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My son rode a bike 5 years or so ago w/the bladder kit. And has had one ever since. He can feel the difference even in sweepers. With the piston it will stick and suddenly go or whatever making a simple sweeper sketchy at his speed. The bladder fixes that. KTM rears have always been sensitive to overheating especially with new pads. You have to adjust the lever some.
Heck, I had a bunch of older shocks cluttering up the under bench space, and, the old beastie had a bit of a tendency towards shock fade when it was still a Linkaged bike, in some of our 4hour GNCC type races, especially at a Sand Whoop infested course.
So, grab a resi, from a 83 Floater, remove and weld up the primitive compression adjuster, make a new end cap for the shock resi, the 02 bladder and cap fitting in the 83 resi, and you've got a Hell of a lot more oil capacity.
Shock fade : Gone. Oil would come out the same colour as it went in, whereas, std, it would come out thoroughly cooked.
I've been meaning to put one on the Ohlins TTX, but, well, I really don't come remotely close to hammering nowadays - I Plod Along, stoically. 😉![]()
Not really fair to compare the sand tracks which everyone knows gets rougher. What about all the harder pack tracks?
Bear, would a bigger standard reservoir provide the same results?
Edit: if so, why wouldn’t KTM plus up the race team shocks? Could it be just appearances?
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So KTM MXGP riders don't seem to have issues with shock on much rougher tracks than in AMA, but we should disregard that because those tracks don't count. Got it 😄
Hard packed tracks is rougher or best case same, and it's because MXGP have 2 days of racing with limited prepp, and more classes on most races.
Space is one thing, it's fucking tight in there. And I guess just increasing the reservoir isn't giving you leverage since shock body is where most of the oil is spending most of the time.
Google searching indicates that across 450 brands, the oil volume in shocks is approximately 110-120ml. So no smoking gun when it comes to wp oil volume vs showa or kyb.
It's around 500ml in a shock. But you are right in that it doesn't differ much.
Even small changes could make a difference reg heat and cavitation.
Maybe they got some oil that was not to spec?
The should just run a bladder
They do.
I assumed they would use IFP as WP are a huge believer in that
I was saying the AMA tracks are rougher, which is logical. It's hard to make bumps when they start out as hard packed freeways like some of the GP tracks. Would make sense of the KTM shock fading in AMA vs GP.
No prep can equal no bumps.
Any extra Oil capacity is a Good thing, but, not a universal panacea.
A slightly larger reservoir, enabling more oil - well it won't be much of an increase.
People mostly don't know how little oil Is in the actual reservoir, given the size of a bladder / the depth of the piston setting - it is, buggerall, in the vast majority of shocks. And, you have to be cautious - you need to consider the expansion of the oil through heat. I remember at Fox, a (rough) rate of expansion was regarded as 10% - but that's just a layman's percentage: all you experts, I'm Not interested in debating numbers.... The oil expansion through heat, is the main ( of course, material expansion through heat is a part of it) reason for shock pressures to rise, If you Are using a Noble Gas, by the way.
I've Always checked the fluid displacement into the reservoir through the shaft travel. It's good to know. In some cases, with a piston, there's scope for said piston to be set at a slightly lower depth than standard for more oil - in some though, there can be absolutely No 'room' to play with. Bladders, well, that volume is a set thing, though, changing the actual bladder size / resi size can be an option.
As I wrote, I had some shocks to hand, had a (slight) problem, and, as I, at the time, spent much of my days working on suspension, and wanting to minimise my time doing my Own suspension, decided to be 'Mad Scientist Bear' ( which, many will agree with my being) and made a 'something'.
It kept me amused for the arvo it took to do it and the mount set up for the resi, and gave me better performance, and, lessened the frequency of oil changes = more time for other Bear Brained things to do!
As to the ever raging Bladder vs Piston debates = I've been privy to many dyno runs of many shocks / forks ( and watching a 'to destruction' test of Long Travel Trophy Truck type shocks can be quite, Quite entertaining - and, it makes you grateful for the bullet proof layers of glass between you and the unit(s) being 'killed') and have never really seen much difference in heat , or, even 'sticktion' /friction between the two 'solutions'. With the caveat of a piston set up being a Good piston setup. Bloody Hell, some can be horrendously tight!
I've a hankering to try the SKF "Piston with Membrane" set up, one day. But, like everything, I hear horror stories ( as in, them 'butterflying' over - WTF? Yikes!) about them, as well as glowing praise of them. That will be a while off, as I've fresh oil in the Ohlins, and I'm just trundling around like the Old Man That I am, at the moment, and rarely, at that.
I don’t think there is much heat transfer in a remote reservoir shock. The remote reservoir gives room for a bladder (in old school shocks) and enables N2 pressure to back up the seals, provide some shock preload, and simplify rebuild ability IMO. The smaller reservoirs in modern shocks have less surface area for air cooling. But the teams know this so it’s a perplexing problem to re-emerge.
No its not logical. A shock that barerly works on a hard packed track would be toast on a proper sand track, or even a mixed track like the ones in MXGP.
Your assumption would be incorrect.
My suspension guy likes bladders just because they’re easier to service/bleed than a piston.
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This made me think back to the old, giant remote reservoirs that Yamaha use to mount on the front downtube. Funny that 40+ years later we have small reservoirs mounted above the exhaust. Go figure.
https://www.cnbctv18.com/business/bajaj-auto-ktm-management-restructuring-overhead-reduction-rajiv-bajaj-19721503.htm
Probably goes a long way towards explaining Chase's move to Kawasaki. Does not sound good for the racing side of things.
This was largely expected knowing bajaj's business philosophy. I've seen past statements from leadership that indicated cutting edge R&D and racing aren't their focus.
The 'gassed' bladder is in the RM Floater era, reservoir, thence the oil in it, in the oil area space of that reservoir left by the bladder, through the RM hose ( which is a large ID hose, with large port banjo and straight fittings - not a stupidly small ID brake line and fittings ).
The Reservoir on the original KYB shock is Full Of Oil.
Somewhere I've got notes of the extra oil capacity gained, ( I recall, vaguely, pretty much doubling the oil volume), along with all my valving changes done to the KYB while still in use, plus all the valving I did to to Ohlins TTX I used in the PDS conversion.
I will be doing the same to the TTX shock on my PDS'd conversion. I made a landing for the resi to mount on with the Top Mounted Airfilter airbox I made for PDS set up. Just waiting on a couple of parts to come, for an update / refresh to the Ohlins.
Just listened to Monday's Pulpmx where they called Mark Johnson of REP and asked what he thought. Sounds like he thinks it's the same thing that I found to be the problem with mine (which was valved by a factory level suspension company). 'Pressure balance' insufficient.
That means cavitation, they're likely using too much valving on the piston, which means they need a bigger shock shaft diameter.
Well in that case, maybe it’s time to sell the TE and buy a Beta..
"Survivability"
Sounds like Bajaj might have a different idea in mind when they say, “Ready To Race”
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