Bicycle tires -- a primer for commuters..
August 20, 2011 1:32 PM   Subscribe

Tell me everything I need to know about tires and tubes for my new daily commute on a bicycle!

I've been cycling for years, but always in relatively safe places (parks, designated bike roads, military bases) and usually in situations where it was a short walk back to my car and I wasn't trying to get anywhere on time. I.e., if anything mechanical failed, no big deal.

But I've recently started school at a large urban campus about 5 miles from my apartment, and I'm biking to school. My first week of school I had two flats. One of them was almost certainly caused by my book bag sliding off the rear rack and tearing off the valve stem, so I'm not sure there's a pattern here or anything. But now I'm paranoid. What should I know about bike tires and tubes as a new commuter in a large city with crappy roads? (Okay, it's Los Angeles.)

Relevant facts:

- I ride a Bianchi Strada, which takes 700x25 tires.

- I weight about 210 lbs, and my books and computer and other school gear weigh 35-50 lbs. depending on the day. (The school stuff is in a pannier over the back wheel.)

- Just five miles each way. I try to avoid traffic and use side streets, but I still have to cross five major roads. Long hill at the end, but otherwise fairly flat.


1) Should I be pumping up my rear tire more? I believe I'm pumping it up to the max recommended pressure (120 psi), but (a) I always lose a good bit detaching the pump, and (b) it seems to squish outward a little when I sit on the seat and the pannier is full. I've read that "there shouldn't be more than 15% deflection" when the tire is properly inflated... but I don't know what that looks like. Does anyone have a good rule of thumb for how much deformation is too much? (Also, does anyone have hints for how to minimize air loss when removing the pump?)

2) Should I buy new tires? These tires are 6 years old, but the bike was in storage for two of those years, so let's say four. Couldn't really estimate how many miles. The tread on the contact surface is worn away and the sidewalls show some cracking, but I'm given to understand that happen before they need to be replaced.

2a) Should I buy kevlar-lined tires? My wife's cousin recommended Gatorskins. Anyone want to recommend aye or nay?

3) Are weekly or monthly flats just part of a commuter's life? Should I plan on carrying spare tubes, tire levers, and a pump? I only had three flats in the previous fours years of riding, but very little of that was on poorly-maintained city streets, so maybe that's not a good guide. I never carried that stuff before when riding for pleasure, although I did carry a CO2 canister for small leaks.

3a) If yes to the above, how do you plan your commute, given that you may have to stop and change flats all the time. Do you tend to leave ridiculously early every time?
posted by thehandsomecamel to Travel & Transportation (22 answers total) 8 users marked this as a favorite
New tires for sure. Old tires crack, and grit gets in cracks.

Gatorskins are good, but I prefer Specialized Armadillos. Literally the only time I have flatted the Armadillo in two years is when a screw from a construction site went through my sidewall-- twice. Don't get tires with tread unless you're going off-asphalt. Small rocks get in tread.

I wouldn't worry about carrying spares; I don't for a 2-mile commute, and I wouldn't for a 5-miler. It would probably take me less time to walk my bike home/to work than to change my tire on the sidewalk.

If you flat more than once a month, there's something wrong with your tires, tubes, wheel, or riding technique (in that order). Even once a month is a lot, though maybe normal for LA?
posted by supercres at 1:43 PM on August 20, 2011 [1 favorite]

Oh, pressure. Pressure is a double-edged sword. Too little and you might snakebite your tube. Too much makes teensy holes worse. 120 is a lot; I fill my 25mm tires to 100, though my bike and load are lighter. If you're primarily commuting, rather than distance riding, and your rims and frame can handle it, I'd get slightly wide tires this time around (32 at most). You can run the same load at lower pressure
posted by supercres at 1:46 PM on August 20, 2011

Have someone experienced look at the wheels, the alignment, that rubber band inside that protects the tube from the spokes. I've gone a long time without flats then had a run of bad luck. Fully inflated is important, but a couple pounds is not ultra critical.
posted by sammyo at 1:50 PM on August 20, 2011

Here's a good article (PDF) about that 15% tire drop number. 120 psi or a bit less should be fine. I second the notion of getting wider tires, if you can fit them in your frame.

