105 v Ultegra Cassette

Page may contain affiliate links. Please see terms for details.

2Jags

New Member
My new Cube Agree should arrive at my LBS any day now. It is a Compact, no triples available, with ultegra kit that comes with the stock 12-25 cassette but I have asked that the shop swap out the cassette for one with 27 or 28 teeth to give me a lower gear for climbing/duff knees.

LBS say they can only get a 105 12-27 cassette but the difference with this and ultegra is negligible.

Is there much difference and could this lead to any compatibility problems? Should I stick with the stock 12-25, see how I go and then swap out later if I struggle with this set up?

Any advice would be welcome.
 

rich p

ridiculous old lush
My new Cube Agree should arrive at my LBS any day now. It is a Compact, no triples available, with ultegra kit that comes with the stock 12-25 cassette but I have asked that the shop swap out the cassette for one with 27 or 28 teeth to give me a lower gear for climbing/duff knees.

LBS say they can only get a 105 12-27 cassette but the difference with this and ultegra is negligible.

Is there much difference and could this lead to any compatibility problems? Should I stick with the stock 12-25, see how I go and then swap out later if I struggle with this set up?

Any advice would be welcome.

New 105 has a very good reputation. I'd go with it if you need the extra gears as I'm certain you wouldn't be able to detect the difference.
 

gavintc

Guru
I bought a cassette manufactured by BBB as a cost saving measure recently for my commute bike and had a devil's job getting the gears balanced and working smoothly. Eventually, I took the bike to the LBS and he too admitted to having some problems. He then swapped the cassette for a 105 one and it worked fine. My conclusion - use Shimano cassettes. I discussed with the LBS whether there was much difference between Ultegra and 105. He reckoned not much, but it would change a little bit smoother.
 

Banjo

Fuelled with Jelly Babies
New 105 has a very good reputation. I'd go with it if you need the extra gears as I'm certain you wouldn't be able to detect the difference.

I have had 10 speed Ultegra and now 10 speed 105 both are smooth and slick changing. 105 will be fine.
 

e-rider

crappy member
more importantly --- if you have a compact chainset (34/50) and a short cage rear mech; the max .sprocket you can use at the back is 25 (NOT 27).

To use a 27 you need to either get a long cage rear mech or change the 34 chainring to a 39 (which is pointless as you were trying to get a lower gear)

If you already have a long cage rear mech you'll be fine.

I use 105 and it works fine - I'm guessing that the ultegra will be slightly lighter but with no difference in performance
 

threebikesmcginty

Corn Fed Hick...
My road bike came with a 105 12-25 and I recently changed it to an Ultegra 12-27. I went to Ultegra because the rest of the groupset was apart from the cassette. I'm not sure if I notice the difference as far as the groupset goes but those extra couple of teeth are welcome on a steep hill. I got a deal at the time on a 6600 from Ribble - as always very quick service!
 

Crimmey

Well-Known Member
In reply to TUndragumski, the new Shimano systems allow a chain wrap of 33t and not the previous limit of 29t. Also can officially now accommodate a small cog of 28t. 12-27 on a compact with Ultegra 6700 derailleurs is fine.

In regards the cassettes, you will not notice any performance difference. Get the 105 12-27 cassette.
 

HLaB

Marie Attoinette Fan
Slightly OT, My Kinesis is fitted with a 105 38/52 (12-25) at the moment, this thread got me looking at things and I'm tempted by a SRAM cassette, they do a 10sp 11-26. I have a 8spd 11-26 cassette on my Sirrus at the moment and I like the range it gives me without having to drop chainrings :smile:

Wrt the original post i can't recall what the weight difference is between 105 and Ultegra but I seriously doubt it would be noticed and as the 105 does the gearing you want go for it :smile:
 

2Loose

Guru
I also considered what would be required for lower gearing, coming from an mtb with 28-32 min. gearing to a 34-25 road bike. It is (only) Tiagra, btu Shimano say a 27tooth cassette is the largest sprocket, not the 25.

Regardless of this, I have been amazed that the road bike can get up climbs even more easily than the much lower geared (but heavier) bike can anyway, so I am sticking with 25t.
 

gavintc

Guru
more importantly --- if you have a compact chainset (34/50) and a short cage rear mech; the max .sprocket you can use at the back is 25 (NOT 27).

To use a 27 you need to either get a long cage rear mech or change the 34 chainring to a 39 (which is pointless as you were trying to get a lower gear)

If you already have a long cage rear mech you'll be fine.

I use 105 and it works fine - I'm guessing that the ultegra will be slightly lighter but with no difference in performance

Not quite true. I have compact chainset and a couple of years ago wanted to tackle Mt Ventoux, so asked the local shop if I could fit a 12-27 cassette. The answer was Yes, but definitely avoid using the largest 2-3 cogs with the 50 ring. I used the cassette for the holiday and had no problems. On return, I refitted the 12-25. I concede that I did not run the cassette on the bike for a long period, but think I will have put about 600km on it. So, it does work.
 

e-rider

crappy member
Not quite true. I have compact chainset and a couple of years ago wanted to tackle Mt Ventoux, so asked the local shop if I could fit a 12-27 cassette. The answer was Yes, but definitely avoid using the largest 2-3 cogs with the 50 ring. I used the cassette for the holiday and had no problems. On return, I refitted the 12-25. I concede that I did not run the cassette on the bike for a long period, but think I will have put about 600km on it. So, it does work.

yes and the reason you couldn't use the largest cogs was due to chain length - it had to be short because the short cage rear mech couldn't take up the slack if it was any longer - so you can use a 27 with a 34t chainring and short cage rear mech but it's not ideal whereas by either fitting a long cage rear mech or sticking with a 25t max sprocket everything works just how it should
 

HJ

Cycling in Scotland
Slightly OT, My Kinesis is fitted with a 105 38/52 (12-25) at the moment, this thread got me looking at things and I'm tempted by a SRAM cassette, they do a 10sp 11-26. I have a 8spd 11-26 cassette on my Sirrus at the moment and I like the range it gives me without having to drop chainrings :smile:

Wrt the original post i can't recall what the weight difference is between 105 and Ultegra but I seriously doubt it would be noticed and as the 105 does the gearing you want go for it :smile:

According to Weight Weenies it is 10g for the 12-25 10 speed.
 

e-rider

crappy member
Ultegra chains are nice and silver whereas the 105 is grey - that's must be worth an upgrade just for the silver bling look!
 

Soltydog

Legendary Member
I have a spesh Allez Elite & it came with shimano 105, 27t largest sprocket & 53/39t chainrings. AFAIK the rear mech is a short cage (but maybe medium:wacko:) & all works fine
 
Top Bottom