Fork midvalve - shim stack or check plate?

[Yankee Doodle Dandy]

Up until recently sport bike forks used a check plate and a spring /wave washers for a midvalve set up. Dirt bike forks would use a shim stack and after market tuners such as Race Tech would sell kits to change them over to a spring w/ check plate configuration.

The 06 and up GSX-R forks use a shim stack w/ a bleed hole. K-Tech uses a shim stack.

Ohlins uses a check plate w/ wave washers in their 20mm piston kits and a check plate with a spring in their 25mm stuff. They even offer (3) different rate springs.

There is a US Ohlins dealer that offers his own valving in the Ohlins stuff and has been replacing the check plate set up with a shim set up.

Which is a better set up for track use?

[vifferman]

Eggs Zachary. But I prefer the minestrone.

[Pussy]

Bending shim stack mid-valve for the win!
Stock Showa forks on the 06 onwards GSX-R 600 and 750 have the feature.
I have a set of FGK 132 cartridges in my 750 with the mid-valve. Brake dive resistance is excellent. The forks can be run with slightly more rider sag, and still be kept up in their stroke.
Robert Taylor from this site will be able to give you a good explanation of it

[Robert Taylor]

Up until recently sport bike forks used a check plate and a spring /wave washers for a midvalve set up. Dirt bike forks would use a shim stack and after market tuners such as Race Tech would sell kits to change them over to a spring w/ check plate configuration.

The 06 and up GSX-R forks use a shim stack w/ a bleed hole. K-Tech uses a shim stack.

Ohlins uses a check plate w/ wave washers in their 20mm piston kits and a check plate with a spring in their 25mm stuff. They even offer (3) different rate springs.

There is a US Ohlins dealer that offers his own valving in the Ohlins stuff and has been replacing the check plate set up with a shim set up.

Which is a better set up for track use?

25mm, Ohlins with shim stack. Their 20mm stuff is old hat and I have been at pains to get them to change it.
20mm. Race Tech high frequency rebound pistons, the rebound ports are a near identical copy of Ohlins but with a shim stack midvalve.
Much more instant damping response and braking pitch control, absolutely no question.

[Yankee Doodle Dandy]

With the Ohlins 25mm stuff are you modifying the piston so you can use a shim stack or does Ohlins make a rebound piston for use with shims?

[Pussy]

With the Ohlins 25mm stuff are you modifying the piston so you can use a shim stack or does Ohlins make a rebound piston for use with shims?

The rebound pistons have been coming as midvalve ones for a while. At least three years, to my knowledge.
This is, of course, in the 25mm cartridge kits

[Yankee Doodle Dandy]

All the ones I have been messing with have had the check plate and spring configuration.

[Robert Taylor]

All the ones I have been messing with have had the check plate and spring configuration.

The pistons we use are different to current production as delivered. I dont wish to elaborate further on this public forum as its commercially sensitive and there are parasites in our industry that will be reading this.

[Yankee Doodle Dandy]

I poked around online a little bit and it does look like Ohlins went from the spring & checkplate to a mid valve arrangement.

However, I do see Ohlins still uses the spring & checkplate on their current Superbike fork (FGR 800) and their new 30mm cartridges for the R1 use a spring & check plate.

[Pussy]

There must be HEAPS of Ohlins dealers on your continent who will have the info you're looking for. They've got access to the gen on your side, if they are authorised

[Yankee Doodle Dandy]

There must be HEAPS of Ohlins dealers on your continent who will have the info you're looking for. They've got access to the gen on your side, if they are authorised

Help in the US?

You must have never been here.

[Pussy]

Help in the US?

You must have never been here.

You're right.... I haven't.
Surely your Ohlins importer/technical staff will have the gen?

[Yankee Doodle Dandy]

Ohlins USA is useless to me.

Unless you are a factory team or satellite team then you are SOL.

95% of the people selling Ohlins in the US are just shops that change parts. For street based stuff the majority of suspension shops here deal with Penske as they are easier to work with.

[Shaun]

Ohlins USA is useless to me.

Unless you are a factory team or satellite team then you are SOL.

95% of the people selling Ohlins in the US are just shops that change parts. For street based stuff the majority of suspension shops here deal with Penske as they are easier to work with.

I have been trying to tell Robert for years now to get his arse over to the USA

[Yankee Doodle Dandy]

I don't know why I typed for street based stuff, I must have been half asleep. Penske's sales are not limited to street stuff as they have a huge presence on the track also.

Most of the real suspension shops over here deal with Penske as they are easier to work with. They provide much better support and are easier to get custom stuff done.

Off the top of my head, there are only a couple of independent suspension tuners that really work with the Ohlins stuff and one of them is a former Swede that worked for Ohlins.