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Wheel problem
Okay to get right to the point. I have this old mtb that I just got and the
back wheel had some major wobbles to it when I got it. I used the tire and frame as a guide and got the *big* wobbles out. Then last night I was going to ride it for my after dinner short ride and I had a flat tire, I took the wheel off the bike, took the tire and tube off the rim and patched and re-assembled. Now when I spin the wheel my tire rubs on my chainstays. I have tried changing the angle of the wheel slightly and it seems that if I do the tire rubs on the other side. Now I know this is probably caused by the tire not being mounted back on the rim in exactly the same place. My question should I try to *re-true* the back wheel using my tire / frame method. Or is there some other simpler solution to my problem? Ken -- Remove "-dispose-trash" for email address My personal webstie: http://kcm-home.tripod.com/ My blog: http://mind-dribble.blogspot.com/ |
#2
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Ken wrote: Okay to get right to the point. I have this old mtb that I just got and the back wheel had some major wobbles to it when I got it. I used the tire and frame as a guide and got the *big* wobbles out. Then last night I was going to ride it for my after dinner short ride and I had a flat tire, I took the wheel off the bike, took the tire and tube off the rim and patched and re-assembled. Now when I spin the wheel my tire rubs on my chainstays. I have tried changing the angle of the wheel slightly and it seems that if I do the tire rubs on the other side. Now I know this is probably caused by the tire not being mounted back on the rim in exactly the same place. My question should I try to *re-true* the back wheel using my tire / frame method. Or is there some other simpler solution to my problem? Ken -- Remove "-dispose-trash" for email address My personal webstie: http://kcm-home.tripod.com/ My blog: http://mind-dribble.blogspot.com/ Not necessarily 'simplier' but take the wheel to a decent bike shop. have them true and dish the wheel and put the tire back on. |
#3
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Ken wrote:
Okay to get right to the point. I have this old mtb that I just got and the back wheel had some major wobbles to it when I got it. I used the tire and frame as a guide and got the *big* wobbles out. Then last night I was going to ride it for my after dinner short ride and I had a flat tire, I took the wheel off the bike, took the tire and tube off the rim and patched and re-assembled. Now when I spin the wheel my tire rubs on my chainstays. I have tried changing the angle of the wheel slightly and it seems that if I do the tire rubs on the other side. Now I know this is probably caused by the tire not being mounted back on the rim in exactly the same place. My question should I try to *re-true* the back wheel using my tire / frame method. Or is there some other simpler solution to my problem? The simplest solution is a new wheel. But that requires cash, and I'm a cheap bastid. You trued up the wheel but didn't take into consideration the dish of the wheel, and thusly, the dishing is screwed. Centering a wheel without a wheel stand or bicycle stand in two flips and one (or two) beer(s): First, get a cold beer. Open beer. Sip. 2. Put the bike, wheels up, on the floor, table, workbench or Starrett pink granite surface plate. Use shop rags or old tee-shirts to keep from marring the bike's saddle and bars. 3. Deflate tire. 4. Open quick release on brakes. 5. Loosen wheel quick release, remove tire, reinsert back into dropouts, make sure that the wheel sits all the way in the dropouts, tighten quick release. 6. Take a scale (ruler) and measure how far off center between the seat stays or chain stays the rim is. 7. Loosen the side that is closest to the chain or seat stays 1/4 turn. Tighten opposite side 1/4 turn. Keep doing this until you have it roughly centered with the scale. To keep track of spokes you have worked on, I suggest using a hash mark from a marker or use the valve stem as a point of reference. 8. Check for wheel hops by placing a scale against the outside of the rim and spinning the wheel. Fix them as best you can. Try to keep from inducing hops throughout the following steps. (this is why you removed the tire) 9. Check beer. Beer must have hops. I suggest a beer and wheel hops-check each time around the wheel. 10. Once you have it roughly centered and sortof hop free, close quick release on brakes. Pick a brake pad, and mark it. Measure a distance from that pad to the rim and write it down. 11. Remove wheel. 12. FLIP wheel around, reinsert into dropouts backwards. Tighten quick release. 