12-30 cassette with 105 mech

muttley_109

I'm thinking of putting a 12-30 cassette on a Cannondale CAAD10 which is currently fitted with a 105 5700 mech. Im not sure if it is a 5700 or a 5700A. i'll check tomorrow. I also have a 5701 mech I could use if needed.

Has anyone successfully done this? There seems to be quite a bit of conflicting info about so i'm not sure if it will work.

Thanks

Ben

borisface

It depends on the angle of the rear mech drop-out and whether there is sufficient clearance so the rear mech doesn't come into contact with the sprocket. If the B-screw which screws into the dropout is sufficiently long you can run a 30. You can swap the B screw around so that it faces the opposite way which may give you an extra mil or two. Sheldon Brown's website has details on how you do it. You may also need to lengthen the chain.

It didn't work for me, so I had to get a mtb mech, summat like a deore. If you do this you'll be able to run a 34 or maybe even a 36. Make sure you get a 9 speed mech rather than the 10 speed, as 10 speed mtb mech won't work.

Strangely enough, although my 105 wouldn't cope with anything bigger than a 28, I have just got an apex (on my touring bike) to work with a 34 although max stated is 32.

mamba80

Have a look on shimano tech docs under 105, will give you the info you need.

mr_evil

I am using a 12-30 with a 5700 rear mech (original, non-A). Not only does it work, but the b-screw is only set about half way, so it would probably work with a 32 too. Presumably my frame has a particularly long mech hanger.

So, try it and see.

freezing77

12-32 works on my Ribble gran fondo with a 105 5700. It did not work on a friends Bianchi.

buckmulligan

Yeah I'm looking to do the same thing ahead of a trip to the Alps this summer. Did a lot of research online and as you say lots of conflicting info. According to Shimano max sprocket size is 28T, but this is only the worst case scenario and on certain frames will take more.

Also check whether you've got the short- or medium-length cage, because (assuming you're already running a compact chainset) you'll be 1 tooth over the stated max capacity for the short-cage mech as well. I think this has a bit of flexibility as well though.

I'm just going to buy a cheap Tiagra one and see though, it's the only way you'll know for sure.

muttley_109

I've ordered a 12-30 ultegra cassette. As you say its the only way i'm going to know for sure. I'm sure I can get it to work on one of my Bikes!

markhewitt1978

Another person who runs 12-30 with 5700 checking in

slowbike

I've put 30-12 on my wifes bike with a medium length 5700 - worked fine for 200 miles last week...
£15 for a 30-12 cassette isn't a huge amount to lose if it doesn't work.

arlowood

I've run a Tiagra 12-30 cassette with a 105 5700 short cage mech on three different frames over the last couple of years.

No problems really with any of them save for a bit of tweaking of the B-screw on the most recent build (2004 Trek 5200)

As said above, the Tiagra cassette is pretty cheap so if it doesn't work you've not lost a lot and can sell it on to recover some of you original outlay.

careful

Another person who runs 12-30 with 5700 checking in

And another - on two bikes, no problems.

littledove44

I have an 11-34 on mine. Is that a record then?

markhewitt1978

littledove44 wrote:

I have an 11-34 on mine. Is that a record then?

Can't be a record, it's a cassette!

I'll get me coat...