This will most likely stir some comments.....is your front sprocket on the right way? From factory my front sprocket had the boss to outside. When I replaced it at about 20,000km I did the same. But during the weekend I was checking the chain and with it in 1st gear and trying to turning the rear wheel backwards whilst sighting down the chain I noticed the chain hooping toward the center of the bike suggesting something was not right. After checking and double checking the index marks on the adjusters and measuring the axle to swing arm pivot lengths were equal, I pulled off the front sprocket and noticed a wear mark on the inside consistent with the something out of alignment and being I had eliminated the rear axle and the cush hub has new bearings and the swing arm bearings feel tight, I started looking closely at the built-in offset on the front sprocket. If the sprocket is flipped it should help alleviate the wear issue I am having. My next task will be to check alignment and see if I can prove my theory. It will interesting to here your guys comments on what you see on your bikes..... Attached is the manual picture and pictures are of OE sprocket and JT. So, which way round is your sprocket and do you have any wear marks on the inside like I do?
the "boss" is supposed to be on the outside. Was and is like that on both my Terras and i don't remember such a wear pattern when i changed chain and sprockets. I think it was reported here that the chain rubs on the frame if you mount it the other way around or something like that. If the chain moves to the center of the bike i'd expect the wear to be on the other side of the sprocket?
So I have checked the alignment and the front sprocket (with boss to outside) and it is out of alignment. Flipping it over puts it ni-on perfect. I am running DID VM2520 chain (very narrow for its size) and will most likely get away without chain hitting the frame. The lower foot peg bolt protruded by about 3mm which I have shortened to reduce any problems. Shifting the rear sprocket over by machining the cush drive hub is also an option, this would allow front sprocket to run with boss to outside. It will be interesting to here if others are seeing the same problem...
Haven't got the time right now, will have to wait until the weekend. I've also only ever mounted the JT sprockets with their part numbers readable from the outside, maybe they've got it wrong on this one? Checking won't hurt. TKS for the heads up
I'll check but its never been off since factory. Just checked the manual and it appears the RH side of the bike is the "index" in other words the adjuster spacer is tightened to move arm across to the right side of the bike (does that sound right?) and mine appears all the way across. I physical check it later.
My JT rear can be mounted with offset in or out, mine is out....(the flat side against the cush drive). So if I flip it, it will help when front is mounted with boss out, but its not enough to get fully in line. Rear offset is about 1.5mm, yet front boss is about 3mm.
Kiwiape, I just saw this thread. I have the opposite wear on my countershaft sprocket(on the outside). Mine looks like it is the original sprocket? The flange is on the inside and it is stamped EXT on the flat side. Also the flat washer is missing,just the cone washer and securing bolt. I ended up stretching a string across the rear sprocket to the front. It lined up perfect. I am confused, I thought I would find it showing the front too far to the outside causing the wear. I have never saw this condition ever before on any mc owned. I too wonder if anybody else has any input. Thanks
I looked at it again and found I have old timers, the flange is outward and stamped EXT.As a last resort, I pulled the swingarm up to put the suspension in riding position. The chain seems to run straight and true on the sprockets. The rear has no real wear like the front. All I can think is my front sprocket is wearing out? Kiwiape,I reread your posts. If you have any chain looping, your sprockets are out align. I took off the chain guard to look along the top of the chain. It gives one a better view. Also looking at your first sprocket pics, the one on the right seems to have a champher built in where as the JT one does not? Can you try stretching a string across your sprockets with the chain removed?
I used a chain guide "sight" and it confirmed it was out of alignment...if you wind the rear wheel backward in gear the chain will hoop if out of alignment. With boss to inside the alignment is almost perfect compared to boss to outside.
