CityCyclingEdinburgh Forum » Questions/Support/Help

mending punctures?

(38 posts)
  • Started 11 years ago by SRD
  • Latest reply from chdot
  • This topic is not resolved

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12

  1. SRD
    Moderator

    Have just spent very frustrating afternoon trying to mend punctures. None of it helped by our unfamiliarity with Presta valves, nor our inability to decipher instructions for pump, nor discovery that 'spare' tube also had puncture (after installing it). But main issue seems to be failure of patches to actually stick. What am I doing wrong? Both my tubes of glue seem very blobby. Is it possible they are dried up? Am I not roughing the surface enough? Argghhh....!

    Edit - should I try the self adhesive patches in the ebc sale?

    (uberuce, if you can explain pump function, I wil buy you a pint at the rule!)

    Posted 11 years ago #

  2. Instography
    Member

    What I do (which generally works) -
    - roughen surface around hole - not much. Not even visibly roughened.
    - spread a thin layer of solution around the hole slightly bigger than the patch
    - wait for rubber solution to become just slightly tacky
    - apply patch and press in place. If it's the type with the foil backing and cellophane covering, I just leave the covering on. It saves me ...
    - dusting the area around the patch with chalk or talc. Something to stop the rubber solution bonding to the tyre
    - inflate and enjoy.

    If you're doing something like that then maybe the solution is 'off' (if that's possible).

    My other alternatives are the little Park clear patches. Never failed me.

    More recently I've taken to just throwing the punctured tubes away. Wasteful but life's too short and I've only had about two or three punctures in the last year. I can live with the cost.

    Posted 11 years ago #

  3. SRD
    Moderator

    'thin layer of solution'. This is the part I struggle with. It goes on in blobs, and with gaps. Impossible to spread to even layer. One tube is ancient; one more recent.

    Posted 11 years ago #

  4. chdot
    Admin

    "wait for rubber solution to become just slightly tacky"

    As I say when I'm showing people how to fix punctures.

    "What do you do next?"

    "Put the the patch on"

    "No"

    "Put chalk on" (yes really)

    "No. - WAIT"

    1/4 hour not too long

    Posted 11 years ago #

  5. DaveC
    Member

    SRD,

    Use the opening of the glue tube to spread the glue round evenly once you have squeezed out a small blob of the stuff.

    Posted 11 years ago #

  6. SRD
    Moderator

    DaveC. - yes, that is exactly what I try to do :(

    Posted 11 years ago #

  7. Instography
    Member

    What's with the pump? I'm guessing for a Presta, it maybe has a key on it so that the head goes over the valve and gets pushed down and then the key gets flicked over to seal the pump onto the valve. Inflate, flick key back and pull head straight off. Job done.

    Posted 11 years ago #

  8. LivM
    Member

    The sticky patches serve me fine, but I generally just use them for fixing punctures when I'm out and about and time limited. If I am fixing at home, then I use the rubber patches the old fashioned way. I find that the glue and patches are so cheap that it would make sense for you to get a new tube, just a small one though, as if you don't use it often then it will go gunky as you have found.

    Posted 11 years ago #

  9. LaidBack
    Member

    Have another 20" tube at shop. In tmrw for tour at 10. Then out till after 2.

    Posted 11 years ago #

  10. SRD
    Moderator

    Thanks LB. Helios' schwalbes holding up. It's the dahon skinnies giving me grief.

    Posted 11 years ago #

  11. cb
    Member

    "'thin layer of solution'. This is the part I struggle with. It goes on in blobs, and with gaps. Impossible to spread to even layer."

    I've never had that problem so it sounds like a dodgy solution problem to me.

    Posted 11 years ago #

  12. wee folding bike
    Member

    I found the ready stick ones don't last and a wee while later they come unstuck.

    Posted 11 years ago #

  13. Arellcat
    Moderator

    SRD, are they still the Conti Grand Prix tyres on your Dahon? Lovely fast things and best at 90-100 psi.

    I keep Park instant patches in my repair kit for emergency use, but have never really liked them. For permanent repairs I use only Tiptop's glue and patches. The glue does dry out if you don't use it for a couple of years, but when fresh it spreads nicely.

    Some sandpaper to roughen the area of the patch, plus a bit more. If you're in the house, scrub that bit of the tube first with citrus degreaser.

    Put the glue on. Shop tip: wrap the tube around the back of your hand, with the thing stretched just a little. Make a fist. This keeps the tube flat and steady for the glue application, and helps make sure there is no air left to creep out of the hole to create bubbles in your glue.

    I think the trick to getting an even layer on the tube is not to press down while squidging it out. I tend to be on the generous side and make sure there's a thick enough layer to stop it going off before I've covered the area. Let the glue go tacky as Insto said, but if you're doing it in the warm and dry, you can leave it for 10-15 minutes. It'll look like it's dried out by then.

    Foil off and stick the patch on. I keep a pair of tweezers in my repair kit so that I don't accidentally touch the underside of the patch. My bike has rim brakes and my fingers will be all covered with aluminium dust just from removing the tyre. It's important to press the patch down onto the tube really hard. Work from the centre outwards. Don't remove the cellophane until you're totally sure the patch has dried. Alternatively, just don't bother removing it.

    In lieu of talcum powder, aluminium dust works pretty well.

    Posted 11 years ago #

  14. gembo
    Member

    Sometimes in the puncture kit there is a little rubber pipe? If glue too localised I have used the pipe to spread over the tube. Not sure if that is what it is for. I leave a minimum of five minutes to get the tackiness. The outside temp is also a big factor. At this time of year all works better inside the house and keeping the glue and tube in a warm room before you start the procedure. Curiously for a thing I have done many many times like clockwork it can still be fraught with errors etc.

