32T Cassette/Derailure Options

[MikeW-71]

That's a good point, my Defy runs a 12-30 Tiagra which has got me up everything so far. It depends how much steep stuff you'll be climbing (ie. 10%+ )

 

[aerobrain]

Yeah a 12-30 was my fallback but I'd still need a new rear mech as the short cages only seem to go up to 28T.

Currently have an Ultegra medium cage, if that'll work with a 30 then that might be worth a try.

There are at least two monster hills (for me) Hardknott and Wrynose. And its generally up and down for the 150 miles so just thought a real big bail out gear would come in handy for both steep hills and recovery on some longer shallower ones.

Some very useful tips guys, cheers.

 

[aerobrain]

Yeah a 12-30 was my fallback but I'd still need a new rear mech as the short cages only seem to go up to 28T.

Currently have an Ultegra medium cage, if that'll work with a 30 then that might be worth a try.

There are at least two monster hills (for me) Hardknott and Wrynose. And its generally up and down for the 150 miles so just thought a real big bail out gear would come in handy for both steep hills and recovery on some longer shallower ones.

Some very useful tips guys, cheers.

 

[Peteaud]

Yeah a 12-30 was my fallback but I'd still need a new rear mech as the short cages only seem to go up to 28T.

Currently have an Ultegra medium cage, if that'll work with a 30 then that might be worth a try.

There are at least two monster hills (for me) Hardknott and Wrynose. And its generally up and down for the 150 miles so just thought a real big bail out gear would come in handy for both steep hills and recovery on some longer shallower ones.

Some very useful tips guys, cheers.

The 28T that Shimano advise is not gospel.

Most will run a 30T because it is not the rear mech that sets the limit, it is the hanger. The longer the hanger then the more clearance you have.

Plenty of new bikes came with 30T Tiagra as standard, making Shimanos tech docs look stupid.

 

[aerobrain]

The 28T that Shimano advise is not gospel.

Most will run a 30T because it is not the rear mech that sets the limit, it is the hanger. The longer the hanger then the more clearance you have.

Plenty of new bikes came with 30T Tiagra as standard, making Shimanos tech docs look stupid.

IF there is a problem is it likely to be bad shifting or a mechanical failure?

If its bad shifting then I'll just try it and see. Just don't want to risk anything snapping as I've just had a £200 bill as my hanger broke :-( my own fault as I didn't replace it after a crash!! Lesson well and truly learnt!!

 

[Peteaud]

If in doubt go for a longer mech, the 105 long cage is very good, but most bike will run a 30t without issue. The diameter of a 30T is only just larger than a 28T. Put your gears into large large and see how much play you have in the rear mech, if you have loads, then the 30T should fit on without problems.

 

[aerobrain]

If in doubt go for a longer mech, the 105 long cage is very good, but most bike will run a 30t without issue. The diameter of a 30T is only just larger than a 28T. Put your gears into large large and see how much play you have in the rear mech, if you have loads, then the 30T should fit on without problems.

Yeah I suppose in simple terms if there's enough arc from small small to large large with some spare either end then nothing's under undue tension. Starting to understand the minefield now lol. Cheers :-)

 

[aerobrain]

You know when you have that moment of realising something's much simpler than you thought!!! Chain capacity of a mech is the number of links (length) of chain the cage needs to take up I.e 2 extra links for the two extra teeth on a 30. Feel a bit stupid now for over complicating it :-)

 

[Peteaud]

Yeah I suppose in simple terms if there's enough arc from small small to large large with some spare either end then nothing's under undue tension. Starting to understand the minefield now lol. Cheers :-)

The arc of the rear mech is adjusted by the B screw, so if your bike has a long hanger, then no adjustment is needed, short hanger bikes will need adjustment. My old Defy 2 did take a 32T on a standard 9 speed tiagra, but is was right on the limit, so a 30T ran fine. I did over 1000 miles before i changed bikes with no issues.

 

[aerobrain]

Cool cheers!

 

[Cycleops]

I run exactly the set up you have mentioned and it's fine, with a 105 med cage. The 105 doesn't come in long cage.

 

[Peteaud]

I run exactly the set up you have mentioned and it's fine, with a 105 med cage. The 105 doesn't come in long cage.

105 GS then.

 

[Kies]

My Giant Defy 4 compact has a 32T cassette.

Yep, so does my Brothers Defy 3 with Sora.

That's a good point, my Defy runs a 12-30 Tiagra which has got me up everything so far. It depends how much steep stuff you'll be climbing (ie. 10%+ )

I enquired at my lbs about a 12-30 105 cassette, and he said he needs to check before saying yes!!! I will do it myself me thinks.
Would my Defy have a short or medium hanger?

 

[Boon 51]

On my road bike an Allez Comp I took the cassette off (12/28 Tiagra) and fitted the bike with a Sram PG 1050 11/32 with a longer chain and its brill with no noise at all.
For me its an 11/32 every time as I live on a mountain and I just need it...

 

[Cubist]

Same here. 105 med with an 11-32 10 speed on the Cube.its a Deore cassette, although any MTB cassette will do. Woollyhatshop often has bargains in.