Tuesday, 28 August 2018

True or false? The acceptable limit when truing a wheel

What would be the acceptable limit when truing a wheel for a bike with rim brakes? I hate truing wheels and I’m pretty rubbish at it, but I like to do all my own repairs. The wheel went out of true and I adjusted it, first making it a little better, then making it worse. I’ve now got it running within 1mm to 1.25mm. Is this acceptable or do I need to have another go?

francovendee, via the forum

Since it’s your bike and you’re doing the work, you get to decide whether you have done an acceptable job… You might conclude it’s fine, provided the rim doesn’t touch either block during a wheel revolution, and you can’t sense the wobble when riding. Radial run-out feels worse than side-to-side – and is for many people harder to cure. Consider buying an authoritative book on the subject, such as Gerd Schraner’s The Art of Wheelbuilding.

Richard Hallett

Cycle’s Technical Editor

This Q&A was published in 'Cycle' the magazine for members of Cycling UK. To contact the experts, email your technical, health, legal or policy questions to editor@cyclinguk.org or write to Cycle Q&A, PO Box 313, Scarborough, YO12 6WZ