Gear Ratio's!?

nosoapwatching

Hi, i am a relatively newcomer to cycling and enjoy touring events. like to climb hills more so than race or decend, what is the best chain ring/ gears/ etc i should use to allow do this. i hear talk of compacts, 50-34 etc but this all means nothing to me sorry........

velo.2010

Tends to go Triple, compact, standard in order of easiest to use gears for climbing.

Triple tends to be 52-39-32 or variations of that. Compacts are almost always 50-34 and standard chainsets are typically 53-39. Numbers refer to teeth in the big rings at the front.

The small rings or sprockets at the back range from close ratio, racing 11-23 to mountain friendly 12-27 teeth.

If your light and a good climber a compact is ideal for this country. I can get away with a standard for the wicklow mountains but to venture abroad I would need a compact.

Hope that helps, plenty of info on wiki and cycling sites.

DualFrontDiscs

Without over simplifying matters, your gears are there to help you maintain your cadence over varying terrains.

So, for uphill you want a gear that's 'low' enough that you can maintain your cadence without having to stomp too much on the pedals.

For downhill you want a gear that's 'high' enough that you're not spinning out (as if there's no pressure on the pedals) at your cadence.

As with everything, everyone is different.

DFD.

on_the_nickel

I'm getting a new bike soon and am wondering if I should get a compact or stick with a standard.

I'm currently using a standard, 39/26 being the lowest gear available. I don't struggle that much up the hills of Cork, but occasionally when the gradient is > 10% I go looking for a lower gear and get the awful sound of nothingness.

I intend to go and do some European climbs, hopefully the Etape or La Marmotte or similar at some stage, probably not for a few years though as the kids are still a bit young.

So, any thoughts? For what it's worth, I'm decently fit, definitely intend to get fitter, but 6' 2" and around 13.5 stone.

niceonetom

I've just done the Marmotte. I think you'd have to be mental or a total beast to use anything other than a compact or a triple for it. I used a compact with 11-28 on the back and I used all of it. I'm no slouch either.

For Ireland a compact with an 11-23 or 11-25 is plenty.

dexty

Hi, interested in this tread, I have an 8 speed 12-25 cassette on the back of my bike and for the mountains I was thinking of upgrading to a 10 speed 12-28 and was wondering would it make much difference? It's a shimano groupset and i see SRAM have an 11-32 cassette available. Do I have to stick to Shimano or could I put an SRAM cassette on? Also is it difficult to change a cassette and do the gears have to be re ajusted to compensate for the extra 2 cogs? cheers, D

niceonetom

dexty wrote: »

Hi, interested in this tread, I have an 8 speed 12-25 cassette on the back of my bike and for the mountains I was thinking of upgrading to a 10 speed 12-28 and was wondering would it make much difference? It's a shimano groupset and i see SRAM have an 11-32 cassette available. Do I have to stick to Shimano or could I put an SRAM cassette on? Also is it difficult to change a cassette and do the gears have to be re ajusted to compensate for the extra 2 cogs? cheers, D

To go from 8 to 10 speed you would need to upgrade your shifters and derailleurs too - it's not just a question of buying a cassette.

SRAM and shimano cassettes are compatible (at least at 10 speed), I use SRAM cassettes in an otherwise ultegra drivetrain. Works fine.

11-32 is beyond the capacity of any shimano road derailleur though - it's a mountain bike cassette. Even my 28 is technically beyond the limits of my derailleur which is only rated for 27. There's a new SRAM Apex groupset out that can take huge rear cassettes though so if your really want a double that can go up walls that could be an option.

dexty

ok thanks for that Tom, sounds like i'll just upgrade the bike!!! will going from a 12-25 to a 12-28 make a big difference on hills? Cheers, D

DualFrontDiscs

dexty wrote: »

Hi, interested in this tread, I have an 8 speed 12-25 cassette on the back of my bike and for the mountains I was thinking of upgrading to a 10 speed 12-28 and was wondering would it make much difference? It's a shimano groupset and i see SRAM have an 11-32 cassette available. Do I have to stick to Shimano or could I put an SRAM cassette on? Also is it difficult to change a cassette and do the gears have to be re ajusted to compensate for the extra 2 cogs? cheers, D

Without over complicating matters, you can't mix Shimano, SRAM or Campagnola compenents and you can't mix different 'speeds'; 8 speed, 9 speed, 10 speed, etc.

The reason you can't mix manufacturers is that whilst the components perform the same functions they do so in a different way, so they need to be 'mated' with the matching component from the same manufacturer.

The reason you can't mix speeds is, the greater the number of gears, the thinner the components. If you think about it, your rear wheel today has an 8 speed cassette. You could physically fit a 10 speed cassette to the wheel. But now, instead of 8 speeds, you have 10, something's changed. What's changed is the width of the individual cogs. So you would need a new chain aswell. And the chain attaches to the chainrings at the front, so they would have to change also. And your shifters only have 8 clicks, with spacing for an eight speed cassette, so you'd have to change those also.

Hopefully that makes sense.

DFD.

SamB64

Personally, unless you enjoy the techy side then I'd keep it simple.

Go for a triple with a wide ratio block on the back and just get used to keeping yor cadence above 80. This will give you lots of experience of changing and selecting gears while protecting your knees.

If you really want to get into your gear the Sheldon's site has a good tool on it

http://www.sheldonbrown.com/gears/

Hope this helps,

Sam.

nosoapwatching

cheers for the response guys, looks like i have to just toughen it out and get used to not having the comfort of a triple anymore! thanks again.