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Goddam punctures!!!!

Iain CIain C Posts: 464
edited March 2008 in MTB beginners
Back into mountain biking after a very long absence and I've just bought a Trek Fuel Ex-7 and I love it to bits. However two things are ruining my riding and that's punctures and mud (see other post...)

Punctures first...I'm getting almost one a ride at the moment! First I broke a valve stem off whilst airing up after fixing a puncture...oops, probably my fault. Then I've had two more punctures (probably thorns) and I was advised if I run them really hard (about 60psi) I'll get on better, as I only had a little Canondale mini pump thing. So I went off to one of those Cycle Promotions Sunday sale things (quite good actually) and came back with Slime protectors (the belt things that fit between tube and tyre) and a Blackburn track pump.

All blown up to 60 PSI and guess what, another puncture, this time in the front! I took it apart on the bridleway and to be honest it looks more like the tube had started to split along it's length slightly rather than it being a puncture...I could not see any tyre damage.

So my questions are...

1-What pressures should I run? Bontrager Jones tyres on Bontrager Race Disc wheels and I am reasonably lardy at 14.5 stone and the bikes a full susser. If I have to blow a tyre up in the field with my mini pump is there a good rule of thumb for pressures if I don't want to carry a gauge around with me?

2-Why did it split today? Too much pressure? The words "Cheng Shin" on the tube? Slime protectors? An ancient curse?

3-If I have to replace a tube "in the field" I'll obviously try and keep it as clean as poss but it's tricky. When I get home and can clean it should I be taking it all apart and religously removing every last dust particle from inside the tyre?

Thanks in advance!


  • Random VinceRandom Vince Posts: 11,374
    when you check then you should check that there are no thorns or anything sticking through the tyre or tyre wall.

    best way of checking how much pressure there is would be to squeeze the tyre, when its hard to get it to distort would be about when it's ready to ride.

    not sure what mine are at the moment, probably about 60
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  • S_J_PS_J_P Posts: 908
    From my (albeit limited experience...)

    Go for more robust tyres. I've had a lot of puncture-free success with Panaracer Cinders, and a brief dabble with Maxxis Minion tyres.

    Buy decent tubes from a well known brand. Even consider Downhill tubes. So long as you make sure there's no chunks of dirt in the tyre, and you've removed all the thorns before replacing the tube (run your fingers around the inside of the tyre to check there wasn't a second puncture-inducing thorn) you should be okay. Just fix the punctured tube at home, and stick it back in your bag for next time.

    Don't bother with slime-strips, they're heavy and tend to move out of the way. I also dispute that they work too.

    Run around 45psi. This should be hard enough to bounce off some puncture producing materials, but not too hard. In the wet, reduce this a bit (35psi minimum)

    Buy yourself a CO2 inflater (around £15) it's a hell of a lot easier than a mini-pump!

    Alternatively rather than faff around with all the above, increasing weight of the bike and forcing you to carry spare tubes, levers, patch-kits, pump, CO2 cartridges etc, Go tubeless :D
  • nferrarnferrar Posts: 2,511
    I run Trailraker PR's with 40-45psi, not had a puncture yet (15st to)... Ofc you can just be unlucky whatever combination of tyre/tube/psi you run. 60psi is to hard for off-road stuff IMO but fine for bridleways, some tyres might not be rated that high though (although I'd have thought tubes would be fine).

    As for pumping them up with a gauge out on the trail, just squeeze them a few times at the psi you want to run them and rely on your memory when it comes to it :p
  • KonaMikeKonaMike Posts: 805
    Punctures are a nightmare!!

    I have Continental Gravity tyres on my Fury and despite running 40+ PSI im getting regular punctures,I was thinking about just filling the tubes with sealant .I might try Cinders as im not impressed by the winter performace of the Conti's anyway.
  • S_J_PS_J_P Posts: 908
    Pana Cinders aren't great in the mud, they clag up pretty easily. They're great in damp to dry conditions though.
  • i have slime tubes and have not had one puncture yet, if i have i do not notice it.

    my girlfriend had slim tubes too, we went out on about a four hour ride, the next day i stripped the bikles down too clean and stuff, and i found she had a thorn go into her tube, the sealent had obviously clogged it up therefore preventing her tyre going down on the trail.

    i think its luck, sometimes they work other times they dont.

    60 PSI is to much though. Drop to 40.
  • KonaMikeKonaMike Posts: 805
    Thats it then ! Im gonna give slime a try :)
  • S_J_PS_J_P Posts: 908
    If you're determined to go the non-tubeless route, then tubeless sealant in an innertube is an inexpensive and relatively lightweight (compared to slime-strips) method of puncture-proofing your tyres.

    You can purchase Wheelmilk or similar for around £8 a bottle, and that should do you for around eight wheels, or a couple of years with one pair of wheels.
  • PrintsPrints Posts: 86
    have you ever found an intruding object? eg. thorn

    if not then remove your rim tape and use some electricians tape underneath wrap a layer round the rim and then replace the rim tape

    with machine built wheels sometimes metal shavings from the milling of the spoke hole can be stuck inside the rim and they are very sharp. This just helps to seal them in and prevent them from popping the tube from the inside.
  • GhallTN6GhallTN6 Posts: 505
    I've been running Maxxis High rollers, both 2.10 and 2.35 for about 6 months now and only ever had 1 puncture, this included a ride with 5 others who suffered a total of 13 punctures after going up a bridleway that had just had a thorny hedge cut (don't even try to work out the maths!).

    However, I've always thought that I was running at about 35-40 psi, but after trying my new track pump yesterday it turns out I've been running at about 30, how much this has affecting my performance I'm not sure, but I've pumped them to 40 now.

    For just over 20 quid from chainreactioncycles, the joeblow track pump looks like its worth every penny.
  • Neily03Neily03 Posts: 295
    I run 25F and 35R in my Bonty Mud X 2.0s ( i weigh 12 stone) and have never had a puncture with them. 8)
  • GhallTN6GhallTN6 Posts: 505
    pumped my Maxxis high rollers to 40psi for yesterday's ride, 2 out of the four of us got punctures, which didn't incluede me.

    The 40 psi made a great difference, much quicker, and I feel i use the rear sus better as well to compensate, the bike felt a lot ligher and more agile as well.
  • Iain CIain C Posts: 464
    OK thanks for the tips all!

    I cleaned the inside of the tyres out, swapped the Cheng Shin rubbish for NuTraks, made sure the slime strips were loctated spot on and went to 40psi on the track pump. Good ride on Saturday, lots of VERY hedgy/thorny areas...and...

  • omegasomegas Posts: 970
    I have been using slime strips for over a year on 2 bikes and no punctures.

    Check the ends of the strips for no sharp edges ( I feathered the edges down with sand paper) as some people have had punctures were they have cut in to the tube.
  • Mark_KMark_K Posts: 666
    Iain if your on a ex7 are your rims/tyres not tubless compatiable if they are thats the best way to go!
    I was sceptical about going tubless on my ex9 but so glad i did, no more puntures (running bonty tyre juice) and totally transforms the feel from the tyres ???
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