UKC

I have a Trek 2.5 Alpha Madone which is now three years old and has an Ultegra compact groupset. I'm happy as Larry with it, but climbing is becoming a chore and I'm not getting any younger.

I don't want to splash out on a new bike with a 'triple' (Granny ring) and its been suggested that I change the cassette, and with the right one, I can maintain my top-end speed but could significantly lower the bottom-end gearing and therefore making climbing easier.

It sounds like the perfect solution but thoughts from the cycling aficionado's would be very welcome

In reply to bluebealach:

I'm pretty sure that a standard ultegra rear mech will only handle up to a 27 rear sprocket but you can get one with a medium cage

In reply to bluebealach:

A 12-28 or even a 13-28 would be better as you wouldn't lose as many middle gears.

E

In reply to bluebealach: if you buy the 6700 Ultegra GS rear derailleur that will take a 30T cassette which shimano now do in the Ultegra range as a 12-30T. Will cost about £90 for this assuming you are running ten speed 6600.
You will also need a new chain. Ribble are doing the KMC X10 SL TI N GOLD for £39.16 instead of £60. Nice bit of bling and a very good chain to finish it off!

In reply to bluebealach:

If you're already on a compact then changing the cassette is the way to go. What size cassette do you have at the moment? If you want to keep your top end gear ratio the same then you need one with the same size small sprocket and a bigger large sprocket, e.g. if you have an 11-25 then try an 11-28

Check the maximum cassette size of your derailleur though, you might need a medium cage if you want a really big cassette

In reply to sleavesley: I am sure some people run a SRAM PG1070 11-32T with the above derailleur although the shimano manual wont back this claim.

In reply to bluebealach:

When you're looking at the sizes of the individual sprockets you'll find that the ones with an 11t very rarely have a 16t with a jump from 15t to 17t.
I promise you - you'll miss the 16t more than the 11t.

E

In reply to a crap climber:

At the moment its a 12-25. The guy in the cycle shop did say that I would have to 'lengthen' the derailleur??

It does seem to the the monetary answer as long as I wont be jeopardising something else.

Not planning anything silly, just the Bowland Fells area.

In reply to Enty: Thanks Enty....I think you have a point there.

In reply to bluebealach: I would look at getting a 12-27 or even a 12-30 if your rear mech can take it, my 105 mech has a max sprocket size of 28 although I've managed to use a 32 tooth sprocket without any issue so it may depend on the frame a bit.

In reply to sleavesley:
I believe I am yes a new chain costing about £60 was mentioned.

Its sounding like this is a distinct possibility from the positive reaction I'm getting....thank you.

In reply to bluebealach:

Bloody hell a 10s Ultegra chain is 18 quid at Wiggle.

E

In reply to Enty: Think the shop would wear it if I got some of the odds and sods and get him just to do the fitting??

In reply to bluebealach: had a look for you. Upgrade to 6700 GS derailleur and 12-30t cassette ultegra with the KMC chain above is £175. Cheaper option is to get a 105 cassette as that's what came with your bike anyway.get the 12-28 for £34 and a KMC X10 L in silver is about £23. If you lived local I would do it for you but unfortunately you don't!

In reply to bluebealach:

No - but I'd question 60 quid for a chain. Even fitted.

E

In reply to Enty: the KMC SL DLC is £70 but does come in Barack and red or black and celeste for Bianchi owners. Pure bling mind even with its diamond like coating.

In reply to sleavesley:

Ha ha!!

E

In reply to sleavesley: Forget the 'bling'?? I get embarrassed putting on the lycra.....

To be honest, upgrading to 6700 GS derailleur and 12-30t cassette ultegra with the KMC chain sounds the way to go.

I don't mind spending a bit more cash as this may be my last road bike and by doing this I'm saving a packet by not buying a new bike!

In reply to bluebealach: then buy it and do it yourself. It's a straight forward job. Have a look at the park tools website for guidance.
I'm down near Chester if you wanted to combine a ride of some hills with doing the above first.

In reply to Enty:

even Dura ace chain was only £30 in Evans.

and probably cheaper elsewhere.

In reply to sleavesley: The remark was a bit 'tongue in cheek' I'm afraid and me and anything other than a big hammer are really not that compatible!!

I'll speak to the guy in the bike shop who seems now to know his stuff and get it done as previously described - the 12-30 gearing seems to fit the bill.

As for the ride round the Chester hills, thanks for the offer and as soon as I've done a few runs, I'll give you a shout - I may need some practice for a Skye Sportive next year.

In reply to Hat Dude:

Bugger, can anyone else confirm this?

I've just packed my bike up for a trip down to Enty's neck of the woods and put a 12-28 cassette on my back wheel and packed it all away without checking it. Pretty sure mine is a standard short cage Ultegra rear mech

In reply to woolsack:

If you're running a 34t compact it should be fine. Mrs B is running a short cage Veloce mech on a 28/34 and it works.

In reply to woolsack:

It'll work mate.

E

In reply to Enty:

Otherwise the bike shop in Malucene will be getting a new customer

In reply to bluebealach:

Already discussed for you: http://www.ukclimbing.com/forums/t.php?t=556245

In reply to woolsack:


On my old bike I have a compact chainset, a 12-27 cassette with a short cage mech. It works fine but I would say it is not ideal when you're on the small chainring and the smallest sprockets on the rear but this is something to avoid anyway. The problem seems to be undue slack in the chain.

In reply to Hat Dude: Mine is a 53-39 chainset so I'm going to have my work cut out on some of those small hills down there

In reply to bluebealach: I had a similar problem to yourself which I solved for nothing (already had the tools to remove cassette)! Found someone on the CTC website who had some old sprockets (24 & 28t) - he sent me them for the price of postage.
1. Cut through with a hacksaw between two sprockets to dismantle the cassette completely.
2. Replaced the 23 with 24 and the 25 with the 28.
3. Reassembled cassette using the spacer destroyed in stage 1 with one salavaged from an old disused cassette (tip: never throw away such things).

While I was at it I bought a cassette with a smallest 14t which, after the doctoring described above, gave me 14-15-16-17-18-19-21-24-28. Since I had a 50t big ring I decided a 95" top gear was fine. If I didn't need a 110" gear when I was doing sub-hour 25 mile TTs in the '60s I sure as hell didn't need one for pootling around in my dotage!