20c Road tires?

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Permalink Reply by Kevin Mulcky on November 7, 2008 at 3:58pm

I have a pair of the 23's. They are so nice and supple. When i first got them i kept getting off and checking the pressure in the tires, they were very forgiving even at 120psi. Unless you have a really narrow rim, i think the 20's wont be able to form a round contact patch which will probably increase the rolling resistance. Plus, at 160psi, they'll transmit so much road buzz they might ruin your nice day. I'd say leave the 160psi for the track or tt events.

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Permalink Reply by Chi Tour de Cure on November 7, 2008 at 4:35pm

Narrow tires sacrifice handling. That's why even professional riders on time trial bikes sometimes slide out in situations that are normally benign - they have sacrificed handling (yes, a byproduct of the contact patch) for a narrow profile and lighter weight - and their 19 and 20 cm tires are usually tubulars, which have a more supple road grip.

Since they'll run at a higher pressure, the rolling resistance is reduced, but you're going to sacrifice comfort also. As you might have read, even though you have less rolling resistance, it's less efficient to run a higher pressure if you're actually bouncing over small road imperfections, which happens with high-psi, narrow tires on streets and paths.

IMH0, 20cm widths are for specialty purposes - TTs or road racing in ideal conditions on smooth surfaces. I would not purchase them for every day or even general racing use. The $10 is worth it, or I'd shop around for a better deal in a 23 cm tire.

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Permalink Reply by Ali on November 7, 2008 at 4:41pm

Please also keep in mind your tire size is also limited by your wheels...For example I have 16c rims and I can run both 20c and 23c tires...But if you have 19c rims I would be very weary about running 20c tires...Also believe it or not most rims will have a pressure rating...So make sure to check with your rims' manufacturer to be able to handle 160 psi. Last thing you would want to do is roll over a pothole to look down to see your rims are buckling...

What Kevin said above is true about road buzz too...Also another thing to consider here are cornering grip, 20c tires will lead to having significantly less contact area which would mean less cornering grip...I am always of the group that 23c are the best compromise between cornering grip, comfort and rolling resistance. I have run both 20c and 23c tires and I feel more confident when I am cornering on the latter...I don't get that eerie vibration and feel as if my bike is milliseconds away from sliding under me...

-Ali

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Permalink Reply by Tommie on November 7, 2008 at 4:51pm

I'm gonna agree with Chi Tour

1) larger contact patch = more stability. especially in cornering
2) smaller tire = more flats
3) 3mm difference in tire = how much less rolling resistance exactly? 1-2 watts worth? you'd do better to loose a 1/2 lb off your body.
4) higher psi = feeling road = more road fatigue.
5) weight? see 3.


If you want cheaper tires search the web for Hutchinson Equinox 23s. Ive seen them run for as low as $13 cause they're last year's model. They're good training tires.

FYI: if you want to reduce rolling resistance easily. Talc your tubes when you install them. I forget the math and mechanics in it but it helps to reduce rolling resistance (and pinch flats) because the tube slides a bit more easily when the tire comes in contact with the road. Go as Leonard Zinn.

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Permalink Reply by Adam on November 7, 2008 at 5:26pm

Thank guy's yeah I better go with the 23s... for all the reason's you said...

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