Gearing

mtbjohn

Hello all, I need a little help sorting out my road bike which I bought in 2007.

Bike is a Scott cr1 pro with compact gearing. It has a ultegra crankset with 39 / 53 teeth and a ten speed 12 / 25 rear cassette .
Problem is I have never used the bike because I find it way to hard to get up the steep hills due to the gearing. Seems a waste to be leaving such a nice bike in the spare room and using a tricross bike for long rides due to it having such a wide gear selection. What can I do to make the bike usable for my ability? Can you change a ring on the crankset, if so what do you recommend? Also, what would be the best option with the rear cassette?

Bike details for ref are - http://www.bikepedia.com/QuickBike/Bike ... &Type=bike

desweller

53/39 is a standard double, not compact gearing. That's part of your problem. I don't know what the PCD is of your chainrings, but chances are it's such that you won't be able to get a smaller chainring that will fit.

Alternatively you could fit a wider cassette, say 12-28, but you'll lose out a little bit on the gaps between ratios.

EV!lution

Shimano do a ultegra 11-28, will make it easyier to get up them hills

mtbjohn

My tricross has a 30 (smallest one) on the front and a 34 (biggest one) on the rear. I guess this is where I need to get my road bike to. Can I fit a mountain bike rear cassette to my road bike?

desweller

The Shimano 10-speed MTB blocks are a different spacing to the road units (I think). So it's not an option. But you should try a compact chainset first. If you get hold of one second-hand then it should not be too expensive. Alternatively you might look at a triple chainset, but that will start to get expensive as you'll need to replace your front derailleur and possibly the left shifter as well.

30x34 is super, super low gearing BTW. Not necessary on a road bike unless you're either going up gradients better than 1-in-4 or attempting very long climbs with a fully loaded tourer. And I speak as a slow fat bloke with a number of 1-in-5 and 1-in-4 hills around me.

mtbjohn

Thanks for the replies chaps. I did the coast to coast last year and there was a couple of steep climbs on the ride, did that one on my tricross bike. I remember one hill being like a wall. Anyway, managed the ride ok ish and my thoughts are now on the way of roses bike ride next year. Thinking of the road bike but worried about the big hills.
I will try a compact and a larger rear cassette and see how I get on locally before committing to do the ride on it.

Wirral_paul

As above really. Sounds like you need to swap chainset for a compact. This would immediately give you two lower gears than your current lowest of 39x25 as both 34x23 and 34x25 are lower. This may well be enough so i'd just swap the chainset and see how you go. If you need to go lower still then you can look at an 11-28 cassette. While the steps between gears due to the wider range cassette appear quite large, this isnt quite as bad due to the smaller chainrings effectively closing the gaps up.

Diogenes

Wirral_Paul wrote:

As above really. Sounds like you need to swap chainset for a compact. This would immediately give you two lower gears than your current lowest of 39x25 as both 34x23 and 34x25 are lower. This may well be enough so i'd just swap the chainset and see how you go. If you need to go lower still then you can look at an 11-28 cassette. While the steps between gears due to the wider range cassette appear quite large, this isnt quite as bad due to the smaller chainrings effectively closing the gaps up.

+1

Also I would not worry about the steps between gears, in my experience the steps between close ratio cassettes designed for racing are too small for general riding. Obviously the mech needs to cope with the changes and the changes will be slightly more "clunky" but it does not really matter.

D

IShaggy

Diogenes wrote:

Wirral_Paul wrote:

As above really. Sounds like you need to swap chainset for a compact. This would immediately give you two lower gears than your current lowest of 39x25 as both 34x23 and 34x25 are lower. This may well be enough so i'd just swap the chainset and see how you go. If you need to go lower still then you can look at an 11-28 cassette. While the steps between gears due to the wider range cassette appear quite large, this isnt quite as bad due to the smaller chainrings effectively closing the gaps up.

+1

Also I would not worry about the steps between gears, in my experience the steps between close ratio cassettes designed for racing are too small for general riding. Obviously the mech needs to cope with the changes and the changes will be slightly more "clunky" but it does not really matter.

D

I'd go for a change in cassette first. Much cheaper and almost as effective for lowering gearing as 39x28 = 36.6 inches, which is not far off 34x25 = 35.7 inches.