Getting a smaller small chain ring

[Tynan]

Hello

I've driven yet another set of running gear to the point of collapse, ctw has started at work and I'm going to see if Evans will do me parts for the current bike on the back of a new SS/fixed

I have a double and live on the outer ring, the inner has seen the chain perhaps ten times in a year when I've been crawling up significant hills on rides in the smallest combination I have and really not liking it

Soo, I was thinking that if I replaced the chainset entire, I might keep the same size outer ring but get a smaller inner ring for those special occasions

Is that likely to be difficult/expensive to source and are that mechanical implications regarding chain length etc?

Yes, I'm being lazy and no I can;t say what I have now other than it's whatever Condor fit to Fratellos routinelt in campag 10 speed for a double

I'll stroll to LBS this weekend but it'd be nice to know something in advance

Thanks

 

[HLaB]

I've never done it but I'm under the impression you just have to make sure the bcd and bolt pattern of the new chainring match the old. I'm considering something similar with my Kinesis if I ever meet some serious hills it's a 52/38 (11-25rear), I may drop it to a 52/36 (12-27) its a compact however (110mm?) which makes that pretty simple but i'm unsure about the Campy 39/53 double, if I was moding that I'd just change the rear (currently a 12-25). Another couple of issues is can the front dérailleur and you cope with a larger step between chain rings.

 

[GrumpyGregry]

Speak to Spa; their forté is this sort of thing.

 

[TheDoctor]

Depends what the chainset is.
If it's a compact (110 BCD), then smallest inner chainring is a 33T, but 34T is easier to find.
Shimano road (ie 130 BCD) your smallest inner is 38T, and Campag road it's 39T.
You can't go smaller as the bolts get in the way...

 

[Tynan]

thanks Doc (and Greg) I'll give it a wipe this week and see what I have now

sadly as ever, anything involving additional cost is going to have to be swerved, grin and bear it I suppose in the gearing I have when I have to, worse case

I get on very well with the cassette I have which is 13-25 from memory

 

[sunnyjim]

Depends what the chainset is.
If it's a compact (110 BCD), then smallest inner chainring is a 33T, but 34T is easier to find.
Shimano road (ie 130 BCD) your smallest inner is 38T, and Campag road it's 39T.
You can't go smaller as the bolts get in the way...

I've got a 18T great granny on my trike - but it did involve a bit of bodging...

 

[zoxed]

To get down to a 17T inner ring: http://www.abundantadventures.com/mt_plus.html

 

[TheDoctor]

Well, if you want to go mad, a triple will go down to a 24T.
Add a casette with a 34T sprocket and you should be able to ride up cliffs and walls!!
18T great-granny ring eh? *approves*

I have actually seen a home-built 36T inner ring for 130 BCD.
Well, I say 'ring' it was more of a pentagon really.