Who rides a standard crank?

[winjim]

That looks like a 3300. I assume it's a short cage. Does it look like this(short cage SS)?

Or like this(long cage GS)?

Capacity is as follows:

So assuming a SS mech, you have 52-40=12 difference on the front, leaving you 29-12=17 spare to use on the rear. You can therefore use the full 11-27 range on the rear should you need to.

Shimano specs are notoriously conservative so I reckon you could probably get away with a 28 or maybe a 30.

 

[Andywinds]

Thanks Chris, yes it is a SORA, it looks like the post I was writing disappeared. I might find one on Ebay and change, there were a few second hand floating around. Just for info my current cassette is a 12/23, so having a small 11 might be good for slight downhills. Thanks very much for helping.

Others may be able to confirm, but it looks to me like one of these, a Sora 3300:

http://sdeals.com/index.php/home/gears/rearmechs/product/13108-shimano-sora-rd-3300-rear-mech

If so, that gives a capacity of 29t and a maximum sprocket size of 27t (though you *may* be able to get away with a 28t largest).

So an 11-27t cassette is really about the best you can do with the current set-up - I'd say this is different enough from your current 11-23 cassette that it's a worthwhile change to make on the hills. This would give you a bottom gear similar to what I have on my road bike (42/28 with 27" wheels). If you are doing regular hill climbs to keep the fitness up then this should be enough to get you up pretty much anything in one piece, though there'll still be a bit of out-of-the-saddle honking involved. To lower the gearing any further you'd have to replace the derailleur with a medium or long cage model.

TBH now that long cage derailleurs exist I don't understand why modern bikes aren't furnished with a lower low gear in 90% of cases, since most riders would be grateful for them at least some of the time!

 

[Andywinds]

Yes Winjim it is the smaller SS, great thanks very much.

That looks like a 3300. I assume it's a short cage. Does it look like this(short cage SS)?

Or like this(long cage GS)?

Capacity is as follows:

So assuming a SS mech, you have 52-40=12 difference on the front, leaving you 29-12=17 spare to use on the rear. You can therefore use the full 11-27 range on the rear should you need to.

Shimano specs are notoriously conservative so I reckon you could probably get away with a 28 or maybe a 30.

 

[Andywinds]

If I fit an 11/27 would I need a bigger chain?

 

[winjim]

If I fit an 11/27 would I need a bigger chain?

Quite possibly. If you're getting a new cassette then a new chain is a good idea anyway, so they wear together.

 

[ChrisEyles]

As @winjim says, I think you could probably get away with an 11-28t cassette on that derailleur - if you get it done at a bike shop you could ask them to try one and see if it works. If you can find 12-28t that'd be even better IMO (I never use the 11t sprocket on my 11-32).

Let us know how you get on!

 

[Andywinds]

Ok thanks Chris, I am just deciding on what to do.

As @winjim says, I think you could probably get away with an 11-28t cassette on that derailleur - if you get it done at a bike shop you could ask them to try one and see if it works. If you can find 12-28t that'd be even better IMO (I never use the 11t sprocket on my 11-32).

Let us know how you get on!

 

[winjim]

As @winjim says, I think you could probably get away with an 11-28t cassette on that derailleur - if you get it done at a bike shop you could ask them to try one and see if it works. If you can find 12-28t that'd be even better IMO (I never use the 11t sprocket on my 11-32).

Let us know how you get on!

I use an 11-30 with a 34-50 on my 9sp 3400 and it works if you get the chain length exactly right, so I think an 11-28 should be fine with a standard chainset. Agree about the 11 tooth sprocket though, it won't get used. Personally I'd go for a 12-28 with that setup.

 

[Andywinds]

Ok thanks Winjim.

I use an 11-30 with a 34-50 on my 9sp 3400 and it works if you get the chain length exactly right, so I think an 11-28 should be fine with a standard chainset. Agree about the 11 tooth sprocket though, it won't get used. Personally I'd go for a 12-28 with that setup.

 

[Dogtrousers]

What is a standard crank?

Little explanation here: http://www.bikeradar.com/road/gear/article/what-is-a-compact-crank-38845/

Edit: ooops. Didn't read the whole thread. Seems to have been done to death. Oh well, this linky won't hurt.

 

[MrGrumpy]

12-25 and 53/39 at front, never had a compact chain set bit I'm sure I would get on fine with that as well.

 

[ChrisEyles]

@MrGrumpy that's a pretty tough bottom gear to turn up the hills! If you're anything like me, I'll bet you pull some interesting faces on the way up My highest low gear is a single speed 1950s roadster with 42/18 gearing, and that's definitely *interesting*!

 

[MrGrumpy]

Can get up everything round about here on it in fact rarely in the 25x39 . However there was the 1 in 6 on Sat which was 1st gear and spin up!

 

[MrGrumpy]

Oh that same 1 in 6 have done on my fixed 48x16 . However I would of been quicker getting off and walking

 

[ChrisEyles]

Haha, good effort climbing 1:6 in 48/16 - chapeau. I'd love to try out a fixed gear, but all my riding options are so hilly around here I'm rather put off... it's hard enough work with gears!