    Posted 11 years ago #

  15. Arellcat
    Moderator

    Gembo, the rubber tube is for the older types of Woods valves that didn't have a spring-loaded inner core. Presta was designed for high pressure; Woods (aka Dunlop or Bicycle) was low pressure, and was more or less superceded by the Shraeder valve.

    Posted 11 years ago #

  16. chdot
    Admin

    "Not sure if that is what it is for"

    Nope.

    It's for old style Woods valves where a rubber tube covers a hole and becomes the valve.

    Posted 11 years ago #

  17. chdot
    Admin

    Explain twice.

    People might begin to believe...

    Posted 11 years ago #

  18. chdot
    Admin

    https://www.google.co.uk/search?q=woods+valve&hl=en&tbo=u&tbm=isch&source=univ

    Posted 11 years ago #

  19. gembo
    Member

    I always wondered about that. Presumably the repair kits manufactured in countries where Dunlop / woods tubes still about? Dunlop brand has been re activated not by original rubber company but using the D logo which I like

    Posted 11 years ago #

  20. chdot
    Admin

    Posted 11 years ago #

  21. remberbuck
    Member

    A couple of points? Are you sure that your replacement was punctured before you put it in? The original cause may still be there, and it might not be the obvious piece of still penetrating glass. I once went through three inners before discovering that there was a tiny tear on the tyre just under the rim, which was only obvious when I changed position for inflating and saw the inner ballooning.

    And for Prestas, persevere, they are OK once you get used to them, and are the acceptable price for cooler
    rims. Do you make sure that there is play in the valve before trying to inflate? The obvious move is to unscrew as far as you can, but this can jam, meaning that the pump just blows back on itself. The nippple also has an unfortunate habit of snapping, particularly if you are not dead straight on when inflating. Some makes - Contis come to mind - have unscrewable valves meaning that you don't have to throw away an unpunctured inner, just replace the valve from another.

    Finally, I keep the rim ring loose until the tyre is fully up - it allows play with the tyre and rim, meaning that fit is OK. Someone said they didn't see the point of the ring, and just left them off, but after a pinch puncture on the valve, I prefer securing the tyre below the rim.

    Posted 11 years ago #

  22. SRD
    Moderator

    @remberbuck thanks for the tips. we found a youtube video about prestas which covered some of that, but your descrip/advice very helpful. now I'm worried though, I ordered a spare tube which says explicitly it fits the exact tyre, but with schraeder valve. will it not fit in rim? sigh.... (bet it won't fit any of the other 20" wheels we have either...).

    And thanks for the tips re checking for puncture causes. Good points. Part of my problem was that I wasn't sure if the reason the rube woul;dn't inflate was because of the pump, the valves, or punctures!

    @arellcat yes. same tyres. fun to ride on :) but why is one tube 18" and one 20"?

    Posted 11 years ago #

  23. LaidBack
    Member

    Schraeder valves need bigger hole. Bike works could drill out for you.
    ICE trikes use these so I'll swap if you like. Dahon though will need quite narrow inner.

    I second the TipTop brand - can buy extra patches from shop.

    Locate puncture but always find out why. Mark the tube by ringing the hole in biro. Some holes are invisible once tyre is down. Then feel inside the tyre to see if anything is a bump on inside. These often contain a shard that becomes pointy under pressure!

    Five mins of glue drying and a decent patch centred within your biro pen mark. Roughen tube there before glueing....

    All been covered but happy to look at if you want.

    Posted 11 years ago #

  24. remberbuck
    Member

    LB,

    I'd never, ever attempt to drill a rim to take a Schraeder. There is a point to narrow rims having small outlets that can only take Prestas, and that is structural integrity and strength.

    As said, the trade off for cooler rims.

    Posted 11 years ago #

  25. Arellcat
    Moderator

    why is one tube 18" and one 20"?

    Good question! I think it was more an error in my selection than something being out of stock, but hey, they both work.

    Posted 11 years ago #

  26. LaidBack
    Member

    remberbuck...

    I've never done it myself and would imagine Bike Works only does if rim is suitable. So I agree - get a second opinion. TBW are fairly cautious as they see many rims thinned with brake use.

    Bikes I sell are mainly using tyres in 37mmm width and above. Rims therefore are fairly chunky.

    Posted 11 years ago #

  27. deckard112
    Member

    Appreciate this post is specifically for repair advice but I'm curious to know if the posters here would always attempt to repair rather than replace?

    Given the relative cheapness of innertubes vs saving ones sanity/health/marriage(!)I must concede I never repair tubes these days and always carry a spare or two when out and about.

    Posted 11 years ago #

  28. Baldcyclist
    Member

    @deckard112 I haven't patched a tube since I was 14. They are cheap, and I don't puncture that often (4 times last year I think, 5 maybe), so why do it.

    Another Presta tip... Once tyre is inflated, screw the valve almost tight, and then un-screw one half turn. Once they have been pumped up a few times and the pin bit gets bent a little bit, they can lose air when fully tightened. Not the first time I have gone out to a flat tyre with no apparent explanation.

    Posted 11 years ago #

  29. Wilmington's Cow
    Member

    I'm in the 'always patch' camp. Only takes a few extra minutes and to be honest I quite like the feeling of 'mend and make do' - each one is a bit of a nostalgia trip to being taught by my dad (after using two gert big dessert spoons to lever off the tyre) how to repair a puncture.

    Though I will admit that nostalgia-kick is less keenly felt when it's dark, windy, 3 degrees below and hailing.

    I probably replace bar tape more often than tubes!

    Posted 11 years ago #

  30. steveo
    Member

    I'll patch a few times then replace, though on the road side I replace and patch later.

    Posted 11 years ago #

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