Vintage Dirt Bike Q & A

I get a clunk sound and when turning the handlebars from stop to stop and it appears to be coming from the front hub. I can see the front brake backing plate slide approx 3/8ths of an inch in and out when the clunk is heard. The brakes stop well. Is this a wheel spacer issue or is my hub shot? If it is the hub, are there any replacements available or what can I use instead? Thanks in advance for your help.

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osu_cowboy

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osu_cowboy

i don't know for sure but is the axel tightened properly. i sure wouldn't ride it untill you find out what the problem is

Yes, axle is properly torqued. I will post a picture of what the issue is. It looks to me like there is a spacer missing on the brake side, but I don't have point of reference so that is why I am not sure what the problem is.

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osu_cowboy

In the picture you can see a gap between the brake backing plate and the fork. As the handlebar turns stop to stop this gap closes and makes the clunking sound that I am hearing. Is this a hub issue or is there a spacer that goes in that gap?

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osu_cowboy

i'm not sure with out seeing the inside of the hub and brake but losen the 4 nuts on the one fork leg and then tighten the axel bolt then tighten the 4 nuts i don't think their is any spacers on the front wheel for a picture of the front wheel parts google parts fish and look up your make year and model find the front wheel and there it is all the parts to the front wheel

I suspect you have the incorrect front axle or for some reason the axle is not screwed deep enough into the left-hand fork leg. There are no spacers in this set up. There is a step in the axle that pushes against the hub that then pushes against the brake backing plate and everything is held snug against the left-hand fork leg. Then you clamp the right hand fork-leg down onto the axle with the 2 (1978) or 4 (1979) pinch bolts. I have later 1983 forks on my 1979 CR250R but the principle there is the same. However having had different sets of forks pass through my hands I did notice that the step can be in different places on the axle. Use the wrong axle and you will get a gap and/or the front wheel being off-set.

You must not ride the bike without this being corrected. Any gap will mean the lug on the fork leg is not 100% seated in the channel on the front brake backing plate. At best you would rip your brakes and hub up...

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF

So I went and tightened the pis@ out of the axle and I got the gap closed. I still think something is not right because I had to really man handle a 3/4 inch drive rachet to get it to turn. I wonder if the axle is bent or maybe just galled up after 30 years? At least the backing plate is seated and the clunk is gone.

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osu_cowboy

you should probibly take that front wheel off the forks and diassemble the front hub to see whats going on. (very ease to do) you should'nt need to tighten the axel with that much force. i would check it! just think about a axel or hub braking or a sized bearing at 60 mph you won't like it

I would take that pressure off your forks quickly. Remove the axle and use a washer or two or three to make up the gap. Make shift spacer. I bought a couple 1ft lengh tubes with the same dimensions of a couple popular axle spacer sizes and cut them to lengh to make custom spacers.