What’s Your Tire Pressure?
December 1, 2009 at 9:40 pm | In tires | 6 CommentsTags: tires
From time to time, I’ve fiddled with tire pressure settings on my bike, but have settled in at a psi that I think works for me.
The 23 mm tires that came with the bike listed a max pressure of 115 pounds. I used to pump them to 105, for no particular reason, except that 115 seemed like it would give me a really hard ride — just a guess on my part. When I switched to 25 mm tires, I reduced the pressure to 100 pounds for awhile, but lately I’m back at 105 again.
I was influenced by the Sheldon Brown post which says the load tires must support dictates the pressure. Since I weigh roughly 210, the 105 psi per tire made sense to me.
But now, I’ve come across something else. An article from Bicycle Quarterly says the optimum tire pressure is that which results in a “tire drop” of 15 percent. Tire drop is the amount of compression in a tire when it bears weight. According to the article, anything more than 15 percent reduces your speed. If your tire drop is less than 15 percent, your ride will be less comfortable.
A graph accompanying the article shows tire pressures for different rider weights and different width tires. Turns out that I’m pretty close to where I ought to be, but there’s a wrinkle: the tires are supposed to be pumped to different pressures. On a road bike, the weigh distribution is 40 percent front, 60 percent rear. Yipes! In my case, that means my front tire would be inflated to only about 85 pounds, and the rear to 125.
I’ve gone with lower pressures on the front before, and wound up with a pinch flat for my trouble. So while I find the tire drop article interesting, I don’t think I’ll be making any drastic changes in my tire pressure any time soon. What’s your take?
Warped tires — what?
September 17, 2009 at 10:06 pm | In tires | 11 CommentsTags: tires
A few weeks ago, I mentioned that I had a warped rear tire that may have been responsible for my broken front derailleur. At least, the tire — because of its bent shape — rubbed against the derailleur.
The derailleur was fixed, and the tire replaced. But now, here’s what the front tire looks like: 
Remember, the other warped tire was on the rear. This is on the front. The warp is more obvious when it’s next to the brake.
I haven’t noticed any ill effects from riding on this thing. Last Sunday, it went on a 30-mile ride with no issues. It turns out that this was the tire I did the time trial on two weeks ago, too.
I suppose I should replace it, but there doesn’t seem to be any urgency to it.
So I’m trying to figure out what caused it.
The wheel appears to be true — it’s the tire itself that’s bent.
Some folks have suggested that it’s the way I mounted the tire on the wheel — but this tire has been on the wheel for quite awhile now, since February. The warp didn’t become obvious until quite recently.
Because of all the 100°+F (38°C) days we’ve had this summer, the garage where I keep the bike has been a broiler. I’m guessing late afternoon temperatures inside the closed-up garage were in the 120°F (48°C) range. I wonder if that had anything to do with it? The badly warped rear tire had been hanging from two hooks in the garage most of the summer, until I got it down to replace a tire that had a screw puncture it. I assume the hooks in the heat could have softened the rubber enough to warp it.
Maybe it’s the brand. These are Hutchinson Top Speed Pro Tech Kevlar (whew!) tires. The Hutchinsons are the only tires that have warped. Specialized, Vittoria, and Continentals have been fine.
So what do you think? Have you ever experienced this kind of thing? Should I replace the tire right away, even though it isn’t causing me any problems?
Oh, and before the snarky comments come in — I took the picture after our club ride last Sunday, and washed the bike later that evening.
Tire poll results
September 6, 2009 at 4:27 pm | In tires | 5 CommentsTags: flat tire, tires
The other day I asked Bike Noob readers to send their tire recommendations. This, after dealing with a couple of flats myself, and getting an email from a reader who has had a rash of flats. The question was, What tire do you recommend for puncture resistance?
While I was pleased with the responses, there were not enough to create a meaningful sample. However, of those who did respond, a clear trend emerged: Continental Gatorskins.
Riders praised Gatorskins for their ability to last many, many miles without flatting. Some suggested that Gatorskins aren’t as “nimble” feeling as other tires, but were willing to make that tradeoff to avoid flats.
The only other tire to get multiple mentions was another Continental model, the GP 4000S.
I put a Gatorskin on the rear wheel this week, after my experience with a warped tire (although I suspect the warping was the result of my hanging the tire in a hot garage for several months). No problems after 60 miles of riding, so I’m happy, but that’s not enough to come to any conclusions.
