Yamaha TRX850 Enthusiasts Forum

Ok question, I know that Thundercat forks are supposed to fit in, R1 can be made to fit. But what other forks wil go in, i.e. would Thunderace forks fit or are they too wide for the standard yokes?

Dave E

Thunderace are (i think) 46mm diameter, way bigger than TRX.
R6 are 43mm and a couple of people have transplanted them successfully, although there is no space for speedo drive and the forks have to be modded accordingly.

Without modding or replacing yokes you are looking for 41mm diameter forks, such as Yamaha
FZR600R and
Early Fazer 600

Other makes:
Early Honda Hornet 600
Suzuki Bandit 600
Suzuki SV650

Most of them are no better than the TRX forks, whereas T'cat forks offer rebound and compression on top of preload. In addition, the other forks will require diff mudguards or making up brackets so not really worth the hassle!

slow codger wrote: Ok question, I know that Thundercat forks are supposed to fit in, R1 can be made to fit. But what other forks wil go in, i.e. would Thunderace forks fit or are they too wide for the standard yokes?

Dave E

VTR

anything will fit.. Just depends how keen you are.

suzuki GSXR will fit if you have a little patience.

Unfortunately I dont have the time, what with other projects and working silly hours, which is why I was wondering what would go straight in, and what would be an improvement on European stock front shocks.

Dave E

slow codger wrote: Unfortunately I dont have the time, what with other projects and working silly hours, which is why I was wondering what would go straight in, and what would be an improvement on European stock front shocks.

Dave E

Well, why not fill them with Ohlins internals
...a tad better would be the thundercat ones with Ohlins...
...or take a step further and put in some cartridge emulators...and Ohlins

Keep saying Ohlins but hey....i´m from Sweden!

send them to maxton and get them to work there magic on them!

i agree with what ppl are saying about getting em rebuilt.

you KNOW they will fit, and you get basically brand new forks !

Didnt a few ppl on here get em rebuilt and said they were 10x better ?

I got my std ones rebuilt with Ohlins internals. Took a while before I noticed the difference though. I think they need rebuilding again soon, 3 yrs and 30,000kms later.

Bob

that would only be seals + oil, since the good stuff is already in there.

Wombat wrote:I got my std ones rebuilt with Ohlins internals. Took a while before I noticed the difference though. I think they need rebuilding again soon, 3 yrs and 30,000kms later.

Bob

This comes up so often we should at least try to standardise terminology.
This is my read on the issue, please feel free to chip in.

Stock fork is just that. Damper rod internals - just a couple of holes in a tube for compression damping, another two plus a secondary pair adjustable in 4 steps for rebound.

"Revalved" stock fork. As a damper rod fork can only be "revalved" by enlarging or brazing up and redrilling the fixed holes and/or changing oil weight treat suppliers of this service with caution.

Upgraded springs. Aftermarket springs of differing rates to suit rider weight supplied by companies such as Ohlins, Eibach, Racetec, WP etc.
Fitting springs made by Ohlins does not qualify for the expression "Ohlins internals"- this is consistant with competition regs around the world that seperate the concepts of spring changes from damping mods.

Upgraded internals with stock forks. Splits into three categories.
a) Upgrades to the damper rod. Racetec from the USA and I belive K-tec from the UK offer competing versions of the same concept. The stock damper rod has the compression holes drilled to offer no resistance and a replacement valve is placed between the spring base and the top of the rod. This valve operates in the same way a valve in a cartridge damper lowering resistance (damping) as shaft velocities rise.
b) Replace damper rod with a catridge kit. A company in the USA ( http://www.Traxxion.com ) offers complete cartidge kits for the SV650-41mm damper rod fork like the TRX. Expensive at over $us1000. Ohlins and WP do not offer kits for the TRX.
c)Thundercat/YZF600 front end. Easy swap. Adds proper cartridge dampers with adjustments for way less than any other alternative but still will neet to be resprung and revalved to suit TRX. Maintains geometry,speedo, clamps, wheel, mudguard. Looks stock for those with insurance and or enforcement issues. Supply of straight front ends not good in Oz.. better in UK.

Any more ideas out there?

DFH

Ohlins internals, Ohlins internals, Ohlins internals. Ohlins internals, Ohlins internals.......................(should I go on?)

Wombat wrote:Ohlins internals, Ohlins internals, Ohlins internals. Ohlins internals, Ohlins internals.......................(should I go on?)

Yes please... on their website Ohlins list only forksprings and no other internal components as being availble for TRX forks.

So if you have fitted components from Ohlins designed for TRX forks that are not in their web catalogue,
or have adapted somthing Ohlins produced for use in another bike then please let the cat out of the bag.

Thats the purpose of bike specific forums after all....

DFH

There are 2 sorts of spring supplied as original, the soft japanese filling rattling ones and the harder European ones. So thanks to Martin I have already uprated my suspension onto the first rungs of the ladder.

Dave E

am i reading right thundercat forks replace trx forks and you can still use the trx wheel mudguard etc etc? or is it a complete thundercat swap?