Vintage Dirt Bike Q & A

I am converting my '79 CR125 from 23" rim to the 21" rim. Now that I have it together, I am finding the rim is offset to the right (3/8 clearance R, 1" clearance L). After doing some looking I find that the rim is directional (marked with an arrow), the rim is currently running "backwards".

My dumb question is if this counter rotation will cause the offset I am seeing, or is there something different to look for? There are no spacers or missing parts according to the diagrams. I did have the "old" 21" rim on the bike and it ran centered.

Just rebuilt the wheel, new rim, spokes, and bearings. I'll be mounting the 23" back on the bike tonight to see if the direction matters. BTW - the entire front end is '79 CR250, no mix/matched parts.

Yes it did ride fine with the smaller rim on the front prior to tear down.

Jim

I don't know about that particular model but I have changed rims on other elsinores. Before you disassemble the old rim from the hub, you should have measured the offset, which is how much the centerline of the rim is away from the centerline of the hub. You do this by laying the wheel down on a flat surface and measure the distance from the flat surface to the rim. When you re-lace the new rim you adjust the spokes so that that this distance is maintained.

I would double check that you have all the spacers and that they are all installed correctly. To center the rim between the forks you will need to move the rim over 5/16" by adjusting the spokes to pull it to the side with the greater gap. On the rims that I worked on, there was only one way that the rim would mount because the holes in the rim were angled so the spokes would point to their proper attachment holes on the hub. If the rim was mounted backwards the holes would not point the right direction.

Good luck