The only issue with Continental tires is their price. Gatorskins cost about $50 apiece, and the GP 4000S run more than that. However, their proponents seldom mentioned cost — I guess people are willing to pay if it means they have the peace of mind of not worrying about flatting. Sharp-eyed consumers can find bargains online, though. Jeff Hemmel says he paid $31 each for his GP 4000S tires at Pro Bike Kit (probikekit.com) with free shipping to the U.S.
Other tires that got favorable mentions from readers included Schwalbe Marathons and Specialized Armadillos (several for each), Maxxis Columbiere, and Michelin Lithions.
Reader Mike from California had high praise for his Lithions:
I am a heavy guy at 270+ lbs. and Lithions are all I will run. I rarely flat and the last one I replaced on the rear had over 1300 miles on it and had NEVER flatted, not once. It was still at pressure after a 40+ mile ride when I discovered that it was worn all the way around and the casing was beginning to peel.
Several readers mentioned the importance of good rim tape. It’s probably worthwhile to replace the stock rim tape on your wheels with some new stuff, and to replace it every three years or so.
Here’s wishing you a flat-free Fall.
(I noticed that no one is running the Hello Kitty tires pictured in the original post.)
Flats — get different tires or ride it out?
September 1, 2009 at 7:26 pm | In tires | 11 CommentsTags: flat tire, tires
After my experience with a flat two weeks ago, and a warped tire last week, this e-mail from Don in California hit home:
Flats have been bugging me for what seems to be the past month. I had a double blowout with old tires. I put on new tires and am still getting them, including averaging about one a week to the point that I’m considering changing to a different type of tire. The ones I’m using now are Forte Pro DC, the same tire that came with my bike. I had only ONE flat in about the first 1800 miles of riding. Now they are coming on like lemmings. Should I look at changing tires? If so, what brands should I consider or should I just try to ride this string of flat luck out?
My reaction to times like this has been to change tire brands. I’ve run Specialized, Vittoria, Hutchinson, and Continentals. I have yet to find a tire that will last a full year on the bike, although one managed to hang on for over 2,000 miles. Kevlar belts seem to help, but they’re not a panacea, either.
Furthermore, I have a special request of Bike Noob readers: Give Don a suggestion in Comments about dealing with flats, but send me a separate e-mail naming your favorite make and model of tire. Include a line or two about why you like them best. I’ll collect the votes and see if there’s a single tire that’s head and shoulders above the rest, and I’ll post about it at a future date, when I’ve got enough data.
Patched tubes vs. new ones
August 27, 2009 at 6:44 pm | In Equipment, Maintenance | 11 CommentsTags: flat tire, tires, tube
Last weekend, I flatted on my Saturday morning ride. I was only two miles from home, and was too worn out to change the flat then and there, so I called my wife and had her perform sag duties.
That evening, in the cool of my kitchen, I pulled out the tube and replaced it. The replacement tube had two patches, but they looked pretty sturdy. I generally will patch my flatted tubes and reuse them, so doing this again wasn’t anything out of the ordinary for me.
Sunday morning, I went out to the garage 20 minutes before the club ride was due to begin, and to my horror, found that the tire had gone flat overnight. Yikes! I pulled the wheel from the bike and hauled my tire levers and floor pump into the kitchen again. Then, I grabbed a new tube that was still in its box, fresh from the bike shop.
I scrambled to get the tube replaced and the tire remounted on the wheel. Everything seemed okay, so I quickly filled my water bottles and dashed to the coffee shop to meet the club ride. I got there within five minutes of the start — a record time for me at replacing a flat tire.
Then I proceeded to worry throughout the ride that I had been too hasty, and that the new tube might not be seated correctly, or any of a dozen other things that could cause me to flat again. But the tire performed well, and caused me no problems.
Obviously, I had missed a leak in the repaired tube — the one with two patches. There should have been a third one in there. The question is, when do you patch tubes and when do you replace them?
I’ve got four older tubes hanging from the wall in my garage right now. Each has one patch. Each would be called upon as a replacement tube if I get a flat (although since I’m running a new tube in the tire now, I would probably just go ahead and patch it, and remount it).
But is that a wise policy? Are patched tubes less durable somehow than new tubes? How many patches can you put on a tube and still have it give good service? How do you deal with the question?
