Real world diff in speed due to tire size
#26
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i have 700x28 Conti Grand Prix 4-Seasons on my foul weather bike. it's a good wet weather tire.
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#28
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You don't need a second wheel set to do this. It only takes a few minutes (five if you're slow) to swap a tire once the wheel is off the bike.
#29
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Those look interesting, how do they do in nice weather? I am currently half way through the life of my first set of tires, Panaracer T serve 700x28. Any idea of how the two pair up? Someday I would like to have more then one set of wheels so I can swap out tires based on riding condition, but for now I have one set so I am looking for something that will work well in both dry and somewhat wet weather. (Wife won't let me ride in really wet conditions
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#30
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#31
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they're fine in all seasons, hence the name "4-seasons". you certainly wouldn't want to use them in a race, but for commuting and general getting around town riding, the conti grand prix 4-season is a great all-around performer in my opinion. it hits that weight/performance/durability venn diagram sweet spot just perfectly for me, but tires are an incredibly personal thing, so YMMV.
nope, i never ridden on T serves, so i can't comment on how the two compare.
even better than having multiple wheelsets is having multiple bikes. N+1
#33
Those look interesting, how do they do in nice weather? I am currently half way through the life of my first set of tires, Panaracer T serve 700x28. Any idea of how the two pair up? Someday I would like to have more then one set of wheels so I can swap out tires based on riding condition, but for now I have one set so I am looking for something that will work well in both dry and somewhat wet weather. (Wife won't let me ride in really wet conditions
)
)
#34
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Interesting assertion.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
#35
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Interesting assertion.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
#37
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Interesting assertion.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
The term employ was "speed" not "acceleration."
#38
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No it wasn't. Speed was correct.
#39
Good point about the quality and construction of the tire making the biggest difference.
I have ridden quality tires (gator skin or equivelant) from 23 to 32 mm. Personally on a commute I can’t tell the difference between the speed of a 23, 25, or 28mm tire. When Racing, I can but that is mostly about the sprint.
32mm is starting to be a bit slower for me. 28mm is the sweet spot.
FYI, on a mountain bike knobby, I ride about 17mph. on a road bike (that I normally commute on) I ride about 20-21mph.
However, at slower speeds, (say 15mph), a bigger tire will have less rolling resistance (basically less deformation, and follows the road contors better) and actually be faster at speed (although because of weight, slower to accelerate). When riding at 15mph or slower, I’ll take the bigger tire. At those speeds, the lower rolling resistance are more important than the weight and aero advantages of a big tire.
I have ridden quality tires (gator skin or equivelant) from 23 to 32 mm. Personally on a commute I can’t tell the difference between the speed of a 23, 25, or 28mm tire. When Racing, I can but that is mostly about the sprint.
32mm is starting to be a bit slower for me. 28mm is the sweet spot.
FYI, on a mountain bike knobby, I ride about 17mph. on a road bike (that I normally commute on) I ride about 20-21mph.
However, at slower speeds, (say 15mph), a bigger tire will have less rolling resistance (basically less deformation, and follows the road contors better) and actually be faster at speed (although because of weight, slower to accelerate). When riding at 15mph or slower, I’ll take the bigger tire. At those speeds, the lower rolling resistance are more important than the weight and aero advantages of a big tire.
#40
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On the whole, it is an interesting question. Nevermind introducing frame flex and transfer on the power to rear wheel, grip, etc...
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#42
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As is the difference in speed due to wheel circumference, but you brought that up. I was simply trying to determine if your claim was obviously right or wrong. It turns out that there are enough factors that go each way that I'd need to see (or do) the math to come to a conclusion.
#43
My car runs 13 inch wheels, the summer tyres are 155 while the winter wheels are 185.
The car gives up a little ride quality on the smaller and narrower summer tyres but the mileage and the accelleration improve noticeably... the wider winter tyres do handle better but that is a function of them being very good tyres (Nokian).
BMW did a bunch of wheel tests and found that the move to oversized rims and tyres degraded the performance, handling, and economy but the market demands are what made them concede to running a slightly less efficient wheel / tyre and with cars you just need to boost the engine to compensate whereas on a bicycle, the engine is pretty limited.
