Am I too heavy for my bike?

[BassMasterson]

I recently bought a used Raleigh road bike with 700x23 wheels. I really want to get into riding it as much as I can to lose weight, but about every other time I go for a ride i get a flat in the rear. I've tried different tubes, different air pressures, and even bought a new tire but nothing is working. I weigh about 240, so could it be just that whenever i hit a bump it pops due to the weight on the rear tire? It's driving me crazy and I haven't ridden in a week just because of it. Any suggestions?

 

[alfeng]

Before giving up on your Raleigh, try a 700x28 tire & tube on the rear wheel ...

BTW. It probably won't hurt to check the rim tape -- opt for VELOX tape if you decide to change it.

 

[BassMasterson]

I'll try the rim tape first. Thank you for the suggestion. I'm super poor, so I can't afford too much, so a $4 fix sounds excellent.

 

[maydog]

I know of a lot heavier riders cruising on 700x23c without trouble, just make sure that you are inflating to the max or near max rated pressure of the tire. That said you will probably be happier on 25c or larger. Take note of where and how your tube is being damaged. Flats due to rim strip issues will be on the inside radius and look very different than a flat caused by piercing. Snakebite flats are two parallel cuts on the outside radius and are the result hitting an obstacle with a, typically, under inflated tire. Also check the tire over for embedded debris since it can cause frequent flatting. For example, I had a flat on my ride into work today. While the tire was off, I found one metal fragment in the tire. Upon inflation, I found another, a piece of wire strand sticking out. The tire was flat after a mile, I repeated the inspection and found a black metallic shaving elsewhere in the tire. These pieces were very small and required close inspection under good light to find. If money is tight, learn to patch your tubes. Most tube damage can be repaired for pennies on the dollar. Get rema F0-P patches, rubber cement from an auto parts store and some sandpaper. I perfected my technique years ago and get more miles out of my tubes than I do my tires.

 

[Orville]

Are you over-tightening the valve ring nut when installing new tubes? That is a common error with new cyclists that causes leaks at the valve stem.

 

[BigSkyFatGuy]

I weigh 265 and ride a carbon road bike with 700x23 tires and haven't had any problems with being too heavy. I run max air pressure and check it before every ride.
You've gotta be having some other kind of problem. I'm fairly new to this too but I'd try the cheap fixes already mentioned before I'd buy new wheels/tires.

 

[retrogrinch]

Bass… Just a head's up that most of the "modern" road race bikes are designed for 23c tires and the maximum width that will fit is a 25c. Even if the frame of the bike can accommodate a larger tire many of the road brakes won't fit larger than 25c. If your bike is designed for commuting, touring or cyclocross then it'll fit MUCH wider tires.

Based on your description it sounds like the issue is the tire having a blowout when you hit a large object or bump. A few causes:
1. Most likely is that the tire is under inflated. I check tire pressure on my race tires (25c) before every ride. The thin tubes and tires leak air naturally. So the 120 PSI from yesterday will frequently be down to 110. As mentioned by others, check the tube to see how it failed - two holes indicate a pinch flat (snake bite), one large hole indicates a blow out.

2. It could be the tires are too light duty… High end race tires have nice supple sidewalls. These give a great feel and are faster (less rolling resistance) -BUT- this comes at a cost of strength, reliability and endurance. Heavier duty tires (Continental Gatorskins, Specialized Armadillo, others) have a much stronger and more rigid sidewall that not only resists cuts but also reduces snake bites (pinch flats). The more supple race tires will need more air pressure to avoid pinch flats. Look for the thread count (TPI - or Threads Per Inch). Higher TPI will be more supple and fragile. Lower TPI will be stiffer and more durable as the threads are larger, stiffer and more sturdy.

3. Tire/rim fit could be the problem. If there was a single large hole, and especially if the tire bead is partially off the rim, then there is a problem with how the tire was mounted or the tire/rim combination is bad. It has been a long time since I've seen a tire/rim problem where tires come off the rims, with all the cheap stuff coming in from China I wouldn't be surprised. When mounting the tire to the rim, partially inflate the tire to 80 PSI or so, then check to make sure the bead of the tire is well seated with the rim. When you spin the wheel the tire should not have any bulges - check for bulges to the side by looking down on the wheel, and check for bulges by looking from the side.

4. Rim strip not installed properly. If the rim strip is too wide, or is installed such that it is the bead of the tire needs to seat, then this could be allowing the tire to push off the rim. A tire coming off the rim is obvious as the resulting BANG sounds like a gun and the tire bead will be outside the rim.

