Why vinyl rim tape is a bad idea.

[Globalti]

My cycling buddy and I were descending the dangerous steep hill into Settle this afternoon when from behind me I heard a bang, hiss-hiss-hiss and a yell. Looked round and saw my buddy coming gracefully to rest in the hedge, luckily no damage done.

Investigation showed that his thin, flexible latex/butyl inner tube had herniated into the spoke holes in his rim when the rim heated up under braking, softening the cheapo vinyl tape. Eventually one gave way and the tube burst into the nipple hole. Happily there's a bike shop at the foot of the hill so we were able to buy two rolls of good quality Specialized tape. Knowing that @SamR has the same wheels and therefore the same rim tape I bought him two rolls and as soon as I got home we removed his tyres and this is what we found:

The stiffer butyl tubes he uses had herniated to a large extent but not enough to burst. At speed on a steep hill this could be a killer.

The two smaller holes are an exact "cast" of where the rim is joined.

Remember kids; use cloth tape!

 

[youngoldbloke]

My cycling buddy and I were descending the dangerous steep hill into Settle this afternoon when from behind me I heard a bang, hiss-hiss-hiss and a yell. Looked round and saw my buddy coming gracefully to rest in the hedge, luckily no damage done.

Investigation showed that his thin, flexible latex/butyl inner tube had herniated into the spoke holes in his rim when the rim heated up under braking, softening the cheapo vinyl tape. Eventually one gave way and the tube burst into the nipple hole. Happily there's a bike shop at the foot of the hill so we were able to buy two rolls of good quality Specialized tape. Knowing that @SamR has the same wheels and therefore the same rim tape I bought him two rolls and as soon as I got home we removed his tyres and this is what we found:



The stiffer butyl tubes he uses had herniated to a large extent but not enough to burst. At speed on a steep hill this could be a killer.

The two smaller holes are an exact "cast" of where the rim is joined.

Remember kids; use cloth tape!

Good advice! (alhough changed thetyres on my Kysriums today and was surprised - again - to find NO rim tape as the spokes are not accessed from the rim well).

 

[Globalti]

Then I don't think you need rim tape, unless there are sharp edges inside the rim. I ran a couple of layers of electrical tape around my Ksyriums just to protect the tubes.

 

[youngoldbloke]

Then I don't think you need rim tape, unless there are sharp edges inside the rim. I ran a couple of layers of electrical tape around my Ksyriums just to protect the tubes.

I've left them as they were, just used a dusting of talc on the tubes/tyre inners as the tubes were showing signs of adhering to the shiny metal of the rim. No sharp edges.

 

[SamR]

I have to admit, it was very scary to look at the rim tape after we took it off, I didn't think it had melted, rather it was supposed to be like that with the tape going into and therefore covering the holes in the rims.
My tyre could have blown out at any point, who knows where I would have been or how fast I could have been going. Doesn't bear thinking about.

 

[Yellow Saddle]

[QUOTE 3868116, member: 259"]Herniated - new word of the day![/QUOTE]
Yeah, now how shall I work it into a conversation before I forget it?

 

[alecstilleyedye]

thick electrical tape is fine; the stuff from poundland et al is not...

 

[SamR]

Just wanted to contribute again and say the picture doesn't do justice to the size of the domes created by the melting of the rim tape into the nipple holes, they were very big. Easily 8mm

 

[migrantwing]

Not doubting you, but are you certain that the rim tape didn't have those 'bobbles' on it from new? My friend had a rim tape that was like this and the 'bobbles' actually sat in the holes in the rim. I have no idea what the rim tape was as it's been a fair few years now. Probably just some generic/OEM rim tape.

 

[screenman]

Can we see a photo of the other side of the tape, as I also have seen tape that looks like that when new.

 

[slowmotion]

If you are tempted to use fabric rim tape as a substitute...it's a blooming nightmare to work the tyre rim bead round the wheel well when you try and put on a tyre.

 

[Poacher]

Not doubting you, but are you certain that the rim tape didn't have those 'bobbles' on it from new? My friend had a rim tape that was like this and the 'bobbles' actually sat in the holes in the rim. I have no idea what the rim tape was as it's been a fair few years now. Probably just some generic/OEM rim tape.

So you have to buy rim tapes with the same number of bobbles as your wheel has spokes? How about the two smaller hernias to fit where the rim is joined?

 

[Smurfy]

Velox cloth (fabric) tape on all of my rims. It will last the life of the rim if you put it on properly.

 

[screenman]

So you have to buy rim tapes with the same number of bobbles as your wheel has spokes? How about the two smaller hernias to fit where the rim is joined?

I think they come as a pair.

 

[screenman]

Anybody using plugs?