Tyre Widths ?

[Banjo]

I am replacing the 700 x 40 tyres on my Hybrid bike. I mostly ride on roads or fairly smooth paths so am going a bit slicker this time.

The rims are 25 mm across outside and 17mm across inside Can I use a 32 or 35 mm tyre?

I am tempted by the Michelin Pilot City and Bontrager Nebula Plus.

 

[John the Monkey]

Sheldon Brown's give some suggested minima and maxima for tyres on particular rim sizes;

http://www.sheldonbrown.com/tire_sizing.html

(Scroll down the page)

My hybrid went from 700x38 tyres to 700x32 (Schwalbe City Jet) without too many problems, but do check the size of your rims.

 

[Banjo]

Sheldon Brown's give some suggested minima and maxima for tyres on particular rim sizes;

http://www.sheldonbrown.com/tire_sizing.html

(Scroll down the page)

My hybrid went from 700x38 tyres to 700x32 (Schwalbe City Jet) without too many problems, but do check the size of your rims.

Thanks for the link. According to Sheldons Graph 32 or 35 are both in the OK sector.

 

[marinyork]

Go 32 as the largest. You'll not see much difference on 35.

 

[Randochap]

What kind of difference are you looking for?

If you are looking for a "faster" tyre then you won't necessarily notice any difference by changing to a narrower tyre.

Performance is not so much affected by width as construction/tread. There is a common belief that narrow tyres are somehow faster. The 42mm tyres on my Bleriot will outperform many narrower 700C tyres.

I don't know what tyre you are presently running, but if you are looking to maintain comfort while improving performance, go for a better quality tyre with as little "tread" as possible. You can find very good performance tyres in the range of 35mm. Continental, Schwalbe, Vittoria among others, all make excellent examples in 700X35-37.

What you are looking for is a supple tyre with a fast rubber and no big treads to squirm and rob energy. You can find that in a wider tyre. And -- contrary to stubborn belief -- they don't have to be inflated to 120psi. In fact, large volume tyres are happy at 50-80 psi and their characteristics are comfort and speed over real world surfaces.

 

[Gerry Attrick]

I can heartily recommend the Panaracer Pasela TG in 32mm which I have on my tourer. Fast, grippy and comfortable. Godd p****ure protection as well.

 

[Randochap]

I can heartily recommend the Panaracer Pasela TG in 32mm which I have on my tourer. Fast, grippy and comfortable. Godd p****ure protection as well.

Good tyre.

 

[marinyork]

What kind of difference are you looking for?

If you are looking for a "faster" tyre then you won't necessarily notice any difference by changing to a narrower tyre.

Performance is not so much affected by width as construction/tread. There is a common belief that narrow tyres are somehow faster. The 42mm tyres on my Bleriot will outperform many narrower 700C tyres.

I don't know what tyre you are presently running, but if you are looking to maintain comfort while improving performance, go for a better quality tyre with as little "tread" as possible. You can find very good performance tyres in the range of 35mm. Continental, Schwalbe, Vittoria among others, all make excellent examples in 700X35-37.

What you are looking for is a supple tyre with a fast rubber and no big treads to squirm and rob energy. You can find that in a wider tyre. And -- contrary to stubborn belief -- they don't have to be inflated to 120psi. In fact, large volume tyres are happy at 50-80 psi and their characteristics are comfort and speed over real world surfaces.

It's a bit odd that you comment on threads when I comment about tyre sizes I've ridden on whereas on another totally different thread where a hybrid bike is being recommended being upgraded for much narrower tyres and expensive wheels you won't deign to comment .

I agree with User, there's a bit difference between 35, 32 and 28s.

 

[Banjo]

Ordered them.

Thanks for the replies.At my level of fitness/proficiency I dont expect to notice a huge difference but have ordered a pair of 700x 32 Michelin City Pilots from Chain reaction.

http://www.chainreactioncycles.com/Models.aspx?ModelID=28138

Will report back once I have done a few hundred miles on them.

 

[Randochap]

It's a bit odd that you comment on threads when I comment about tyre sizes I've ridden on whereas on another totally different thread where a hybrid bike is being recommended being upgraded for much narrower tyres and expensive wheels you won't deign to comment ..

