11-27 cassette

forgotrafe

Last summer I fitted my bike (2010 Cannondale Synapse) with an 11-27 cassette rather than the 12-25 it came with.

Not only did this spread the gears out a bit more (nice), it helped enormously with the hills which I was finding a struggle with the compact chainset (previous bike was a triple). My rear mech is Ultegra 6700 (presumably short cage) and that's fine with the 2 extra teeth.

Chatting to someone at work and she's also gone from triple to compact and struggling a bit on the hills. She wanted to go back to a triple but I suggested swapping out her cassette would be much cheaper and problably solve the problem (she's way fitter than me).

But can't find an Ultegra 11-27 cassette or indeed any 11-27 cassette except a way-out-of-price-range Dura Ace one. Her bike has an Ultegra rear mech which I presume short cage (not had a chance to look at it or get the model number yet).

Questions:

I believe 11-28 isn't an option without a medium cage mech?
Does anyone make an 11-27 cassette?
Any other advice (other than get much fitter!)?

maddog 2

9 or 10 speed?

Mister W

All Shimano rear mechs should cope with a 28t cog. Officially the max is 27t for some of them but lots of people run 28 without any problem. The length of the cage simply changes how much chain slack it can take up. A long cage mech is required for a triple chainset because it needs to take up a lot of chain slcak when you're on the small ring. A short cage mech is fine for a double.

rickwiggans

I run a 28T cassette with an Ultegra short cage R.D. It's fine - you'll probably have to tweak the B-screw a little.

forgotrafe

Thanks for the info.

I did check before posting and official line on my mech was 27T max.

Both bikes are 10sp.

Being much fatter and far unfitter than the girl at work, maybe I'll try the 28 and give her my 27

I can measure it, but would I need an extra link in the chain going to 28? Got away with existing chain on a 27.

maddog 2

10spd is available in 12-27 and 11-28

the latest rear mechs (5700, 6700, 7900) can handle 28t no problem.

older ones are officially only rated at 27t max, as said, but usually can manage 28t with a tweak of the tension screw and a not-too-sloppy chain but it does depend on mech hanger length, which is not always the same length, so it's not guaranteed it will not rub the top jockey.

No need to lengthen the chain. Not unless the current length is super tight.

rickwiggans

Should been fine - coz in any case, you won't run on the 28T whilst on the big ring WILL you?

Mccaria

The 6700 rear derailleur is designed to take the 11-28 block and will work with a 14 teeth differential on the front chainset..

http://bike.shimano.com.sg/publish/cont ... ype-..html

forgotrafe

Thanks for all the advice, really helpful.

maddog 2 - couldn't find 12-27 either on the likes of CRC. Though 11 is handy when gravity is on my side

Mccaria - thanks for that, the thing I found said 27T but that quite clearly says 28T for my 6700 SS.

Girl at work is bringing her bike in on Fri. I'll see what rear mech she has and will go from there, but quite favour 11-28 for me and give her my cast-offs

forgotrafe

rickwiggans wrote:

Should been fine - coz in any case, you won't run on the 28T whilst on the big ring WILL you?

No! Not least because I like my drivetrain to be silent

rowings MTP

Sram do a 11-27 cassette (PG1070?) which was on offer on Wiggle last week for £50ish and is Shimano compatible. May even be a 28T option aswell.

I fitted one last year but did find the spacing between gears was a bit stretched so swapped to a 12-26. Do you need to keep the 11T ring?

maddog 2

forgotrafe wrote:

maddog 2 - couldn't find 12-27 either on the likes of CRC.

105
http://www.merlincycles.co.uk/Bike+Shop ... SSETTE.htm

Ultegra
http://www.merlincycles.co.uk/Bike+Shop ... 0-CASS.htm

DA
http://www.merlincycles.co.uk/Bike+Shop ... e_1712.htm

forgotrafe

11/12 or 26/27/28 are all options though I have to say I really like my 11-27.

Thanks for the SRAM idea though.

forgotrafe

Thanks maddog - forgot about Merlin!

Thanks everyone, you'll help make a pretty young girl very happy.

maddog 2

this thread is useless without pics


[sorry]

forgotrafe

LOL!

janwal

I run the Sram 11-28 on my triple and enables me for the most part go most places on the middle ring.It fitted without any mods apart from a 1mm shim on the back of the cassette to take out any play.Mike at Highonbikes has them on offer at the moment for only £41.95,just choose your size.He offers excellent quick service,have used him many times.He answers any email queries quickly aswell.
http://www.highonbikes.com/drivetrain/c ... speed.html

maddog 2

the Openglide (OG) Sram cassettes are fine but I prefer the shifting on the newer powerglide versions (PG).