Big fat tubeless tire pressure?

[TEMPLE]

Hi all, I just put a pair of 30/32mm Specialized Roubaix Pro tubeless tires on my bike and I was wondering what kind of pressures people with a similar setup are using for tires this big? The biggest road tires I had before the big tires were a pair of 28mm Schwalbe Ones (clinchers with tubes), which I had at 70/75 psi front/rear. I had 26mm Mavics (tubeless) before the chubby tires, and had them at a similar pressure as the Schwalbe Ones. No problems with either setup.

So, I am onto bigger tires now! I want to take advantage of the plush ride and long distance comfort. I'm about 205 pounds (on a good day) and will be sticking to paved surfaces only, and typically ride 100+k on my longer rides. There are good roads around here for the most part. My question is this: how low can I go? How low SHOULD I go? Maybe 60/65 front/rear? Even lower?

Thanks!

[hobbanero]

depends on what they actually measure out to on your rims. When I use a Roubaix 30/32, it measures out to about 33mm on my rims, which have a 21mm internal bead width. On narrower rims, your tires will have less air volume. I am 175, and ride 60 psi on those tires with no issues. Anything more and I am actually creating a harsher ride than higher pressure in narrower tires.

Start at 60/65 and if you never, ever, touch the rim when you hit holes, drop 5 psi. At a certain point, you are not going to have enough sidewall support in corners, and the tire will feel like it is squirming as it buckles a bit on high speed corners. Add a few psi when that happens.

[Likes2ridefar]

That’s about what I ran them at, then let them drop till I can tell I’ll ding the rim if I hit something like a curb at the wrong angle or they feel ready to roll cornering hard. That is typically around 30ish psi.

[Hakkalugi]

700x38 Gravel King tubeless file treads at 45psi is working wonderfully for me. I’m 205lbs, and I keep telling my wife I wear it well.

[SlowPokePete]

I've been running my GK38's at 38-40psi, I weigh about 190.

SPP

[coreydoesntknow]

I don't think it necessary to keep dropping psi until there's a possibility to hit the rim rim, really below 60 your going to start losing responsiveness and start gaining rolling resistance.

That being said sometimes I'm lazy in the winter and wont pump my tires up for a week or more and I'll find that I've been riding around with 45psi in them just fine

[oldpotatoe]

Originally Posted by TEMPLE

Hi all, I just put a pair of 30/32mm Specialized Roubaix Pro tubeless tires on my bike and I was wondering what kind of pressures people with a similar setup are using for tires this big? The biggest road tires I had before the big tires were a pair of 28mm Schwalbe Ones (clinchers with tubes), which I had at 70/75 psi front/rear. I had 26mm Mavics (tubeless) before the chubby tires, and had them at a similar pressure as the Schwalbe Ones. No problems with either setup.

So, I am onto bigger tires now! I want to take advantage of the plush ride and long distance comfort. I'm about 205 pounds (on a good day) and will be sticking to paved surfaces only, and typically ride 100+k on my longer rides. There are good roads around here for the most part. My question is this: how low can I go? How low SHOULD I go? Maybe 60/65 front/rear? Even lower?

Thanks!

Pump them up higher than you think they ought to be and with a tire gauge, go ride them and experiment. 'Feel' is 100% subjective. What 'feels great to one rider could feel awful to another..

[saab2000]

Originally Posted by Hakkalugi

700x38 Gravel King tubeless file treads at 45psi is working wonderfully for me. I’m 205lbs, and I keep telling my wife I wear it well.

I just got a set of these and will install them next week when I’m home again. I plan about this pressure as well.

My current tires are some older Michelin Jet’s, with a width of 32mm or maybe a bit more. I am running them with tubes. Lately I dropped the pressure about 10 PSI to about 45R/42F. This has resulted in a definite improvement in ride quality but at my weight, slightly lower than yours, I can go no lower. I bottomed out a couple times last night on some really rough stuff. They may be slower but they don’t actually feel like it.

Looking forward to the tubeless experience and the wider tires. I wonder how closely related these tires are to Compass tires, which are also manufactured by Panaracer.

[grnrcr]

700x30 Schwalbe G-One set up tubeless on Reynolds Attack disc wheels. 50 front + 55 rear. Perfect for road or gravel (fire road with plenty of loose rocks). Bike feels bouncy every time I experiment with higher pressure on the road. I’m 165lbs.

[Hakkalugi]

Originally Posted by saab2000

I wonder how closely related these tires are to Compass tires, which are also manufactured by Panaracer.

I had a set of Compass and a set of Pacentis, both 650b x 42. I can’t see any difference, but the Compass delaminated and killed a tube. The Pacentis are still going strong tubeless on my wife’s bike.

[ColonelJLloyd]

Originally Posted by Hakkalugi

I had a set of Compass and a set of Pacentis, both 650b x 42. I can’t see any difference, but the Compass delaminated and killed a tube. The Pacentis are still going strong tubeless on my wife’s bike.

The Pari Motos use a casing that would seem to be the same as the Compass Extralight. The difference is the tread. The Pacenti tread is thinner (expect less mileage).

[TEMPLE]

Thanks very much everyone, great feedback. I think my initial 60/65 plan (based on dubious internet sources) was a bit too high in view of what PLers are riding in terms of pressure. I think I'll start at 50/55 and see how it goes. Unfortunately, my first decent experiment is going to be the Tour de Victoria on Saturday (this was not intentional, and there is a long and boring story about why I screwed up my tire situation right before one of my "goal" rides) but at least I have a good ballpark now. Much appreciated!