Punctures on the inside of the wheel?!?

[ElephantsGerald]

Well I had my first and second punctures on my Wisper 905SE yesterday.

Luckily the 1st one happened about 0.5 miles into my commute, so I was able to walk home and take the car to work.

I was riding along when I noticed a strange clicking coming from the rear wheel on each revolution. Just as I slowed down to investigate the tyre blew.

Yesterday evening, I eyeballed the tyre and couldn't see any signs of damage. I took the tyre off the rim, felt all around the inside of the tyre, and still couldn't find any damage.

I took the inner tube out and found that the puncture was actually on the inner side of the tube (i.e. the spoke side).

I then looked and felt all around the inside of the rim and still couldn't find any reason for the puncture.

I gave all the spokes a tug, and they all seemed reasonably tight, certainly no broken spokes.

Mystified, and hoping for the best, I put in a new (Continental) inner tube, put everything back together, and pumped it up to 55 PSI. Because the light was failing I didn't ride the bike, I just put it back in the shed.

This morning, I opened up the shed and realised that the rear tyre was completely flat again, so the new tube has obviously blown too!

So, here are my questions for the forum:

• How on earth have these punctures happened?
• What can I do to repair them?

Any suggestions gratefully received.

Regards,

Elephants

 

[flecc]

Normally these are caused by a protuding long spoke piercing the rim tape, so the best bet would be to rmove the rim tape and inspect all the nipple heads for a protuding spoke or other metal piece sticking up. At the same time inspect the rim tape for any metal particle or stone etc sticking to it.

Together with a thorough rim inspection that should eliminate the possibilities. This sort of puncture was common many years ago when it was normal to build with long spokes and grind off the ends at the nipples, but they are rare now.
.

 

[Mussels]

I've had plenty of these on my Wisper and mostly in the back wheel. It's not the spoke ends as the rim has a large recess the spoke nipples are in so they are nowhere near the tyre. It is a bit like this one:

There is rim tape around the larger holes that the nipples are inserted through and this rim tape is all that stops the inner tube bulging through the holes. I am getting a load of punctures that line up with the holes and I used to think broken spokes were causing all the punctures but now I think the weak rim tape may have a lot to do with it. I changed the rim tape a couple of weeks ago but haven't really had a chance to test it as the bike has been in the repair shop. I replaced it with cheap Halfords stuff that seemed to be far stronger than the original.
As well as the rim tape the holes haven't been deburred particularly well and whilst not sharp to the touch there are raised edges which could cause a problem when high pressure air pushes the inner and rim tape onto it, though I'm not a cyclist and this could be perfectally normal in wheel rims.
Something else I noticed was that after repairing the punctures the repair would fail in the centre of the hole and I can only imagine it is because the repair patch is being asked to hold back more pressure than it is designed to, but the Halfords repair patches may not be the greatest either. I had a puncture after I changed the rim tape but that was just before it went back to the shop so I haven't had a chance to find the cause yet.
It's a bit of a rambling answer as I'm not sure myself but if anyone knows a common reason for this I'm all ears.

 

[flecc]

I didn't know Wisper used these rims, but Mussels is right about the rim tapes on this type, some barely strong enough to withstand the pressure, so a rough hole edge could well be the problem. You should be able to find a stronger rim tape in a local cycle shop, where they often stock fairly stiff ones.
.

 

[ElephantsGerald]

Thanks flecc and Mussels,

Very interesting info. I'll check out the holes and the rim tape tonight. I wonder why this should suddenly have become a problem after 800+ miles though...

Regards,

Elephants

 

[Mussels]

Thanks flecc and Mussels,

Very interesting info. I'll check out the holes and the rim tape tonight. I wonder why this should suddenly have become a problem after 800+ miles though...

Regards,

Elephants

I don't think I've quite managed that distance yet so think yourself lucky.

 

[Danny-K]

I didn't know Wisper used these rims, but Mussels is right about the rim tapes on this type, some barely strong enough to withstand the pressure, so a rough hole edge could well be the problem. You should be able to find a stronger rim tape in a local cycle shop, where they often stock fairly stiff ones.
.

For some years now all I've been offered by bike shops is the plastic rim tape. Being somewhat of a traditionalist, I much preferred the old fashioned 'fabric' type rim tape. However the proof is in the pudding - I have never suffered a puncture due to a protruding spoke using these tough plastic rim tapes, (then again I don't tolerate excessively protruding spokes or sharp hole edges either).

