A buddy of mine owns a BMX shop in Cambridge, MA. By the time a customer's BMX rim is at the end of it's rope, it usually looks like it's been through a war on account of all the dents. But they can still be trued. Maybe not trued perfectly, but enough to make any hops almost imperceptible. The technique is basically this: where there is a hop (outward protrusion on the rim), the spokes need to be tightened slightly. To compensate for the added tension in that area, the spokes on the opposite side of the rim may need to be loosened (relaxed) slightly. It's an iterative adjustment- so you start with say, one quarter of a turn with the spoke wrench, and re- check, and repeat.... It's a little bit more complicated than that, but not much.
On Oct 9, 8:48 am, JGS <jonat...@jonfipro.com> wrote: > There is a slight up and down movement in the rim, but not so much > that it ever interferes with braking. There is a ding in the rim at > one point which is where the hop occurs. The rim is fairly true side > to side, but maybe not perfect. I don't see any cracking, but I > haven't removed the rim tape. I feel like there is some intermittent > grabbing when I brake hard but other than that, I don't feel the hop > when I'm riding. I'm pretty light, like under 150, though I'm usually > carrying 15 lbs of stuff with me, so I'm well well under the Atlantis' > carrying abilities. I ride the bike mostly as a commuter in NYC so > other that the wheel totally collapsing on me and causing me to slide > under a truck, I'm not that worried about a failure. I won't be in > the middle of a middle of a mountain pass on a tour. Also, I get > pretty extreme hits to my bike all the time. I think NYC riding is > one of the harshest on a bike. There are a constantly serious > obstacles that sometimes can't be avoided. Sooner or later you are > bound to see that metal grating too late and hit its 4 inch lip at > full speed or barely hop your front wheel over some caved in asphalt > and take a major hit on your back wheel. That means though i take > extremely good care of it, I really can't be precious about the bike. > Thanks for the advice! > > On Oct 8, 10:15 pm, Dave Craig <dcr...@prescott.edu> wrote: > > > Hmm . . . one of those things that's really easier to diagnose in > > person . . . > > > How 'bout a little more info? Is there an up and down movement at the > > rim, or is it just the tire? How much movement are we talking about? > > Can you feel it when you ride? Is the rim true side to side? Check out > > the areas around the spoke holes. Are there any cracks? Take the tire > > off and remove the rim strip. Is there any obvious cracking inside? > > > Ordinarily, serious damage to a rim is caused by a solid hit - usually > > not "I got a ding in the rear wheel somehow" kind of stuff. Did you > > hit something hard? I have seen rims fail due to worn sidewalls and > > even defects - with these the braking often gets funky as a first > > sign. Do you get any intermittent regular grabbing when you apply the > > brakes? > > > In addition to the above info, I'd need to know a little more about > > you and how you ride before I could give you any advice. Are you > > heavy? Is this a touring bike headed for Mongolia or do you just ride > > around town?, etc. > > > Standing by . . . > > > DC > > > On Oct 8, 6:34 pm, JGS <jonat...@jonfipro.com> wrote: > > > > Hi all, > > > > My Atlantis got a ding in the rear wheel somehow. When I turn the > > > bike upside down and look at the wheel spinning there is a slight up > > > and down movement. I took it to a local mechanic and they said that > > > it couldn't be trued out and were sort of noncommittal about whether > > > the wheel needs to be replaced. The brakes don't rub the tire or > > > anything, but the hop is visible. > > > > I'd love to hear the opinions of some of the experience mechanics on > > > the list. Do you think I need to replace the wheel? What affect will > > > this have over time? > > > > Thanks for the advice! --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to rbw-owners-bunch@googlegroups.com To unsubscribe from this group, send email to rbw-owners-bunch+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en -~----------~----~----~----~------~----~------~--~---
