Am I too heavy for my road bike tires?

Question

I am wondering if bike tires have a weight limit. I have to admit, I am a large guy at 6'3" 250lb (190 cm, 113,5 kg), and I have always had issues with my road bike's tires getting pinch flats. I could never seem to put enough air in the tire to keep the rim off the road on bumps, etc. I ride a mountain bike now and I haven't had the same issues. Though of course they are a lot knobbier/thicker.

The tires are 27 x 1.25

Answer 1

Pinch flats are due to under-inflation of tires. On a road bike you should be inflating your tires to 120-130 lbs.

Also, you need to check and re-inflate your tires every time you ride. I just keep my pump right next to my bike, and wind up adding air every 2nd or 3rd day.

I see you added tire size - those are older bike tires, they don't inflate as high as road bike tires, I'd try pumping them to 65 lbs, and if you are still getting pinch flats, go up 5 lbs at a time until it stops.

You can tell a pinch flat because it will look like a snake bit, 2 small holes close together.

If you do not get any pinch flats at 65 lbs, you can try going down 5 lbs at a time until they return, then you know the range your tires need to be at to be properly inflated.

The most important thing is to check tire pressure every time you ride, as bike tires can lose up to 5/lbs a week from just sitting. These are high pressure tires, so they lose air much faster than low pressure car tires.

Cheers, Mike

Answer 2

I'm just a tiny bit smaller than you (~10 pounds lighter, depending on what I've eaten that week) and have ridden 700x25 tires/32 spoke rims with no problem. Granted, I keep my tire pressure high, and go over curbs like I'm carrying a baby inside a priceless ming vase, but still.

Answer 3

I raced 5 Ironman races (so 112 Mile / 180 Km) bike segments and did training for that for 5 years. I raced at 235 lbs and now I am riding 30 miles to work at 270 lbs (alas!) and I do not have an issue with pinch flats.

My road tires I run at 120 lbs or so of pressure. Though with the recent hot weather my pump was not getting the pressure that high due to over heating.

So I would say, no to your question.

Answer 4

You didn't tell us at what pressure did you inflate your tires and that's a important thing when it comes to pinching the tire.

Road bike tires can be easily inflated up to 7-8 bars (100-115 psi) and for your weight, I think this would be enough to protect your tire.

I ride a trekking bike and inflate the tires to 4.5 bars (65psi), similar weight as you and I don't have problems with pinched tires. Granted, the tire dimension is bigger, but the pressure is also half of what the road tire would have.

Answer 5

I'm 95Kg, but probably over 100Kgs when I'm loaded up for the commute.

I broke both the wheels on my cheap hybrid, and then snapped the frame.

That's now replaced with a BMC Streetfire. The frame is holding up well, but in 4 months I've bust a spoke on each wheel, and the guys at my local shop (excellent shop - Apex on Clapham High street) reckon its only a matter of time before I break the wheels as they are light, don't have many spokes and 'not designed for London commuting'.

I was wandering if anyone had any thoughts before I start spec'ing out some hand builts.

Answer 6

My girlfriend and I inflate the tires on our touring tandem to 90 psi. The bike carries both of us plus two fully loaded panniers in the back. At 90 psi in the tire with what probably ends up being over 350 lbs on the bike, we have never had a pinch flat. That said, I drive the bike very carefully to avoid hitting anything with a sharp edge (lots of driveways have a nasty edge on them). I wouldn't recommend over-inflating your tires (they're rated for a reason), but if you're getting a lot of pinch flats, you might consider riding a little more conservatively. A little caution can go a long way toward making things last.

Answer 7

You are under inflating your tires. I am 6'8", 270 lbs and ride successfully on 23x700 at 120 lbs pressure. I had pinch flat problems with 23x700 on my tandem which were resolved by using 25x700.