Bonneville America Forums Forums Technical Forums General Tech Slight dive to the right during hard braking

OK guys, just finished changing the fork fluid on the bikes, pretty straightforward other than the missing part in the damper tube from the factory and all. I am running stock springs. I am running a 50/50 mix of 10W and 15W fork oil. Pumped the forks about 10 times each, put everything back together and ran it around the block a few times to check it out. All seems normal unless I hit the brakes fairly firmly or in a panic stop, where the front end dives (feels more like a twisting action) to the right some. Any ideas where to start, what to look for?

is there any noise from the springs? hold the front break and shove down hard a few time to see if there is any spring noise. maybe one of them is binding in the tube.

i switched to progressive springs and has some noise in one when i checked. I just took the weight off of the front, unscrewed the top plug and reset it. no problems now. never drove it when making noise, but i could have caused the same problem (i think).

I'll check that. Also might try pulling one spring and flipping it, to see if one is in upside down (the stock ones are pretty hard to tell apart, and I know the progressives can go in upside down.

I eliminated all brake dive with Ricor Intiminators and stock springs: http://store.ricorshocks.com/ProductDetails.asp?ProductCode=TR-041-20-1001

What is it you're riding again, Greg? Just wondering about the duel vs. single rotor thing.

Its a Ducati 1190 Duodesmodicidalamacchiatocappacino Milano....


Only problem is that the brake is on the left, while it dives to the right. If it were torsion from braking I would think it would dive toward the braking side...

That might even be an alignment issue, I wouldn't think the rotor or which side it is on could cause an effect like that without wheel flex. But most likely it is an imbalance in the forks. Really curious with what it turns out to be. A easy spring rate check might be to swap the springs and see if she dives left.

I flipped the right spring (the one I did) but no real difference. I left the left fork as was since Triumph reassembled that one.

well, the torque to the right seems to have gone away when I put on the fork brace that the front fender mounts onto. I may have a fork seal leak, since they used the old seals, but will watch it...

If the brace squared it away, that points to a weaker spring rate on the right, Me, I would throw in a matched set, a lot of bikes work just fine with no brace at all, if the right spring is considerably weaker, that's going to put stress on the mounting fasteners and female threads in the aluminum forks as to the brace, in my hillbilly engineering opinion.

OK, I'll bite, these are the original springs from the factory, so should be matched already, no?

Bad heat treat on one? Pull them both out, if the lengths are significantly different side by side unloaded, the short one is probably fatigued and has taken a set. It happens, I bought a new set of Rancho springs for an old jeep, front and back, every time I hit a decent bump, the right front spring lost a little more arch on the main leaf, and I had to replace it, no, Rancho did not stand by their product, but that's another story. Spring rates are repeatable and standardized by their carbon content and the respective heat treat process, another factory spring will be close enough for safeties sake. Buying a matched set only ensures the same amount of flex cycles and usually both will have shared in the same heat treat batch. Ergo matched springs. But by all means, ascertain you have a bad one, before you start spending money.

I have already been considering some Progressives anyhow, so may do this once I get the leak/nonleak issue resolved. Have already pulled off the cover so I can see the dust seal area, and will do a 10-20 mile ride to see what's up.