Front fork vibration

clivew · Post by **clivew** » Tue May 01, 2007 9:50 am

Hi all. I apear to have a problem I seem to be getting vibration from my front forks at the bottom when accelerating. The head bearing etc are fine. The brakes have been striped and are all fine. (thats what i thought the problem was as they were sticking)

Also they apear to be very hard if i go over a bump. I have ajusted them to be as soft as i can now but to no evail.

Anyone got any advice. Perhaps i should look at having them re-built

meemo_meh · Post by **meemo_meh** » Tue May 01, 2007 10:25 pm

Standard TRX forks hard over bumps??? hmm.... something sounds a miss there... unless they are bottoming out. Probably your best bet would be to give them a good servicing; replace the oil, seals, and check out the condition of the springs and shim stacks, might have something broken/stuck in there.

Sometimes, (not very often), there is movement in the fork itself by means of the tubes being loose. I took my rear shocky out as it was what felt like (shaking) so I took it out but couldnt see any problem with it internally, so took it to the pro's and thery found that the chrome shaft was too thin and therefore alllowed movement, so I had it re-chromed to about 4 times the original thickness of the surrounding chrome and it has worked like a charm since. But that was a rear shocky, I have not heard of it happening to from forks yet..

Best of luck with it anyway.

Rural Rat · Post by **Rural Rat** » Wed May 02, 2007 12:02 pm

Just a silly thought. Have you made them so soft that they are always in the firmer damped portion of the stroke. I have been caught out with dirt bikes like this. Might be worth increasing the preload and giving it a try.
Good luck
Rat

clivew · Post by **clivew** » Wed May 02, 2007 12:31 pm

Rural Rat wrote:Just a silly thought. Have you made them so soft that they are always in the firmer damped portion of the stroke. I have been caught out with dirt bikes like this. Might be worth increasing the preload and giving it a try.
Good luck
Rat

I have messed with the pre load but to no avail. I am going to loosen them up and make sure they are true and straight when fitted but im sure they are. If that fails my m8 is going to re-build them for me. Thanks for the advice lads, i will keep you informed

dfh · Post by **dfh** » Wed May 02, 2007 1:24 pm

I have messed with the pre load but to no avail. I am going to loosen them up and make sure they are true and straight when fitted but im sure they are. If that fails my m8 is going to re-build them for me. Thanks for the advice lads, i will keep you informed

If your mate considers a rebuild to include,..

a) Replacement fork springs (circa .9kg/mm for Anglo Saxon adult males)
b) New seals and scrapers ( forkseals cheap, scrapers weirdly expensive)
c) New bushes, those teflon coated copper rings about 1.5 mm thick and 25mm tall. ( my guess is that they are stuffed in your forks)
d) fresh fork oil.. 15wt or 20 wt

... then all is good and it should cost at least $350 AuD (about 150 plus VAT of your warm pommy beer tokens). If not, take your forks to an expert as a rebuild is more than fresh fork oil and a giggle.

For best results fit a set of Race Tech Cartridge Emulators. Made in the USA these little jiggers cost $200 AuD. Dunno about the pommy importers but these things combined with the appropriate fork springs make a huge difference for little cash.

Good luck

DFH

clivew · Post by **clivew** » Fri May 04, 2007 9:45 pm

dfh wrote:
I have messed with the pre load but to no avail. I am going to loosen them up and make sure they are true and straight when fitted but im sure they are. If that fails my m8 is going to re-build them for me. Thanks for the advice lads, i will keep you informed
If your mate considers a rebuild to include,..

a) Replacement fork springs (circa .9kg/mm for Anglo Saxon adult males)
b) New seals and scrapers ( forkseals cheap, scrapers weirdly expensive)
c) New bushes, those teflon coated copper rings about 1.5 mm thick and 25mm tall. ( my guess is that they are stuffed in your forks)
d) fresh fork oil.. 15wt or 20 wt

... then all is good and it should cost at least $350 AuD (about 150 plus VAT of your warm pommy beer tokens). If not, take your forks to an expert as a rebuild is more than fresh fork oil and a giggle.

For best results fit a set of Race Tech Cartridge Emulators. Made in the USA these little jiggers cost $200 AuD. Dunno about the pommy importers but these things combined with the appropriate fork springs make a huge difference for little cash.

Good luck

DFH

I all ready have a new set of progressive springs and seals. The lads that does them is no bodger. He has been rebuilding bikes for twenty years . and now spends most of his time rebuilding forks and maintaining motorcross bikes for a second income. He is now that busy that he is going full time mechanic as the money is much better and he enjoys it more. He used to be sponserd by fowlers motorcross by suzuki. As for the forks I havent got the sums of money your looking at and i dont screem about scraping me knees down unfortunatly due to being a fairly tamed driver most of the time. Once you have been t-boned it slows you down a bit

I will be happy for a standard set up with no vibration

Thanks for the advice though m8y.