changing casette for more climbing

thebourke

I have a Cannondale Cyclocross 105 bike that I bought about 5 years ago...

Its got a 28t cassette..

I do a bit of cycling up sally gap...Wicklow...Bohernabreena etc..however I found i really struggle on the steep parts ...should i be looking to change my cassette etc or is that possible?

i'm not an expert on bike maintenance..any advice would be welcome?

i use the bike for more climbing than flat cycling....

GoHardOrGoHome

Not an expert but I got a 32t cassette and it made a world of difference. Bigger difference between number of teeth on each sprocket so not as smooth a change going up and down the gears.

magicbastarder

yes, you can change your cassette; you'd also need to change your chain too.

thebourke

what about front and rear derailleurs...do they also need to be changed?

magicbastarder

depends; shimano claim a max of 28 teeth for what i suspect is a 5800 short cage, but AFAIK it can take 30.

your front derailleur won't need to be changed though.

strmin

Just remember that as soon as you have 32 at the back, you will want 34 next time you on steep parts. That's how it works.

nilhg

CX bike is likely to have a CX chainset 46/36, if the OP were to change that to a compact it might be enough to boost the climbing and give a little more speed on the downhills?

Macy0161

https://boards.ie/discussion/comment/117646223#Comment_117646223

You can get rear derailleur hanger extensions - Wolftooth Roadlink is the famous one, but you can get unbranded a lot cheaper on Ali (or even Amazon if you don't want to wait).

Paul Kiernan

OP - if you tell us model and sizing of existing chainset and rear mech it'll be easier to work out what the limitations are.

thebourke

My mistake its a Tiagra not 105!

Its a canndondale caadx tiagra cyclocross bike bought new in march 2017

rear derailleur - shimano tiagra

front derailleur -shimano tiagra

shimano tiagra 10 speed

caasette 28t

crank FSA Omega Alloy | 46/36

bb30

i got a new chain last december 2020.

smacl

https://www.boards.ie/discussion/comment/117669635#Comment_117669635

On that setup, I'd be going to 50/34 up front and 11/32 rear. Great thing about Tiagra that it is a cheaper groupset so this type of changeover shouldn't cost an arm and a leg. If you put a wanted in the adverts section you might find someone with compatible parts who has move up to 11 speed.

magicbastarder

main caveat there is that bike parts have been in very short supply recently, so it'll be harder to buy bits now than it was a year or two ago.

CantGetNoSleep

Could you also change the 46-36 to a 46-30? I know that FSA have had some sub-compact chainrings before the likes of Shimano, the first gravel bikes often seemed to have them

Might be the easiest in terms of fewest parts to swap as it is just a new inner chainring, 30-28 would give you a much easier time than 36-28, and a move to 50-34 would likely require a full new crankset, cassette, chain and possibly even a derailleur.

I'm not sure if it is possible on that chainset & front derailleur though - someone else will be more knowledgeable than me

smacl

https://www.boards.ie/discussion/comment/117671635#Comment_117671635

If the BCD is right, SPA cycles have a decent range of 10 speed chain rings, see https://www.spacycles.co.uk/m8b0s148p0/Drivetrain/Chainrings-Cyclotourist Changing from 36t to 30t could possibly require a different front mech if such a thing exists. I haven't seen 30t ever used as the small ring on a double before.

hesker

Not just a matter of BCD I think. Also have to take chain wrap into account and make sure the RD is up to the task.

Zen0

I have a similar (CAADX 2015) bike. Changed the rear cassette to one with 30/32 teeth and changed the small chainring to a 34 (FSA do one and it’s surprisingly lighter than the one it replaced). Didn’t bother changing the big chainring, but I tend to spin rather than grind. I’ve been up Priest’s Leap with that arrangement.

Zen0

This seems to be the updated version of the inner chainring I got:

FSA Super Compact Road N10/11 Chainring | Chain Rings | Wiggle

It's now rated 10/11 speed but I believe it should work. Only changing the inner chainring means you don't need to reposition your front derailleur.

thebourke

I didn't realise you could actually change your inner chainring...

So I could potentially have a 46/34 t then in the front?

Is there much difference in getting a 32 or a 34t cassette?

Am planning to get down to priests leap in cork next month....

Zen0

Yes, you can have a 46/34 in the front. That’s what I run on my cross bike, which has become my commuting/adventure touring/gravel bike.

The difference between a 32 and a 34 on the back is not huge until you are at the limit of your endurance on something really steep. But in reality you will make do with either. The real issue is what your rear derailleur can accommodate. For that, Shimano’s tech docs are your guide. Just Google Shimano tech docs and your groupset number.

Enjoy Priest’s Leap, it’s a real test of climbing ability in a magnificently remote location.