13. Measure with a scale again between the rim and the same pad you picked before. Subtract. Divide by two. 14. Check beer for hops. 15. Proceed to loosen the close side and tighten the far side until the rim has moved the distance you calculated. 16. Center brake pads on wheel. Use thumb adjustment on cable to bring pads closer to the rim. Measure pad-to-rim again. 17. Remove wheel. 18. Flip wheel and reinsert into dropouts the right way 'round. Tighten quick release. 19. Sip some more beer. Hops in beer=Good. Hops in wheel=bad. 20. Tweak spokes until you have moved the rim 1/2 the difference, again. Recenter brakes, and bring them even closer with the thumb adjustment. Flip wheel. This time it should be pretty much dead-on. If you go slow, sip beer, and take your time, it shouldn't be difficult. -- BMO |
#4
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Ken Wrote: Okay to get right to the point. I have this old mtb that I just got and the back wheel had some major wobbles to it when I got it. I used the tire and frame as a guide and got the *big* wobbles out. Then last night I was going to ride it for my after dinner short ride and I had a flat tire, I took the wheel off the bike, took the tire and tube off the rim and patched and re-assembled. Now when I spin the wheel my tire rubs on my chainstays. I have tried changing the angle of the wheel slightly and it seems that if I do the tire rubs on the other side. Now I know this is probably caused by the tire not being mounted back on the rim in exactly the same place. My question should I try to *re-true* the back wheel using my tire / frame method. Or is there some other simpler solution to my problem? Ken -- Remove "-dispose-trash" for email address My personal webstie: http://kcm-home.tripod.com/ My blog: http://mind-dribble.blogspot.com/ Your attempt to take out the wobbles may have pushed the rim out of center between the locknuts. You need to make sure the wheel is centered. This is best done with the tire off or with a Park Tool Centering gague WAG-4 as shown in: http://www.parktool.com/repair_help/wag.shtml at the above URL you will also find a link for wheel truing. The rear rim is likely bent. You efforts to true it may meet with short term success, but will likely lead to spoke failure as some spokes will be carrying more than their share of the loads and other will go slack under dynamic loading. -- daveornee |
#5
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On Thu, 5 May 2005 07:42:58 -0400, "Ken"
wrote: My question should I try to *re-true* the back wheel using my tire / frame method. Or is there some other simpler solution to my problem? Your first mistake was using the "tire/frame method" in the first instance. Instead you should have used the "rim/brake pad method". Assuming you have a way to support the bike (like a repair stand), take the tire and tube off the rim, put the wheel back in the frame, and true the wheel using the brake pads as a reference. You can do an acceptable job of centering the rim in the frame (dishing) by flipping the wheel over (cogs on left side) and making sure the rim is the same distance from the pads as when properly mounted. Once you have the wheel acceptably true (hey, it's just an old MTB) remount the tire and tube. If there's still a wobble to the tire check how you've mounted it. jeverett3ATearthlinkDOTnet http://home.earthlink.net/~jeverett3 |
#6
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On Thu, 5 May 2005 07:42:58 -0400, "Ken"
wrote: Okay to get right to the point. I have this old mtb that I just got and the back wheel had some major wobbles to it when I got it. I used the tire and frame as a guide and got the *big* wobbles out. Then last night I was going to ride it for my after dinner short ride and I had a flat tire, I took the wheel off the bike, took the tire and tube off the rim and patched and re-assembled. Now when I spin the wheel my tire rubs on my chainstays. I have tried changing the angle of the wheel slightly and it seems that if I do the tire rubs on the other side. Now I know this is probably caused by the tire not being mounted back on the rim in exactly the same place. My question should I try to *re-true* the back wheel using my tire / frame method. Or is there some other simpler solution to my problem? It's your "tire/frame method" that hosed up your damn wheel in the first place. Or second place assuming it was imperfect when you started. True the rim to frame, not the tire. The tire's made of rubber and air and flexes and shifts, truing to that's like nailing jello to a tree. In fact, you're at the point where you'll need to get the tire off of there to salvage this thing. The beer and wheel truing post explains this all pretty darned well. I'll recommend his advice. Ron |
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