Fork braces and suspension compliance


23 replies to this topic
  • sgifford

Posted December 28, 2005 - 10:13 AM

#1

I installed an rswracing.com fork brace a few days ago on my 650L.

I noticed after riding a bit that the front suspension was very harsh. Getting off the biking and pushing down on the handle bars, I could tell that the forks were binding. It was like a severe case of 'stiction'.

When I loosened the clamps that mount the brace to the sliders, the fork up/down movement returned to normal. Right now I have the brace clamped on just tight enough to keep it from moving around, but I wonder if it will stay put when I crash and/or hit rough terrain and the forks are slamming up and down.

Have any of you with fork braces experienced this? Is the placement of the brace on the sliders critical? I have them about 3/4" down from the top of the sliders. I hope it's not necessary to sacrifice a bit of fork compliance to prevent fork flex.

  • cheff

Posted December 28, 2005 - 11:08 AM

#2

I got the SRC, and I clamped it down as tight as it would go. I think, I might have used a torque wrench if it asked for one during installation, but I don't remember. I am sure the instructions will say. But I never had the forks bind, I don't see how that could happen with the SRC brace, I don't think you could generate enough pressure to compress against the tube.

  • Boy Honda

Posted December 28, 2005 - 11:15 AM

#3

I have had the same experience with my rsw brace. It looks like its time to call rsw and see what the deal is. It might just be the torque spec. that was not sent with the brace to begin with. sgifford, do you have any contact info for rsw?

  • sgifford

Posted December 28, 2005 - 12:56 PM

#4

Boy Honda: which bike did you install his brace on? A 650L?

Here's the contact page from their website:

http://rswracing.com/contact%20us.htm

I sent Ron Wallace an email earlier today, and I just left a phone message for him as well.

I didn't receive any instructions on torque values, so I don't know how tight the allen bolts should be. I read a lot of positive feedback about his brace before I bought it, so I'm hopeful this will be resolved quickly.

  • goblin127

Posted December 28, 2005 - 08:57 PM

#5

When installing a fork brace did you have the bike off the ground? The bike should have the entire front end suspended and the front tire off the ground. Try loosening the brace now that the wheel is not touching anything with the forks fully extended.Also check to make sure the forks are at the same hieght in the tripple clamp.

  • TREADMARKS

Posted December 29, 2005 - 03:57 AM

#6

RSW brace here as well.

When first installed it was binding the forks.

I performed a digital measurement of my fork lowers while bike was on lift and axle pinch bolts were loose. There was 20k difference center to center. The centerline of the brace was .020 shorter than my forks. I split it in half (.010) and cut two shims and fitted them between the lowers and the brace on the inside. Torqued everthing with some blue loctite and suspension is as smooth as ever with no flex.

FWIW the upper clamp that I bought with the brace fit like a charm!

  • bork

Posted December 29, 2005 - 05:46 AM

#7

Good job "treadmarks" ! BTW ; How did you determine center of forks accurately.And I'm not sure I follow where you checked . Center to center of fork tube at triple clampps and C-C at fork axle and then fork hole centers on brace ? Or could it be after loosening and retightening axle allowed forks to relax on axle. I think in SRC directions they say torque axle last for this reason. But not 100% sure, getting old. :applause:

  • roadcam

Posted December 29, 2005 - 08:24 AM

#8

I have the SuperBrace, and its instructions emphasized the axle nuts must be loose during installation of the brace, to eliminate any 'bind' ... may be the same with yours .. :applause:

  • Boy Honda

Posted December 29, 2005 - 09:22 AM

#9

I called Ron and left a message yesterday. He left me a message last night. He said to install the brace 1/4" from the top of the lower fork tube and to torque to 10ft-lbs.

Mine is mounted on a XR600.

I mounted the brace with the bike on a stand and everything loose. Top and bottem triples, front axle brace all loose. Then I started with the top triple clamp and worked my way down tightening the lower triple and then the brace and finally the front axle.

I found that when I innitially installed the brace with everything tight the brace had to be tapped in to place.

It seems to work great now. The clamping force of the bolts around the top of the lower fork legs distorts the metal enough to cause the stiction. It was easy to reproduce the stiction by overtightening the bolts. As soon as I loosened them everything was back to normal.

  • husky123

Posted December 29, 2005 - 05:00 PM

#10

Boy Honda to the rescue!

