Change rear cassette, go to a compact or both?

coolhandbilko

Hi there, first post and probably been asked before so apologies for going over old ground. Currently running tarmac elite 53-39 and 13-25 in summer and allez elite compact 50-34 (standard cassette(too lazy to go to shed to check)) in the winter. Discovered cassette on tarmac wasn't standard issue and guess previous owner was time trialling with that set up. Happy in top gear of Allez and could do with a little more top end so was happy with 53-39 on Tarmac although don't spend too much time in top gear of Tarmac. In fact Tarmac round home is fine as Essex is pretty flat. Did Tour of Britain SW stage on Tarmac and struggled like hell on climbs (it was tough, honest gov!). Would like to do more sportives this year and as they usually involve some interesting hill climbs feel I need some kind of change.
Should I change back cassette to a 12-27 or 11-28 and if I do will it make that much difference. Or should I change 53-39 to a compact 50-34. Or should I change back to a compact and also change rear cassette to 11-28 thereby giving me ability to climb and a little more top end.
And finally what are the implications of these options, ie what else will I need to do should I go for it.
If nothing else, I would at least like to get Tarmac back to roiginal spec.
Thanks for your help
CHBilko

Mister W

Why do you want to get the Tarmac back to standard spec. If what you've got is working for you then why change it? You can get yourself some significantly lower gears by changing to a 27 or 28 (8 or 12% lower than you have currently) which would be a cheap and easy change. You could also change the 53 chainring for a 52. If you still find you need lower gears then consider a compact but it's a much more expensive option so it should always be your last choice.

jc-bike-person

If they are compatible you could swap the compact on your Allez onto the Tarmac
This would tell you if you ‘need’ a compact on the Tarmac for Sportives
Just find some hills and give it a go
You could also decide if the 12 is enough on a 50 at the top end

(PS- a 12-25 sounds pretty standard to me)

northpole

When I tackled my first sportive last year in the south downs it was quite a shock - so much for gently rolling countryside as someone had described to me!!
Immediately afterwards I changed to a compact and I would strongly recommend you do the same - it really made a world of difference on the hills.
I'm surprised you can't tell this between your existing bikes.
Ideal match for the compact is an 11-25 cassette unless you have monster hills to face when 12-27 or 12-28 may be more appropriate.
That's only my opinion - we all seem to approach hills differently in terms of ability, cadence, etc.
Peter

dcj

+1

chrishd883

You could try tp work out what range of gears you need.

Ride the Allez and see what gears you need at the bottom end, ride the Rarmac and find what top end you think you need. The look up on a gearing table to find the gearing range in inces that best suits you. This costs nothing but time and will let you know your options!

With my fitness levels / strength (i.e. low!) I have bikes set up in compact and triple that have the same range!

But I would think that if you did the Tob on a 53/39 you might not need to go as far as a compact.

As an alternative I would suggest the first step is to fit a wider rear cassette range.
If you need more - change your inner ring for a smaller one.
This might be enough for you!

coolhandbilko

Thanks chaps, that's given me food for thought. I think I will definitely try some of those suggestions. The difference between the compact and 53-39 is quite apparent but what I was trying to get an idea of is how much of a difference would there be by changing cassettes as opposed to chain rings. My suspicion is, probably not a lot. But if I have a play around with swapping components (which I am reasonably confident I can) then I should get a good idea of what I need. Keep you posted.

thanks

chb