My Moulten is set up as an all rounder with 16 inch wheels and 1.25 tyres at 85psi... it does not give up a thing to a comparable bicycle with 26 or 700c wheels.
My P20 rolls on 1.5 marathons at 70 psi and is set up for touring and there is no difference between this and my expedition bike that rolls on some fast rolling 26 by 2.0 tyres.
I also ride a few bikes with 32 mm tyres and they aren't slow by any measure and the ride improvement is worth it.
The car gives up a little ride quality on the smaller and narrower summer tyres but the mileage and the accelleration improve noticeably... the wider winter tyres do handle better but that is a function of them being very good tyres (Nokian).
BMW did a bunch of wheel tests and found that the move to oversized rims and tyres degraded the performance, handling, and economy but the market demands are what made them concede to running a slightly less efficient wheel / tyre and with cars you just need to boost the engine to compensate whereas on a bicycle, the engine is pretty limited.
My Moulten is set up as an all rounder with 16 inch wheels and 1.25 tyres at 85psi... it does not give up a thing to a comparable bicycle with 26 or 700c wheels.
My P20 rolls on 1.5 marathons at 70 psi and is set up for touring and there is no difference between this and my expedition bike that rolls on some fast rolling 26 by 2.0 tyres.
I also ride a few bikes with 32 mm tyres and they aren't slow by any measure and the ride improvement is worth it.
#44
Generally speaking:
The wider the tire the heavier the tire. Heavy tires are slower than lighter tires. A wider tire will also require a wider tube, which is heavier. And there is the issue of wind resistance, which goes up exponentially.
However, on rough roads and offroad, the opposite can be, and often is, true.
The wider the tire the heavier the tire. Heavy tires are slower than lighter tires. A wider tire will also require a wider tube, which is heavier. And there is the issue of wind resistance, which goes up exponentially.
However, on rough roads and offroad, the opposite can be, and often is, true.
#45
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My car runs 13 inch wheels, the summer tyres are 155 while the winter wheels are 185.
The car gives up a little ride quality on the smaller and narrower summer tyres but the mileage and the accelleration improve noticeably... the wider winter tyres do handle better but that is a function of them being very good tyres (Nokian).
BMW did a bunch of wheel tests and found that the move to oversized rims and tyres degraded the performance, handling, and economy but the market demands are what made them concede to running a slightly less efficient wheel / tyre and with cars you just need to boost the engine to compensate whereas on a bicycle, the engine is pretty limited.
My Moulten is set up as an all rounder with 16 inch wheels and 1.25 tyres at 85psi... it does not give up a thing to a comparable bicycle with 26 or 700c wheels.
My P20 rolls on 1.5 marathons at 70 psi and is set up for touring and there is no difference between this and my expedition bike that rolls on some fast rolling 26 by 2.0 tyres.
I also ride a few bikes with 32 mm tyres and they aren't slow by any measure and the ride improvement is worth it.
The car gives up a little ride quality on the smaller and narrower summer tyres but the mileage and the accelleration improve noticeably... the wider winter tyres do handle better but that is a function of them being very good tyres (Nokian).
BMW did a bunch of wheel tests and found that the move to oversized rims and tyres degraded the performance, handling, and economy but the market demands are what made them concede to running a slightly less efficient wheel / tyre and with cars you just need to boost the engine to compensate whereas on a bicycle, the engine is pretty limited.
My Moulten is set up as an all rounder with 16 inch wheels and 1.25 tyres at 85psi... it does not give up a thing to a comparable bicycle with 26 or 700c wheels.
My P20 rolls on 1.5 marathons at 70 psi and is set up for touring and there is no difference between this and my expedition bike that rolls on some fast rolling 26 by 2.0 tyres.
I also ride a few bikes with 32 mm tyres and they aren't slow by any measure and the ride improvement is worth it.
There's a noticeable difference in stability with wider tires and larger circumference above 120 or 130 mph due to the reduction in rev/sec reducing the perception of smaller defects from the wheel manufacturing process. Especially when the road surface is of high quality.
