Rim tape failing

[J1888]

Please explain stress corrosion in plastic or cloth tape.

Edited by moderator

 

[NickNick]

Will try and pick up some velox tape then on my way back to Brum and hopefully it will do the trick. If not then replacing this crap wheel will move to top of priority list!

 

[Ajax Bay]

better still, a couple layers of electricians tape pulled taught leaving a hole for the valve.

‘electricians tape’ is so far from ‘ideal’, as to be useless as rim tape.

Agreed. Not recommended. I've gone away from the plastic rim tape and prefer the Schwalbe fabric tape, which my LBS will sell me off their 50m roll. The Velox tape looks like it's fabric too. I find that plastic tape invariably slips up to one side or the other round part of the rim, in extremis exposing the edge of a spoke hole.

Thicker, and less susceptible to stress corrosion.

How do you find out whether one (plastic) rim tape is thicker than another? Whilst 'modern' plastic rim tape may be less susceptible to 'stress corrosion' is this actually an issue - ie does rim tape fail like this? As far as stress corrosion is concerned, what are the symptoms of a plastic rim tape which has suffered 'stress corrosion' (breakage at the valve hole point)? Plastic rim tape does get brittle after a while so is this stress cracking?

 

[Milkfloat]

I am another gorilla tape user. I use it on everything including tubeless.

 

[Racing roadkill]

Agreed. Not recommended. I've gone away from the plastic rim tape and prefer the Schwalbe fabric tape, which my LBS will sell me off their 50m roll. The Velox tape looks like it's fabric too. I find that plastic tape invariably slips up to one side or the other round part of the rim, in extremis exposing the edge of a spoke hole.

How do you find out whether one (plastic) rim tape is thicker than another? Whilst 'modern' plastic rim tape may be less susceptible to 'stress corrosion' is this actually an issue - ie does rim tape fail like this? As far as stress corrosion is concerned, what are the symptoms of a plastic rim tape which has suffered 'stress corrosion' (breakage at the valve hole point)? Plastic rim tape does get brittle after a while so is this stress cracking?

The scientific technique, to test susceptibility to stress corrosion, involves clamping a strip of the material under test, of defined dimensions, in a particular way. It’s then stretched until it breaks, and graphs of load vs time, are collected, for 4 different rates of application of load. We then analyse these graphs, and use a statistical regression algorithm, to plot probability of failure, against strain. This gives us a figure called stress corrosion coefficient, ( nd). To cut a long story short, the higher the ‘nd’ value, the more grief you can give the material before it fails to fulfil the purpose for which it was designed. In layman’s terms, how much handling / grief you can give a material, is proportional to the nd. Generally speaking, more elastic ( softer / more supple ) materials, have better handling characteristics, than harder less elastic materials, but the softer materials tend to have a lower ultimate failure strain figure. Stuff like ‘Velox’ tends to be able to take more repeated hits, but if they take a severe hit, the probability of a sudden failure is greater, harder stuff ( like electrical tape ) can take less hits, but the hits can be harder without a failure. When you’re dealing with a bicycle wheel, in it’s typical environment, you want the former.

 

[Blue Hills]

Did someone say Velox is the only true tape? Ha! Like hell. It rots inside wet wheels. Shimano blue is the only true rim tape.

I've never found water or even moisture inside my wheels.

Are you a bog snorkeller?

 

[Blue Hills]

Will try and pick up some velox tape then on my way back to Brum and hopefully it will do the trick. If not then replacing this crap wheel will move to top of priority list!

https://www.planetx.co.uk/i/q/WSVXRT2M/velox-rim-tape-2m-roll

postage to pay though you may be able to offset that with some other purchases.