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Re: Tubular Repair

Posted: Tue Aug 15, 2017 1:33 pm
by urbanspaceman
Thanks sungod - very grateful.


Was looking for some advice as I noticed that a chunk had been taken out of one of my tubs (see below).

I've absolutely no idea how it happened, and have now replaced it, but I'm curious as to how it happened so it hopefully never happens again.

Does anyone have any thoughts at all?

Image

Re: Tubular Repair

Posted: Tue Aug 15, 2017 1:33 pm
by Weenie

Re: Tubular Repair

Posted: Tue Aug 15, 2017 4:53 pm
by sungod
i've had that a couple of times with a momentary lock-up of the wheel, both times it happened when braking hard and then hitting a patch of grit/dirt on the road

Re: Tubular Repair

Posted: Tue Aug 15, 2017 9:14 pm
by urbanspaceman
Brilliant thanks mate

Re: Tubular Repair

Posted: Thu Aug 17, 2017 10:49 am
by Sleepless
In last 2 days, my rear Veloflex Roubaix tire lose air after hard descends. I thought it was a puncture on the first time and used Vittoria Pitstop but it went flat in like 20 minutes again. Luckily I've arrived home at that time. I tightened valve extender and shook the tire a bit and it was back to normal. Today it happened again. There seems to be no puncture as there's no sealant leak visible. Any ideas?

Re: Tubular Repair

Posted: Thu Aug 17, 2017 11:17 am
by sungod
i never found pitstop any use as all

have you tried putting a bit of ptfe tape on the threads of the extender?

now that you have sealant in the tube, you need to work very fast once it is deflated as otherwise the tube may stick to itself and then tear apart when re-inflated

Re: Tubular Repair

Posted: Thu Aug 17, 2017 12:01 pm
by dj97223
I've had good experience with PitStop but, like other sealants, it won't fix everything. And I haven't had the dreaded tube sticking to itself. You could try a little orange seal, but first try to locate the source of the leak (inflate and dip in a shallow tub of water) to see whether the problem is the tire or the valve.

Re: Tubular Repair

Posted: Thu Aug 17, 2017 12:53 pm
by 1415chris
Very tiny puncture, when the air is leaking slowly from the tub, may not give you obvious sings.
I had one in Veloflex Carbon. Even with the sealant it re-opened itself on one or two occasions after the period when the tubs were not in use.
If you use valve extenders with removable core (if not, strongly recommend start using) you have more chance with normal sealant like No-tubes, Orange (have a good experience with both) than with the Pitstop (applied twice, failed twice). In the era of Co2 pumps there is no advantage of having sealant in pressurized canister, especially if its effectiveness is very questionable.

Re: Tubular Repair

Posted: Fri Aug 18, 2017 5:33 pm
by Sleepless
Thank you guys. I was on holiday so couldn't do more than just pumping. I'm back home now. I'll investigate and report back.

Re: Tubular Repair

Posted: Fri Aug 18, 2017 5:54 pm
by sungod
btw another thing i've seen... when sealant gets in a presta valve, it can actually clog it so that it does not close fully unless manually tightened

Re: Tubular Repair

Posted: Fri Aug 18, 2017 10:43 pm
by dj97223
Yes, Orange Seal can do a number on the valves and cores, and I suspect other sealants can cause the same problem. I think the clogging can be largely avoided by storing the wheels with the valves sitting at 4:00 or 8:00.

Re: Tubular Repair

Posted: Sun Aug 27, 2017 5:23 pm
by Sleepless
Yep, it's the valve. I removed and cleaned it. So far so good.

Re: Tubular Repair

Posted: Sun Nov 19, 2017 3:28 am
by sabba
man just when i though i have tubeless tires maintenance under control you learn something new.

i have this happen to me recently too. thanks

Re: Tubular Repair

Posted: Sat Nov 25, 2017 7:58 pm
by MikeMoore
Just bought a pair of cross tubs that had been stored flat with sealant in. Of course one blew up when I tried to inflate it. As they only cost me £20 I thought it was a good opportunity to try and repair it by replacing the tube (http://www.sheldonbrown.com/brandt/tubular-repair.html).

A massive ball ache, but I managed it! Lots and lots of talcum powder seems to be the key :)

Re: Tubular Repair

Posted: Mon Jan 15, 2018 8:23 pm
by bcmf
Anyone ever have a valve stem come clean out of a tube?
Have a Conti comp with loads of thread left and very few nicks in it and the valve starting turning when trying to inflate it and the whole valve stem/neck came clean out of the tube.
Be a real shame to bin it!

Re: Tubular Repair

Posted: Mon Jan 15, 2018 8:23 pm
by Weenie

Re: Tubular Repair

Posted: Tue Jan 16, 2018 10:40 am
by sungod
you could fit a new inner tube, it's a bit fiddly but might be worthwhile if the tub is otherwise ok

of course you can use a latex tube too :)