A flat every week is too much. Monthly is still quite a lot but is more reasonable.

I've had good luck with my Panaracer T-Serv tires. The Schwalbe Marathon series also gets good reviews.
posted by xil at 1:52 PM on August 20, 2011

Gatorskins and the cheaper by $10 Schwalbe clones are awesome. I relied on these for bike commuting when I was doing so daily 2003 - 2007. Check your tires after each ride for embedded glass and stones and remove the bits if you want them to last longer.
posted by zippy at 1:54 PM on August 20, 2011

As supercres stated, Specialized Armadillos. I just had my first flat and it must have been a slow leak as I arrived home just fine and it was flat the next morning. I found the hole in the tube but I just could not find and breach int the Armadillo. I commute year-round in Boston and use several bikes. What I most *don't* want is a flat in inclement weather. In the summer I use my "no chance of rain bike", my "chance of rain bike", and my "rain bike". My rain bike is the same as my all winter bike, the only difference is it has Specialized Air Nimbus Armadillos in the summer and Nokian studded tires in the winter. After 3 years the Nokians have never flatted and the Armadillos just had their first flat, but didn't leave me stranded as I still made it all the way home without a road repair. Winning.
posted by Rafaelloello at 1:55 PM on August 20, 2011

Best answer: Continental Gatorskins, Specialized Armadillos and the Schwalbe tires are all very durable and flat-resistant, however they ride like they are made of cement.

I recommend a less-aggressive kevlar-belted tire such as a Panaracer Tourguard. If you make sure to keep it at the recommended tire pressure, which for a 700x25 tire is about 100-120 p.s.i., you should be fine. At your weight you should consider moving up to a larger tire, such as 700x28 or 700x32. You will not lose very much speed, but your bike's ability to carry your weight will be improved. See if tires that large will fit on your bike.

Also, don't ride in the gutter. There is a ton of broken glass there. Ride a few feet away from a curb. If you don't feel safe doing that, find another route that has bike lanes or paths.

Personally I would only use the higher-end, rough-riding flatproof tires if the cheaper, better-riding tires didn't work out.
posted by twblalock at 2:03 PM on August 20, 2011

All good advice up above. Get yourself some tyres. I prefer Gatorskins to Armadillos which I found terribly harsh. Bank on a puncture every couple of months but if you've got a spare tube and co2 inflator it's no big deal. Nice bike, by the way!
posted by dmt at 2:06 PM on August 20, 2011 [1 favorite]

Losing air when you detach the pump head - There are two chambers of air when you pump your tires:

1. The air between your valve stem and the interior of your tube.
2. The air between your valve stem and the interior of your PUMP!

the air that "leaks" out when you detach the pump head (properly) is the air between your valve stem and the the pump, you shouldn't be losing any air from your tires.

f you have a pump with a gauge you might be tempted to believe you've lost air because every time you attach your pump head to the tire you lose some air from the tire as it equalizes pressure with the air in the pump. It's kind of like opening your window in the winter to see if your furnace is keeping it hotter inside than outside.
posted by Rafaelloello at 2:09 PM on August 20, 2011 [1 favorite]

Just as a datapoint, I've flatted Armadillos for no apparent reason. Although there are different grades of Armadillo.

25 mm tires are kinda skinny for street riding. I'd consider putting on something fatter, which would let you run lower pressures at your weight and give you a better ride. I'm pretty sure your bike can take fatter tires than 25 mm.

It's possible that you are not blowing off a lot of air from your tire when you remove the pump, btw—a lot of that air is coming out of the pump, not the tire.

One tip I would offer is to check the bike's tires well before you need to leave when you're commuting. As often as not, when I've flatted my street bike, it was a slow-ish leak that only manifested after a night of sitting. You don't want to discover you've got a flat when you're ready to leave and pressed for time.
posted by adamrice at 2:10 PM on August 20, 2011

I'd definitely do new tires, and 25mm is pretty narrow for commuting purposes; 28 or 32 (if they fit) would help you corner better ride more comfortable--and you don't have to pump them up to 120psi to be comfortable. I've got 37mm on my main commuter, and some people get bikes with 26" wheels so they can go even wider.

