I think the STW article missed this…

Am I mistaken or does this almost turn your fork into a weird frankenstein oleo strut?

I’m not sold on the concept of your fork hardening up under high speed hits, if anything, I’d want the spring to resist low speed hits and blow off on high speed hits.

Does it mean that you could run the spring pressure really low and essentially rely on the compression and air spring valve to hold the fork up?

I’m not sold on the concept of your fork hardening up under high speed hits, if anything, I’d want the spring to resist low speed hits and blow off on high speed hits.

I suppose it depends on the magic how much, a certain American on a YT seems to like the idea. I read it more that it gives you a firmer fork on the big hits so you get more from your inches. Just using it as HSC means you can take the hits and have a plush fork for the regular stuff but when you land the big one/case it keeps the nose up and slows your rate of absorbtion which is much better (if your going to hit full travel on both versions a slower deceleration is better)

I understood it’s as if you have an adjustable bottomless token?

Is that wrong?

Yep, that was my understanding too

Ditto.

They must mean you can tune the forks progression on the fly?

Not seen any suggestion it’s automatic

It’s essentially just an adjustable replacement for the bottomless tokens. Instead of having 1,2 or 3 tokens you can twist a dial and have 2.2 tokens or whatever you want. Think it’s very neat myself.

So what’s the difference between the boost and none boost cartridge then?
I thought all the Pike internals were the same be it boost or none?

That’s very clever. It isn’t a continuously variable volume spacer, it is a fixed large volume spacer with a speed sensitive valve controlling whether the forks acts as though it has 1 volume spacer in it (that’s the space it takes up) or the full amount of volume spacers.

So under low speed compressions the fork remains fairly linear because the valve to the upper air chamber remains open. Under high speed compressions the fork ramps up much more strongly in the last third of travel (almost no effect on the midstroke). And the ramp control sets how quickly the fork has to be moving before it closes the valves into the top air chamber, thus increasing the spring ramp up.

Similar effect to Manitous HBO and IRT combo?

nickc – Member

I understood it’s as if you have an adjustable bottomless token?

Is that wrong?

That seems to be how its been presented in the bike press so far, clearly bike journos are not as clever as they would like people to think.

Also, although it’s a bit irrelevant now with so many of us using those under fork bridge mudguards, the reverse casting MRP are showing is long overdue!

I have this on my MRP forks.

<Borat>Is niiiice!</Borat>

I didn’t realise it was speed dependant though, which explains why I could never feel it squishing by hand but rarely bottom out the forks. Top marks.

Where are people getting the info that it is speed-sensitive?

If so, why would it have the manual 16-point adjustment?

Looks to me like you twiddle the top bit to open and close vents in the bottom of the cartridge, thus mimicking different levels of token use?

I guess reading wasn’t your strong point at school ^^^

Because that’s exactly what it says!

“This dial opens and closes a very small port at the bottom of the cartridge; the smaller the port, the harder it is for the air to pass through and vice versa.”

That suggests it’s a purely manual adjustment though?

I guess reading wasn’t your strong point at school ^^^

Nice to meet you too.

Similar effect to Manitous HBO and IRT combo?

Nope, IRT is a three chamber system, where you pump up a primary and secondary chamber whilst the negative chamber self equalizes. It’s very similar to the Ohlins RXF fork and the Showa Triple Chamber motocross fork. HBO is a hydraulic bottom out. A chap over on MTB-News.de also produces a similar system for the Pike (google Pike AWK).

I’m still not a believer in this, if the valve is speed dependant, then surely the fork is going to spike more easily on square edged hits? Or can it be thought of as more force dependant? Square edged hits or roots and rocks tend to use the midstroke but the hits produce very very fast shaft speeds, it was my understanding that things like drops which eat more into the travel tend to see lower shaft speeds. This is why avalanche are able to tune their blow off valve on their open bath cartridge to blow the high speed compression off on square edged hits, but keep it for drops.

You’re thinking about it wrongly. It is a speed dependent engagement of a parallel harder rate exponential spring which only engages in the last third of travel.

It is nothing to do with damping and it has no effect on the spring rate in the beginning or midstroke.

So to clarify, this MRP device only changes the fork performance when the shaft speed is high AND you are using the last third of travel. The rest of the time (low shaft speed or first two thirds of travel) it will behave exactly as a Pike with 1 token.

You should be able to tune it so that the fork never bottoms out harshly but you get to use more of the travel more of the time, whereas with the bottomless tokens you have to accept that the fork will get harsher deeper into the travel if you want to keep from bottoming out hard.

Maybe we need to think of it as a speed sensitive bottom out control.

Hit something hard and fast and it adds a bit more support to the bottom of the stroke to prevent you bottoming out harshly.
Hit something more slowly and the support is less so you get to use all that travel and the bottom out isn’t going to be as harsh anyway.

but obviously its tuneable so applies to more than just bottom out situations.

From VitalMTB.com article

Ha, was just going to post that. Nice and clear whats going on. Interesting challenge tuning that along with the damping too.

Of course what this doesn’t do is provide more support the whole way through travel. I have 3 tokens in my 29er Pike so I can keep it soft for initial sensitivity but not blow past the mid travel, bottom out is obviously firmer because of this. According to that graph with a RAMP id lose the mid support but keep the firm bottom out.

Oh, and FYI.

Available end of the month, £129rrp

That’s it – speed sensitive bottom out control.

I’ve noticed a lot of riders try to use the tokens to improve midstroke support but in my opinion it’s not a great way to do it. However, as you can’t adjust the negative spring the only other ways to control midstroke support (air pressure and low speed compression) also affect the beginning stroke. I gather the Lyrik has a softer beginning stroke than the Pike (bigger negative spring) so you’re not alone in your forky desires…

Rockshox standard suggestion for a 130mm 29er Pike is for 3, and this is the same for all of the shorter travel versions of adjustable travel forks. Guess the MRP ramp is only for the full enduroists 😉

Thing is, for anyone but a top DH racer, how harshly one bottoms out is all rather irrelevant, because it all happens in the last 10mm of travel. So, the loads are high anyway, meaning what your tyres and doing, and critically, what the rider is doing, and how strongly they are positioned is much much more important.

STATO – Member

Rockshox standard suggestion for a 130mm 29er Pike is for 3, and this is the same for all of the shorter travel versions of adjustable travel forks

Rockshox standard suggestions for setup are often total bobbins though. Too soft springs, random amounts of air or air spacers… They said I needed an extra soft for my lyriks, I fitted a soft and still spent the entire time in the bottom of the travel, had to go up 2 sizes from their recommendation to medium… And my 150mm 29er Pikes came with 2 in despite that recommendation chart saying one so even they don’t seem to know what they think.

(so I’ve gone up 1 from their retail setting and 2 from their inexplicably different website recommended setting, and it works pretty well but might still add another…)

So for a given PSI, according to that graph, it does affect the midstroke chief, but to a lesser degree than tokems? I actually quite like that, as it would possibly keep the shock more supple on roots. Linear to highly progressive in the last bit of travel is how the WRC cars are setup, I believe. If it genuinely doesn’t affect high shaft velocities in the mid stroke of the fork – then ut looks like an awesome idea.

I’d like to see a graph that takes into accountboth shaft speed and force, I’m probably being really thick but I could see the fork choking on fast mid sized hits – if it’s purely speed dependant. Unless what they mean by speed dependant is actually force dependant.

Maybe we need to think of it as a speed sensitive bottom out control.

Hit something hard and fast and it adds a bit more support to the bottom of the stroke to prevent you bottoming out harshly.
Hit something more slowly and the support is less so you get to use all that travel and the bottom out isn’t going to be as harsh anyway.

but obviously its tuneable so applies to more than just bottom out situations.

This makes it sound remarkably like that oleo strut DH bike that was reviewed in Dirt mag. What was the name of it?

I’d like to see a graph that takes into account both shaft speed and force, I’m probably being really thick but I could see the fork choking on fast mid sized hits – if it’s purely speed dependant. Unless what they mean by speed dependant is actually force dependant.

Sounds speed dependant, as in how fast air can flow through a tiny hole. It looks like it does apply at the mid stroke slightly as the max line is the device applied. At 1/2 travel any high speed hit would compress the air in the main chamber but that air couldn’t then get into the ramp chamber quick enough, so you get the effect of tokens applied.

I think the slow speed version of the graph is just the min line, as in its not applied because the hole for the air is so big youd have to hit the fork faster then you ever would to get any restriction to the flow. Of course as the device take up some space it still follows the 1 token curve.

My take anyway.

Gah – just seeing now that it only goes to the equivalent of three tokens – I use four and am tempted to go with a fifth

How much sag do you run George, that many tokens sounds a bit daft to be honest. Even if you weigh 250lb.

Unless it’s because you’re running a short travel model.

Tom, look at the chart I posted. For the shortened versions of forks you need to fit tokens to get the same spring curve you would get on the longer fork.

Yeah, see my edit 😛

Anyway, nice to see that we the consumers are outwitting the journos. Maybe singletrackworld should employ some of us 😛

Tom_W1987 – Member
How much sag do you run George, that many tokens sounds a bit daft to be honest. Even if you weigh 250lb.

Unless it’s because you’re running a short travel model.

It’s a 140 29er, Tom, 29ers (and shorter travel ones) take more tokens

Doubting myself now… do I have 3 or 4?

Edit – yep 130/140 29ers take 5 max, I have 4. 120 29ers take 6 max

This makes it sound remarkably like that oleo strut DH bike that was reviewed in Dirt mag. What was the name of it?

The Millyard DH bike and Nitroshox?

Kinda (in the case of the Nitroshox anyway, no idea what the Millyard did). Oleo dampers use the damping oil behind the IFP to compress the air. This is just using the air spring piston, the damping is on the other side. functionally it should work the same though.

The harder you hit stuff the smaller the apparent spring volume gets, which only really plays a part towards the end of the stroke.

You can also build air damped shocks, which mean you can do the (to a geek at least) cool thing of getting rid of the damping rod entirely, the air spring canister sits on the shock, and the bit where the oil damper is acts as a constantly changing volume to mimic the force a hydraulic damper would apply!

Yes, the thing with the Pike and Lyrik is they use same size negative spring for all the travel and wheel size options. The negative spring is bigger on all the Lyriks. So the Pikes have a segment at the start of the travel where they ramp up, and it’s for the same amount of the travel on all of them. Same on the Lyriks but for more of the travel. Then they’re pretty linear for a lot of the travel. The 29ers start ramping up furthest into the travel and by the smallest amount, the 26 soonest and by the most. The less travel you have, the less of the ramped up bit of the curve you get – and because of having less travel it takes even less force to reach full travel.

It does look like this product won’t work for most 29er riders or shorter travel 27.5 riders. I like my forks fairly firm but fairly linear so get away with only 1 token at 160mm 27.5, 2 at 140mm 27.5, 3 at 130mm 27.5 – but that’s still 1 more than their default setup.