FXR wheel conversion

[r1johnkt]

Hi, Thanks for all your help and info about doing a wheel conversion. All done apart from waiting for my slicks to arrive. A couple of members have asked me to post how I did the conversion. Well this is how I went about the task. First I bought some FZR250 wheels. The rear wheel was running a 15mm axle not a 17mm. So first job was to replace bearings. You can't get in to drift them out so I took out the iner race and welded tags(mig) on the outer race to give some drifting tags. Installed new bearings and bored out the inside bearing spacer(used lathe and boring bar). Also bored out the axle spacers that Came With the FZR wheel(starting point for finding right spacers).
The hardest part of the job was working out the wheel centre and brake disc. This was done by measuring the distance from the FXR wheel centre to the inside of the disc then using this info on the FZR wheel. I had 16mm machined off the disc side of the wheel and 4mm off the bearing face(see pictures). Then it was just a matter of machining spacers to fit. It's an excellent fit down to 1mm difference. I'll live with that! Have to but a new chain due to the larger sprocket. Cheers John

[r1johnkt]

Some more pictures. The front wheel was very straight forward, Runs the Same axle and same size disc. All I had to do was make a couple of spacers. Machined down exsisting ones and used the inside tube from the speedo(never going to use it again so smashed the black casing off and into the lathe it went). I'll post some pictures of the final result once my tyres are on. John

[hmurphy]

That looks wicked! Now for a new pipe/muffler! You should do what I did to mine. I used all the stock parts (pipe and muffler) just gave it a trim and stuffed the bastard underneath the bike. Check it out:

http://www.youtube.com/watch?v=qNhL1...e=channel_page

It looks like this now:

http://www.kiwibiker.co.nz/forums/at...0&d=1244960585

http://www.kiwibiker.co.nz/forums/at...5&d=1244960566

[r1johnkt]

Thanks for that. Food for thought about pipe, think I'll do that. Cheers John

[Buckets4Me]

Nice job

but I think you may need some more links on the chain

[k14]

Nice job john! Very well done! I know how much stuffing around it takes to fit a new set of wheels.

[r1johnkt]

Thanks HMURPHY for the tips on the exhaust. All done and looks well sexy. Wheels on. Just trying to finish the paint before the weekend. Cheers John

[hmurphy]

Cool man!! Now when you crash you won't bust the muffler up! You have made a hell of a lot of progress in a short time! Good stuff!! Head down to welly and show that beast off at Kaitoke sometime.

[FastBikeGear]

Just looking at doing the same conversion as I got given a free FZR 250 wheel and sprocket carrier by one of my customers in exchange for an Ultrabatt battery for his bike.

Discoveries so far.

Need to change bearings to suit FZR 17mm axle but they are available. (Interestingly TZR 250 wheel which is very similar has 20mm axle.)

Sprocket needs to be spaced outwards by 7mm. Need to make a spacing plate to do this that keys into the sprocket locators and also provides new locators for the sprocket to locate onto. Good news is that the FZR sprocket is a 428 size so don't need to change to a heavier 520 chain, rear sprocket that front sprocket as you do with most wheel conversions.

The brake disc side of the wheel is more challenging.

Brake disc mount either needs to be inset approximately 16mm or a new brake calliper mount needs to be fabricated.

Machining down the face of the wheel 16mm is problematic, as it only leaves 5mm of the original 21mm of thread for the three 8mm bolts that hold on the rear brake disc. Normally I would be keen to have at least 8mm of thread insert but preferably 12mm (1 & 1/2 times the fastnerer diameter) when bolting into a soft grade alloy such as the wheel are made of.

Another option to offsetting the brake disc is to make a top hat or machine an offset rear brake disc.

Not decided what options I will go with yet.

[Henk]

Leave the sprocket side alone, that gives you 9mm to machine off the disk side and enough meat for the bolts, you'll never use the rear disk anyway and you won't notice the offset in the rear wheel.

[FastBikeGear]

Leave the sprocket side alone, that gives you 9mm to machine off the disk side and enough meat for the bolts, you'll never use the rear disk anyway and you won't notice the offset in the rear wheel.

Hmm I had wondered if I would notice the off set and whether it would make me even slower one way around the track than the other! Shit I if I make the offset even bigger I could end up with a two wheeled side chair rig.

[Henk]

Hmm I had wondered if I would notice the off set and whether it would make me even slower one way around the track than the other! Shit I if I make the offset even bigger I could end up with a two wheeled side chair rig.

Mine is out at least that much and I run mid pack A grade, haven't noticed a difference between lefts and rights.
The two wheeled sidecar idea may have merit, easier to transport, you might have to make a detachable third wheel and leave the pillion pegs on. That would make the class even sketchier than it already is.