changing Ohlins Front fork spring question

[gigantic]

I finally got the proper fork spring for the front Ohlins shock I bought last september... you thought the guys that waiting for the 17's have it bad... at any rate how difficult is it to change the front springs? can this be done with basic tools?
thanks,
Lance

[acidburn]

call or ping RamJet.
Its a headache.
Have it done.
If you need to ask you dont want to do it, not on this item.

[repoe3]

aside from some spring compressors that will fit the spring...per roger's instruction, its a no brainer. but i have not done it myself.

repoe3

[acidburn]

i thought you had to take the top of the shock off?

[motoyoyo]

It's a very simple job. You have to remove the shock and back off the preload collars all the way until they fall off the threads if needed. The top spring retainer just has to push down and over to clear the top shaft mount. Slip off the old spring and put the new spring on and thread the preload collarsrs back into approximate position. Don't worry if it's exact because you will have to measure sag settings anyway. You may have to pull the shock a couple times to adjust sag, but it's way easier to do that off the bike than trying to adjust the collars while mounted on the bike.

[RoundelRider]

Thanks for the tip moto.......Im going through the same thing as gigantic right now with a spring thats too soft. Im sending mine back to the distributor where we got it from, there switching it for free since it wasnt done correct the first time (I think it was dropped shpped from Ohlins)

[roger albert]

Interesting. That method won't work on the older ones, as they're not sufficient adjustment range to release preload. Maybe the later ones differ in design. Now I'm curious.

[motoyoyo]

On the 36PR front Ohlins there is quit a bit of room to unload the preload on the spring. At least it was that way on my shock. I have never had to replace a rear spring, but the front was a piece of cake. With a centerstand it was also very simple to take the shock off the bike to make adjustments to preload. The front preload was critical to the handling of the bike too. I found about 30mm of rider sag in the front to be good for me. I have been playing with the rear adjustable height and keep raising it little by little for quicker handling while keeping the front the same.

[gigantic]

FWIW, Nate is running about 24-25mm sag and no extra height in back and 15mm extr up fron, accomplished by spacers betwixt the shock body and upper front subframe. the rebound knob also has a corresponding amount of material removed, so everything fits.

[acidburn]

how do you guys measure the sag?
from unooaded to loaded or more comlicated, full lengther of the travel?
I use a tie wrap on the front, loaded to unloaded.

[motoyoyo]

Tie wrap on right fork leg and lean the bike over on the side stand to get the unloaded reference position. With the suspension unloaded by slightly pulling over on the side stand, slide tie wrap down til it touches fork wiper. Slowly position the bike upright without introducing any downward force. Return to side stand and measure distance from wiper to tie wrap. This is the bike sag. Now, slowly sit on the bike and return to upright and put yourself in riding position, then carefully return the bike to the sidestand and unweight the suspension. This distance is the rider sag. I know you probably already knew all this acid, but in case someone else needed some details. I just leave the tie wrap on all the time to get some feedback on max travel.

[RoundelRider]

Helps if you have someone to hold the bike upright while your fully seated in riding position.

......this same tecnique goes for the the rear as well, except use measuring tape and known marked points on the final drive and tail section

[acidburn]

Moto, thanks, yes i was not clear with my question.
Are you guys pretty much agreeing that 30mm is the total sag that works well, bike and rider?
I am intersted in what most see as a bike sag number.
I guess thats not a valid question though if we are all using diffspring rates,
RamJ what are you seeing?

[RoundelRider]

Originally posted by acidburn
I am intersted in what most see as a bike sag number.
I guess thats not a valid question though if we are all using diffspring rates,

Couldnt the sag be the same between all of our bikes, as the spring weights are making up the difference in our (riders) weight.

Im sure theres a ideal sag for these bikes, but it also depends on how your riding them, touring or playing N8 on the track!

[gigantic]

I'm going to try Nate's settings ext weekend, to see how things improve. I've determined that the front end slippage that I've been experienceing is mostly suspension and slightly tire/temperature related. so I'm dropping the rear and raising the front and cranking up the preload to between 25-30, front & rear. N8's about 60 pounds lighter than me, too and has heavier springs fore and aft than I, too.
Lance

[motoyoyo]

Lance, keep in mind that you will not have the extra front shock shaft height that N8 has on his bike. Also, his numbers are probably mostly a result of trying to keep the cylinders off the tarmac and not necessarily the best overall handling characteristics. N8 could probably whip this bike around pretty dang good no matter where the sag settings were. For a pure hardcore race R11S I'm sure ground clearance becomes the most important issue.

For general and aggressive street riding, we get pretty good ground clearance already from the longer than stock rear Ohlins and a short paralever arm. I find the bike's handling to be very nice and sharp at around 30mm front sag no matter which spring is used. Any lower in front tends to slow down steering, but raising the rear can sharpen steering. Raising the front doesn't seem to hurt handling much as long as you are keeping the front tire on the ground at all times. Short sag settings up front can cause the front wheel to hop over rough terrain. I find that rear sag is not as sensitive as the front since I'm always jacking around with the preload adjuster anyway to get the attitude where I want it. I still would try for around 20-25% rider sag front and rear to get in the right range.

[gigantic]

Nate has the same Ohlins front as the rest of us. he put a 15mm spacer between the shock and frame & and had the preload knob machined so that only the knurled portion remained. He said it was for ground clearance and it also quickens the steering, without placing too much weight up front, like jacking up the rear will do (I'm paraphrasing here...). he's raising the front, not lowering it. and we all know about the paralever being counterintuitive... raising it effectively shortens the wheelbase.
I suspect that the front end issues (skipping, chattering) have been related to my rear shock having too much ride height (6-7mm), placing too much weight on the front end. plus I'm f@%&ing huge!
I agree, Nate's sag settings aren't likey going to be the best for most of us, but seeing as my riding has shifted to 20% street, 80% track, I'm interested in checking it out first hand. I can always back it off for the street, although changing the front is a pain. next rebuild I might just have to go for the Jeffro Bling-alicious front remote pre-load adjuster...

[roger albert]

motoyoyo's input and explanation all sounds right to me, though on a bumpy or hilly course, running as little as 30mm sag can leave you running wide when the front wheel can't drop down fast enough to keep up good contact pressure. I like 32-35mm of sag on the front of the S, rather than the more normal 35-40, but most shouldn't see a problem at 30.