Question on wide wheel centering

OK, so I've seen all the discussion over the years about using a wider wheel than stock. Say I use a wheel from a newer sportbike that uses a 180 section width tire. I know that I use a offset sprocket, so then do I jsut line up teh two sprokets, make a couple spacers for my swingy and then get off to the races? Or do I line them up, check the wheel to make sure its centered with the front one, and then modify my countershaft sprocket or sprocket carrier so that its perfect?

My machinists intuition would be to center the wheel in the bike, get a countershaft sprocket thats too wide, and machine that down, instead of machining the sprocket carrier on the wheel. How thick is the mounting area on your typical wider countershaft sprocket? As in: how much could you theoretically take off before tis too thin? Does anyone make custom wide countershaft sprockets to customer provided offset?

Your right. first you align the front and rear wheels, then find out what spacers you need for the rear wheel. Then you go to the offset sprocket. pingleonline.com, schnitzracing.com have the offsets you need.

And it'll be exact? Do most newer sportbike wheels have the sprocket in the same offset from the wheel centerline?

mine was not exact. I used a 5/8" offset front sprocket, then had to shave some material off of the rear sprocket hub and a little on the wheel where the hub makes contact to bring the rear sprocket in a little. I am using a 190 rear tire.

So would I be better off using a 1/2" offset sprocket? 1/8" is only ~3mm. I guess I'll have to get it all mounted and judge for myself.

do you care about having to clearance(cut)your frame?
ideally you would have both wheels centered,we do not live an ideal world.
there have been bikes that have come from the factory with as much as 3/4(19mm)offset,not just harley's there was certain year gixxers that were offset as well.
when sticking these big wheels (170 and bigger)in these old bikes you either compromise or do some heavy mods.
which you do is up to you.
i did not want any frame mods,at all whatsoever.so i run my 200 now 190, 3/8's of an inch offset to the right(away from the chain)and was able to get passed everything by running a 520 chain and building my own 3/8's offset countershaft sprocket.
don't know if this helps.
lemme know if i can help you,
leon holmes

Yeah I guess I just have to get everything mocked up and make the decision. I'm not really opposed to clearancing the frame. I'm only planning on a 180 tire, so maybe that with a 520 chain, a custom countershaft sprocket and a little milled off the sprocket carrier could do the trick.

When you made your sprocket, did you mill it out or weld a couple pieces together? I can machine up a couple parts to be welded, and I know a guy who's good with a tig. I figure press fit the parts to make sure they're bang on straight, and hand them over to the welder.

So I asked PMFR how much a custom sprocket would be, $450, 4 week lead time hahahaha.

I think two stock sprockets, a little 4130 round bar, an hour on the lathe, and a six pack for my welding buddy suits me a little better

you are on the right track there t_dub.i used a piece of some heavy walled pipe that i dug out from under my layout table and machined it for the spacer.i took two counter sprockets (one that fit the splines and one that had the teeth)and torched the splines out and the teeth off (accordingly.the sprockets are very hard and i smoked a carbide tipped lathe tool when i went to machine them off and out.cutting them with the torch and letting them cool slowly in the room seemed to soften them enough to machine them.i had machined some shoulders on the sprockets to set my offset and make sure everything was square.then pressed together and tigged up all the seems and while it was still orange from welding i quenched it in an old bucket of used motor oil until it quit bubbling and then let it cool at room temperature.not zactly scientific but it has worked this long and seems to wear well.hth.

leon holmes

5 gallon bucket of water and 1 of those big card board cans of salt dumped in it should work about right for tempering

good idea plummen thanks for that.

leon holmes

Thanks guys, that sounds like a plan. I figure a good carbide bit should be able to cut a sprocket, or was that what you used? If not I'll go the anneaing and tempering route. The salt water will work better than the oil for hardness, but it might get too brittle depending on the carbon content of the steel. If you cool too fast theres a point where you start forming this stuff called martensite which is almost as brittle as cast iron.