rsm42

Hi,

I'm a newbie to road biking and have a question which may seem a bit dumb ? Just purchased a 56 cm Claude Butler San Remo 2013 Road Bike. The tyres on the bike are 700 x 23c.

I was a bit surprised about how hard the ride the bike is.......I've read some reports on the web that you can increase the tyre size to give you a more stable and comfortable ride - is this correct ?

If so, is there a limit I could increase the tyre sizes on the current wheels. For example 700 x 25 c - could I even go up to 700 x 30c ? Also would I need larger inner tubes ?

Many Thanks,

canam73

I don't know that bike, but you should be able to go to 25mm and maybe higher. Look and measure around the brake bridge on the rear of the frame and where the rear tire comes closest to the seat tube and chain stays and see what kind of clearance you have. On the front check around where the tire passes through the fork for any issues.

It is general guideline that a tire's maximum width be no more than double the interior rim width (inside the hooks). For many road rims that is 13-14mm which would suggest a 28mm max on the tires.

And for reference, I weigh 180lbs and typically ran 23mm tires at 100f/110r. I could go down to 90/100psi without pinch flats with a 25mm tire. I have since switched to using 23mm tires on wider rims which also allows me to run at 90/100.

Note that rim specs often list the rims exterior width, but not always interior. If that is what you have, subtracting 5-6mm should get you close to the interior. So the common 19-20mm ext will have an interior of 13-14. The 'new' 23mm rims that are popular usually have an interior width of 17-18, and that is also similar of many touring and sport rims that have been around for a long time.

Also, you are really asking about 'tires/tyres', not wheel size.

Tim_Iowa

No questions are dumb if they lead to a greater understanding and enjoyment of your bike.

Yup, an aluminum (aluminium?) bike will be light, but will also be stiff. Skinny, hard tires don't help. Wider tires are the easiest way to increase the comfort of a bike. (Secret, they'll even be faster. Studies prove 700x28 is faster on normal pavement than 700x23, because you get a smoother ride, wasting less energy)

To find the size your bike will fit, as canam73 said, measure the clearance around the tire. I'm afraid that your bike will most likely have quite limited clearance. It has been designed around short-reach brakes (39-49mm), so you'll be able to fit 700x25mm tires, and maybe 28mm. Definitely no bigger. Fit the biggest you can. Unfortunately, some makers label their tires inaccurately; their actual size will be bigger or (usually) smaller than the label's size. For my bike with the same clearance limitations, I find the Grand Bois Cerf Blue tires at 27mm are the most comfortable it can fit.

There are some bikes that aren't so racy and fit wider tires. "Classics" bikes (like the Specialized Roubaix or Trek Domane) are just a little bit less agressive, for more rough-surface riding (supposedly inspired by the classics races on cobbles). Cyclocross bikes are still quite fast but have room for ~35mm tires.

You could also change to a smaller wheel size (650b) to get more brake clearance. But the necessary parts (new wheels, tires, brakes) would cost you about as much as you spent already.

Fit the biggest tires you can and enjoy the ride. Then, upgrade once you know what you really want in a bike.

hueyhoolihan

if you can take a couple pics with the current tire at the chainstays, seatstays and front fork. the PSI you are using and a pic of the size markings on the tire itself, there are more than a few people here who can give you a pretty good estimate as to the widest tire your bike can accommodate (present company excluded ).

lungimsam

This site tells you how to figure it for your frame size. You could ask your LBS also about what is the widest your rim can take.

https://janheine.wordpress.com/2013/0...ire-can-i-run/

rsm42

Thanks all

Homebrew01

What's your tire pressure ?? Consider dropping it a bit. 120 psi is going to be rougher than 95

darb85

lower psi, over 100 has negligable rolling resistance changes. and 25c tires should fit

rsm42

Front is 60psi rear is 70psi

canam73

On 23mm? What do you weigh?

Most people ride those at or over 100.

Homebrew01

That's a bit low. More likely to get pinch flat when hitting bumps/holes.

kreeess

^^ agree

rsm42

Ok pumped up to 100psi changed saddle and invested in decent cycling shorts.
Much better ride despite getting soaked this morning.

thanks all

canam73

Riding in the rain, great, you're in.

Now start obsessing about wheels.