genejockey 

Well, if he's a performance artist, he really commits to the work, because I have met him IRL, and he really is as large and as shirtless as he claims.

GhostRider62

I rode a 23mm front tire on PBP in 2019. PBP is 1218 km over several days and nights.. No problems and no kittens died. I'm fine generally with 25 mm tires. Yes, I have ridden wide, supple for tens of thousands of miles. Conti GP5000 25 mm work best for me.

I'm 220 and bike with gear was 45lbs although was maybe 205 then.

We do not know if TdF riders are on 23, 25, or 28 mm tubies at any given stage. I guarantee they have a narrow tire up front on a TT

LarrySellerz

idk probably recommend them thicc slicks to try and make them laugh

Rdmonster69

Thanks Big Gravel !!

I'm going back to the dumpster Vodka thread for a while

Road Fan

Just a little science if I may. The ability of the tire to support weight is based on the area of the tire contact patch and the air pressure. There was a sketch in Post 84 I think, which illustrated this point in a side view. If you are going to support ⅔ of the 300# on the rear tire, it has to have 2 square inches on the ground when squished by the 200#, and 100 psi, less area if you pump up to 160 or whatever. Your 23mm tire is less than 1" wide, so no matter how high you can pump that tire is badly distorted. For the sidewalls to splay out from under the rim, which tends to pull the bead area away from where it is seated, under normal conditions (more like 100 # for the tire).

When you tend to pull the tire away from the bead the bead might just give a bit and make a small gap. The big-time tire pressure can force the tube to stretch out through that litlle gap and blow through that hole like a balloon. Moments later it bursts like a balloon with a sound like a rifle shot next to your ear.

The sidewall of your tire should have the maximum tire pressure molded into the side. One should never fill the tires up higher than that, and actually it's most likely supposed to be an absolute maximum that is never supposed to be exceeded. This is something your new boss at the bike shop will tell you, accompanied by a dope slap (if you watch NCIS). This problem is especially likely if you are too hasty when you install a tire and not careful about getting all those bits you cannot see to settle into the correct spot.

Bottom line, for this weight you are wrong to use that skinny tire on a skinny rim with that much weight. No offense intended, just some straight talk.

A wider tire and rim will not distort so badly, and can handle the load with much less added pressure.

I know these things because I'm an engineer. We know everything, or at least a lot about simple mechanics and machines.

No, I had it wrong; we know everything. (LOL!)

cxwrench

You pinch flatted because you didn't look where the hell you were going.

Polaris OBark

My daughter, who weighs considerably less than that, just got a Trek Domane that comes with 32mm tires. (The shop did do its part, however, by pumping them up to a stupidly high pressure.)

LarrySellerz

If youre an engineer you should know that you can pump tires higher than the recommended pressure range, its not going to fail because you put an extra 20 psi in it. Heck you could probably run almost double. Whats gonna happen, the rim fails? 23s are perfectly safe, ive never had a shop tell me im too heavy to ride 23s.

t2p

no votes for 18's ?

18's pumped to ... 160 psi ?

LarrySellerz

shouldn't matter if its properly inflated, evidently there wasn't enough pressure because I managed to get a pinch flat. Thats like saying "you shouldn't have hopped the curb if you didn't want a pinch flat" like youre kind of right but its ignoring the root cause,

MattTheHat 

Yes ear protection whilst pumping your tires up to 140 psi is essential. Some wear Bluetooth ear buds while listening to music to accomplish this. I’d like to point out just how truly dangerous this is as you won’t be aware of who might be driving up behind you. And you won’t be able to jump out of the garage in time to save yourself!

Yes, this is a parody thread. It has not disappointed!

smd4

Why do you think a tire rated for 145 psi would “let go” at 140? You guys sure seem like a nervous bunch!

alcjphil

Six pages and counting. Larry may well set a new personal record for this absurd thread. Is there a Strava record for this?

MattTheHat 

I think BF should consider legal disclaimers on posts like these. Following Larry’s advise here could get someone hurt!

I’ve had a tire blow off the rim at the recommended maximum inflation of 90 PSI. I don’t know why but blow off it did. It even appeared to be properly seated.

MattTheHat 

How do you feel about 160 PSI?

tomato coupe

2019? It would have been puppies back then.

smd4

Not in a tire rated for 145.

Polaris OBark

This is as close to a confession as we are likely to see.

icemilkcoffee 

There is a maximum pressure printed on the tire for a reason. You are tempting fate by putting in an extra 20psi. And by the way, 140psi is most likely higher than the maximum pressure rating for your clincher rim as well. For example I found this maximum pressure chart for Easton rims:
https://wheelbuilder.com/content/EastonRimPressure.pdf
Note that for 23mm tire, the maximum pressure is 120psi. Clincher rims/tires are not designed to be run at 140psi. You need to run tubular tires if you insist on running at that pressure.

Koyote

How did I miss this thread?

LarrySellerz , a while back many of us told you that running a psi that is 50% over the recommended max is foolish. It's the reason why you're blowing tires.

You don't need ear protection; you just need some common sense.

Road Fan

I said the tire shape was distorted AND the beads were not set in properly, since you said you are in too much of a hurry to do that carefully, in your first or second post. You're right the carcass is not likely to burst. Bike shop folks will train you how to make customer's bikes safe, and one of those techniques is not to over inflate, as well as to install tires properly. And it's not just about catastrophic failure, it's about accelerated wear, for example wearing throgh the tread too fast, exposing the cords, and then having the carcass fail. There are a bunch of hazardous scenarios which are not generally safe.

You might think this is all crap but if that blowout had happened while you are on a mountain road in a fast, tight curve at 30 mph, your ride could have a really bad ending.

As far as the rim failing, I don't know if it will or worn't with that much stress pushing the sides out. But I would suggest not taking the chance. I've just been reading a wheel builder talking about how he cannot guarantee handmade wheels made of rims he can'r be sure of or did not supply, because he's seen cracks running from spoke hole to spoke hole in some used rims which customers have wanted him to re-use. This actually does sound like rims which could separate.

smd4

Nonsense. You think a rim’s printed “maximum pressure” is the absolute top end, and a few pounds over and “she’ll blow?” You guys ever hear of proof testing?

You guys would need a change of underwear when my steam locomotive goes over it’s MAWP of 190.

genejockey 

I think you mean, 290 psi.

genejockey 

Is the boiler made of lightweight aluminum less than 2mm thick?

smd4

Dumb comparison. The question isn’t about materials, its about factors of safety.

You think a manufacturer isn’t going to build in some extra safety on top of its “max” recommendation?