I have been really happy with Continental Contact City and Panaracers on my commuting bikes. I've had one flat in three years of bike commuting and I think it was because the tire was underinflated, so that really shouldn't happen all that often.
posted by substars at 2:12 PM on August 20, 2011

I've been using Gatorskins since March and while I'm happy with them, I did manage to get a puncture flat a few weeks ago from a centimeter long dagger of glass that I picked up on Adams, though. It took my brain a second to make the connection that that thing I could hear was something embedded in my tire. I remove the glass and crossed my fingers it was ok. It was another 4 or 5 miles before the tire was too flat to ride. I don't know if it would have mattered, but I have the Gatorskin hardshell on my rear wheel and regular Gatorskin on the wheel that flatted. I sort of wish I had just spent the extra $10 on the hardshell for my front wheel.

How often are you inflating your tires? Did you check to see what your flat looked like when you changed the tube? You can usually tell if it was a pinch vs a puncture, which would help answer your question. Regardless, I wouldn't want to ride with cracked sidewalls.

I learned the sad way that I really need to carry a patch kit and related tools with me even when I'm only going to be a few miles from home. The idea of schlepping my bike with a flat ~1 mile was not a fun one. That one was my own damn fault for not checking to make sure my tires were properly inflated before heading out--all it took was a car forcing me into really busted pavement on Hollywood.

Cracked sidewalls are bad. I like my Gatorskins, though they did once fail with a direct hit from a pointy shard of glass.
posted by mandymanwasregistered at 4:31 PM on August 20, 2011

Best answer: A few things-

700x25 tires are simply not made for a 260 pound load. The chance of getting a pinch flat when you hit the edge of a pothole or something is enormous. In pothole-strewn Oakland, I have gotten pinch flats using 700x32c touring tires, especially if they are underinflated.

To gain more insight on what pressure you should be running, check out this article from Bicycle Quarterly, harvested from the Sheldon Brown article about tires

Looking at the Strada, you can definitely run at least 28c tires, and probably bigger. The bigger the tires, the happier you will be. Lots of good advice about kind of tires to get above. Another great one is the Vittoria Radonneur, which my wife has put thousands of commuting miles on with only a single flat.

Though you shouldn't expect a monthly+ flat, flats will happen. For a five-mile commute, you should bring levers, a spare tube, and either a pump or a C02 inflator. You might consider practicing a few times to make it possible to change a flat quickly. Once you get the hang of it, you can swap a tube in just a few minutes.
posted by rockindata at 4:42 PM on August 20, 2011 [3 favorites]

Seconding rockindata's comment. Those CO2 catridges and a little practice make changing a breeze. However, I don't fully agree with the weight comment. He's right that it's above optimum load but I run 700x23s and I'm a few pounds above that. However, I did invest in some Velocity Deep-V rims (hand-build, knock on wood) and they are bulletproof. So far, no probs and I do a daily 20 and 30-40 on weekends. On the other hand, I'm not commuting but on a nice riverside paved trail. Do cross a few major roads though between there and home. Better rims, in particular hand-builts, will ensure more reliable weight distrib. I am in love with my Deep Vs and cannot recommend them enough. Also, as an aside, with that much weight .... regardless of what kind of tires/etc you run, get used to double-checking your spokes by touch every few days. Bad spokes and tacoing rims can contribute to your flats issues.
posted by damiano99 at 4:54 PM on August 20, 2011 [1 favorite]

Bike commuter for about 2 years now here. Haven't had a single flat in the course of my commute in that time, and a few of the roads are in fairly nasty condition. I guess it helps that I have fatter tires, but supercres has it right -- if you're getting flats on a monthly basis with a 5mi commute, something else is very wrong. Also, don't bother changing tires on the road with a 5mi commute.

Presumably there are some buses with bike racks that parallel your commuting route? Changing a tire on a sidewalk is a time-consuming and seriously unpleasant experience that you will presumably want to avoid unless you're completely stranded.

