Explain wide front tyre, narrow rear tyre setup

tintin40":20n7az4h said:

BITD i thought this tyre set up wrong and still do. A narrow knobbly on the front keeps the handling quick. A fat tyre on the back with big knobbly for grip as bikes are rear wheel drive.

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so you're saying you do the opposite… narrow front, wide rear?

RockiMtn":ibzfi1f6 said:

tintin40":ibzfi1f6 said:

BITD i thought this tyre set up wrong and still do. A narrow knobbly on the front keeps the handling quick. A fat tyre on the back with big knobbly for grip as bikes are rear wheel drive.

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so you're saying you do the opposite… narrow front, wide rear?

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That's what i ride. 1.9 back 1.7 front. or some times 2.1 and 1.9. BITD i used 1.5 front & 1.9 back.

Suits me

Consensus for single speeding before it went all purpose built was wide rear narrow front. Wide rear for max footprint and thus traction, narrow front just to keep weight down. Personally i never had issue with traction and used same width both ends. However i had a matched pair of Specialized front and rear tyres, front was 2.1 with gnarly shoulders, rear was 1.9 which proves even the manufacturers were thinking wide front narrow rear.

velomaniac":1rm3qndi said:

Consensus for single speeding before it went all purpose built was wide rear narrow front. Wide rear for max footprint and thus traction, narrow front just to keep weight down.

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I doubt it.

Which bit ? :?

If you think I'm talking Bo*****s just say, dont beat around the bush. Its what was stated on a couple of sources in the late 90's and so I gave it a go. Didn't agree with it but was experimenting at the time.

looking at whats "new" these days and there are plenty of people running half fat bikes for all the reasons as above...but I've not seen one with a fat tyre on the back only?

The one reason to have narrow rears like smoke lites in the uk in addition to mud clearance was to cut through the mud to the hard pack underneath worked well for in the saddle mud pluggin'. A wider front tended to 'float' to give you a good compromise between steering and drag when 'ice breaking' through mud.

velomaniac":30p9m0yt said:

Which bit ? :?

If you think I'm talking Bo*****s just say, dont beat around the bush. Its what was stated on a couple of sources in the late 90's and so I gave it a go. Didn't agree with it but was experimenting at the time.

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I doubt it because the traction needs of a singlespeed are barely any different than a geared bike and surely you'd want less weight on the wheel you are spinning with your legs?

Might have been a UK thing...Most singlespeeds I saw back then had about the biggest rubber in the front as they could since a lot were rigid.

velomaniac":1gly90kk said:

Consensus for single speeding before it went all purpose built was wide rear narrow front. Wide rear for max footprint and thus traction, narrow front just to keep weight down.

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I'm not sure this makes sense. Traction at the rear is mainly a longitudinal thing, as the contact patch is always going to be longer than it is wide. You might get a fractionally bigger contact area longitudinally with a wider tyre, but that might be more than counteracted by a narrow tyre's greater ability to cut through a loose surface and find grip. And I doubt whether sacrificing lateral grip in order to save a few grammes is often a good trade off at the front, at least in summer conditions anyway.

There's also the question of profile, many different tires have different profiles and behave differently at varying pressures.

For road with a hardtail, I run a big 1.75 back tyre with a pointed parabolic profile. Deeper grooves in a thicker tire help in the wet, and they go to 100psi and don't lose much air. They also provide a bit more cushion than the narrow tires, and don't snakebite so easily, so with no fork to soak up a big bump a fatter tire is more durable, and generally hitting stuff if you really mess it up it's the front wheel that takes it, but it's routine that you hit something with the back wheel and all your weight on that axle, with no suspension it's much tougher with a big rear tire, but counter-intuitively it's a harder ride, there's more pressurised air in the tire so it's more bouncy, like a hard rubber ball, less damping from the tire wall changing shape. The contact patch is visible in the dry as a lighter dust mark, and it's actually slightly narrower than the contact patch on the front, 1.2, which has a flatter circular profile and a good 180mm of travel in the forks.

I have been told by pro riders that this is a bit wrong for a mountain bike, but it works pretty well for me on the current road setup. Matching tires makes for the best handling, so I will probably just put a big one on the front matching the rear one on next.