When to replace a tire
April 13, 2009 at 8:49 pm | In Equipment, Maintenance | 6 CommentsTags: tires
My saga of the hard-to-seat tire got me thinking about tire replacement in general. As I said, I felt it necessary to buy a new tire because of my upcoming MS 150, and I wanted it in time for last weekend’s 52-miler.
The original tire was new in February. Because of its kevlar tread, I was hoping for some puncture resistance. But I don’t think anything could have survived the piece of glass that got this tire. It was kind of a fluke, too, because the cut was duplicated halfway around the tire.
They weren’t even cuts, exactly — more like a hole, about an eighth of an inch in diameter. When I ran my fingers over them, I could feel a slight bulge right around the hole itself. It didn’t affect a larger area around the holes. Because the holes weren’t big, I decided to keep riding on the tire.
The next day, I did a club ride for 38 miles on city streets and rural country roads. No tire problems. In fact, I didn’t even think about the tire. It’s been on several rides since then, for a total of a bit over 200 miles.
When the replacement tire arrived in the mail, I didn’t change it immediately. I was even considering doing the 52-miler on the damaged tire, since it seemed to be performing fine. But I happened to be sitting in the living room reading a bike book, and it said, if the tire is cut, the cut could turn into a puncture. If it bulges, it will turn into a puncture more quickly.
I went out to the garage and took another look at the tire. Not only could I feel the bulge, I could see it. That’s when I had my wrestling match with the replacement tire.
I know of some riders who are rather cavalier about their tires. They’ll ride until they see the tube pushing through the tread, or until it wears down to the threads.
What’s your rule of thumb for replacing your tires? How far or how long are you willing to ride when you know the tire is less than 100 percent?
Mounting a new tire
April 11, 2009 at 8:28 pm | In Equipment, Maintenance, Rides | 12 CommentsTags: hills, tires
I set a record the other night. It took me a full hour to get a tire mounted on a wheel.
I bought a new tire to replace one that had some severe cuts on the tread. Since I had a 52-mile ride coming up Saturday, I didn’t want to risk anything — even though the cut tire had seen a good 200 miles on area roads since getting cut in two places by broken glass three weeks ago.
New tires are not as elastic as they get to be with some riding. This one was right out of the mail order box. I put one foot inside the tire, and tried to pull up on it like a rubber band. No give at all. I turned the tire several times, and pulled each time, to try to add a little bit of stretch to it.
Then, on the wheel. Getting one side into the wheel wasn’t too much of a problem, although even here, I had to patiently work the remaining three inches over the rim. I got the deflated tube inside the tire, then started stretching the other side over the rim.
It was fine for about half the tire’s circumference. Then, it didn’t want to cooperate. Again very patiently (a rarity for me) I worked the bead over the rim bit by bit, and popped it into place. Finally, I had five inches to go. It wouldn’t go. It was as though the tire had reached the limit of any stretch built into it. Whenever I managed to get a small section of bead to pop over the rim, the bead at the other end popped out. It seemed I would be unable to get the tire seated properly.
I know you’re not supposed to use tire levers to mount a tire. There’s some danger they might puncture the tube. I yielded to temptation. The levers worked — sort of. I now had only a three-inch section that refused to mount.
I worked it, and worked it, and worked it. And finally, it happened. The remaining part of the bead popped into the rim. I carefully checked to make sure the tire was seated properly all around, inflated the tire and put it on the bike. Elapsed time: one hour.
I change tires when they flat from time to time, but I haven’t had a lot of experience putting new tires on. They’re very different from changing flats, when the same tire that has miles on it is put back on the wheel. I’ve never had a lot of trouble with those, because use has stretched them out. It’s the brand new tire that was the troublemaker.
These are kevlar tires — I don’t know if that would make any difference or not. But I do remember that the only other time I mounted a brand new tire — one that was not kevlar — I didn’t have anywhere near the trouble.
Any suggestions for making the mounting of a new tire any easier?
P.S.: I was glad today that I did get the tire mounted. I did a hilly 52-mile route from Dripping Springs to Johnson City, Texas, and back again. It was a training ride organized by the Hill Country Ride for AIDS, but I used it as my last hurrah before the MS 150 next weekend.
A lone rider approaches the rest stop in Johnson City.
My bike with its new rear tire in Johnson City. Still with torn bar tape, and with one silver and one white bar plug.
I just hope the weather next weekend is better than we had today. It was forecast to get to 80F, but never got above 60, with a chilly northeast wind blowing all morning.
