worth getting narrower tires? (currently running 40mm)
#51
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I might get flack for this, but I'm going to link to Jan Heine's Myths in Cycling (1): Wider Tires Are Slower
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I don't think you read his post thoroughly. The article is 'myth...wider tires are slower'.
#54
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Op here, reporting back with some rock solid, incontrovertible, highly subjective results!
Cycled to and from work today with the tires at a shade under 50psi, down from 70.
It was much more comfortable, particularly on the rough canal path, but even on the rough bits of road that have been repeatedly dug up and patched.
Can't say if I'm faster with the lower pressure as I was cycling with a 12kg pack so not my usual spin, but I did notice that where i used to think the front wheel drifted a little, but then though it must be my imagination, it was much more stable and precise now.
The only model I can think of that would cause this is that at 70psi, there was far too little tire on the road so it was not as stable.
May let a few more psi out of the wheels but need a more precise pressure Guage first.
Cycled to and from work today with the tires at a shade under 50psi, down from 70.
It was much more comfortable, particularly on the rough canal path, but even on the rough bits of road that have been repeatedly dug up and patched.
Can't say if I'm faster with the lower pressure as I was cycling with a 12kg pack so not my usual spin, but I did notice that where i used to think the front wheel drifted a little, but then though it must be my imagination, it was much more stable and precise now.
The only model I can think of that would cause this is that at 70psi, there was far too little tire on the road so it was not as stable.
May let a few more psi out of the wheels but need a more precise pressure Guage first.
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Op here, reporting back with some rock solid, incontrovertible, highly subjective results!
Cycled to and from work today with the tires at a shade under 50psi, down from 70.
It was much more comfortable, particularly on the rough canal path, but even on the rough bits of road that have been repeatedly dug up and patched.
Can't say if I'm faster with the lower pressure as I was cycling with a 12kg pack so not my usual spin, but I did notice that where i used to think the front wheel drifted a little, but then though it must be my imagination, it was much more stable and precise now.
The only model I can think of that would cause this is that at 70psi, there was far too little tire on the road so it was not as stable.
May let a few more psi out of the wheels but need a more precise pressure Guage first.
Cycled to and from work today with the tires at a shade under 50psi, down from 70.
It was much more comfortable, particularly on the rough canal path, but even on the rough bits of road that have been repeatedly dug up and patched.
Can't say if I'm faster with the lower pressure as I was cycling with a 12kg pack so not my usual spin, but I did notice that where i used to think the front wheel drifted a little, but then though it must be my imagination, it was much more stable and precise now.
The only model I can think of that would cause this is that at 70psi, there was far too little tire on the road so it was not as stable.
May let a few more psi out of the wheels but need a more precise pressure Guage first.
Comparing that 700x42 tire bike with my 700x38 tire bike, the 38mm tire bike coasts with ease compared to the 42mm tire bike, but it's due to better wheels and bearings IMO. The 38 mm tire bike has always coasted better no matter the tire selection.
Last edited by FiftySix; 10-20-20 at 12:30 PM.
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The same consideration of balancing suspension vs hysteresis losses exists for any tire width, the balance point just happens at different pressures in tires of different width as a wider tire is effectively harder at the same psi. For 26x1.6" touring slicks, I tend to go with 50-ish psi; for 23s I prefer around 110 psi.
#57
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As I ride streets of varying pavement quality (smooth to pothole-ridden to cobbles), also some gravel and fire roads quite often, I don't consider going below 35mm, this 38mm width being the sweet spot which lets me go pretty much anywhere, save for deep sand, and still cruise at 20mph on pavement.
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This has nothing to do with tire width but rather everything to do with tire pressure. Overinflated tires become inefficient due to suspension losses, particularly on rougher surfaces, underinflated tires are inefficient due to hysteresis losses. Overweight cyclists or those riding on very rough surfaces (eg. cobbles, offroad) are faster on wider tires because running sufficiently low pressures on narrow tires would risk pinch flats.
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That’s a $300 to $500 wheel that was essentially turned into junk because the rider failed to understand that tires need enough air to keep from being beat to pieces on the rocks.
