Jump to content
CBR1100XX.org Forum

Sag/Preload?


Red J

Recommended Posts

I measured the sag today, and I came up with these numbers:

Front (bottom triple clamp <-> top of the fork debris shield):

Extended: 4.3"

Static: 2.3"

Sag: 2"/50.8mm

Rear (Exhaust clamp bolt center):

Extended: 20.9"

Static: 19.1"

Sag: 1.8"/45.7mm

225lb rider. (not me, friend. I weigh 190, but I figure with gear and a tankbag...)

Full fuel.

I've heard that the sag should be set at 30% of the total travel for the forks. I'm way off, if this is the case. I know fuck all about suspension tuning, but I'm interested in anyone's comments. I'm running Ohlins 1.05kg/mm springs up front, and stock everything else, with 29k on it.

J.

Link to comment
Share on other sites

With the 1.05 Ohlins up front and the stock spring out back you should have no trouble setting the sag where it should be, simply add preload (spacer length) on the front and turn in the ajuster on the back a few turns, measure, repeat as neccesary.

No black art to setting sag, just get the proper rate springs (you've done that) and go to it. Might involve pulling the caps on the forks off a few times, but it's not complicated. Start with spacers longer than you think you'll need so you don't end up with a 1/2" stack of washers in there.

Make note of any attitude change made by setting the sag (front raised more than the rear, as it looks like you may need in this case) so you can compensate by shimming the rear or dropping the triples a bit, or the thing may end up steering like a truck

Pete, loading the crap out of the stock .89kg/mm springs may net you the sag you want, but it won't change the spring rate. .89kg/mm is way too low a rate for your weight.

Link to comment
Share on other sites

Much thanks, guys. I assumed that I'd have to jack the rear preload to offset the front uprated springs, but I didn't think that I'd have to jack with the front this much. That's a pretty massive change...

So, if I aim for 25-30mm, and go for the same fork angle as I have stock (within reason), that would be a good place to start?

This, in addition to the rear spacer, or not worry about that now?

J.

Link to comment
Share on other sites

Nailed 30mm in the front and rear. Man. Looks like the mother is going to fall over. I need a longer kickstand... :wink:

Foggy and raining like a bastard out there, so I'll not find out if it's better until later in the week.

J.

Link to comment
Share on other sites

Trying the 1" sch. 40 PVC until I ride it. Pop is going to the store today, get some 1.375x.120 wall 6061 aluminum tubing for the real deal.

Hopefully I can resist the temptation to anodize them. Might be hard.

I looked at a VFR's fork caps, I do believe that they'd fit on our bikes, but I'm reluctant to order the hardware to try it out. The adjusters aren't cheap. I'd almost rather get DK to work my forks over and be done with it.

Should quit fucking around and get the PAIR plates done...

Link to comment
Share on other sites

I've always wondered about the use of PVC for spacers myself. Plastic is soft and will be sandwiched between a steel spring and an alum. cap...but it appears to be an accepted way of shimming.

re the VFR caps, are they 43mm and used to adjust spring preload only?

There was recent reference to a UK site that was making up some adjustable preload caps for the XX....seems like if the VFR caps would fit , someone would have done it by noe BUT... you never know.

If you find out, let us know

Porter

Link to comment
Share on other sites

PVC:

I'll use it to dial the preload in, but not for long term use. I see no problem with that logic.

VFR caps:

I've considered buying the parts, but it seems that the best way to acquire these is new. Don't see a predominance of VFR forks laying around. Everything required, minus a few little pieces, is in the neighborhood of 150. If it works. This is just what I've heard, and priced out online. I've not spent significant time searching for used VFR adjusters.

Seems pretty expensive, just to adjust front preload on the fly.

I'll take the 150 and put it toward 954 forks.

J.

Link to comment
Share on other sites

I got the Hyperpro springs. They are a little bit longer than the stock springs and are slightly compressed when the caps are screwed in. They are also progressive rate springs. I get 27mm of sag with me and all my bags on it-I weigh 200lbs with gear on. There is 29mm of sag with two people [ 370lb for both with gear on] and all our crap on.

No spacers needed and I like the fact that they have a higher spring rate near the bottom of travel.

Link to comment
Share on other sites

I got the Hyperpro springs. They are a little bit longer than the stock springs and are slightly compressed when the caps are screwed in. They are also progressive rate springs. I get 27mm of sag with me and all my bags on it-I weigh 200lbs with gear on. There is 29mm of sag with two people [ 370lb for both with gear on] and all our crap on.

No spacers needed and I like the fact that they have a higher spring rate near the bottom of travel.

I got my Hyperpro springs installed by the factory. Mine was the testbike for the XX-riders to test on our summer-meeting 2003. I have had 30 people trying the springs, and 28 bought them. If you want to improve even more, try using a 6mm spacer on top of the rear shock (NOT the spring), and drop the front about 30mm. Just let the forks stick out 30mm more than standard. This was the bike leans more to the front, and it will turn more easily, without compromising stability. Even fully loaded the bike is a lot better, and in my opinion the best purchase to be made on the bird ever. I would not know any improvement possible that will have such a dramatic positive efeect on the standard bike!

How much did you pay for the set?

Link to comment
Share on other sites

I don't remember how much I paid for my Hyperpro spring. A year and a half ago, I got front and rear springs + 2.5 weight fork oil. Later on I got a Hyperpro rear shock and spring with remote hydraulic preload adjustment and fast and slow compression and rebound damping. This mad it much easier to balance the handling for solo mountain riding and 2 up long distance riding, etc. It now takes me only 5 minutes to adjust my suspension to my riding circumstance. I love this set up.

BTW: Hyperpro had m fill out the minimum and maximum weights I carry so they could give me the proper spring.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

Terms of Use