Fitting 11-32 teeth cassette onto a road bike

[simmi]

I am going to be doing a few proper hills in the Matlock area so to give myself a little help I wanted to fit a 32T cassette.

I ordered the cassette a few weeks ago but didn't get round to ordering a MTB spec rear derailleur.

Well anyway I was just messing about really and fitted the cassette to my bike with the original shimano tiagra rear derailleur.

It seems to fit just fine, the top jockey wheel is close to the 32T cog when in use but it is not touching and when I put it under load it moves a couple of mm further away if anything.

On a very short test around the block everything seems fine hard to tell for sure with a 32T on the flat my cadence was about 150 and still was not working the gear but could tell nothing was rubbing.

Am I missing something? I don't want to get halfway up "Bank Road" or "Riber" and find out then.

 

[black'n'yellow]

I don't think you're missing anything. If you've tried it under load in your new 'lowest' ratio - and provided all your other gears still work fine - then it sounds good to go. Presumably you swapped the chain for a longer one?

 

[simmi]

I don't think you're missing anything. If you've tried it under load in your new 'lowest' ratio - and provided all your other gears still work fine - then it sounds good to go. Presumably you swapped the chain for a longer one?

Cheers B'nY', I swapped the chain for a new one, I thought the same as you and cut it one link longer but this proved to be too long for the 11T on the cassette so ended up using it at the same length.
I have manually moved the derailleur and there is still plenty of travel in each direction when on the highest and lowest gear ratios.

 

[Peteaud]

http://www.cyclechat.net/threads/9-speed-tiagra-11-32.117720/

Check all the gears, it does work but gets close.

I ended up with a 30T and really pleased with it.

 

[black'n'yellow]

ok - so long as you're not cross chaining 50-32 or anything like that, I think you'll be fine..

 

[Rob3rt]

http://www.cyclechat.net/threads/9-speed-tiagra-11-32.117720/

Check all the gears, it does work but gets close.

I ended up with a 30T and really pleased with it.

I pushed harder on the pedals, it worked wonders

 

[TheDoctor]

I've done exactly this - 10 speed SRAM 11-32 cassette, with a Sora compact (!) and a 105 rear mech (!!)
There's no way on earth it should work, but it does

 

[simmi]

http://www.cyclechat.net/threads/9-speed-tiagra-11-32.117720/

Check all the gears, it does work but gets close.

I ended up with a 30T and really pleased with it.

I've done exactly this - 10 speed SRAM 11-32 cassette, with a Sora compact (!) and a 105 rear mech (!!)
There's no way on earth it should work, but it does

Cheers Peteaud and TheDoctor looks like you have already done exactly what I have, it gives me a little more faith it will be OK.

It is very flat by me so usually my 12-23 combined with a compact crank are great.

I just wanted the 32T for one ride and will then be changing it back until needed again.

 

[TheDoctor]

Getting a 32T under a rear mech not designed for it is a bit suck-it-and-see. I can only assume I've got a longish rear mech hanger.
Having said that, a half-decent 9 speed MTB mech will hardly break the bank if you need to get one. But definitely try with the existing mech first.

 

[Tynan]

you're all gay weedy legs

man up the lot of you and put proper cassettes back on

tsk

 

[TheDoctor]

And just what are you trying to imply, petal?

 

[simmi]

I have been doing a little bit of thinking as to why it has worked.
I only needed 2 things to be right for it to work first the hanger must be long enough so the mech can physically fit under the cassette and second the arm length has to be long enough to allow for a change from 11T to 32T.
I think the arm length was the one where luck played a part with my bike design and 56cm frame the chain length fell nice with a little play at each end of the scale.
Maybe if I had had a 52cm or 60cm frame or a different design of bike it would not have worked because too much of the chain play would have been at one end of the scale, and the chain can only be altered in 1 inch lengths.
That is why I would guess MTB rear mechs have very long arms to allow for all possibilities.

 

[youngoldbloke]

Agree re mech hanger. How does the frame size make any difference? Aren't the chainstays a constant length for any given frame?

 

[Peteaud]

Its all down to the hanger.

It works with some bikes only.

Mine (2010 giant Defy 2) was right on the limit with 32T but the 2012 Giant comes with a 30t as standard.

Lucky i have some cassettes laying about from mountain bikes.

For what its worth any issue just fit a deore rear mech.

I dont know why manufactures keep fitting different toothed cassettes, the 2010 defy was 25T, 2012 was 30T and 2013 is 28T

I live in a hilly area (The Blackdown Hills) so do like a bail out gear

 

[twowheeler]

Getting a 32T under a rear mech not designed for it is a bit suck-it-and-see. I can only assume I've got a longish rear mech hanger.
Having said that, a half-decent 9 speed MTB mech will hardly break the bank if you need to get one. But definitely try with the existing mech first.

+1

Gordon