Also, when touring in France a few years back, I suffered a puncture in which after repair and before refitting, I ran my fingers round the inside of the tyre to check if the offending intrusion or whatever was still present. (I'd failed to see any object by sight alone), and promptly felt a mild frisson of pain in one of my fingers. It was as if a surgeon's scalpel had sliced through my finger - the blood - well, I almost feinted! I had great difficulty stemming the flow. It was like a river. Nowadays, I try to to run a paper tissue round first and see if it tears or snags. But that doesn't always work, so I still run my my fingers round it s-l-o-w-l-y with extreme lightness of touch.

Oh the 'scalpel'? Nothing but a common thorn!

 

[flecc]

That was nasty Danny, thorns can do a remarkable amount of damage. I agree on the plastic rim tapes, but some new bikes still come with very thin soft rubber tapes, and they can barely hold the pressure from the tube when used on recessed rims. I swapped these soft rubber ones out from my two eZee bikes when I converted them.
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[Blew it]

Nutrok

A couple of years ago, I went to a local bike shop wanting a new rim tape. What I had in mind was those rubber things that just stretched around the rim. He ask me what type of rims I had, when I told him double wall, he said "no, you need this type".

What he sold me was a tape called "NUTROK". It's a very stiff woven fabric which is adhesive on one side. At the start of the roll is a hole for the valve, and once that is correctly positioned you simply stick it into position around the rim. Cut it to length allowing a small overlap and smooth the end down.

I find that when repairing a puncture, it stays put when teasing the tube out. All to many times I have found the old rubber type would slide sideways and get caught under the tyre bead, preventing it from popping out evenly when re-inflating.

Regards.

Bob

 

[ElephantsGerald]

I got some Zéfal self-adhesive reinforced woven cotton rim tape from my local bike shop yesterday.

I'll have another go at fixing up the bike this weekend and report back.

In the meantime I'm rather frustrated about being trapped in the car again...

Regards,

Elephants

 

[ElephantsGerald]

Well I spent a fair bit of the weekend with my bike in bits. Heres the outcome:

The rim tape wasn't the problem, although the fitted rim tape is pretty flimsy, and it broke as a result of my attentions.

I applied the Zéfal adhesive cotton tape, which is much sturdier, and actually stays where its meant to be.

I eventually found the real source of the problem, which was some damage to the tyre wall, just where the tyre disappears into the metal rim, so its a new tyre for me (I guess I'll follow the crowd and get some Marathon Plus's).

I'm pretty sure the damage was caused/exacerbated by the v-brakes rubbing against the tyre wall (thanks to some shoddy brake adjustment on my part ); something to bear in mind in future.

I'm guessing this doesn't shed any further light on your wheel problems Mussels?!?

Regards,

Elephants

 

[JohnofCambridge]

Interesting Elephants. This has been quite an educational thread for me at least

I worry not so much about my Wisper rear v - brakes ( which are difficult to adjust without taking the rack partly off and even after adjustment somewhat soggy in operation) ; I worry more about the dynamo which is set what seems a long way away from the tyre sidewall, compared to previous bikes I have owned.. The spring of the dynamo is pretty hefty too! A clear and narrow line has appeared on the tyre wall as a result of some late night rides.

I am thinking of giving the dynamo up and resorting to independent battery power.

I guess if we all knew how many problems tyres could give we would think twice about riding. Thank goodness I have done well over a 1000 wisper miles without a puncture so far!

 

[john]

I eventually found the real source of the problem, which was some damage to the tyre wall, just where the tyre disappears into the metal rim, so its a new tyre for me (I guess I'll follow the crowd and get some Marathon Plus's).

I'm pretty sure the damage was caused/exacerbated by the v-brakes rubbing against the tyre wall (thanks to some shoddy brake adjustment on my part ); something to bear in mind in future.

Yes, V brakes can easily catch on the tyre and quickly damage it, particularly a problem if the rim is not quite true. Spin the wheel all the way around to make sure that it can't touch the tyre at any point.

 

[Mussels]

I'm pretty sure the damage was caused/exacerbated by the v-brakes rubbing against the tyre wall (thanks to some shoddy brake adjustment on my part ); something to bear in mind in future.

I'm guessing this doesn't shed any further light on your wheel problems Mussels?!?

Hopefully I'll get my bike back sometime soon and I'll be able to find out what the issue is.
I know it's not the same problem as I had to replace the rear tyre after the sidewall parted company with the beading and the punctures carried on, but the wheel I'm getting back is rather different to the original one so hopefully the problems will stop.

 

[Mussels]

Hopefully I'll get my bike back sometime soon and I'll be able to find out what the issue is.
I know it's not the same problem as I had to replace the rear tyre after the sidewall parted company with the beading and the punctures carried on, but the wheel I'm getting back is rather different to the original one so hopefully the problems will stop.

A few hundred miles on and no more internal punctures. A few external ones though.
I don't know for sure what caused them as I've had a new rim as well but my guess is still the weak rim tape.

 

[Phil the drill]

Inner wall punctures (another victim)

Having done about 1500 mls on my original (Kenda) Wisper tyres and inner tubes, on some pretty rough lanes with no punctures to date, I confess to feeling a little smug.....Until today. 1.5 miles along the first 3.5 miles of up hill lane and a sudden bang, hiss, and I'm on the rim (back wheel) . Had to push the bike nearly 1/2 mile to a place I could safely tackle the puncture. Turned out to be on the inner aspect of the tube. No visible damage to the tyre casing anywhere. Anyhow, puncture fixed, and another 1.5 miles on - you guessed it - bang, hiss, clunk clunk etc. - on the rim again (back wheel again). Couldn't believe it!! Another puncture, also on the inner aspect of the tube, different place from the last one and no visible cause either internally or externally! After breaking the zip on my panniers removing the puncture repair kit (again) and now getting very late, I fixed the puncture and rode the rest of the way home expecting it to happen again, which fortunately it didn't , whilst trying not to leave all my precious belongings scattered all over the route home like some giant paperchase .
I've no idea why they happened (may 'cos it's Friday and I was in a hurry?).
Is this a bicycle version of what my brother calls the 'critical emotion detector' fitted to all computers (the one that detects the urgency of the job in hand and tailors the severirty and timing of the ensuing crash to achieve maximum inconvenience) ?
Who knows, but I reckon its new rim tapes, tubes and Continental puncture resistant tyres on the shopping shortlist for now...

Cheers, Phil.

 

[Mussels]

Who knows, but I reckon its new rim tapes, tubes and Continental puncture resistant tyres on the shopping shortlist for now...

I have a Continental pucture resistant tyre on the back (TravelConti), it's been on there about 2 weeks. I've had 2 or 3 punctures in it and something has cut through the tread and fabric, now looking for the reciept to take it back under the guarantee.

 

[Phil the drill]

I have a Continental pucture resistant tyre on the back (TravelConti), it's been on there about 2 weeks. I've had 2 or 3 punctures in it and something has cut through the tread and fabric, now looking for the reciept to take it back under the guarantee.

Oh dear!

Maybe I'll just do the tubes and rim tapes for now......

Phil

 

[ElephantsGerald]

I'd suggest theres an obvious reason why you got 2 punctures one after the other, you just haven't spotted what it is yet.

When my tyre blew out, I initially couldn't find the cause because the problem wasn't where I expected it to be, so I wasn't looking in the right place. In my case the problem was that the tyre wall had frayed right where it diappears into the rim, which wasn't at all what I was expecting.

Before getting new tyres I'd try taking the tyre right off and feeling all around all of it.

For the record, I went for the thoroughly recommended Marathon Plus's, and I'm very happy with them. I replaced both tyres, so now I have a spare Kenda in case of emergency.

No harm replacing the rim tape, the rubbery thing thats fitted as standard is a bit flimsy and moves around a lot when mucking around with the inner tube. At least with sticky backed fabric rim tape you know its going to stay where its supposed to be.

Regards,

Elephants

 

[Mussels]

In my case the problem was that the tyre wall had frayed right where it diappears into the rim, which wasn't at all what I was expecting.

I had the same problem from a Kenda after a week, the sidewall had seperated from the bead. A boot worked as a temporary fix but the tyre was knackered.
This was a blowout and very different to the internal punctures, poor rim tape seems to be a fairly well documented cause of punctures. The difference is apparent though as the holes appear in different places.