Tire Pressure for Gravel

[Stalkan]

I have a relatively new build on an OPEN UP with 650B Kinlin TL-23 custom wheel build. I am running Schwalbe Thunder Burt in 650b by 2.1" and while I think I have nailed down the pressure I want/need to run on the street, I am a little in the dark as to what to run on gravel. I had nasty spill on a gravel descent while I was still working out what pressures to run and it has me really gun-shy even on my road bike on asphalt. Any how, the spill happened while I was still trying to sort out the best compromise for mixed riding use and I think I may have been a bit high in the front. Now, with all the things that contributed to my wreck the high psi might have been the least of the factors, but that doesn't change the fact that I am probably running too much psi for the conditions/roads I ride.

The roads I ride are in Northern Virginia. They vary from week to week and even from one section to the next. Some are hard packed dirt with only a few sections of loose and deep gravel while other parts can be completely covered in new gravel. Also, I live in the foothills of the BlueRidge Mountains, which means I go up and down quiet a bit.

On my commute, which is completely paved, I am running ~23 front and ~27 rear.....I think I have this pretty dialed in, but for gravel, I am thinking it's too much. I normally weigh in right around 62kg and the bike is right at 8560g.

What is everyone else running as far as tires/wheels and at what PSI?

[Tomstr]

Do you have some photo's of the gravel roads? There can be a lot of difference in what people call gravel unfortunately.

[Stalkan]

I don't think I have any of the roads I ride, but I grabbed some from Google on what they look like and tried to capture the variety. I hope they help.

[Marin]

For these roads I'd suggest a 28" 27 to 30mm tire at around 4 bars


I do a lot of mixed surface riding on my Ritchey Road Logic in central Austria on 27mm Open Paves, and they work really well.

[Stalkan]

For these roads I'd suggest a 28" 27 to 30mm tire at around 4 bars

Before I had my UP I would regularly ride the same roads using my AR with Shwalbe One tubs in 28 at 60/70....That's pretty much the pressure I run regardless and didn't change it just because I was on gravel. However, I also wasn't almost exclusively on gravel, as it was more asphalt riding with just a few miles on gravel. Yes the road bike with wider tires works for gravel, but it wasn't the most optimal of setups. It lacked comfort, confidence, speed, etc. Way better than rolling with a 22 or 23 tire, but still not even approaching the UP with the fatter tires or even a proper CX tire.

[Stalkan]

Michelin Mud 2 tires 700C tubeless at 38 psi for gravel. I think I would run 20 PSI on my 650B Rocket Rons 2.25's.

Only running one wheel set now, and I really like the extra compliance I get from the 650s over the 33s I've run in the past. If you don't mind what do you weigh? And do you run 20 front and rear? for me 20 in the rear tire causes a lot of sag and bouncing when pedaling.

[DutchMountains]

I run about 3 bar up front, 3.5 bar rear (say about 40 / 50 psi); this is with Continental 4Season 32mm (real width: 34mm) tyres and I weigh 62kg. I think a little less pressure would be even better, but gravel is only a small part of my daily rides.

The Compass 650B tyres would probably do nicely on roads like these.

[Stalkan]

72 kg. Depending upon conditions I'll go anywhere from 20 to 24 in the rear.

Well, you're about ~10kgs more than me, but I think i'll roll with what you have to see what I get. Getting back out on some dirt trails today but lots of pavement between here and there. Also, this is my first time back on any rough surface since I took my last spill (7 weeks). Going to run 20/23 and see how that goes.

[Stalkan]

20/23 turned out to be pretty good. Granted most of my ride was pavement, a big section single track and MTB trails, with only some gravel, but it was a good pressure for the terrain and the bike. It didn't feel too low on the pavement, in fact, if anything it felt very fast (i.e. smooth). No bottoming out on any roots or rocks and traction was never an issue.

I liked it so much that I ran the same pressure up front and only raised the rear 2psi for this AM's commute. My bag adds a bit of weight so I wanted some extra cushion to avoid bounce. Felt pretty good, very similar to Sunday's ride. I think 20/23 is going to be my go to pressure, with maybe an experiment just a touch lower in the front.

[wkwt]

Let's see this UP!

[Stalkan]

Weight and build spec here: viewtopic.php?f=122&t=138742#p1254712

[wkwt]

Yeah! Nice!

[Tomstr]

Dayum, first UP that I like. 27,5 wheels make it look very tough, it probably rides like that too. Job well done.

[Stalkan]

Thanks guys! I'm pretty happy with how it turned out and agree that 650Bs are the way to go. The ride is just phenomenal with all that volume. I keep dropping my pressure to see where I might be too low, but I haven't found it yet, at least not for road.

[wkwt]

Just curious why you chose the Aeronova aero bars on the UP? For ?aero or style or other? They look so out of place that it's cool [emoji41].