On my R75/5 SWB, the front wheel appears to have internal wheel weights. Two are roughly 120 degrees apart with a third bunch of spoke weights near the valve stem to offset the internal weights. The internal weights appear to be anchored with bolts through the wheel in the same fashion as a valve stem. I say "appears" because I haven't yet removed the tire to confirm. Does anyone have any experience with this? What would be the goal? This bike was originally owned by a woman of small stature and when I acquired it, there were other modifications to address this. Do you think the extra weight was placed there to somehow compensate for a slight rider or to deal with the known front end stability issues of this model? Should I leave them in place or remove?
Thanks in advance.
Sounds like something aftermarket. I'd strip the tire and tube and balance the wheel. Slash 5 wheels are notoriously crudely balanced and I am not surprised about your find with the internal weights. I'd make sure the rim was not oval'd or running out side to side, then balance it before and after mounting the tire. One hundred grams, in my experience, though not much can be a problem at 60 mph.
It sounds to me as if someone has fitted "rim locks" to the wheel. These were standard on some makes of motorcycles up until the mid-1970's. They still persist on dirt bikes, where low tire inflation can't be counted on holding the tire to the rim. At any rate, modern road tires DO NOT need rim locks due to the higher inflation rates and the knurling found on the inside of the alloy rim.
I highly suggest you remove the tire and discard it. That will allow close inspection of the wheel. Any extra holes in the rim, other than the valve stem hole, MUST be filled or the tube will bulge through and break itself. I typically use round head screws on the inside, and place the nut and lock washer on the outside. Tubes move inside the tire. Therefore, any rough or sharp corners will puncture the tube.
In my experience, most of wheel imbalance was due to tire construction. Modern tires have almost eliminated this. This is the biggest reason to strip off all wheel balancing weights during tire replacement. Fit a new rim strip too.
Hope this helps.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
They were indeed rim locks. I didn't know about these. Thanks for the great advice!
Glad I could help, sir.
Unlike the ribbed tires that came new on your bike, which you may now be removing, you'll want a modern front tire that has no ribs or center groove. A lot has happened to roads in the intervening years making those older tire designs "hunt" and/or feel unstable at even moderate speeds on modern roads. The bike will feel much more "solid" and road worthy with a front tread that incorporates rain grooves that cut across the face on the diagonal.
Owning an old Airhead is easy.
Keeping an old Airhead running great is the true test.
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