Yamaha TRX850 Enthusiasts Forum

Folks, I'm doing some serious fettling of my TRX (YZF750 SP front end, YZF 750 rear, big bore engine, flatslides, akrapovic, R6 back end etc) and one of the problems I have at the minute is that the YZF swingarm and 180 section tyre puts the rear sprocket about 3mm further outboard than the original TRX.

As I see it I have two options

1) get an offset front sprocket made up - easy but puts more strain on the output shaft bearings

2) machine 3mm of the rear sprocket carrier to move the sprocket back to the original TRX position. This is also fairly straight forward and is also attractive because it won't strain the gearbox output shaft.

however...........

the problem with option 2 is that the plastic slider that fits over the the swingarm at the pivot end, will not longer line up with the chain if I do this.

The slider seems to be a fairly important bit that stops the chain chewing through the swing arm!

Does anyone have any idease for how I can get around this?

use the search button. it's been covered in detail before

And if you are finished, make sure you post a picture because it sounds more then interesting!

Thanks! Just about to start searching!

ummm whn i swapped my trx rear end for the yzf one all i did was reverse the sprocket worked fine for me its still about 1mm out of line but ive seen worse on a totally stock bike!!! had a cbr600 that was almost 7mm out and it was totally stock

oh and deffo post some pics up
ive gone down that custom route
yzf front end with ohlins cartridges , ohlins rear with yzf swinger , r1 rear end and 675 front end , just not done owt to the motor as my pockets are temporaly dry from loosing my job



deffo get some picies up alont the way.

When I fitted my YZF arm it needed a spacer on the LH side between the frame and the swingarm pivot.... I think my arm had been modded to fit an FZR1000 Genesis or something. Anyway; with this done and the sprocket carrier machined down 3mm it lined up with the chain slipper spot on....

Number8 wrote: yzf front end with ohlins cartridges....

Where did you get these from?

honkdawillydahonk wrote:When I fitted my YZF arm it needed a spacer on the LH side between the frame and the swingarm pivot.... I think my arm had been modded to fit an FZR1000 Genesis or something. Anyway; with this done and the sprocket carrier machined down 3mm it lined up with the chain slipper spot on....

Number8 wrote: yzf front end with ohlins cartridges....

Where did you get these from?

came from an ex bsb bike ,there was a guy in snadbach that was breaking a couple of whithams old bikes, think there from something else that had been modded to fit , thats where i got the hole front end from, it was either that or the harris factory swing arm he was getting shot off

really whish i had more £££ at the time , he had 2 pairs of dynamags for the yzf that woulda fitted ,the harris factory swinger and a set of proper ohlins frorks!! but that would been well over 4grands worth of bits!!!

im just confirming what everyone else is saying..

Flip your rear sprocket around. It should have a slight machined indent which faces the outside, just unbolt it and make it face the inside.. Works well. Ive done it. (but i also got a dished front sprocket which i made, but you wont need it.)

Thanks for the advice folks.

Just finished with fitting the YZF SP front end and now waiting for the engine to come back from the tuners so I can fit it into the frame and play around with the sprocket alignment.

ohhh.. engine tuning.. what ya get done ? or just a nice quality rebuild ?

JE big bore/high compression pistons, gasflowed / skimmed head, 'povic full system and 41FRCRs.

should do the trick