Also, can we talk about the fact that you're carrying 50lbs of books to class each day? Go rent a locker at the library, or find some other system that doesn't require you to lug around the weight of a small child in books each day.
posted by schmod at 5:15 PM on August 20, 2011 [1 favorite]

@ damian099

The issue isn't as much the wheels/rims (though those will need replacing with some sort of solution similar to yours at some point, as most rims are designed for around a 180-200lb rider load) as the fact that riding on regular roads is a different world from riding on a riverside trail. There are potholes, there are gaps in the pavement, random sharp things. All of those cause pinch flats.

The other thing is that with 50 pounds(which is an enormous amount!) on the rear rack, there is a huge amount of weight on that rear wheel, which further increases the importance of having decent sized tires. That is also dead weight, which is very different from live weight (i.e. that of the rider and a pack)
posted by rockindata at 5:38 PM on August 20, 2011

Response by poster: Thanks to everyone so far for all the great advice!

I went out and checked my tires and rims today for sharps (nothing found!), and in the process realized I was actually riding on 700x23's, rather than 25's. So even skinnier than people were contemplating.

I'm wary of a wider tire, I guess, because I like the speed of my bike as it is now. OTOH, the speed when I have a flat is zero, so.... I may have to look into a larger size. :-)

schmod and rockindata mention the weight on the rear rack -- I've been aware that that's making a lot of difference in both the smooshiness of the rear tire and the handling/speed of the bike. But it's not really something I can do much about. I'm in law school, and I've got large textbooks that I have reading in every night. I have been thinking about getting a small backpack for my laptop and maybe one of the books, just to shift some of the weight forward. I don't know how much that would get me, but it might help a bit...?
posted by thehandsomecamel at 5:54 PM on August 20, 2011

Best answer: Riding 700x23's, on a completely unloaded race bike, is still going to result in random pinch flats. There is a reason that when you race (using 700x23s) you have spare wheels in a truck that follows you! That is also why pros tend to use tubeless tires.

700x28 is still a pretty skinny tire, and you may have better handling because the tires will be more properly shaped under load.

As for your books, at some point you are going to kill your current rack, since most aren't rated for more than 35 or so pounds. Then you do, make the investment in a Tubus rack, or a Surly nice rack. Right now, some Good Panniers may make life much easier. I tend to like stuff by Ortlieb- the Germans really know how to make a good pannier.
posted by rockindata at 8:11 PM on August 20, 2011 [1 favorite]

Response by poster: Excellent. I think I'm going to get on ordering some 28's tonight. Thanks again to everyone.
posted by thehandsomecamel at 8:18 PM on August 20, 2011

I stand corrected. I hadn't looked at it from that point of view. You're dead on! I was approaching it more from mechanical failure rather than flats. After re-reading his question, your answer is much more correct to me.
posted by damiano99 at 9:28 PM on August 20, 2011

Another vote for the Vittoria Randonneur tires. I use the 28's on my commuter and the only time I've gotten a flat in 3 years was running over a huge nail. I was commuting 30 miles a day on them for about a year so I put some considerable mileage on them. If you can fit bigger tires, go for it though. I have 38's on my touring bike and the difference between that and the 28's in my pothole ridden neighborhood is huge.
posted by bradbane at 1:02 PM on August 21, 2011

For my money, even 28mm is way too thin. I went down to 1.25" (32mm) and after a few weeks started suffering tail bone pain. Back to 1.5" (and corresponding lower pressure) and all was good. For a long time I rode a 1.25" on the front and 1.5" on the back, actually :P
(700c should run a little smoother than 26", but not enough smoother, I don't think)

I use Mr Tuffy for puncture resistance. You definitely need something, or you will be fixing flats every couple of weeks.

CO2 doesn't do high volume tires very well (click "Inflation Chart" to see what I mean). It might be worthwhile on tires up to 28mm, but nothing bigger than that. You just run through the cartridges like mad. Also, isn't there something about the rubber most tubes are made of reacting badly with CO2... Here, CO2 leeches out very quickly.
posted by Chuckles at 5:45 PM on August 22, 2011

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