The same consideration of balancing suspension vs hysteresis losses exists for any tire width, the balance point just happens at different pressures in tires of different width as a wider tire is effectively harder at the same psi. For 26x1.6" touring slicks, I tend to go with 50-ish psi; for 23s I prefer around 110 psi.
To me, there is more of an issue with underinflation than with overinflation. If the tires are overinflated, I can adjust with riding style by keeping my arms and legs loose and flexible and by hovering over the saddle. That’s just my riding style anyway. Underinflated tires feel squishy, bouncy, and corner poorly in my opinion and experience...just like the flat tires they are.
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Last edited by cyccommute; 10-21-20 at 09:09 AM.
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I'm talking about 'properly' inflated tires, not 'under' inflated. I don't like squishy tires either but I'm not going sacrifice ride quality and traction to avoid a maybe once a year pinch flat. Nor will I use higher pressure than what I would like to avoid rim damage. AFAIC that means the rider needs bigger tires/more air volume. Same as you I've been doing this for decades and not had a problem. Like you I can't remember the last time I had a pinch flat.
#60
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Much...far too much...to do is made about tires bouncing and losing forward momentum. Narrow tires run at very low pressures may feel comfortable but the rider is losing more energy to the tire bounce (hysteresis) than they would if they were running very hard tires that might bounce off the occasional rough spot. While overinflation is a problem on very rough surfaces, it is much less of an issue on smooth pavement.
Last edited by HTupolev; 10-21-20 at 03:50 PM.
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Overinflation is a problem even on very smooth roads. For example, on new rolled asphalt, the study described in this article measured a 190lb bike+rider on 25mm GP4000 tires as having an optimal point of 110PSI, but being faster at 60PSI than at 120PSI.
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I'm talking about 'properly' inflated tires, not 'under' inflated. I don't like squishy tires either but I'm not going sacrifice ride quality and traction to avoid a maybe once a year pinch flat. Nor will I use higher pressure than what I would like to avoid rim damage. AFAIC that means the rider needs bigger tires/more air volume. Same as you I've been doing this for decades and not had a problem. Like you I can't remember the last time I had a pinch flat.
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I used a gauge when I first mounted the tires Since then, go by feel. Running Conti Speed Rides. 42cm.
Had no problems, other than putting too much air in here wanting to soften them mid ride. No going back, they ride really well, good traction, no flats. What else could I ask for?
Had no problems, other than putting too much air in here wanting to soften them mid ride. No going back, they ride really well, good traction, no flats. What else could I ask for?
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A 33 mm tire inflated to “barely half of [40 psi]” is seriously under inflated. I don’t use “high pressure” on wide tires. I use the proper pressure. If you use 20psi on 33 mm tires, what pressure am I supposed to use for 2.1” tires (55mm)? Half of what you use for a 33mm? 10 psi?! Really? That’s a flat tire
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I guess you're not familiar w/ cyclocross? At 165lbs I used 22-23 rear and 19-21 front all the time. Katie F'n Compton is around 140lbs and is always in the teens...17-19psi. Do some research. I run 18-20 front and 20-22 rear on 2.6" mtb tires. No dents in my rims. If I inflated to over 30psi I'd be sliding all over the place.
For my weight and my riding style, around 40 psi is just right for the pressure I use for mountain biking. 80 to 110 psi is right for road tires, depending on the width of tire.
Assuming that you are talking about mountain bike tires, I’m not sure what you are doing but higher pressure doesn’t result in “sliding all of the place” in my experience. Higher pressure makes mountain bike tires bounce a whole lot but it doesn’t cause them to slide out.
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I have done research in addition to having decades of practical experience with regards to tire pressure...I couldn’t care less about cyclocross or any competition, for that matter. All the research I’ve done on mountain bike pressures and road bike pressures fall in the range of what I use for mountain bike riding and for road bike riding...and have used for decades without having the benefit of the calculators...with a 2.1” tire. I don’t have any bikes that can take a 2.6” tire nor would I even use one that wide if the frames could take them.
For my weight and my riding style, around 40 psi is just right for the pressure I use for mountain biking. 80 to 110 psi is right for road tires, depending on the width of tire.