I'd love to see that BMW study because I don't believe what you're saying is true for the global market where speeds are higher and road quality is better due to lower environmental variation.
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#47
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That's because in the US/NA, you run them at low speeds (below 80mph).
There's a noticeable difference in stability with wider tires and larger circumference above 120 or 130 mph due to the reduction in rev/sec reducing the perception of smaller defects from the wheel manufacturing process. Especially when the road surface is of high quality.
I'd love to see that BMW study because I don't believe what you're saying is true for the global market where speeds are higher and road quality is better due to lower environmental variation.
There's a noticeable difference in stability with wider tires and larger circumference above 120 or 130 mph due to the reduction in rev/sec reducing the perception of smaller defects from the wheel manufacturing process. Especially when the road surface is of high quality.
I'd love to see that BMW study because I don't believe what you're saying is true for the global market where speeds are higher and road quality is better due to lower environmental variation.
For snow, wheels that are big, but narrow are the best. They don't look very nice, but go anywhere:
#48
A couple of years ago I switched from 700x28 GP 4 Seasons to 700x35 Marathon Supremes. The Supremes are designed as a touring tire while the GP 4 Seasons are designed as a training (ostensibly for road racing) tire, so apart from width the Marathon Supremes have higher rolling resistance due to their construction. On the bike I could feel that difference. The Marathon Supremes roll really well for a touring tire, but they felt more sluggish than the GP 4 Seasons. So I decided to collect some data to see how much slower they were. I didn't approach this scientifically. I just got on the bike and rode to work going as fast as I could. I figured the difference between that and the best times I had recorded on the GP 4 Seasons would tell me how much slower the Marathon Supremes were. I ended up beating my previous best time for that route.
To summarize, even accounting for the difference in tire construction that typically comes with wider tires, you aren't likely to see a measurable difference in speed if you're focused on speed. On the other hand, the wider tires will almost certainly feel slower. They may also cause a bit more fatigue to maintain the same speeds, or you may ride slower because your legs are telling you that you should.
To summarize, even accounting for the difference in tire construction that typically comes with wider tires, you aren't likely to see a measurable difference in speed if you're focused on speed. On the other hand, the wider tires will almost certainly feel slower. They may also cause a bit more fatigue to maintain the same speeds, or you may ride slower because your legs are telling you that you should.
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#49
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From what I know: with the same outer wheel diameter (rim+tyre widths) - having a larger wheel and a lower tyre profile (i.e. thinner tyre) provides for less comfort, but better high speed handling (up to a point).
For snow, wheels that are big, but narrow are the best. They don't look very nice, but go anywhere:

For snow, wheels that are big, but narrow are the best. They don't look very nice, but go anywhere:

To be fair, I did state circumference, which suggests that the wheel/tire combo gets larger. If it stays the same, it more of a discussion concerning tire sidewall stiffness.
Ladas are great. I was at my lifetime favourite party when I called a Belorussian a Lada after calling an Italian woman a Maserati, she wasn't super pleased, but the night ended well anyway. We had a long discussion about why it's "White Russia" after I saw three women consecutively vomit in the sink ... those Swedes can party but the Finnish liquorice vodka tends to do that to people
#50
Interesting assertion.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
Smaller wheels have a lower moment of inertia, but must spin faster at the same road speed.
Smaller wheels are lighter (all else equal), but must spin faster at the same road speed.
The spokes of smaller wheels must move through the air at a higher speed, but the air resistance against the spokes acts with more leverage on a larger wheel.
I'm not sure if all of those effects balance or not.
All else equal, larger wheels handle road irregularities more efficiently.
If the tires are thicker on the same wheel, the wheel doesn't turn as fast ... let's see how this reasoning holds up. The spokes still have to travel the same distance horizontally in the same amount of time, so that's the same. Chopping up and down though, that would be slower. So the drag from spokes would be less with a thicker tire. Whether that's more or less than the extra aerodynamic drag from the tire being larger, I guess that would depend on a few other things.





