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odearja
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Discussion Starter · #1 ·
I am currently riding an escape with 32's. I am curious about switching to a higher pressure, lower volume tire and I am thinking of maybe mounting 25's on my bike. My only question is, how universal are the average wheels on the market today? I am not sure how thin I can go on my current set before I really need to just buy new wheels.
 

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That is like a 19mm wide rim (and tubular), routinely used for road racing (in addition to what I assume is your CX set-up). Going with a 25 would be more than fine. You could easily go to a 21 or 20. I wouldn't go any narrower than my rim width. A 23 or 25 should be plenty.
 

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Well I don't do any racing, but I do want the higher tire pressure usually associated with the narrower setups.
Why, are your current tires too comfortable for you? The switch to narrower tires will give you speed only if your current tires are "stiffies" and so have high rolling resistance. This is true of many 32 mm tires on the market but certainly not all. Higher pressure alone will not make you faster.
 

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odearja
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Discussion Starter · #7 ·
Squeezing out a bit more speed would be nice, but my intent is to try and reduce rolling resistance. I am a 230lb rider and that creates a larger flat spot on the bottom of the tire. With a higher pressure, I should be able to reduce that.
I just found 32's that are rated for 120 psi which should help over my current 65psi tires.

Does anyone think I am going about this wrong and do you have other suggestions?
 

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Squeezing out a bit more speed would be nice, but my intent is to try and reduce rolling resistance. I am a 230lb rider and that creates a larger flat spot on the bottom of the tire. With a higher pressure, I should be able to reduce that.
I just found 32's that are rated for 120 psi which should help over my current 65psi tires.

Does anyone think I am going about this wrong and do you have other suggestions?
32mm tubulars with a max 120 psi? Link please. What tires are you currently running? I feel like we need more info in order to appropriately weigh in. What kind of riding are you doing on what kind of terrain?
 

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odearja
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Discussion Starter · #9 ·
Not tubulars. Clinchers..... I found them on Giants site.
Most of the riding I do is paved bike trails and this summer I will start really putting on miles by using country roads. Both with light to moderate hills (about 800ft total gain over a 20 mile trip)
I live in central Illinois so the asphalt isn't fantastic but still is decent shape, and the country roads typically have some small loose gravel towards the side.
 

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odearja
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Discussion Starter · #10 ·
......I don't have the tires near me now, but the whole bike is stock factory. I am still new to this but I am getting to the point where I want to make some upgrades.
 

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I agree with above, especially as a "clyde" (I'm about same weight as you), stick with wider tires. 700c x 28- ~37. The only thing you gain by going thinner is a bit of weight loss and a loss of comfort & potential pinch flat protection, both the latter afforded by the higher volume of wider tires.
The wider contact patch doesn't make you slower, from what I understand.

BTW, where you at in central IL? I went to school in Normal and have family there & near Springfield.
 

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odearja
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Discussion Starter · #12 ·
I agree with above, especially as a "clyde" (I'm about same weight as you), stick with wider tires. 700c x 28- ~37. The only thing you gain by going thinner is a bit of weight loss and a loss of comfort & potential pinch flat protection, both the latter afforded by the higher volume of wider tires.
The wider contact patch doesn't make you slower, from what I understand.

BTW, where you at in central IL? I went to school in Normal and have family there & near Springfield.
I actually live and ride in Decatur.
From what I have read, the wider tires form a less Out Of Round situation which would be going the right direction if I understand it right. The weight reduction of thinner tires and decreased wind resistance won't make a noticeable difference given how aerodynamic I am haha. I was only considering the higher pressures regardless of how wide the tire is.

I've heard comfort will be sacrificed, but since I've never been on anything with such hard tires I may not like it as much ultimately. There is only one way to find out.
From what you pointed out..... Maybe I will just leave my setup the way it is.
I am already quietly searching for my next bike so maybe I shouldn't invest much into this one.
 

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Sorry for the confusion. To me, Escapes are a rim, made by Velocity, and accommodate tubular tires. That was the basis of my responses. It seems your Escape is a bike model? Not familiar to me.

And I agree with logbiter's input, at your weight, the pros of a thinner lighter tire are outweighed by the cons.

And a wider contact patch doesn't necessarily make you slower. Look at the big movement in road rims, they are making them wider, so wider isn't necessarily worse.
 

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odearja
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Discussion Starter · #14 ·
Sorry for the confusion. To me, Escapes are a rim, made by Velocity, and accommodate tubular tires. That was the basis of my responses. It seems your Escape is a bike model? Not familiar to me.
Yea now I can understand the confusion. Yes, I have a Giant Escape which is an entry level hybrid.
 

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It's instructive to know where the power you develop is lost when you're riding at steady-state.

Most of it is lost to air drag against your body.
After that, probably bike frame and wheel drag. That's where a narrower tire has some potential to "faster" you.
Finally, mechanical losses. This is drivetrain friction and rolling resistance from tires. This is where a tire with a better carcass has some potential to "faster" you.

You might see some improvement in speed at low speeds if you go to a different tire, especially if you have one that rolls like ass. Some stock tires for hybrids are pretty awful. Your highest speeds won't be effected much - those are all about air resistance. Sitting up and wide on a hybrid means that you lose more power to air resistance than if you were a bit lower and a bit narrower. You can actually get some of that with different setups, but I find it hard to make a flat bar bike comfortable like that, and my elbows still stick out; YMMV.

Anyway, I wouldn't worry about trying to go a lot narrower. 32 mm isn't too crazy a width. But if you have 20 tpi tires with extra rubber to prevent flats (Schwalbe makes some like this, can't imagine how they'd ride. :p ) you might be happier with 60 or 120 tpi tires with a lighter, more flexible puncture resistant device.

As far as what can go on your rim - Sheldon recommends a tire with an ETRTO width of 1.45 times the internal width of the rim as a minimum. I think that's a pretty good parameter - one wants a clincher to swell to a bit wider than where the bead hooks are to get a nice, firm connection, and it provides some protection for the rim. Hybrids are all over the place on rim width, so I won't speculate about what yours has. But it's likely to be on a sticker, or maybe stamped, on the rim somewhere. Or you can just take your tire off and measure.

IME, there is no advantage to higher pressure per se. For any given tire size, there are two good pressures for me - an on-road and an off-road pressure - and for a narrower tire, that pressure is higher. But the higher pressure is more of something I accept because I want a narrower tire.
 

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odearja
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Discussion Starter · #18 ·
This is one of those great "start mid-thought" threads. No offense.

So, what was the original goal?
I'm still new enough to this that everything is a mid thought. We all start somewhere right? The best place to learn anything is not by listening to paid journalists but listening to the people that are out there living the dream.
Truth be told, I have a beginners bike and not much of a budget and I am trying to find ways to extract as much fun and joy out of this rig and see what it can do. I wouldn't want to do something drastic like drop hundreds into new wheels when I am planning on buying a new road bike next year... I don't know what I am getting, but I plan on test riding a defy and z85 first thing.
 

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One more suggestion. You mentioned, I think, that your current 32 mm tires are rated for 65 psi. There's generally a lot of safety margin in those numbers. I'd try pumping those up to 80-85 and see how they feel. Might make a noticeable difference.

If that doesn't give you the improvement you want, those higher-pressure 32's you saw might be worth a try. They're probably a more supple casing than what you have. At your weight, I wouldn't go to a smaller tire. You'd need much higher pressure to avoid pinch flats, and that would make the ride worse (and slower, most likely).
 
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