please help: gullible bike shopper, Ultegra casette

[su22]

I need a new casette for hill climbing and I've been advised to get a 12-27 casette with my 52/39 double chainring. A bike shop told me that in order to put the 12-27 on my bike I need a new long rear derailleur, and a new chain to fit the new dimensions of eveything. I've already checked-in the bike for the new casette, RD and chain, setting me back $300 AUD.

Then a friend of mine says the new long rear derailleur and chain arent necessary! Who's right, and am i being a gullible bike-shopper?

I'd very much appreciate your thoughts here

 

[gclark8]

Fleecing the sheep!!!

Just buy a cassette!

I see your TCR is 9 speed, ask around for a HG50 or HG70 12-27, they are much cheaper than Ultegra, particularly if is not for everyday use.

A chain whip and Cassette tool from Shimano-Pro is about $20, then you can change them yourself.

 

[Ozark Bicycle]

I need a new casette for hill climbing and I've been advised to get a 12-27 casette with my 52/39 double chainring. A bike shop told me that in order to put the 12-27 on my bike I need a new long rear derailleur, and a new chain to fit the new dimensions of eveything. I've already checked-in the bike for the new casette, RD and chain, setting me back $300 AUD.

Then a friend of mine says the new long rear derailleur and chain arent necessary! Who's right, and am i being a gullible bike-shopper?

I'd very much appreciate your thoughts here

Your existing RD will work just fine. You may need a new chain if your existing chain is too short to clear the so-called "big/big" of 52/27. Try it on a workstand and see. (The alternative is to remember to never use the "big/big" combo, but that can be dangerous in actual use and I wouldn't recommend it.)

PS- Were I you, I would find a less greedy/more knowledgeable LBS.

 

[sergen]

If you already have an Ultegra rear derailleur then you can simply swap the rear cassette with no further worries. It will take a 27 at the back but nothing lower.

If you wanted to go even lower than a 27 then you'd have to shell out some money on new components. With Campagnolo, for example, I think they're RD's can handle a 29 at the back.

 

[capwater]

I'll echo the thoughts that a new RD is not required, but depending on the age of your existing cassette you may end up needing a new chain due to wear. But, get the cassette first and see how it shifts before investing in the chain.

 

[Ozark Bicycle]

If you already have an Ultegra rear derailleur then you can simply swap the rear cassette with no further worries. It will take a 27 at the back but nothing lower.

If you wanted to go even lower than a 27 then you'd have to shell out some money on new components. With Campagnolo, for example, I think they're RD's can handle a 29 at the back.

Gotta disagree here. That RD is rated by Shimano for a 27T max cog. In practice, a 29T will be fine, maybe even a 30T(depends a bit on the rear dropout). Shimano, like Campy and all the makers, is very conservative on the max cog spec. My general advice to everyone who wants to try to exceed the max cog spec on their RD by a couple of teeth is to try it (preferably on a workstand) before you pony up for a new RD.

 

[sergen]

Gotta disagree here. That RD is rated by Shimano for a 27T max cog. In practice, a 29T will be fine, maybe even a 30T(depends a bit on the rear dropout). Shimano, like Campy and all the makers, is very conservative on the max cog spec. My general advice to everyone who wants to try to exceed the max cog spec on their RD by a couple of teeth is to try it (preferably on a workstand) before you pony up for a new RD.

That's probably very true about the manufacturers being conservative - but since Shimano do not manufacture an Ultegra sprocket lower than 27, if you were to use, for example a Campy 13-29 cassette would this not create issues with the chain shifting between sprockets? I thought that there's a slightly different spacing distance between all the manufacturers' sprockets which may cause problems shifting.

My new bike is arriving early next week and it's fitted with Ultegra hollowtech triple chainring and a 12-27 in the back. That may sound like very generous gearing but the truth is that the hills around where I live are killers and I would actually love to go down to a 29 at the back. Can this be done?

 

[Ozark Bicycle]

That's probably very true about the manufacturers being conservative - but since Shimano do not manufacture an Ultegra sprocket lower than 27, if you were to use, for example a Campy 13-29 cassette would this not create issues with the chain shifting between sprockets? I thought that there's a slightly different spacing distance between all the manufacturers' sprockets which may cause problems shifting.

My new bike is arriving early next week and it's fitted with Ultegra hollowtech triple chainring and a 12-27 in the back. That may sound like very generous gearing but the truth is that the hills around where I live are killers and I would actually love to go down to a 29 at the back. Can this be done?

Your crank has 52/39/30 chainrings. The easiest first step might just be to swap the 30T inner for a 28T. IME, your FD will handle this just fine, given proper adjustment. (And a 28/27 is the same gearing as a 30/29.) Then, in the future, if you need even lower gearing (and I understand, living here in the Ozark and Ouachita mountains!), you can seek out any (not just Ultegra) Shimano compatible cassette with a 29T (or maybe 30T) max cog.

What's your new bike?

 

[otherworld]

27t will be fine for your setup as it is. Chain length could only possibly be an issue at at 53-27 and there's no need to use that combination anyway.

Find a bike shop that you can trust. i.e one that doesn't bull **** you or try to rip you off like the one that's spun you this story in the first place. Ask a few this same question and go with the one that gives you the right answer.

Good Luck Jay.

 

[sergen]

Your crank has 52/39/30 chainrings. The easiest first step might just be to swap the 30T inner for a 28T. IME, your FD will handle this just fine, given proper adjustment. (And a 28/27 is the same gearing as a 30/29.) Then, in the future, if you need even lower gearing (and I understand, living here in the Ozark and Ouachita mountains!), you can seek out any (not just Ultegra) Shimano compatible cassette with a 29T (or maybe 30T) max cog.

What's your new bike?

A 2005 Giant TCR Composite 2 (It's the UK version which has a triple chainring).

It's quite pathetic really, but I'm soooooooooo excited!!! And since Christmas is nearly here I guess it's contributing to my child-like mood at the moment. But I'm going to have to pick my days of riding carefully. It's been -2 celcius at night lately I don't fancy wiping out on a descent.