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I have a rigid 26 with 29 wheels and Schwalbe cx pro 30c tyres at 50 psi. Today I double pinch flatted on a tiny root. Last week I pinch flatted on a stick.
These wheels are normally used on a full sus with no issues.
People have been riding off road on narrow tyres for years, where am I going wrong?
Are cx wheels narrower and make a taller tyre? Are gravel tyres a lot wider?
Has anyone managed ghetto tubeless on tiny tyres?
I really like the way these tyres slice through mud and the speed on the road so would like to keep the cx aspect of this bike. If the problem is the 29 wheels ,do cx wheels have ye olde mtb wheel spacing?
People have been riding off road on narrow tyres for years, where am I going wrong?
If you are pinch flatting then you are going wrong with your PSI being too low for a tubed tyre.
I ride 25c tyres off road but they are pumped up 'very hard' (I measure by pressing my thumb on tyre!)
more pressure
50psie is what I run in 40c gravel tyres tubeless to stop pinch flats. For a 30c tyre with tubes you'll have to go higher.
I run tubeless on my gravel bike.
I had my first 'snakebite' flat for years (decades?) on an early ride n my gravel bike running 700x38 at 40psi. It was on a fast descent when I hit a pot hole with the rear wheel.
I have gone tubeless and upped the pressure to 55psi and no problems (hopefully).
Putting 50+ psi in tyres seems strange after running mountain bikes at <20psi for years
This to me is a major part of why the whole 'gravel' thing happened when it did, supple, narrow
tyres off road with tubes is a recipe for pinch flats unless you're running very high pressures of course.
CX was obviously there way beforehand but they ran Tubulars to get round that problem.
How much do you weigh? In any case the answer is more pressure.
Line choices are different. You need to be looking for the smooth bits and hopping things. Very different from a bouncy MTB where you think about grip and carrying speed.
I run tubes.
When using my CX as a gravel bike I use 50+PSI on a 33mm and weigh 75kg.
In a CX race I will drop down to below 30 depending on the course. Anything like roots or rocks and I have to go higher.
In the 3pks I think I ran 70PSI! The max I dared. But that is very rocky.
For CX tubs and tubeless provide some of the answers. For gravel there's a risk of damaging rims if you constantly bounce off things that would have given you pinch flats.
I have gone tubeless and upped the pressure to 55psi and no problems (hopefully).
40psi max in 42c and 33psi max in 50c for me, helped also when I went to 25mm internal rim width.
Either you are riding like a sack of spuds and just clattering into everything or you need to up the pressure, or both.
Been thinking about this and in the summer I was riding stuff like this on holiday.
With sus forks I would have been going even faster. Not a flat all week.
Strange.
People have been riding off road on narrow tyres for years, where am I going wrong?
30c tyres off road is where you are going wrong. Back in the day I used to inflate my 2.1s to 45psi with tubes to avoid pinches. There's a reason MTB tyres started off fat and got fatter.
The 'no, you really CAN ride a gravel bike anywhere!' brigade will turn up now and say 'no, you really CAN ride a gravel bike anywhere!' and this is true, technically, but you do have to go really quite slowly and carefully in many places when the ground is rough. That's why, living in a rocky area, I don't ride a gravel bike for long distance stuff; I opted for a rigid 29er so I could use 2.35" tyres at 23psi.
Been thinking about this and in the summer I was riding stuff like this on holiday.
With sus forks I would have been going even faster. Not a flat all week.
That kind of trail is not really a pinch flat risk because it's consistently rocky and slow so you go in with an appropriate speed to begin with. And because it's so uneven and loose you're always going to be going slowly on a narrow tired bike anyway. Pinch flats are much more likely when you are zipping along some smooth dirt and there's an exposed root, or a flint nodule or something. Bang!
I have Schwalbe CX Comp 38s which measure up about 40mm. I have them at 45psi with tubes and do all sorts of local crappy road surface and easy bridleway riding. I'm 94kg and not pinch-flat/died yet.
tubeless with rimpact inserts 32-40psi 38mm works a treat
Just looked at the tyres and it does say minimum 55 psi. Pumped up to 70 and see how I go.
Is there a really tough inner tube that would help?
50psie is what I run in 40c gravel tyres tubeless to stop pinch flats. For a 30c tyre with tubes you’ll have to go higher.
What is it you're worried about pinching?
Some really high pressures being quoted up there, even for tubes.
Just adding to the consensus above, I'm 85kg and run 40psi in 40mm gravel tyres (tubeless or tubed, it makes no difference, to date I've pinch flatted a tyre and a tube on separate occasions when I've gone lower than 40).
I'll run down to 35psi in my 35mm CX tyres but only for actual CX, on gravel tracks they feel like they need 45psi minimum, I've definitely felt the rim a couple of times recently pushing along lumpy landrover tracks. I'd probably run 50psi minimum if I was going long distance gravel in the summer, but then, that's what the 40mm tyres are for...
Struggling to understand how you pinch flat a tyre? Are they burping away from the rim?
You know you can pinch a tubeless tyre @john_l ? When I was running lower pressures almost every time I did proper off road with supple tyres I'd pinch the tyre so there was a hole in the tread and one by the bead. Sealant doesn't get to the ones by the bead so they never seal.
Now at 50psi with tyres with 30tpi casings I only really puncture on glass. I'm 72kg but ride my gravel bike hard and a lot.
Never knew that. I'm 65kg and rarely go above 30psi, even on 33s. Also ride gravel/cross hard and a lot.