#$%^&!@* pinch flats!
February 15, 2009 at 9:07 pm | In tires | 2 CommentsTags: flat tire, tires
Got up and out earlier than usual yesterday morning. My wife is on the local Advertising Federation cycling team that rides in the Hill Country Tour for AIDS, and they have regular training rides leading up to the Tour. It was in the 40s, overcast, and breezy, and Mrs. Noob decided she wasn’t riding. But I was.
I assumed it would be just a few Ad Fed folks, but when I got to the elementary school where the ride starts, I found it was a full-blown training ride organized by the Tour. At least 50 people turned out. There were even three SAG vehicles.
This was an easy ride, because it’s still early in the season. A number of riders were even more noobie than the Bike Noob. Lots of hybrids, even a few cruisers, and some riders in mid-weight jackets and blue jeans. The route was the Mopac loop I take all the time. One loop is eight miles, and riders had the option of doing as many as three.
The ride organizers explained the route and procedures. They passed out cell phone numbers of all the SAG vehicles. They went through all the common hand signals. Then it was time to leave.
I was among the first half dozen riders out of the parking lot. The wind actually wasn’t as bad as it was for the last couple of weekends, and I had dressed right, even wearing full-fingered gloves, so I was all warmed up by the time I got to the end of the first lap.
Going around the second time, I picked up a little speed over the first lap. A couple guys passed me on a downhill, but I passed them back going uphill. As I approached the intersection with a major road, I checked behind me to see if it was safe to cross over to the left shoulder and prepare for my left turn. It was. Still looking back, I started my turn to cross to the left. When I looked back to where I was heading, I saw it — then I hit it.
“It” was something squarish. There was no way I could avoid it. My rear tire went flat immediately. I stopped on the left shoulder, assessed the damage, then walked the bike back across the road to change the tire next to the right shoulder.
Once I got the tire off, I did the usual inspection to try to find whatever caused the flat. But I could find nothing. Remember, these were the new Kevlar-belted tires I bought just last week. I was displeased. I checked the tube, but a cursory examination there turned up nothing, either. Unfortunately, when I ride, I wear prescription sunglasses that have only my distance prescription, and not my bifocals. So I can’t see anything close unless I hold it inches from my eyes.
I pulled the spare tube from my seatbag, and had just about got it and the tire back on the wheel when one of the SAG vehicles pulled up. He held the wheel while I pumped up the tire. We put it back on the bike, and I packed up my seatbag.
When I turned back to the bike to resume the ride…the tire was almost flat again! The spare tube must have had a leak! Defeated, I put the bike up on his carrier, and he drove me home.
Back in my garage, I grabbed the first tube that had flatted, and took a closer look at it. There it was: the “snake bite” — two small punctures side-by-side. Whatever I had rolled over caused a pinch flat.
I blame myself on two counts: I didn’t see the thing that caused the flat (it turned out to be a a small rock, about three inches across by two inches thick — it was still in the road when I rode by it this afternoon), and I probably didn’t have enough pressure in my tire. If you saw last week’s post about the new tires, you know I planned to experiment with pressures to find what was right. I had already ridden at 100 pounds, and for this ride, I was down around 95 — maybe a tad less.
The late Sheldon Brown, my main source of information for all things bike, says tire manufacturers are conservative when they put recommended pressures on the sidewall. Brown says if the tire bears a 100-pound load, a 25 mm tire can be pumped up to 110 pounds. Since I weigh about 210, that’s about 105 pounds per tire. Hutchinson recommends a tire pressure of 101 pounds max.
This afternoon, I pumped the tires up to 100 pounds again, then went for a ride. No problems. I may still fiddle with pressures, but they’ll be firmer, not softer. And I guess if I find the energy this week, I’ll be patching two old tubes.
Switching to 25s
February 8, 2009 at 7:49 pm | In Equipment | 3 CommentsTags: Equipment, tires, Veloway, wind
Challenging day for a ride. Temp 73F (nice!), but wind from the south at 16 mph, gusting to 36. It was even blowier than last week, when I cut the ride short because the gusty winds made the bike seem unstable.
But I rode today anyway, because I have new toys. Actually, they’re a lot more important than toys. I bought new tires. The ones on the bike were showing signs of wear. The Specialized Mondo Pro on the front was the original tire, so it’s been on almost a full year. I felt it was losing grip, and the surface was cut up. The Vittoria Rubino Pro on the rear was a nice tire, but had flattened in the center of the tread, and was due for a replacement.
So I put on a pair of new tires. They had to have puncture resistance, and I decided that they had to be 700C x 25mm, rather than 23s. Nashbar had a nice price on just the tire I was looking for, so the bike now has a pair of Hutchinson Top Speed Kevlar Protech tires.
Why 25s? I mentioned a couple of months ago that one of our club members had switched to them, and liked them. That planted the idea. After reading more about the difference between 25s and 23s, I concluded that they were worth trying.
I figured my best bet on a windy day like today was the Veloway. It’s a three-mile circuit, so it would be into the wind half the time, but thickets of cedar and live oak that line the track block the wind somewhat, part of the time.
The ride over there was a taste of things to come. A gentle downhill a mile into the trip often gives me my highest speed of the ride, but today going into the wind, I topped out at 16 mph.
One benefit of the 25s was immediately apparent. They were more stable in the wind. I was also putting the good advice I got last week about riding in the wind to good use, and that helped — but the tires were the biggest change I’d made, and I was pleased to see the difference.
Once I got on the Veloway, another difference was evident. Better grip. I could attack the turns on the course with more confidence than I’d had with the old tires. I did five laps and then headed home, for a total ride of 21 miles. The 25 mm tires do seem to offer a softer ride than the 23s.
One of the arguments people use against 25s is that they have greater rolling resistance than 23s. According to Al Ardizone in the Feb. 5, 2009 edition of Road Bike Rider, that’s not true. He says 25s actually have less rolling resistance, and suggests riders use their weight to determine which size tire to ride. I’m still over 200 lbs., so according to his formula, 25s are right for me.
He’s also a proponent of lower tire pressures, for greater comfort with no loss of speed. Al suggests 85-100 pounds pressure. I had been running 105 lbs. in my old tires, and have the new ones at 100 now — recommended pressure is 87-101 lbs. I’ll decrease the pressure a bit on upcoming rides to figure out what’s right for me.
Interestingly, these might be last year’s model, because Hutchinson’s web site doesn’t list a Top Speed model. Their current Equinox seems to have the same specs as my tire. A check of Road Bike Review shows mixed reaction to the Top Speeds — some say they performed well, other say they’d never buy another pair. Anecdotal evidence is interesting, but a sample of only five reviews is not enough to generalize from.
So I’m looking forward to riding with the new tires. I’ll be watching closely to see if they’re as puncture-resistant as billed, and if they deliver increased comfort with no loss of speed. But after only one ride, I think I can safely say that I won’t be going back to 23s.
Broken glass
January 17, 2009 at 7:14 pm | In Equipment, Specialized | 3 CommentsTags: broken glass, tires
I don’t know what conditions are like where you ride, but it seems that the routes I ride have been plagued with more broken glass than is typical.
One particularly irksome spot is in a bike lane on a street that leads to two of my most frequently-traveled routes. Someone smashed a bottle there at least a week ago. It hasn’t been cleared yet.
I seem to manage to avoid the glass, at least the stuff I can see. My recent flats were caused by tiny shards of glass I couldn’t see, because they weren’t mixed in with lots of other obvious glass. It’s still a surprise to me to see that a sliver of glass so small that it can hardly be seen — even when you find it in the tire by running your fingers across it — can cause a puncture.
Part of the problem around here is that we’ve had very little rain recently, so the glass doesn’t get washed into the gutters. It’s bothersome to the point that when I have a ride where glass is not a problem, that’s worth making note of.
The Specialized Mondo Pro tire on my front wheel continues to perform amazingly well. It was the original tire that came with the bike, so I’ve had it for 11 months, and it’s got about 2,700 miles on it. It’s only flatted once, but I think it’s nearing the end of its natural life. The rear tire is the one that flats most often, but I still can’t complain about it. It’s a Vittoria Rubino Pro. However, it doesn’t appear to be able to last as long as the Specialized. I suspect I’ll be hitting the LBS within the next month to get two replacements, and start the serious biking season with new rubber on both wheels.
The city is pretty good about sending street sweepers around to sweep along gutters, but they usually do a street no more than twice a year. If some kind biker from the neighborhood were to head over there with a push broom and a paper bag, the glass problem could be irradicated quickly. Hm. It’s almost two miles from my house, but since I travel it three or more times a week…
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