swapping rear cassette, maximum teeth for road bike

[jifdave]

hi Guys im looking to change the rear cassette on my triban, at the minute i really struggle uphill so want more teeth on the ring. also i run out of gear when on a gentle decline so hoping to swap 25-12 for 30-11
i've been trying to read up on it and i've seen road bikes cant really take more than 27t.
although wiggle has several in the 'road' section that are 30-11.

im confused.... can anyone help?

I know the how to change it and have the tools just the technical guidance im after.

cheers

 

[Pedrosanchezo]

Sheldon is your friend. Check out that link, it's very informative.

You might be able to do it without changing anything but you might have to do some adjusting. It's going to depend on your current setup. See what you think of Sheldon's advise.

 

[malcermie]

hi Guys im looking to change the rear cassette on my triban, at the minute i really struggle uphill so want more teeth on the ring. also i run out of gear when on a gentle decline so hoping to swap 25-12 for 30-11
i've been trying to read up on it and i've seen road bikes cant really take more than 27t.
although wiggle has several in the 'road' section that are 30-11.

im confused.... can anyone help?

I know the how to change it and have the tools just the technical guidance im after.

cheers

Was looking at changing my cassette.........but realized the first thing to change was me!!! I needed to get fitter and to make very small adjustments to saddle height and handlebar angles, Now going up hills that only a month ago I would have baulked at!!

 

[jifdave]

ah i'm working on me, im doing at least 50 miles every weekend sometime 80.
my problem is i've signed up for the kentish killer which at present is a little beyond me, no reason i cant change the gearing back in the near future.

i just feel at present i'll get more out of my training if i manage to ride up the whole hill rather than most of it with a walk to the top.....

@pedrosanchezo thanks for that, should have thought, if in doubt- ask sheldon

 

[Jon2]

Some of the newer rear mechs have a maximum sprocket size higher than 27. I think the Tiagra goes up to 32, some Sram ones are the same. That's why you're finding road cassettes with such high tooth counts. As far as i know, this is pretty recent, so anything more than a few years old will be limited to 27 teeth, but could possibly be pushed a little.

 

[Widge]

I tried to pose this question in the 'Triban O C' thread so would be interested in peoples experience here.
Conventionally, most Road Cassetes seem to be 25 or 26 teeth max.............but Sram does a range of off the peg sizes, including 28 and 30 I think...and I am not sure whether a standard set-up can adapt to this, or whether extra measures need to be taken.

 

[Biker Joe]

You might consider changing the chain ring size.
I currently use a 53/38 on the front, 12/27 8 speed cassette on the back.
Lovely big gear for down hills and a nice low gear for them pesky hard climbs.
Ribble has a nice selection of chain rings for starters.

 

[the_mikey]

You need to find out what cassette the triban3 will take, ie, you need to know how many speeds the cassette needs to have and the maximum number of teeth the rear derailleur will support. Also you may need a new chain.

 

[Widge]

Thanks for that Sheldon link.........his advise seems to be 'suck-it-and-see'! ,,,,but very informative as usual.

 

[TheDoctor]

A quick Google tells me that the Triban 3 has a Shimano 2300 rear mech, which is only rated to take a 26T sprocket. And the cassette is 8 speed.
Now, my 105 rear mech is only rated to take a 27 sprocket, which doesn't explain how it's coping with the 32 sprocket I have on there. In your position, I'd either :-
Get a 12-30 cassette and try it. Worst case, you'll also have to buy a cheap 8 speed MTB rear mech, like an Acera at £15.
Go for broke and buy the Acera mech and a 11-34 rear cassette. That'll get you up anything.
After all, if you're struggling with the lowest gear, there's no point fannying about lowering it by a little bit. You may as well get something that'll let you ride up brick walls and cliffs!

 

[jifdave]

After all, if you're struggling with the lowest gear, there's no point fannying about lowering it by a little bit. You may as well get something that'll let you ride up brick walls and cliffs!

Alas i have chosen to fanny..... ordered http://www.wiggle.co.uk/sram-pg850-8-speed-cassette/ earlier i hope it fits if not, we shall work on a new plan!

 

[TheDoctor]

What ratio - the 11-30?
The SRAM cassetes are nice - lighter than Shimano for the same price IME, and they shift well.
You'll probably need a new chain - I expect the current one won't be long enough.
SRAM or KMC are good and come with a quick link.

 

[Widge]

Thanks for the info, Dr.

jif...be sure to let us know how it runs, won't you?

w

 

[jifdave]

I've gone 28-11 not a huge difference but will just give me a little more both ways. How many extra links would you guess I'd need to add?

 

[BimblingBee]

You will probably get away without adding any and 3 teeth will actually make a surprising difference!