New Ohlins front end review

[cowpoos]

Hey, Poos...
There is a very good article in the April 2009 Superbike magazine on the BPF.
Written by Ken Summerton, who apparently knows what he's talking about. He explains a few shortcomings of the "garden variety" BPF found in the bikes we can buy off the floor.




Don't bother hitting Nicksta up to borrow her copy... I've still got it!

got a scanner??

[Pussy]

[DrZeeple]

We had some pistons made that resembled an earlier Ohlins design that was out of production, but we politely asked Ohlins first if that was okay.

Wouldn't be OP1515-01 pistons would it? I still have some sitting in my parts bin - just like Traxxion's and Penske VDP's, just that these days I never really see anywhere I want to use them anymore! (actually, only one or 2 places I would use a bath-tub piston nowadays, now that I think about it like...)

I follow these threads with some delight from over in Oz/UK or wherever I be - it is always nice to see discussion about suspension, and if only I had RT's way with words; but sadly not...

So, greetings all and nice to make your acquaintance!

Z

[JD Racing]

No special finish on the insides of the tube, the rest is the usual mass produced build quality. I can't believe they resemble anything used on the factory bikes.

The rebound adjusts by a normal needle, the compression adjusts the preload on a spring acting on the compression stack, not a particularly wide range of adjustment. The preload works via a ramp arrangement at the bottom of the fork.

Riders who've used them as standard say they ride very high in the stroke on turn in. Personally I've not played with the valving, 20 & 25mm cartridges have been about for over 10 years and are well down their development path improving all the time, kits drop straight in.
I already have enough on with the 20 and 25mm, the 30mm for the new R1 is coming on well, I don't want to dilute what I'm doing with those chasing a set up on the big piston.

[The Stranger:Me]

we could use many examples to discuss the evolution of the internal compustion engine...but the key is evolution..

Very very few haven't stood on the shoulders of giants in their development of a product or service. How then does someone else standing on their shoulders become wrong.

Another issue I have with regard to protection of an idea is this. Why, by shear dint of the fact one were born first give one a right to claim an idea.
The patenting of the human genome for example or the one click check out patent as developed by Amazon.com

[Robert Taylor]

Wouldn't be OP1515-01 pistons would it? I still have some sitting in my parts bin - just like Traxxion's and Penske VDP's, just that these days I never really see anywhere I want to use them anymore! (actually, only one or 2 places I would use a bath-tub piston nowadays, now that I think about it like...)

I follow these threads with some delight from over in Oz/UK or wherever I be - it is always nice to see discussion about suspension, and if only I had RT's way with words; but sadly not...

So, greetings all and nice to make your acquaintance!

Z

Indeed! But now reduntant in my world as well. Much more emphasis on ''mid valve'' rebound pistons.

[Robert Taylor]

No special finish on the insides of the tube, the rest is the usual mass produced build quality. I can't believe they resemble anything used on the factory bikes.

The rebound adjusts by a normal needle, the compression adjusts the preload on a spring acting on the compression stack, not a particularly wide range of adjustment. The preload works via a ramp arrangement at the bottom of the fork.

Riders who've used them as standard say they ride very high in the stroke on turn in. Personally I've not played with the valving, 20 & 25mm cartridges have been about for over 10 years and are well down their development path improving all the time, kits drop straight in.
I already have enough on with the 20 and 25mm, the 30mm for the new R1 is coming on well, I don't want to dilute what I'm doing with those chasing a set up on the big piston.

Cheers for that, am stripping my first set very soon and Id already heard that the adjustment range is very poor.
I like the idea of 30mm cartridges and have a feeling we may see some in the future. Ohlins already have the pistons by virtue of those they have made for the 09 R1.

[Shaun]

tell me boys, why did Whitepower STOP making a Big Piston fork set up?

[cowpoos]

tell me boys, why did Whitepower STOP making a Big Piston fork set up?

whitepower 4054 forks I think your talking about... have a nosey at the picture I have posted.

[cowpoos]

whitepower 4054 forks I think your talking about... have a nosey at the picture I have posted.

you have to right click and open image in new window...then one left click to enlarge image to read it.

[Robert Taylor]

tell me boys, why did Whitepower STOP making a Big Piston fork set up?

I think because they were struggling with it, that continued development would look to be very protracted and ironically cartridges were coming into vogue.
In fairness on the racetrack Showa seem to have their works level stuff working pretty good, but it is not at all the ''big leap forward'' Team Rockstar Suzuki ( Mat Mladin ) in the States ditched that stuff out of their forks and fitted cartridges

It always amazes me how magazine testers ''run away with themselves'' and people believe all the hype. There is quite a differentiation between the PR fantasy world and the reality of working at the coal face and being familiar with the issues. Every technology has issues / limitations.

[JD Racing]

I suppose it's all a progression of the bending shim stack midvalve in that the manufacturers are now metering solely the swept volume where previously it was a combination of swept and displaced volume. Cartridge pressure is now pretty much out of the equation it's now all volumetric flow rate, with the Showa version tuning the air gap will also be limited as too low an oil level will cause problems with oil volume in the chamber.

I'm not a big fan of all this reduced tuning ability, being able to tune the rod displacement and swept volume gives you far more to work with, we now have two systems working at opposite ends of the spectrum, Ohlins say swept volume is history it's all about displaced volume, Showa say displaced volume is history it's all about swept volume, me being an old caveman think the old fashioned combination of the two is still the best way.

[Robert Taylor]

I suppose it's all a progression of the bending shim stack midvalve in that the manufacturers are now metering solely the swept volume where previously it was a combination of swept and displaced volume. Cartridge pressure is now pretty much out of the equation it's now all volumetric flow rate, with the Showa version tuning the air gap will also be limited as too low an oil level will cause problems with oil volume in the chamber.

I'm not a big fan of all this reduced tuning ability, being able to tune the rod displacement and swept volume gives you far more to work with, we now have two systems working at opposite ends of the spectrum, Ohlins say swept volume is history it's all about displaced volume, Showa say displaced volume is history it's all about swept volume, me being an old caveman think the old fashioned combination of the two is still the best way.

Im a fan of any system that has much less risk of cavitation and as you well realise many systems are on a knife edge re that.

[Shaun]

Im a fan of any system that has much less risk of cavitation and as you well realise many systems are on a knife edge re that.

So converting forks to work seperateky ie left leg Rebound

Right leg compression

This would illiminate any cavitation/lock up/confusement of what is doing what and when

Flow has always been what i have asked you for over the years robert when i did ride, ( And we did win more races than we lost) and the way i understand the big piston to work, would allow more flow of oil, before hitting the shim stack, with NO cavitation?

I am going to have to start doing just test development riding again I think, I can see some fun coming in the new worldThanks for your input JD

[Robert Taylor]

So converting forks to work seperateky ie left leg Rebound

Right leg compression

This would illiminate any cavitation/lock up/confusement of what is doing what and when

Flow has always been what i have asked you for over the years robert when i did ride, ( And we did win more races than we lost) and the way i understand the big piston to work, would allow more flow of oil, before hitting the shim stack, with NO cavitation?

I am going to have to start doing just test development riding again I think, I can see some fun coming in the new worldThanks for your input JD

Stand corrected sir! Left leg compression, right leg rebound and yes indeed big benefits especially in damping response time.
Yes it is fun! And I concur, thanks JD.