Squirrelly steering

Ok so I've done a bunch of work on my 400, but I'm still not 100% satisfied with the way my XR handles.

I swapped to 2007 crf450r forks, which made the bike handle well initially, but I am on the heavy side, so I resprung the front and rear. I'm happy with the springs and dampening, but in the process my steering has become too light and twitchy, I think because the rear is riding higher than before.

I've been thinking that the solution may be to drop the rear around 1 inch with a shock spacer to increase the rake, which would also let me flat foot the bike when I ride on the street which would be nice.

Anybody done this?

I just had my suspension done though havnt had a ride yet but the guy said to make sure I have 25-30 mm static sag not worried about with me on it. As the way the xr rear shock is its an aggressive shock and to run the front forks high in the clamps because of the twitchy steering.

Try 3 1/2 to 4in sag.What is drop on forks(no rider)  Best thing to buy Xr4 Scotts stabilizer.I know big $ but its the way to go.We set ours at full hard then back it off 6 clicks.Also stock xr4 forks 11in- crf forks 12in travel.you have to balance frt to back susp.BTR

>>>>>>>>> run the front forks high in the clamps because of the twitchy steering.<<<<<<<<<<<<<

 

I think you said that backwards for what effect you're wanting to alleviate. Running the "forks" "high" in the "clamps" would lower the front end, less rake and make things more twitchy. You'd want to run the "clamps" "high" on the "forks" or the "forks" "low" in the "clamps", same thing. It's typical to set the top of the fork cap flush with the top of the clamp.

 

I agree with BTR, set rear rider sag to 4". What do you have it set to currently?

I just had my suspension done though havnt had a ride yet but the guy said to make sure I have 25-30 mm static sag not worried about with me on it. As the way the xr rear shock is its an aggressive shock and to run the front forks high in the clamps because of the twitchy steering.

 

What do you mean by an "aggressive shock"? Seems like it is valved for trail

 

I think you said that backwards for what effect you're wanting to alleviate. Running the "forks" "high" in the "clamps" would lower the front end, less rake and make things more twitchy. You'd want to run the "clamps" "high" on the "forks" or the "forks" "low" in the "clamps", same thing. It's typical to set the top of the fork cap flush with the top of the clamp.

 

I agree with BTR, set rear rider sag to 4". What do you have it set to currently?

 

I'm going to go out today and get all the measurements to calculate geometry. I had it set as close as I could get it to 100MM but backed off to minimal preload to try and balance the front which helped a bit but didn't really solve the problem. I have the fork caps flush with the top of the clamps.

 

I thought I would have the opposite problem doing the USD fork swap since they are 1" longer so it is kind of strange. The triple clamps I bought were 24MM offset, which should be same as stock, i'm going to check that as well to make sure i'm not fighting a geometry problem.

I agree with these guys. Set rear sag to 4" and then see what you have on the front for static and rider sag. Get those set 1st then see how it acts.

 

What does it do when you turn? Push right away or knife in then loose traction?

I can see you having a feeling of lighter steering with the new setup, just from the differences in how the weight of the front end is carried over that of stock. Stock, below the lower triple, you have the weight of both the wheel/tire assembly and the bigger/heavier outer fork tubes.

 

If you're right about triple offest being same as stock, then since the new setup is 1 inch longer than stock, I think I'd start with 4" of rear sag and set the forks around 1" above the clamps, experiment from there. Theoretically, that would start you off closest to what the stock setup would put you and what most of us find is the most stable.

 

Be sure you didn't over preload the fork springs when you installed them.

 

Rule out a severly out of balance front wheel/tire assembly. I always static balance mine. I've found that around a 3oz. out of balance problem is pretty typical on a dirtbike wheel/tire setup and enough to be felt in my experience.

I think you said that backwards for what effect you're wanting to alleviate. Running the "forks" "high" in the "clamps" would lower the front end, less rake and make things more twitchy. You'd want to run the "clamps" "high" on the "forks" or the "forks" "low" in the "clamps", same thing. It's typical to set the top of the fork cap flush with the top of the clamp.

I agree with BTR, set rear rider sag to 4". What do you have it set to currently?

Yes sorry I ment run the standard forks at like the first line from the cap. So they are longer.

As for the rear shock if you run it to low it's already working. Eg they when compressing the first part is soft then it comes hard pretty quick something to do wwith the linkage setup in the xrs different to most bikes. It's was resprung with a spring to suit my weight which is why you only need set the static the rider sag should be correct This is coming from a suspension guru who does alot if the top level riders here on aus. And used to race xrs back in the day.

I didn't get a chance to measure things just yet (got stuck at work after losing oil out of my bike) but I think the front is riding too high, going to try moving the forks higher in the clamps tomorrow and see what that does

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now