Quite simply haven't read the thread or comment in question. It isn't a conspiracy.

My experience, based on the bikes I ride, is different. My observations are backed up by many industry tests. Again, rolling resistance is not simply a matter of reducing tyre width and upping psi, as many people erroneously believe.

Rolling-resistance is a complex set of interacting factors.

My resistance is to the unfounded recommendation often offered up to neophytes by the well-meaning but uninformed, to simply put on a narrow tyre and pump it up to the maximum pressure. All this will do is give a very harsh ride on all but the smoothest surface, without any observable performance gain. In fact, it will slow you down!

Top manufacturers are even trying to counter this misapprehension, but old canards die hard.

The most important thing to understand is that casing and tread are key, in concert with choosing the correct width for the conditions.

Try to get hold of the Bicycle Quarterly study "The Performance of Tires."

 

[HJ]

The following is taken from Schwalbe Technical Information:

Why do wide tires roll better than narrow ones?

The answer to this question lies in tire deflection. Each tire is flattened a little under load. This creates a flat contact area.

At the same tire pressure, a wide and a narrow tire have the same contact area. A wide tire is flattened over its width whereas a narrow tire has a slimmer but longer contact area.

The flattened area can be considered as a counterweight to tire rotation. Because of the longer flattened area of the narrow tire, the wheel loses more of its “roundness” and produces more deformation during rotation.
However, in the wide tire, the radial length of the flattened area is shorter, making the tire “rounder” and so it rolls better.

Why do Pros ride narrow tires if wide tires roll better?

Wide tires only roll better at the same inflation pressure, but narrow tires can be inflated to higher pressures than wide tires. However, they then obviously give a less
comfortable ride.

In addition to this, narrow tires have an advantage over wide ones at higher speeds, as they provide less air resistance.

Above all, a bicycle with narrow tires is much easier to accelerate because the rotating mass of the wheels is lower and the bicycle is much more agile.

At constant speeds of around 20 km/h, the ride is better with wider tires. In practice, the energy saving is even greater than in theory as the elasticity of the tires absorbs road shocks, which would otherwise be transferred to the rider and so saves energy.

But then what to Schwalbe know about tyres....

 

[MacB]

Copying equipment that works for pros can often lead to poorer performance for amateur hobbyists, I deliberately exclude dedicated racing cyclists here, at all levels. I did 2 of my 20 mile loops today:-

14.77mph average - steel frame, hub gear, guards, rack, rackpack, 35mm M+ tyres, heavier bike.

15.18mph average - half carbon, half alu frame, derailler triple, no guards or rack, small saddlepack, 28mm M+ tyres

Conditions were wet both times but windier second time so reckon that cost me a bit. My rough calcs show that, conditions being equal, the lighter bike with skinnier tyres would be about 1mph faster as an average. If you then factor in the difference the rack/guards/rackpack and the pretty heavy hub gear make. I'm guessing but would say the 35 to 28mm change in tyres makes almost no speed difference.

 

[marinyork]

That's remarkably consistent MacBludgeon. I find doing the same loop even on the same day varies a lot more than that. I usually get a band of natural variation on pretty much all courses of 2mph.

 

[John the Monkey]

http://www.chainreactioncycles.com/Models.aspx?ModelID=28138

Will report back once I have done a few hundred miles on them.

Definitely - please consider doing a review, if you have time.

Cyclechat Reviews

 

[MacB]

That's remarkably consistent MacBludgeon. I find doing the same loop even on the same day varies a lot more than that. I usually get a band of natural variation on pretty much all courses of 2mph.

I think that's because I'm tending to stay in the one gear and spin on both bikes. Have relented a bit and use the gears for the 'big hill' but it's only 1/2 a mile long. I've come to the conclusion that, though I'll continue to get stronger, the big improvements will come from weight loss. As I'm still hauling 40lbs too much, I think losing that'll make a tremendous difference, especially when climbing.

Since starting I've been gradually upping the gears used, ie never leave middle ring now. But have been static, gearwise, for about a month now. Think I need to look at upping the gear choice again as I'm now spinning out, and freewheeling, too often again. Even on my marathon ride last weekend I only hit the granny ring 3 times, but boy did I need it then Still never used the big ring yet though.