Hydraulic spring perch?

[Yankee Doodle Dandy]

Anyone use these?

At first glance they seem like a good idea but I do not see any professional teams using them.

[Yankee Doodle Dandy]

I am talking about the floating hydraulic ones like in the pic.



It "floats" to prevent the spring from binding and putting pressure on one section on the shaft/seal/bushing.

[Shaun]

I have never seen them Kevin

[Pussy]

I saw a similar thing advertised a few years ago.
Probably would work alright.... no good for me in a roadbike application, unless I wanted to regularly remove the shock to keep the bearing greased to prevent rusting etc

[Yankee Doodle Dandy]

I saw a similar thing advertised a few years ago.
Probably would work alright.... no good for me in a roadbike application, unless I wanted to regularly remove the shock to keep the bearing greased to prevent rusting etc

This is different from the Torrington bearing set up that a lot of people use.

This unit is a sealed hydraulic unit.

[Yankee Doodle Dandy]

Pussy, I think you are referring to this here -



Is there any way to get actual pics in the threads?

[Robert Taylor]

Anyone use these?

At first glance they seem like a good idea but I do not see any professional teams using them.

Yes I have used them and a lot of race car teams use them. Hyperco in the States make them and there are probably a few other companies. Most production springs are not square on their ends, the cheaper the springs the nastier their tolerances usually are. That inevitably means that unsquare springs will when assembled place sometimes a considerable side force on the shock shaft and bushings, creating unwanted friction and accelerated wear. This is a far more prevalent problem in auto racing.
Yes most proffessional motorcycle road race teams dont use them and in fact most teams around the world ( for whatever reasons ) use Ohlins. Here are some thoughts;
1) Through their race department you can purchase an even better standard of race springs that are more finely toleranced and with more inbetween rates, albeit at a higher price. Plus Joe Bloggs and non Ohlins accredited suspension guys cannot just rock up and buy them
2) The Ohlins hydraulic spring preload adjuster that you see on their race shocks not only faciltates quick and easy spring preload changes in pitlane within the tight timelines of practice sessions. Particularly on the current model TTX36 the hydraulic preloader ram is designed to compensate for a little bit of spring untruth. This works very well and is reason enough in itself to have one fitted
3) I particularly like the 3 step camlock preload adjusters you see on many Ohlins budget level twin shocks, they also rock and do an admirable job of compensating for spring misalignment

[Yankee Doodle Dandy]

So you are saying that the Ohlins hydraulic preload adjuster acts in a slightly similar action to this?

[Shaun]

So you are saying that the Ohlins hydraulic preload adjuster acts in a slightly similar action to this?

To what mate????

[Yankee Doodle Dandy]

To the hydraulic spring perch.

[Robert Taylor]

So you are saying that the Ohlins hydraulic preload adjuster acts in a slightly similar action to this?

Effectively yes as it rocks a little. No need of a compensating perch as the job is already done. With manual lockring adjusters certainly yes a hydraulic compensating perch will yield benefits, sizable if a ''nasty'' spring is fitted, probably not discernible to anyone but the Rossis of this world if high quality ''square'' end springs are fitted.

Clever engineers those Swedes....

[Yankee Doodle Dandy]

OK thanks, thats good to know.

Of course, it would only apply to the Ohlins hydraulic adjusters that have oil in them.

[Shaun]

It is quite amazingly noticeable on the Ohlins TTX, how well this actually works

[Robert Taylor]

OK thanks, thats good to know.

Of course, it would only apply to the Ohlins hydraulic adjusters that have oil in them.

Indeed, thats why its always best to purchase off a recognised distributor for the appointed country who has proper infrastructure, cares about after sales service / happy customers and has a vacuum filling machine. We only get very few with air in them and they are bled prior to delivery.
In the automotive world its called a predelivery inspection, inclusive also of making sure the spring rate and valving is in the correct ''window'' for the customer profile / personal stats, tyres used, personal speed etc.
In the States there is as you know a big problem with such service and a sales numbers philosophy that overides it. Big warehouses instead of old world service.
Have a look at a TTX36 at some stage and check circumferentially the clearance of the internal ram on the preloader relevant to the main body. The clearance will be inconsistent as it will be compenasting for the spring truth, or slight lack of, normal with springs.

[Yankee Doodle Dandy]

We only get very few with air in them and they are bled prior to delivery.

They must like you guys better than us here in the US. I have only seen one that did not need filling/bleeding and that came from a former Ohlins employee's business.

In the States there is as you know a big problem with such service and a sales numbers philosophy that overides it. Big warehouses instead of old world service.

Ohlins have been making some changes over here lately so maybe they are looking to improve things. Part of me wonders if they are trying to take back the market from Penske.

They still have the big warehouses distributing though and unless you received the wrong item or there is a defect there is no customer service.