I keep reading horror stories about punctures too big to seal/too big for anchovies or dynaplugs, or of smaller punctures that only seal once you've sprayed sealant all over the back of your frame etc.
Just wondering what causes these punctures?
e.g. if I don't suffer many glass or thorn punctures at the moment (with tubes) I guess I won't suffer any more or less with tubeless, or is there a percentage of glass and thorn cuts which penetrate the tyre but not the tube?
How often do people pinch flat their actual tyre? I did it at least once with a lightweight ghetto MTB setup (Maxxis ADvantages), one hole on each side of the tyre, Stan's fluid spraying out.
What about slashes? I keep reading people saying they've slashed their tyre. I've got lots of 'cuts' in the tread on my road tyres etc. but it's never gone through the casing. I had one small slash on an MTB tyre which didn't cause a puncture but did cause a bulge of innertube to poke out. I caused this pinballing down a rooty section of trail though, not something I'd be doing on my gravel bike. Are the people suffering slashes on their gravel bikes just pushing themselves on rougher terrain etc?
Just curious, I'm mess/faff-o-phobic and swore off tubeless after one too many failures on the MTB, but I could see it being just the thing on the gravel bike for keeping power down over lumpy tracks.
I lifted my bike over a fence and immediately dropped it onto an old metal post that was still sticking out of the ground. 3” slash, job jobbed
I landed a 28mm rear tyre onto a nice square-edged concrete drainage hole, managed to ride home, but the rim was bent and it's been impossible to seal properly since.
Something for the Covid19 lockdown is replacing the rim.
Another rear tyre went too floppy to stay sealed for much more than a day or two.
Other than that, everything has resealed by the side of the road with a bit of patience. I think keeping the sealant topped up helps.
I've pinch flatted twice since December, the cuts were too big to seal. I have Tannus Armour in the rear wheel to protect it now. I suppose it depends on where you cycle, what tyres you're running and which sealant you're using...
Granted this wasn't on my gravel bike, but...
Tubeless makes more of a difference to gravel style riding than any other discipline IMO, at least if you like to take the bike on mixed terrain.
Relatively small volume tyre will puncture a lot on a cross bike over the bumps.
You've got to be riding pretty hard to pinch flat a MTB tyre tubeless - that is a big impact, but it's quite doable on a cross bike. Even riding down a set of stairs will have you on the rim.
I'd be going tubeless just to try and drop pressure a bit more, e.g. am experimenting with 50psi in tubes at the moment (87kg without riding gear etc) and haven't rimmed either wheel yet. Would like to get a bit lower than that though as I was skipping about a lot on a fairly average estate track.
k1100t, what did it take to pinch your tyre? Just getting a bit clumsy on a landrover track, or something a bit more extreme?
I'm personally not fussed about getting gnar down steps and over roots etc. just want to smooth progress on tracks a bit.
what did it take to pinch your tyre? Just getting a bit clumsy on a landrover track, or something a bit more extreme?
@13thfloormonk the first one was failing to bunny hop a pothole as I wasn't paying attention, the rear just clipped the edge. The second was on a submerged pothole, after swerving into a puddle to avoid being mown down by a pick-up truck on a clarty single lane back road. Was running 700c x 40mm tyres on 24mm internal width rims at 40psi on both occasions.
What tyres?, I'd be running 38s on 20.5mm internal, so probably less puncture proof than your setup, but your punctures sound like slightly extreme examples.
40psi feels low to me, I ran that racing CX (on 33c Limus with tubes) and it was fine on muddy race courses but not sure I'd fancy cornering hard on tarmac or hard surfaces. What do you weigh?
Have bit the bullet and ordered some Terrenos, think they're a good medium ground in terms of weight but will still save me a minimum of 85g per wheel even if I run tubes, more if I go with latex tubes or bite the bullet and go tubeless.
@13thfloormonk I'm running Conti Terra Trail and I weight ~70kg. I found anything over 45psi to be too hard, so the front is currently tubeless at 40psi, the back has Tannus Armour and a tube at 45psi. I got though a 208km multi-surface ride with full bike packing kit at the weekend with no issues, and I was running over all sorts of shite.
In the two weeks previous to this a ride, when running tubes, I'd had seven front wheel punctures both on and off road...
Ah OK, so even with bikepacking kit you're probably lighter than me!
I'll start of with tubes in the Terrenos, experiment with pressures and go from there, I guess the ultimate question is how much harder do you need to hit something to pinch a tyre rather than a tube.
I've got a terrano as my front tyre at the moment, tubeless at about 25psi feels about right for not going wandering on the road (I'm 88kg). Had a slow flat in the rear tyre (smart Sam) last week after riding through some glass. Did an epic back wheel drift across a junction before I realized it only had about 10psi in there!
The terrano's been faultess while tubeless. I stuck one on my other bike for a one-off ride with a tube and got a puncture first time
Using WTB Riddlers seems to be a big part of the problem, after tonight's commute home 😡😡
What sort of punctures? (If it's not too painful a subject...)
A slow small one. Think I picked it up on the ride to work, it didn't seal properly - found gunk dribbled round the tyre - first attempt to pump it up on the way home ended with me getting too excited and tightening the pump up so much the valve core came out, put it back in, used my only CO2 cartridge. Tyre went soft again. Pumped up manually, valve core came out, finally found the valve core tightening tool hidden in my seatpack, got the tyre up at the third attempt.
I've had two incidents on my 'gravel' bike with 28C tyres that would have killed a tubeless tyre (although I had tubes in both times):
1) Large cut straight through the tread caused by riding through a patch of broken glass that I didn't see until it was too late - a 3-4mm long gaping cut.
2) Slashed sidewall on a rock sticking out at the base of the hedge on a very narrow road when trying to avoid a Range Rover that was as wide as the tarmac. That left a ~1/2" long cut straight through the tyre from bead to tread. I managed to line it with some plastic, fit a new tube and ride ~30 miles home very gingerly.
Have pinch-flatted tubes many times (going too fast on rough tracks, but the scariest was hitting a random fallen rock on the 30mph+ road descent from the Great Orme towards Deganwy. Thought I might die on that one.)