Assuming that you are talking about mountain bike tires, I’m not sure what you are doing but higher pressure doesn’t result in “sliding all of the place” in my experience. Higher pressure makes mountain bike tires bounce a whole lot but it doesn’t cause them to slide out.
For my weight and my riding style, around 40 psi is just right for the pressure I use for mountain biking. 80 to 110 psi is right for road tires, depending on the width of tire.
Assuming that you are talking about mountain bike tires, I’m not sure what you are doing but higher pressure doesn’t result in “sliding all of the place” in my experience. Higher pressure makes mountain bike tires bounce a whole lot but it doesn’t cause them to slide out.
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In my experience, “traction” doesn’t necessarily mean that the tires slide out from underneath me. They may spin out but, honestly, that’s never be much of a problem and is more related to the tread for off-road use than the pressure.
To mirror your wonder, I wonder about your experience if you can’t grasp the idea that very low pressure risk damage to rims and tires. Two can play at that game.
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#68
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Since this is a tire thread I was wondering if someone can answer a newbie question for me
I ordered a Gravity basecamp LTD27 MTB and it should be here soon and I want to buy a couple of spare innertubes. However, I'm not sure whether the stand pump I have is a Schrader or Presta valves. I also can't find from the website tire description what type of valve the bike comes with
The Schrader looks bigger and I can't tell from pictures just how wide it is, but it looks like it might be too big for my foot pump. Whereas, the Presta valve images that I've seen look more like what I had as a kid. Narrow and skinny
Is there any way I can find out what type of valves the tires on the MTB I ordered come with? If not, what is the most standard valve for a MTB with 27.5" tires?
Sorry to hijcak the thread, but would really appreciate any help
I ordered a Gravity basecamp LTD27 MTB and it should be here soon and I want to buy a couple of spare innertubes. However, I'm not sure whether the stand pump I have is a Schrader or Presta valves. I also can't find from the website tire description what type of valve the bike comes with
The Schrader looks bigger and I can't tell from pictures just how wide it is, but it looks like it might be too big for my foot pump. Whereas, the Presta valve images that I've seen look more like what I had as a kid. Narrow and skinny
Is there any way I can find out what type of valves the tires on the MTB I ordered come with? If not, what is the most standard valve for a MTB with 27.5" tires?
Sorry to hijcak the thread, but would really appreciate any help
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Since this is a tire thread I was wondering if someone can answer a newbie question for me
I ordered a Gravity basecamp LTD27 MTB and it should be here soon and I want to buy a couple of spare innertubes. However, I'm not sure whether the stand pump I have is a Schrader or Presta valves. I also can't find from the website tire description what type of valve the bike comes with
The Schrader looks bigger and I can't tell from pictures just how wide it is, but it looks like it might be too big for my foot pump. Whereas, the Presta valve images that I've seen look more like what I had as a kid. Narrow and skinny
Is there any way I can find out what type of valves the tires on the MTB I ordered come with? If not, what is the most standard valve for a MTB with 27.5" tires?
Sorry to hijcak the thread, but would really appreciate any help
I ordered a Gravity basecamp LTD27 MTB and it should be here soon and I want to buy a couple of spare innertubes. However, I'm not sure whether the stand pump I have is a Schrader or Presta valves. I also can't find from the website tire description what type of valve the bike comes with
The Schrader looks bigger and I can't tell from pictures just how wide it is, but it looks like it might be too big for my foot pump. Whereas, the Presta valve images that I've seen look more like what I had as a kid. Narrow and skinny
Is there any way I can find out what type of valves the tires on the MTB I ordered come with? If not, what is the most standard valve for a MTB with 27.5" tires?
Sorry to hijcak the thread, but would really appreciate any help
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Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
#71
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Thanks you. From what I understand Schrader is more common than Presta, so guess I think Schrader is more likely
I guess what I really want to know is if anyone can tell me if this pump is a Schrader or Presta valve
I guess what I really want to know is if anyone can tell me if this pump is a Schrader or Presta valve
Last edited by Cacti; 10-23-20 at 09:10 PM.
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Yes it would !! Just don't post it on BF unless you wear your asbestos fire suit, you would be flamed for sure !
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Agree. It’s easy enough to get an adapter for Presta from SKS if the bike happens to come with Presta, however.
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