It is rare, but the internal casing of the tire can rupture from a manufacturing defect or from an impact (large pothole or object). This will show up as a bulge in the tire. Replace the tire immediately. I always carry duct (duck?) tape AND nylon strapping tape with me for emergency tire repairs. The tape is wrapped around the handle of my CO2 inflator and pump handles. This stuff has saved my bacon on several occasions. But I digress...

If the tire seems to be too large for the rim, it could be that the tire was not manufactured properly or it could be that the tire happens to run a bit large. Your LBS should be able to help you find a tire which gives a better fit.

Also note that bicycles are designed such that about 60% of the weight is on the rear wheel. Having a larger tire on the back (25c or 28c) and slightly smaller (23c or 25c) up front will work just fine. So don't feel compelled to buy a new front tire if only the back is an issue.

Cheers,
Greg

 

[Froze]

Alfeng is correct, you're too big for a 23mm tire, the rim tape is highly doubtful that it will do anything unless the flats or punctures you're getting are on the underside of the tube. So you'll end up wasting $4 on rim tape, unless the tape is old then eventually that will become an issue but not due to weight.

If I calculate your weight and another 20 pounds for the bike you would have to run 167 psi on the rear tire, there isn't a clincher capable of that psi at 23mm, if I increase the tire size to 25mm you would need 142 which again there isn't many clinchers that will allow you to do that on their max psi label. However if I increase the rear tire size to 28 suddenly you're good with needing 118 psi and most clinchers are rated a bit above that. So I would go with a 28 either all around or a 28 on the rear and leave your 23 on the front and put in about 110 psi in it; this would save you some money because you only have to buy one tire.

Eventually I would probably use a 28 on the rear and a 25 on the front. The only problem you might have is whether or not your bike can handle a 28 on the rear, you have to ask your LBS where you got bike if it can or look up the specs for your model on the internet.

Here is the inflation calculator I got my psi's for, use the 2nd calculator and use your body weight with your riding clothes on, and your bikes weight with it ready to ride (meaning full water bottles, saddle bag, etc) and enter the total of the 2 numbers, leave the F/R weight distribution alone, and then simply plug in whatever mm of tire you want to find out about. See: http://www.dorkypantsr.us/bike-tire-pressure-calculator.html

Also try using a standard tube not a ultralight racing tube, plus try finding a heavier duty tire, not a monster heavy duty touring tire, but one more intended for commuting rather than a training tire. Again your LBS can help you. If you go online Panaracer makes two really nice tires for reasonable cost, one is called the RiBMo PT with a mild tread pattern, and the other is the Pasela TG with a slightly more aggressive tread pattern for better handling on dirt and gravel, both come in a 28mm size. But be careful on loose gravel with a 23mm tire up front, it will dig in and offset you.

 

[retrogrinch]

Originally Posted by Froze
Here is the inflation calculator I got my psi's for, use the 2nd calculator and use your body weight with your riding clothes on, and your bikes weight with it ready to ride (meaning full water bottles, saddle bag, etc) and enter the total of the 2 numbers, leave the F/R weight distribution alone, and then simply plug in whatever mm of tire you want to find out about. See: http://www.dorkypantsr.us/bike-tire-pressure-calculator.html

Yikes! I need to get rid of the tandem!

I typically run 28c tires on the tandem and the combination weight of riders, bike, etc is 350 to 400 pounds. I've also used tires as skinny as 25c but am more comfortable with the 28's. Depending upon the max pressure for the tire, the rear tire is usually 120 to 125 PSI and the front will be 5 PSI less. Note that the rims are a wider (25mm?) heavy duty tandem/touring rim, not the racing 19mm rim. I expect the extra width has helped in supporting the large weight as the tires sidewalls are straighter with the wider rims.

Froze - I second your recommendation for the Panaracer tires. I just put a pair of RiBMo's on the tandem. I've only had one ride but they're fast but have nice sturdy side walls.

If one wants to find durable components for heavier weights, check out the tandem scene. An excellent on-line source is Tandems East.
http://www.tandemseast.com/
Another great source of info is Peter White's tandem parts page:
http://www.peterwhitecycles.com/tandemparts.asp

If they sell it for use on a tandem, it'll hold up quite well for most any Clyde.

Cheers,
Greg

 

[Froze]

Originally Posted by retrogrinch

Yikes! I need to get rid of the tandem!