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • sgifford

Posted December 29, 2005 - 05:13 PM

#11

I discovered the same thing Treadmarks did. There seems to be a very tiny gap between the brace and the forks, and it appears to force the forks to flex inward slightly when the brace is tightened.

Boy Honda: So you reinstalled it 1/4" from the top of the slider, at 10 ft. lbs of torque and the 'binding' went away? You didn't have to use a shim?

Also: I discovered what happens when I bottom the fork now. The brace slammed into my trimmed-down fender, knocking the brace down so it rubbed the tire. I'll trim the fender probably another half inch, but I'm hoping once I get the brace mounted properly that bottoming out the fork won't knock the brace around.

  • sgifford

Posted December 29, 2005 - 05:24 PM

#12

TreadMarks: Did you install the brace (with the shim) 1/4" from the top of the slider? I'm hoping you got yours to work further down than 1/4". At 1/4" a lot of travel is lost.

  • Boy Honda

Posted December 30, 2005 - 07:09 AM

#13

I haven't had the bottoming issue with the forks yet. I'm running old CR500 Forks with 42kg springs. I believe the newer XR600-650s come with fairly light springs. But I also have not jumped the bike since installing the brace. I do remember SCR recommending cutting the front fender as well. I've yet to do that either.

  • TREADMARKS

Posted December 30, 2005 - 09:13 AM

#14

TreadMarks: Did you install the brace (with the shim) 1/4" from the top of the slider? I'm hoping you got yours to work further down than 1/4". At 1/4" a lot of travel is lost.


Mine is mounted as low as possible on the slider. I have about 3/4" of clearance from the top of the tire.

Last night, I removed the shims and checked it again, same deal-it was binding. Then I put it on the lift with the front end hanging, and loosened all the bolts including the axle pinch bolts-except the very top bolts on the top tree.

I carefully put 4.5 psi in each fork and wiggled the bars back and forth while holding the tire still. I put the brace on and just snugged the bolts to eliminate any play. I tried to flex the bars while holding the tire and it was much more rigid. From top to bottom I torqued all the bolts to 10 ft lbs with loc tite-except the axle pinch bolts which were still loose. I let the bike down and bounced the front end up and down and I had pretty smooth movement. Back on the lift and final torqued the top and bottom tree bolts-then the axle pinch bolts.

Off the lift for a test ride. It is pretty smooth-but I don't feel that it is as smooth as it was with the shims in place. I will run it for a while like this and see how she goes.

I did manage to get up to 90-95 with no wobble for the first time. Don't know if it was the air pressure or the brace or just lucky last night-we will see!

  • nmhinton

Posted January 12, 2007 - 11:40 AM

#15

Guys,
my rsw is binding like crazy with less than 10lbs of torque. Where exactly are you putting this shim you are talking about? Is it between the brace and the fork away from the pinch bolts? Any other tips to the proper mounting proceedure? My brace has made my handling worse so far!

  • frankstr

Posted January 12, 2007 - 12:32 PM

#16

Superbrace, Torque at 10 lb's, Never any probs, sorry to hear about the problems..:lol:
Do get the front suspension unloaded when installing.

:confused: :crazy:

  • xr650l bum

Posted January 12, 2007 - 01:22 PM

#17

Here is the answer!!! I put a rsw brace on my xr650l. When I put the brace on, I noticed that it was really squeezing the fork and was causing the binding problem. Then I went and looked at a spare set of dismantled forks and came to the conclusion that it is being attached at a very weak part of the bottom fork. The solution is to drop the brace down to where the top of the bottom fork goes from a nice round cylinder to the ridged part. Again! Clamp the fork brace at the bottom of the round cylinder, this should be about 3/4 or 1 inch down from the top of the bottom part of the fork! The cylinder is much stronger at the beginning of the molded cylinder versus the open end!

  • rebelventurer

Posted January 12, 2007 - 03:51 PM

#18

I have the RSW brace too, was installed with bike on the side stand 1/4 inch down on lower tubes torqued to 15 ft. lbs. no problems at all. did wonders for the handling, and love the upper triple clamp too!

  • wheelnut46

Posted January 12, 2007 - 08:02 PM

#19

Pics of the brace and mounting location?

  • nmhinton

Posted January 14, 2007 - 10:44 AM

#20

I ended up putting "C" shaped shims around each mounting bolt and torquing down to 10lbs or so, and presto! No more stiction and stiffer front end...yeah!





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