Author |
Message |
Thefleshrocket
| Posted on Wednesday, March 23, 2011 - 01:38 pm: |
|
Back when I was originally trying to get the suspension dialed in on my '08 1125R, I lowered the fork tubes so that the tops were flush with the top of the triple. I have previously adjusted fork height to tailor handling to my preference, but in this case, I found this change specifically mentioned in a Sport Rider review of the 1125R. Changing the fork height might have had a positive improvement on handling, but I couldn't really tell. Fast forward to the stock Corsa wearing out and me replacing them with PP 2CTs. Handling went from uncooperative to very agreeable with just the tire change. A couple days ago (after about 2000 miles on the 2CTs), I decided to put the fork back to the stock height to see what would happen. The first thing I noticed was that low-speed turn-in required more pressure on the inside clip-on. The second thing I noticed as that the front end got a bit nervous. I ran the bike up through the gears to about 135mph, and the whole way, the front end had a tiny but noticeable weave to it. The next day, I reverted to the tops of the fork tubes being set flush with the top of the triple. Low-speed turn-in now requires less effort, and the front end twitchiness is gone. I haven't decided for sure that I don't need a steering damper, but I'll let a few more backroads rides determine that for sure. Anyway, those of you who aren't entirely happy with the handling of your 1125s might want to try what I've done here--it definitely has a positive effect in my opinion. |
Jdugger
| Posted on Wednesday, March 23, 2011 - 01:58 pm: |
|
Flush is pretty dramatic, honestly. 5-10mm showing above the OEM triple is common among race set-ups, but those also include additional rear ride height. That's still a bit taller in front than OEM. |
Rob_l
| Posted on Wednesday, March 23, 2011 - 03:00 pm: |
|
TFH You are increasing the wheelbase and trail that's why its less twitchy. But turn in should be slower. What are you doing about the rear? If it feels good do it! |
Nuts4mc
| Posted on Wednesday, March 23, 2011 - 03:30 pm: |
|
watch the front brake line "cable" clamp on the lower triple clamp - dropping the tubes to flush makes the front brake caliper father away from the original mount - I had to make a small extension to mount the clamp so the line wasn't "strained" - I like the way she handles with the tops flush...not so nervous - allows me to concentrate on my entry line from a fast straight away. |
Dannybuell
| Posted on Wednesday, March 23, 2011 - 04:20 pm: |
|
what is the stock position? The modified position is flush? could someone show before and after pictures? |
Jdugger
| Posted on Wednesday, March 23, 2011 - 04:25 pm: |
|
Stock is probably 15mm or so above the OEM triple. |
Duphuckincati
| Posted on Wednesday, March 23, 2011 - 04:53 pm: |
|
I'm not able to fit my click-type torque wrench and socket to the lower clamp bolts unless I remove the pods. What are you guys using tool-wise? |
Bueller4ever
| Posted on Wednesday, March 23, 2011 - 05:44 pm: |
|
I have a slim head torque wrench that fits. I think it only goes up to 90ft lbs, it's small. You could always cut the allen head socket down a little. |
Pwillikers
| Posted on Wednesday, March 23, 2011 - 06:06 pm: |
|
The factory stock setting is 14mm of fork tube showing above the top triple clamp. Dropping the tubes, especially all the way to flush which is a lot, will no doubt slow turn in and increase straight line stability. |
Gas
| Posted on Wednesday, March 23, 2011 - 08:22 pm: |
|
I understand that dropping the tubes should slow the turn-in. I also understand rocket's assertion that it didn't seem to do it on his bike. My experience has been the same as his, but I only dropped mine 10 mm. Could be a subtle weight shift or perhaps something else. Anyway, my turn-in feels the same or easier. Please don't bench-race me. I know what the bike is doing. |
Thefleshrocket
| Posted on Wednesday, March 23, 2011 - 10:59 pm: |
|
Here's how my fork tubes look now. The ridge on the fork is where the fork tubes rest normally, I think. (Tell me how to make that a linked image and I'll do it.) Every time I've had a bike that doesn't turn quickly enough, like my old SV1000S, dropping the fork tubes to be flush with the top of the triple makes the bike steer more neutrally, with less effort. It runs counter to conventional logic, that dropping the front end should make a bike steer more quickly, and I can't explain why raising the front end improves stability AND turn-in. Duphuckincati, I'll admit that I haven't used a torque wrench--just a regular ratchet with a hex head socket. I use the "I know how tight it's supposed to be" torque spec. LOL (Message edited by thefleshrocket on March 24, 2011) |
Thefleshrocket
| Posted on Wednesday, March 23, 2011 - 11:01 pm: |
|
Nuts4mc, I haven't noticed any brake line length issues with the fork tubes lowered. Anyone doing this adjustment should probably check their bike just to be sure this isn't an issue, though. |
Dktechguy112
| Posted on Wednesday, March 23, 2011 - 11:24 pm: |
|
The flesh rocket, the reason dropping fork tubes makes the turn in slower and the bike more stable is because when you drop the forks you increase the wheelbase and the trail. The trail is what makes the wheel want to center ( think of casters on a shopping cart), more trail = slower turn in and more stability. (Message edited by dktechguy112 on March 23, 2011) |