I typically run 28c tires on the tandem and the combination weight of riders, bike, etc is 350 to 400 pounds. I've also used tires as skinny as 25c but am more comfortable with the 28's. Depending upon the max pressure for the tire, the rear tire is usually 120 to 125 PSI and the front will be 5 PSI less. Note that the rims are a wider (25mm?) heavy duty tandem/touring rim, not the racing 19mm rim. I expect the extra width has helped in supporting the large weight as the tires sidewalls are straighter with the wider rims.

Froze - I second your recommendation for the Panaracer tires. I just put a pair of RiBMo's on the tandem. I've only had one ride but they're fast but have nice sturdy side walls.

If one wants to find durable components for heavier weights, check out the tandem scene. An excellent on-line source is Tandems East.
http://www.tandemseast.com/
Another great source of info is Peter White's tandem parts page:
http://www.peterwhitecycles.com/tandemparts.asp

If they sell it for use on a tandem, it'll hold up quite well for most any Clyde.

Cheers,
Greg

The tandem tire calculation is a bit different than for a single rider bike and a bit more complex, see: http://hobbes.ucsd.edu/tandem/hypermail/200404_Apr04/0033.html

Also with tandems it's important to buy tires with a higher profile sidewall instead of lower profile sidewall. And personally I would ride nothing but at least 28's.

 

[Flatire]

At 277lbs I have had some trouble over the years with flats. I would start my making sure your rim tape is covering the spoke nipples like it should. A good wheel set is also important. A strong 36 spoke wheel although not the lightest will stand up to the weight better. I have one set of Mavic's that cost about $200 then I have a set of DT Swiss's that I had custom built for $750. The other thing i do is air my tires with a good floor pump to 110psi. It rides a little rougher but is less likely to pinch flat on rough roads.

 

[lectraplayer]

I'm at 225 or so right now and slowly gaining weight. As mentioned, check to see where the holes in the tube are. It helps to allign the brand logo of the tire with the valve stem. I also use electrical tape (most of a roll per rim) on mine. Flats are rare for me, unless I hit something. 26x2 inch

 

[jbwillson]

I weigh 250. I ride 25mm Continental Gatorskins inflated to 90 front and 100 rear. I've ridden thousands of miles (literally) without a flat. Before these tires I used Maxxis Re-Fuse 25mm without a flat. And before that I used 23mm -- not sure what brand -- with two flats, one of which was a pinch flat from my own poor installation.

I would take my wheels to a shop you trust and have them looked at for burrs or protruding nipples (sounds kinky) or some other flaw. Then I'd ask them about good rim tape. Then I'd ask about tires. And I'd ask them to show me how to put a tire on to prevent pinch flats in the tubes.

I don't think your problem is in the strength of the wheels. If it were, you'd have broken or loose spokes (been there, done that). If you do need new wheels, I'd recommend Velocity Deep-V. I replaced my too-light stock wheels with them, and they're absolutely bomb-proof.

 

[schwinnhund]

Don't sweat it. I am so big that when I got on my bike at the local store to ride home, my cell phone rang, and a nearby pedestrian yelled, "Look out! He's backing up...."

 

[kylerlittle]

I think it would be alright. Besides, what's the worst that can happen? It's no problem. I suggest you to try it first a few rounds, and if the material was good enough then you can just use it normally. If you've noticed a little bit of inefficiency in terms of it holding you, you might want to upgrade a bit.

 

[almecum]

When I got back on a bike it was on a Schwinn Temp with 700X25 and I was 290. I now ride a Cannondale SuperSix with 700x23 with Gatorskins and I am 240.

Do you really know what is causing the flat? Is it a pinch flat or something else. Pinch flat will look like a snake bite on the tube. If you don't have rim tape you have to get it and if cost is an issue use electrical tape and cover the nipples. look and also make sure that you spoke is not poking out of the nipple on the inside.

I will tell you that I put 120psi in my rear tire and 115 in the front and do not get pinch flats. Larger guys can get away with putting max pressure in the tire because we can get them not to bounce down the road. If some 140lb guy did that his efficiency would be way down as the tire would not deflect and he would bounce with every little hole. My next set of tires will be 25 just so I can get a bit softer ride. I did have to move to a 32 spoke wheel due to breaking spokes almost every ride.

 

[swampy1970]

Buy a track pump (aka floor pump).

Correctly inflate your tires prior to every ride. I'd recommend about 125psi in your tires given your weight - that's a pressure that'll be near impossible to get with a hand pump.

I'd also recommend a quality tire. I personally like Continental tires. A 25C tire should work well at around 125psi. Change the rear first if your funds are limited.