groupsets and cassettes, do they matter?

pbassred

I'm thinking about buying a new cassette with a different ratio, The last one I bought was 105. Does it matter? Suppose I got a sora? Would I notice?

keezx

Cassettes don't have ratios's , they have teeth.

pbassred

The relationship between front and back is a ratio.

andy9964

pbassred wrote:

The last one I bought was 105. Does it matter? Suppose I got a sora? Would I notice?

Depending on the year, you'd be a sprocket or two short

Garry H

it needs to have the same number of cogs as the last one

reacher

No m8 they all work as long as you match ten speed with ten speed nine speed with nine speed etc, slight differance in shift quality is all but plenty good enough to use

pilot_pete

pbassred wrote:

I'm thinking about buying a new cassette with a different ratio, The last one I bought was 105. Does it matter? Suppose I got a sora? Would I notice?

As alluded to above, as long as you have the same number of cogs on the new cassette, this is the starting point. So, a Dura Ace 10 speed cassette and your old (assuming it is) 10 speed 105 will both work fine, as will any other 10speed Shimano cassette.

However, if you are going to change ratios as you put it, I assume you mean you want a different size cassette, I.e. perhaps one with lower gears (different number of teeth on some of the sprockets (cogs)? If so, then you need to be aware of the capacity of your rear derailleur - depending on the length of the cage (the two bits of metal that sandwich the pulleys) dictates the capacity of the derailleur. Most road bikes will be sold with a short cage and this has a maximum size lowest gear (sprocket/ cog) that it can handle. Check online for the Shimano technical documents for your particular model derailleur. If you find for example that the maximum capacity for your cassette is a 28 tooth biggest cog, then you will not get it to work if you want to fit a 32 tooth biggest cog cassette.

If you want to fit a larger cassette you can only go up to the maximum cog tooth count stated by the manufacturer (well, to a certain extent - you can sometimes go a little bigger and still get it to work) and if you want to go bigger than that you would have to replace the rear derailleur for one with a longer cage. This is to allow the derailleur to be able to take up the larger variance in chain length required from the small front ring/ large rear cog to large front ring/ small rear cog variance.

The only other issue is chain length - if you fit a different the sized cassette than you are currently running, you may need a longer chain (if you go for a bigger cassette) or to shorten your chain if you swap to a smaller cassette. Once again the Shimano Dealer Manual available online for your groupset has details of how to install a chain, including working out how many links you need.

All the best.

PP

Matthewfalle

Dependent on wear you may need to pop on a new chain but so long as you match 10 for 10, 9 for 9 etc it matters not a fig.

Remember that SRAM will work with Shimano if that helps budgets.

pbassred

Thank you for the advice. I probably didn't ask the question in a precise enough way. Yes you naturally need to match the number of cogs - 10 for 10, 8 for 8 ect. And similarly you can only fit the cassette size that the rear derailleur can accommodate.
What I was concerned about was the performance difference between say SRAM1030 and 1050 or 105 and ultegra - if any .

Ben6899

Some will disagree (I think), but SRAM to SRAM, Shimano to Shimano, Campagnolo to Campagnolo you won't notice a difference in shift quality between, say, 105 and Dura Ace.

Fypo

There probably more of a chance you notice the 60g weight difference between 105 and ultegra than the shift quality difference.

keezx

People who do notice 60 gram on a cassette (while riding) do not exist.

keezx

pbassred wrote:

The relationship between front and back is a ratio.

You asked someting about a cassette and never mentioned the front, so NO RATIO.

agnello

Keezx wrote:

pbassred wrote:

The relationship between front and back is a ratio.

You asked someting about a cassette and never mentioned the front, so NO RATIO.

:roll: