's the key to all of this here. And it's why you can't think of these systems as 'bottom out control' in the same way you can with a hydraulic bottom out damper.

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3/24/2020 5:00 AM
Edited Date/Time: 3/24/2020 5:04 AM

I get what you are saying in terms of the third serial chamber reducing the progression in a way, although I just look at it as a more tuneable version of tokens, but at the same time, is not adding progression a form of bottom out control? In what way is a hydraulic bottom out system not performing the same purpose? - please don’t think I’m arguing this point, I’m more genuinely interested to understand.

Surely The third chamber isn’t ‘removing’ progression but more just changing the Shape of the curve? You could easily give it more progression by just adding more air...

Regarding the showa fork, I don’t understand how a parallel air chamber would have any purpose? Surely they would both then operate at the rate of the one with the higher pressure? Is it not maybe a negative chamber in a similar way to how the RS rear shocks work where they gain extra volume by extending the negative chamber to surround the positive chamber?

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3/24/2020 6:53 AM

A hydraulic bottom out control is speed sensitive. The harder you crash into it, the more damping it provides. It's usually done on the damper side with for example a needle/piston entering from a big chamber with lots of clearance into a smaller chamber at the end of the stroke (just fitting into the chamber with not much clearance). You can then vent that chamber to the general damper volume or close off the complete damper assembly with the smaller piston. That's how EXT does it (at 2:00 you can see the effects of it on the damping).



Otherwise hydraulic end stops are used in hydraulic equipment (think excavators and the like) with the piston having additional geometry to fit into the appropriate hole in the cylinder body, to slow down the movement at the end position. This gives time to the operator to stop the movement before hitting the hard end stop. With the pressures and forces acting on these cylinders, the loads of bottoming out could be very, very high. Adding a hydraulic end stop bumper is very cheap (virtually no additional components) and saves the equipment.
I've circled the bottom out control geometry in the picture: https://i.imgur.com/NBJpg8D.png



As for the third chamber... Yeah, by adding air, you're adding progression. What i was trying to say, if you remove the third chamber and use spacers to achieve the same volume of the main positive chamber, you will get a lot more progression. With a third chamber, the 'volume spacer' volume is reducing through the travel. With a plastic puck, it stays the same. That's why spacers give you a lot more ramp up and a third chamber gives you a much more linear curve than spacers can.

Surely a third chamber is better. But it's another IFP (in essence, it's an IFP separating the two chambers and the movement of it varies the volume spacing), another valve, additional seals, etc., which adds costs, That's why i think RS and Fox don't use such systems. That and, most importantly, a two or three chamber setup is much more difficult to set up correctly. Not a problem fort he tinkerer who's willing to buy a niche product or upgrade his fork from one of the main two, but a big problem for the average joe, who hardly understands what all the knobs on his fork do. And I think problems with wrongly tuned settings on such a complicated product would only backfire for RS and Fox with all the users via OEM installations instead of giving them a benefit through the praise of the vocal few, who want, understand and are willing to put up with a more complicated system in order to get the final few % of the gains.

Regarding the Showa, exactly. Like i said, i think they just sealed off the upper and sold it off as an additional spring. But they just sealed it off to prevent oil leaking down to the bottom of the lowers. This way they kept it on the seals and bushings. They are using a cartridge spring, not like MTB forks, where the slider tube itself is usually the spring casing as well. I wrote this before (in this thread), i think it was a cheap hack that could be sold off as a 'benefit', that does barely anything, my point supported by the low pressure run inside that chamber (just so they preload the seals to provide the correct sealing function for the oil not to drop through.

I'm armchair engineering here based on information and pictures off the internet, I admit that, i could be wrong in many points and I'll happily be proven otherwise.
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3/24/2020 7:48 AM

Primoz wrote:

A hydraulic bottom out control is speed sensitive. The harder you crash into it, the more damping it provides. It's usually done on the damper side with for example a needle/piston entering from a big chamber with lots of clearance into a smaller chamber at the end of the stroke (just fitting into the chamber with not much clearance). You can then vent that chamber to the general damper volume or close off the complete damper assembly with the smaller piston. That's how EXT does it (at 2:00 you can see the effects of it on the damping).



Otherwise hydraulic end stops are used in hydraulic equipment (think excavators and the like) with the piston having additional geometry to fit into the appropriate hole in the cylinder body, to slow down the movement at the end position. This gives time to the operator to stop the movement before hitting the hard end stop. With the pressures and forces acting on these cylinders, the loads of bottoming out could be very, very high. Adding a hydraulic end stop bumper is very cheap (virtually no additional components) and saves the equipment.
I've circled the bottom out control geometry in the picture: https://i.imgur.com/NBJpg8D.png



As for the third chamber... Yeah, by adding air, you're adding progression. What i was trying to say, if you remove the third chamber and use spacers to achieve the same volume of the main positive chamber, you will get a lot more progression. With a third chamber, the 'volume spacer' volume is reducing through the travel. With a plastic puck, it stays the same. That's why spacers give you a lot more ramp up and a third chamber gives you a much more linear curve than spacers can.

Surely a third chamber is better. But it's another IFP (in essence, it's an IFP separating the two chambers and the movement of it varies the volume spacing), another valve, additional seals, etc., which adds costs, That's why i think RS and Fox don't use such systems. That and, most importantly, a two or three chamber setup is much more difficult to set up correctly. Not a problem fort he tinkerer who's willing to buy a niche product or upgrade his fork from one of the main two, but a big problem for the average joe, who hardly understands what all the knobs on his fork do. And I think problems with wrongly tuned settings on such a complicated product would only backfire for RS and Fox with all the users via OEM installations instead of giving them a benefit through the praise of the vocal few, who want, understand and are willing to put up with a more complicated system in order to get the final few % of the gains.

Regarding the Showa, exactly. Like i said, i think they just sealed off the upper and sold it off as an additional spring. But they just sealed it off to prevent oil leaking down to the bottom of the lowers. This way they kept it on the seals and bushings. They are using a cartridge spring, not like MTB forks, where the slider tube itself is usually the spring casing as well. I wrote this before (in this thread), i think it was a cheap hack that could be sold off as a 'benefit', that does barely anything, my point supported by the low pressure run inside that chamber (just so they preload the seals to provide the correct sealing function for the oil not to drop through.

I'm armchair engineering here based on information and pictures off the internet, I admit that, i could be wrong in many points and I'll happily be proven otherwise.

Thanks for explaining that, much appreciated! I've heard mixed responses regarding the performance of the EXT hydraulic bottom out, but it definitely does make a lot of sense for coil shocks and forks too. I'm surprised that few of the new coil fork options being released recently (cane creek and marzocchi) have any kind of progression/bottom out system built into them, makes me think that they are being offered more to meet popular/marketing demand than as a serious technological solution.

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3/24/2020 10:00 AM

Could be that the EXT introduces harshness towards the end of the stroke. It spreads the bottoming out CLUNK from the end of the stroke over the last few mm, so it's doing something, as in lowering the spikey loads applied to the frame and the shock. But it's more noticeable than the bottom out itself even if you weren't about to hit the end stop, just had a fairly long stroke event.

As for the forks,it is interesting, even more so that there are cases where a spring sprung fork doesn't have an 'advanced' damper with a more tuneable compression stack, where you could close off the high speed compression a bit and add more support for large hits through damping.

I can't remember, does Push do hydraulic bottom out on their 11-6?

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3/24/2020 10:02 AM

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