Gearing Compact Over Triple

NWLondoner

My current bike has a triple 50/39/30 with a 11-25 Rear cassette.

Now some of the bikes I am looking at come in either a compact or double only.


The compact has 50/34 and 12/27. How much difference would I notice? I need as much help with hills so would a different rear cassette be better?

I can see both the pro's and con's of both triples and compacts. Personally i am fed up of the adjustment on my triple so would prefer a compact if it can meet my needs.

roger_merriman

almost no differnce in gearing, 30t - 25t/11t = 31.4 inches compared to 34t - 27/12 = 32.9 inches.

but a fair jump between the front chainrings on the compact.

richa

Well... As per Sheldon...

34t/27 => 33.1"

This is the equivalent to 30t/24 (32.9")

So, if you don't need your current 25 cog cassette and think you'll be ok with equivalent to a 24 cog, then you'll be fine.

I believe it might be possible to get a 28t that would work??? That would be 31.9" which would be very close to what you currently have.

Mettan

NWLondoner wrote:

The compact has 50/34 and 12/27. How much difference would I notice? I need as much help with hills so would a different rear cassette be better?

It is possible to use a larger cassette in tandem with a Compact 8/9 speed (not sure what bikes you're looking at?) - due to a chronic Knee injury (ACL) I currently use a 50/34 with an 11-32, giving me a smallest gear of 34/32 - the chainset and cassette are used in tandem with a "MTB" rear deraileur - works perfectly with no major issues, so it can be done - of course, that's not to suggest its the best solution for anyone else (or that it's a better setup than a Triple....) - 34/32 's rarely used, but it is there if necessary.

jswba

I recently went from the the same setup as your old one to the new one that you're proposing. There truly isn't much of a difference in the lowest gears, and I've not struggled up any hills wishing I had an extra cog on the cassette.