Dang, 32c tires are slow
#2
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You need to pedal faster
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#5
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My 32mm tires are barely heavier than a GP5K 28mm. I can't argue the aero thing. I don't think I lost any speed going to them. They are uncommonly good 32mm tires, though, not cheap, heavy, and stiff.
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I, personally, don't have the opinion that 32s are "slow", just that in good surfaces a 28, or 25 would be a little quicker.
I've noticed that OP has some, uh, interesting takes on various topics.
#7
Senior Member
Does really a 4-7 mm change in tire width make a real difference in aerodynamic drag unless the rest of the bike+rider is as aero as it gets? (I doubt that can be said about any rider who isn't attempting a world record)
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And when you factor-in the decrease in weight and rolling resistance, a 25 or 28 will likely be noticeably faster, as long as the surface is smooth.Whereas a 32 will shine on rough surfaces.
It really depends on where you ride. If your routes are silky smooth, it would make no sense to run the larger tire, and vice-versa for a rough surface.
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I'm curious about what metric you used to determine your loss of speed. A few years ago I did a comparison between 2 bikes on which I commuted to work. One was a 33 pounder with 32mm heavy tires and the other was a vintage steel light weight road bike with 25 mm light tires. Over the course of a few months of recording I saw no significant difference in average speed between the two bikes even thoughthe heavy bike felt slow in comparison. The effect of rolling resistance is much dependent on road surface but any advantage of an easier rolling tire quickly disappears as you go faster and wind resistance grows. Lighter tires certainly accelerate faster; however once up to speed the advantage may go to the heavier tire because it maintains momentum longer.
Tires always come with trade-offs. It's really up to you to determine what qualities (objective or subjective) are important to you.
Tires always come with trade-offs. It's really up to you to determine what qualities (objective or subjective) are important to you.
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#10
WALSTIB
Throw away the speedometer. Life is not a race unless your in a race. Just enjoy the ride
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Are you airing them up to the max? If you are, trying running them a little lower, maybe 10-15psi lower, should be faster than running the max.
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Gee..here's a topic that hasn't been flogged to death in the last day or so...though flogged endlessly, countless times before.
Gotta call "troll" on this one.
Gotta call "troll" on this one.
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#13
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Sure, the 0.001% of added drag would be there no matter what. My point was that the difference in air drag from the added few mm in tire width is likely so minuscule that it's negligible in the real world, and the other factors like weight, pressure, casing etc. far outweigh that.
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OP needs to drope the hamer.
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No, they're faster because they have lower rolling resistance.
You are slow because you chose tires that have stiff carcasses with high rolling resistance, and/or you're out of shape.
Try the Continental GP5000. Unfortunately, there aren't a lot of low rolling resistance tires available in that width.
You are slow because you chose tires that have stiff carcasses with high rolling resistance, and/or you're out of shape.
Try the Continental GP5000. Unfortunately, there aren't a lot of low rolling resistance tires available in that width.
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I run 32 Gatorskins at around 60psi on my Cross Check. They definitely seem slower to me but I find at that width light gravel and dirt are fairly easy going even though they're slicks.
#18
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It can be faster when it allows the tire to conform around surface irregularities rather than transmit them to the bike and rider. Vibrating the bike+rider can cost quite a lot of energy. The rougher the surface, and the lighter the rider, the lower the optimal pressure for best performance is. Even on smooth roads, the optimal pressure for most people is usually well before the tire's maximum.
Relevant:
https://blog.silca.cc/part-4b-rollin...-and-impedance
Relevant:
https://blog.silca.cc/part-4b-rollin...-and-impedance
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#19
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Anecdotally remembering studies and opinion is because a 23c tire will be faster on a smooth surface, but most roads are not smooth. As you ride the bumps in the road push against the hard tire and slow you down. A cattle grid with the spaced metal slats shows off this quite well too. A lower PSI tire is able to absorb these small bumps and roll over them rather than being deflected by them. You can try this yourself when you find a patched bit of road that super smooth compared to an older bit of road that's slightly worn and then add in some that's starting to crack up and your momentum is sapped and you have to work a lot harder for the speed.
