23c vs 25c...
 

Is there really a differance? I have 700x25's on my bike now, and need some new tires. I see good deals on Ebay, etc. But, most of them are the 23c size.

Can you really notice a big differance in the way they handle? I am 6'3" and 200#. Would it be best if I just stick to 25's?

Patriot

I'm 215 lbs (I fluctuate between 210 and 220lbs.) and ride 23c with no problems.

I weigh 250 and my favorite is 27c, the Rivendell tires.
Great tire.

The advantages of the 700x25 you're now riding is that they will absorb more road shock. They will also give you a slightly larger contact patch on the road for braking and cornering.

The advantages of the 700x23 are lower rolling resistance (i.e. they're faster). No reason you can't ride these at your weight. Tire pressure is critical. You'll increase your chances of flats (especially the pinch variety) if tire pressure is too low. You want about 110-120/rear and 105/110 front. If you haven't ridden the bike in a few days, you'll need to "top off" the pressure since your tires will have lost 5-10 lbs.
The only other thing you may need to invest in is different tubes if the ones you're running are too wide to install comfortably in the narrower 700x23 tire.

The reason you're finding more selection in 700X23 is that this is the most popular size. If however, you value comfort over speed, I'd stick with the 700x25.

i thought you decrease your chances of flats by decreasing tire pressure. that's why the pros lower their tire pressure for the paris-roubaix down to 90, and down to 100 for wets. when conditions are perfect, they go 120+.

sd

You are correct that lower tire pressures are desirable in certain conditions, but the reason for this has more to do with control, not pinch flatting. To reduce the possibility of pinch flats, the pro mechanics put on wider tires, which hold a greater volume of air. The wider tire permits them to run lower tire pressures. So, to get both control and a lower possibility of flats, they go with a wider tire using lower pressure. To further enhance control and shock absorbtion, they also use a different wheel (commonly 3 cross, 32 spoke).


On really rough surfaces like cobbles, one reason pro mechanics lower the tire pressure is so that the tires don't bounce needlessy off the road surface which reduces control ( you can't control a tire with brakes or steering that is in mid-air). I mentioned higher tire pressure with the narrower 700X23 tires in my post since with this narrower size which is suitable for normal road conditions, there is a higher probability of pinch flats since the volume of air the tire holds is smaller, hence less margin for error due to the reduced ability of the narrower tire to absorb the type of shock that would cause a pinch flat.

In the Tour de France this year, the Phonak team had something like 7 flats in the team time trail because they were using 700x19 Conti track tires in adverse weather conditions.U.S. Postal used wider tires and avoided flats but still posted the fastest time. If you watched the TTT, at the end of this stage, they showed and commented on some of the narrower tires bouncing off the cobblestones that were present as the riders approached the finish line.

I'm 6ft 3ins and 205lbs. The roads around here are pretty crappy, and as a nice compromise, I run a 25c in the back and a 23c up front. There's a couple of reasons for this. Firstly, you can run slightly less pressure in the back. This is good because 1) Gives you more cush 2) Lower pressures allow the tire to conform to the road surface better, giving you better traction, grip and control. Secondly, you have more weight on the rear tire so it makes sense to have a larger tire on the back, and seeing that it's the tire being driven, a larger contact patch on the rear means more power to the ground.

I can't say I've noticed much difference in 'rolling resistance' or speed or anything when I've gone back to a 23/23 - I've just found that as a big guy the combo of 23/25 seems to work really well. I have about 600mi on a set of 23/25 Hutchinson Fusion Long Distances, and they seem to be holding up - definitely worth a look.

when are we going to go biking :)
btw how did that track ride go? i wasnt sure if u were serious about it or not

I'm about your size and weight - 23's will be fine - it's all I ever use.

Certainly a 23 is rideable just as putting 15x135 tire on a Lincoln is rideable, but will be safe? There is a reason heavy cars use larger tires then small lightweight cars; this science applies to bikes as well. If you want max safety and wearability then go with the larger 25 tire especially if your not racing and just using it for street purposes.

I've used the 23's out on the open road this year and so far (fingers crossed) no flats. I keep the pressure up near 120psi. Is it bumpier at this pressure? Yes, but it's something that is tolerable and you will get accustomed to it.



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