Rim wear/ Measuring rim thickness

Cliff · Post by **Cliff** » 31 Oct 2007, 1:46pm

The rims on my wife's bike are beginning to look a bit worn, they are Rigida Novas (5 years old) - does anyone know if these will have a wear indicator somewhere?

Otherwise, is there a simple way to measure the rim thickness? I gather it should be a minimum of 1mm.

Thanks!

pete75 · Post by **pete75** » 31 Oct 2007, 7:42pm

Cliff wrote:The rims on my wife's bike are beginning to look a bit worn, they are Rigida Novas (5 years old) - does anyone know if these will have a wear indicator somewhere?

Otherwise, is there a simple way to measure the rim thickness? I gather it should be a minimum of 1mm.

Thanks!

Don't know about the wear indicator but there is a quick and simple way to measure rim thickness, you just use a micrometer.

Steve · Post by **Steve** » 31 Oct 2007, 10:07pm

Not very helpful! What is a micrometer? Where does one get one? Then what?

andrew_s · Post by **andrew_s** » 1 Nov 2007, 12:51am

a micrometer is useless for measuring rim wall thickness - you can't get it in there.

You can use a vernier caliper if you put something like a spoke (or one for each side) by the rim so the jaws of the caliper are spaced out beyond the rim overhang. You then subtract the spokes from your measurement to get the rin thickness.

The easiest way is to use one of these
I have also been shown similar items on ebay at £5-10, but good luck with coming up with the right search terms.

pete75 · Post by **pete75** » 1 Nov 2007, 7:30am

andrew_s wrote:a micrometer is useless for measuring rim wall thickness - you can't get it in there.

Oh yes you can I've done it. IN fact it'sa vernier caliper which you can't get in very easily that's why I suggested a mike.

Cliff · Post by **Cliff** » 1 Nov 2007, 10:23am

I don't think it will be easy with a vernier - the rim is now concave on the braking surface so would need blocks on both sides. Still, it might be possible.

I guess which will fit in is down to the design - I will just have to check carefully before I order.

I like the special widget and will have a look on Ebay - could take a while!

Thanks for the responses.

pete75 · Post by **pete75** » 1 Nov 2007, 10:34am

Well this would probably be just as useful and it costs a lot less....
http://www.tickintimeworldofwatchtools. ... -949-p.asp

yakdiver · Post by **yakdiver** » 1 Nov 2007, 12:30pm

I don't know where I read it but deflate the tyre measure rim width, then blow up to 120-140 psi them measure again if there is a big increase time to renew rim

Post by Si » 1 Nov 2007, 1:05pm

numbnuts wrote:I don't know where I read it but deflate the tyre measure rim width, then blow up to 120-140 psi them measure again if there is a big increase time to renew rim

What woud you call a big increase?

AndyB · Post by **AndyB** » 1 Nov 2007, 1:40pm

Cliff wrote:I don't think it will be easy with a vernier - the rim is now concave on the braking surface so would need blocks on both sides. Still, it might be possible.

You just need to pad out each side with something of known thickness. Didn't CJ suggest using an old spoke bent to an appropriate shape?

yakdiver · Post by **yakdiver** » 1 Nov 2007, 3:45pm

What would you call a big increase

If the Calipers were a nice sliding fit before and a scratch fit afterwards I think it would be time to fit new rim having a look at it maybe 0.5mm difference

Wildoo · Post by **Wildoo** » 1 Nov 2007, 4:34pm

Hello. We are Wildoo Limited, the UK sales agent for Rigida International.

Rigida Nova has been replaced with the Flyer that definately does have an internal safety line that appears as the rim wears to warn the rider that the rim must be replaced. If I recall correctly the Nova also had safety line inside the rim section.

If the bike is 5 years old and used fairly regularly in all conditions I would suggest that you will be near to needing to replace the rims. It would be advisable to replace them before the safety line appears.

wildoo.co.uk

andrew_s · Post by **andrew_s** » 2 Nov 2007, 1:12am

numbnuts wrote:I don't know where I read it but deflate the tyre measure rim width, then blow up to 120-140 psi them measure again if there is a big increase time to renew rim

I've pressure tested at 160 psi. 120 isn't much above some people's normal riding pressure. It's probably best to leave it pumped up for a fair while too - overnight?
It doesn't half make your ears ring if it fails

Cliff · Post by **Cliff** » 2 Nov 2007, 3:10pm

pete75 wrote:Well this would probably be just as useful and it costs a lot less....
http://www.tickintimeworldofwatchtools. ... -949-p.asp

This looks great.

I am also considering vernier calipers/a micrometer which will fit in the rim - padding out with a spoke seems simple enough and I guess they could be useful for other stuff.

Thanks for all the responses!

Cliff · Post by **Cliff** » 2 Nov 2007, 3:12pm

Wildoo wrote:Hello. We are Wildoo Limited, the UK sales agent for Rigida International.

Rigida Nova has been replaced with the Flyer that definately does have an internal safety line that appears as the rim wears to warn the rider that the rim must be replaced. If I recall correctly the Nova also had safety line inside the rim section.

wildoo.co.uk

Thanks. Is there any way of knowing (from the text on the rim perhaps) if there is an indicator in there?

I agree that they will need changing soon, but I don't enjoy building wheels and inexpensive 650C wheels are difficult to come by!

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Rim wear/ Measuring rim thickness

Rim wear/ Measuring rim thickness

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