However, you need to be careful that you don't air your tires too low else you'll get snakebites where the rim and the inner tube are squished together causing a tear, thus a puncture.
The poor surface can slow you down by making you less efficient riding and thus slower. It's hard to pedal efficiently when the bicycle is juddering and bouncing all over the place.
However, tire width is different from how well the tire rolls. You still need to have a slick or fast rolling compound if you want your bigger tire to be anywhere near as good as a thin tire.
Remember that there is also a bigger contact patch on the surface of the road which should give you a bit more grip. It's a bit like how disk brakes weigh heavier, but for the average rider they'll have more confidence to brake later in adverse conditions so will end up being faster. Disk brakes just work better in the wet - not massively better some would argue, but enough to give a rider a lot more confidence.
I run my 23C tires at 80PSI. (I've had my rear go down as low as 60psi without any issue (also without noticing!) But then if I weigh up the bike a lot I might put more air in them.
However, you need to be careful that you don't air your tires too low else you'll get snakebites where the rim and the inner tube are squished together causing a tear, thus a puncture.
The poor surface can slow you down by making you less efficient riding and thus slower. It's hard to pedal efficiently when the bicycle is juddering and bouncing all over the place.
However, tire width is different from how well the tire rolls. You still need to have a slick or fast rolling compound if you want your bigger tire to be anywhere near as good as a thin tire.
Remember that there is also a bigger contact patch on the surface of the road which should give you a bit more grip. It's a bit like how disk brakes weigh heavier, but for the average rider they'll have more confidence to brake later in adverse conditions so will end up being faster. Disk brakes just work better in the wet - not massively better some would argue, but enough to give a rider a lot more confidence.
I run my 23C tires at 80PSI. (I've had my rear go down as low as 60psi without any issue (also without noticing!) But then if I weigh up the bike a lot I might put more air in them.
#20
Senior Member
I'm sure they're faster on bad surfaces, so maybe it cancels out the slower performance on well-paved roads if you ride a mixture of surfaces?
I, personally, don't have the opinion that 32s are "slow", just that in good surfaces a 28, or 25 would be a little quicker.
I've noticed that OP has some, uh, interesting takes on various topics.
I, personally, don't have the opinion that 32s are "slow", just that in good surfaces a 28, or 25 would be a little quicker.
I've noticed that OP has some, uh, interesting takes on various topics.
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#22
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My experience with Gatorskins was that I didn't know there was a problem with them until I rode something else, in my case going from Gatorskins in 25mm size to GP4K in 25mm size. Then I knew there was a problem with Gatorskins, and now you could rhetorically not pay me to ride them again. I say rhetorically because in the real world it would depend on how much you offered. Everyone's got a price.
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Depends on the tire/pressure. My 32mm GP5Ks are just as fast as 25s or 28s, but much more comfortable and more grip. 25's would be faster for a TT scenario, especially on my wheels since they match the rim width better, but for regular fast rides, I'll take the comfort of the 32s, especially on our crappy roads.
#24
Non omnino gravis
The OP is right, wider tires are crazy slow. I have a 31 mile loop (with ~1,300ft of elevation) that I ride a couple of times a week. Takes about an hour and forty on my Cervelo (on tubeless 23s) but with wide tires? Woof, it takes forever. Could be as much as 6, even 8 minutes more. Just rode it a few days ago on 700x35s and it took 1h48m... oh, that bike also only has one gear.
...and just in case anyone missed it, this was <sarcasm>
...and just in case anyone missed it, this was <sarcasm>
#25
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I noticed that the difference was much smaller when I stopped filling the bigger tires with Jello instead of air. Who knew such a small change could make such a difference?
Mind you, I was using red Jello. If it had been green or yellow, I think it would have been even slower.
Mind you, I was using red Jello. If it had been green or yellow, I think it would have been even slower.