Dannybuell
| Posted on Wednesday, March 23, 2011 - 11:31 pm: |
|
My suspension expert got my bike with very few miles on it. He set it up with his valving and springs. gpsuspension.com The preloads and valving still need to be personally tuned. I have stiff preload and just backed off to vibration-less on compression. rebound is fast enough so the suspension is not falling out from underneath you. A stiffer setup at lower speeds doesn't fall into the turns as much. Going faster the suspension doesn't collapse the with the slightest bit of turn in. A stiffer suspension gives me the ability to feel the energy building with control remaining constant. |
Sparky
| Posted on Thursday, March 24, 2011 - 01:52 am: |
|
Flesh, use the \imagelink{URL} tag described here to post pics hosted on another website. |
Nuts4mc
| Posted on Thursday, March 24, 2011 - 09:34 am: |
|
Mr. Rocket - don't let the "sag" in the front end mislead you in thinking there is "slack" in the line - you should check the setup with the front wheel off the ground - there was a recall on '08 that moved the line to the outside of the fork leg rather than in-between the leg and fender - (tires were known to contact the line !) in moving the line to the outside of the leg the "angle" from cable clamp to caliper were increased - dropping the tubes down in the clamps ( top of tube flush with top of clamp) makes the "run" from the clamp to the caliper longer and with the increased angle it could cause problems - it is cold (for me)and dark and rainy here on the left coast this AM - I'll try and take some pix this weekend - if and when the sun returns! |
Thefleshrocket
| Posted on Thursday, March 24, 2011 - 10:50 am: |
|
DKtech, I understand what you're saying, but it seems that the theory and the reality don't necessarily jive. I'll agree that stability definitely feels like it has been improved by dropping the fork tubes, but it doesn't seem to have come at the expense of flickability--in fact, the bike feels MORE flickable with the tubes lowered. I know it doesn't make sense, but that's how it feels from the saddle. Sparky, thanks for the link. I've updated my post with the linked image. Nuts4mc, I'll check my 1125 more closely to see if there are any line length issues. I did push the line down as low as possible in the clamp that is around the bottom of the triple so that there would be as much slack as possible below the clamp to allow for what I hope is adequate movement of the front suspension without binding or stretching the brake line. I've run the bike like that for a couple thousand miles with no apparent issues, but I'll lift the front end off the ground and confirm. |
Cowboytutt
| Posted on Thursday, March 24, 2011 - 08:32 pm: |
|
Hmmm. Maybe the variable here is the rear ride height and preload. I dropped my forks flush like yours but it made the bike want to go straight just too much. It also noticably raised the front ride height and center of gravity. I settled on splitting the difference and lowered them about 6mm instead of the full 14mm. Seems to hit the sweet spot and I still run them this way. It brought back some of that Buell flickability but also more stable than stock. -Tutt |
Dktechguy112
| Posted on Thursday, March 24, 2011 - 09:30 pm: |
|
Thefleshrocket, pilot power 2ct's are V tires, what I mean by this is the profile of the tire is steep, it allow a sharp turn in. I have read many people's reviews of tires on this forum and the prevailing opinion seems to be that the pilot power is made for this bike. lowering the forks made it more stable, and the tire change made it more flickable with the V profile. |
Thefleshrocket
| Posted on Friday, March 25, 2011 - 02:31 pm: |
|
That sounds like a fair assessment, DKtechguy. I'm definitely pleased with the results. |
Parrick
| Posted on Monday, March 28, 2011 - 01:43 pm: |
|
I was able to torque the pinch bolts with a regular click torque wrench when I was playing with fork height. As I recall you just had to turn the forks to the side and come at it from above. That's on an R. Dunno about a CR. |
Nuts4mc
| Posted on Monday, March 28, 2011 - 08:56 pm: |
|
front brake line/clamp pix
|
Nuts4mc
| Posted on Monday, March 28, 2011 - 08:57 pm: |
|
loose line
|
Nuts4mc
| Posted on Monday, March 28, 2011 - 08:58 pm: |
|
new bracket
|
Nuts4mc
| Posted on Monday, March 28, 2011 - 09:00 pm: |
|
looking down details
|
Thefleshrocket
| Posted on Monday, March 28, 2011 - 11:00 pm: |
|
Nuts4mc, your pics remind me of what I saw when I first lowered the fork tubes. What I did was loosen the rubber sleeve so that it wasn't adhesived to the brake line. I then pulled the line down so that it was mostly taught between the clamp and the master cylinder with as much slack as possible between the clamp and the caliper. I haven't had a chance to take a follow up look at the brake line, but I think that was enough to prevent any brake line binding. Thanks for the detailed, helpful pics! |
Thefleshrocket
| Posted on Sunday, September 18, 2011 - 08:34 pm: |
|
A followup to this old thread since someone linked it in a current thread--my 1125 doesn't have any binding issues with the brake line. The reason is that I removed the rubber grommet that attaches to the brake line and goes between it and the clamp, and slid it up the brake line. Now, even with the front wheel off the ground, there is still a good inch worth of slack in the brake line, and no chance of binding whatsoever. |
|