Bike tyres does a narrow width mean a faster tyre?

warwickbear

I'm looking at schwalbe kojacks to use a 26" mtb on the road as I found them at a reasonable price £15.99 each,the choice that you have is 1.35" or 2",can anyone say if there would be much of a difference between sizes like this?As I want to make my bike quicker as I only cycle on the road and want the least rolling resistance,but I'm not sure which one to order.

N0bodyOfTheGoat

Wider tyre of same model will have less rolling resistance (as contact patch reduces in size along axis of travel), but the more a tyre bulges beyond the rim sidewalls, the more aero drag it will create as you travel at more than ~15mph.

Aero drag is usually more important on the front wheel, as it's the leading edge of the bike.

There's no reason you can't use different size tyres front and back and/or different models... My Voodoo fatbike currently has a 29x2.35" G One Speed up front and a 26x4" Jumbo Jim on the rear for commuting duties, while my Cube road bike has a 700x23mm GP5000 up front and a 700x28 GP4000S II (that really measures ~31.5mm) on the rear.

reaperactual

In theory yes the narrower tyre will give less rolling resistance. In real life not enough to notice. Mountain bikes are not built for speed in the first place.

The road like tread will give you most speed gain compared to any knobbly tyre.

JBA

What width (internal) are the rims on your bike?
A 1.35" tyre won't sit properly if you have 35mm rims.
If your rims are narrow (i.e. around 19mm) then go for the narrower tyre and run them with high pressure to minimise rolling resistance.

Don't worry about aero drag. It will make a minuscule, if any difference to a chunky mountain bike being ridden on the road.

warwickbear

JBA said:

What width (internal) are the rims on your bike?
A 1.35" tyre won't sit properly if you have 35mm rims.
If your rims are narrow (i.e. around 19mm) then go for the narrower tyre and run them with high pressure to minimise rolling resistance.

Don't worry about aero drag. It will make a minuscule, if any difference to a chunky mountain bike being ridden on the road.

Hi the wheel says 559 x 17 so does that mean the inner rim is 17mm,if so would the 1.35" fit and if so what inner tubes would I need to buy?Thanks

warwickbear

N0bodyOfTheGoat said:

Wider tyre of same model will have less rolling resistance (as contact patch reduces in size along axis of travel), but the more a tyre bulges beyond the rim sidewalls, the more aero drag it will create as you travel at more than ~15mph.

Aero drag is usually more important on the front wheel, as it's the leading edge of the bike.

There's no reason you can't use different size tyres front and back and/or different models... My Voodoo fatbike currently has a 29x2.35" G One Speed up front and a 26x4" Jumbo Jim on the rear for commuting duties, while my Cube road bike has a 700x23mm GP5000 up front and a 700x28 GP4000S II (that really measures ~31.5mm) on the rear.

Thanks,that's interesting about the different sizing on front and rear,I shall consider that.

JBA

warwickbear said:

Hi the wheel says 559 x 17 so does that mean the inner rim is 17mm,if so would the 1.35" fit and if so what inner tubes would I need to buy?Thanks

Yes. An ETRTO of 559x17 indicates a 26" rim with an internal width of 17mm. Perfect for a 1.35" tyre.
Just buy whichever 26" inner tube has the closest diameter. Probably a 26 x 1.25-1.75 or 26 x 1.25-2.00.