Thorn Cycles Forum
Technical => Wheels, Tyres and Brakes => Topic started by: in4 on April 04, 2015, 08:15:57 PM
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I thought my brakes sounded as if they were catching on something today. Closer inspection at home reveals this crack in the rim. How I've done that I do not know. I don't ride on broken ground, weigh 80kgs and my supremes are inflated to circa 55 psi ; well within the stated maximum. The crack is only visible on the non-drive side; although I suspect beneath the surface.... Given that these wheels are supposed to be super strong etc. Expletive to be inserted here ******** :(
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Hi Ian!
No worries, I think. That is the standard rim join, generally opposite the valve stem and often covered by the rim label as in your case. It looks the same on my Tandem's Sun rim.
All the best,
Dan.
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Ian, just to follow up...
In the days before welded rim joins/joints and sidewall finishing, the rim was joined with an internal slug, a couple of pins, or...nothing. Spoke tension keeps things together.
However, the rim halves are sometimes slightly distorted by the joining process such that a rim edge may protrude and catch a brake pad. In the old days (as now), it was acceptable to gently squeeze the rim so the offending protrusion was leveled. Some people did this with a file, but I always preferred a vise with copper or aluminum jaw covers so the rim would not be marred. Done with care, it was regarded as acceptable practice. The one Mavic MA-2 on my blue rando bike has well over 32,000 miles on such a "repair" and is doing fine and there's no pad-catch when applying the brakes.
All the best,
Dan.
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Many thanks Dan, I was thinking I'd done something unresolvable. I reckon I can pop it into the vice, suitably lined and give it a little encouragement. I was just about to ask if you would mind moving my wheel moan to the correct place on the forum; I spied the wheels section a little too late in my cathartic post writing!
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Done and done, Ian!
If all of Life's problems were that easy, we'd have it made! :D
All the best,
Dan.