vibration

roy the mechanic

roy the mechanic

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I'll go with Glen to start, balancing the wheels is a whole lot easier, and quicker , than messing with the crank, They reckon that a one ounce of imbalance on a front wheel becomes two pounds at 100 mph! that's why your forks go mad at speed. Don't neglect the rear one, this too has a significant effect on ride quality.
 
Robert Watson

Robert Watson

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If it rotates, balance it. Clutch drum, engine sprocket, wheels for sure. I have an HRD 1949 Comet. When I bought it, it had a 21 in front wheel and a 450 x 21 tire. I drove it about a mile, brought it home and took it apart. Changed out the front rim and tire, and trued it within 10 or 15 thou, and cut 2in off each end of the very wide handle bars, which were the only way you could turn that big front tire. The back tire/rim was the tell tale tho' as at about 50 mph it bounced right off the ground!

I removed the tire and trued the rim from about 1/4 in out down to the 10 or 15 thou. I then put it on the bench and it took off. I know my bench might be a bit off but not that much. Experiment showed a very out of balance rim/brake/hub assembly. I put the tire back on and then balanced the lot. Big amount of weights added!

Now a bike that shook, vibrated, was a pig to ride, is turned into a reasonably nice ride. Now just to replace that clutch with a modern one. Maybe tomorrow.

Look for the easy ones first, and if vibration is still an issue, then the motor needs to come apart!

If it rotates, balance it.
 
Albervin

Albervin

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I have been told by many people over many years that I am unbalanced. I have tried many and varied methods to become balanced but so far nothing has worked.
 
K

Kevin Fowler

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My own experience with bad vibration was cured by removing the brand new front tyre( brand new as in no miles, the bike had been parked with the front wheel on the angle and the tyre just fell into reclining pose. 35 MPH wheel wobble wanted to throw me off. I checked everything and eventually replaced the tyre. Problem solved.
 
C

chankly bore

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Whenever I ride my Comet I dribble from both corners of my mouth, so I'm perfectly balanced. F5AB/2A/7945 since 1970
 
D

derek

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I find hard to see how you can true a steel wheel (they are usually rolled and welded) to 10 to 15 thou! Maybe alloy ones are machined, 10 thou is only 5 thou out of true. I have read a lot on wheel truing and most publication recon, with in 1/8" is good; this would be only 60 thou out of true?
 
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