Rear Cassette ratios?

JoeAllez11

If I am buying a new 10 speed cassette (Shimano 105 10 Spd) what would be the optimum one for relatively flat riding??

Thank you

Garry H

It's s bit like asking for an optimum shoe size ;o). Really depends on how strong a rider you are andcalso what size chainrings you use. For a relatively strong rider, then a 11-23 would be a good place to start. you should be able to take a good guess yourself, based on what you use now...

JoeAllez11

Garry H wrote:

It's s bit like asking for an optimum shoe size ;o). Really depends on how strong a rider you are andcalso what size chainrings you use. For a relatively strong rider, then a 11-23 would be a good place to start. you should be able to take a good guess yourself, based on what you use now...

Okay thank you, I'm quite inexperienced so am trying to get clued up on these things

nathancom

It depends on your Chainset size. I wouldn't advise 11-23 on a double. If you go for a 12-26 you would probably be ok on either double or compact. I am not sure what sizes Shimano cassettes come in tho.

charlie_potatoes

What ratios do you have up front?
I have a compact 50/34t and I find an 11/25 rear cassette fine although for a really steep and long climb I would prefer something like a 12/28. As mentioned its relative to how strong a rider you are?

JoeAllez11

Charlie Potatoes wrote:

What ratios do you have up front?
I have a compact 50/34t and I find an 11/25 rear cassette fine although for a really steep and long climb I would prefer something like a 12/28. As mentioned its relative to how strong a rider you are?

I also have a compact 50/34 on the front but am aiming to upgrade it to a double within 6 months or so. I am still fairly young but am pretty fit for my age and strong too.

Garry H

Try 11-25 and see how that feels. You really are the only person who'll know in the end. i used to use 11-23on a double, but now use 12-25.

fatdaz

I wouldn't replace the compact with a double until your biggest gear is no longer big enough. You're losing flexibility at the expense of bigger gears so if you need bigger gears then great but why bother otherwise

JoeAllez11

Thats a fair point, thanks for the help, I can only find them in 11-25, 11-28

nathancom

A double isn't an upgrade just a different spread of gears. Basically you end up with less overlap allowing you to get some lower gears, with the sacrifice of bigger jumps between the two front gears. It isn't the biggest difference so wouldn't rush to change immediately. On a compact 12/26 will cover you well in case you find the odd hill somewhere and leaves you with a plenty big enough high gear.

JoeAllez11

Does the number (11/28). mean the number or teeth on the cog?

charlie_potatoes

JoeAllez11 wrote:

Does the number (11/28). mean the number or teeth on the cog?

Yes
The smallest and the largest cogs

JoeAllez11

So an 11/28 has a better climbing gear than an 11/25

charlie_potatoes

JoeAllez11 wrote:

So an 11/28 has a better climbing gear than an 11/25

Yes but I find the 25 okay for all of my local hills which are up to 12%