Smaller outer ring on compact chainset?

[Ray]

I have Shimano Ultegra 6700 compact (34/50 - 10 speed) which runs and changes beautifully, but I find the step between rings too large, necessitating at least a double change when going between chainrings. As the 50 also provides higher gears than I ever need (age taking its toll), I wonder about changing the outer ring for something like 44 or 45.
Can anyone advise whether a compatible ring (not necessarily Shimano Ultegra, although I know I risk spoiling the sleek appearance) is available and whether such a change would be likely to upset the slick changing which I now get with the Sti levers and Ultegra front changer?
Or can anyone suggest any other solution, short of a complete change of transmission, levers etc?

[djnotts]

Seems to be a fair bit of info here:

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=4068

MY guess is that a 48 be fine with a "non-compact" front mech - but at <48 a "compact specific" mech would be better. I assume can get 10 speed rings in the size(s) you seek - or if not that 9 speed would do?

[Ray]

Seems to be a fair bit of info here:

http://www.ctc.org.uk/DesktopDefault.aspx?TabID=4068

MY guess is that a 48 be fine with a "non-compact" front mech - but at <48 a "compact specific" mech would be better. I assume can get 10 speed rings in the size(s) you seek - or if not that 9 speed would do?

Thanks for the link (sorry, should have done more of a search before asking!). Some useful info there. My front mech is 'compact-specific' so, as you say, it should probably cope with a smaller ring. I don't think an Ultegra outer is available in the size I'd like, and I don't know whether a 9-spd ring would be equally suitable. Can anyone advise what rings I should be looking for, please?

[gaz]

You need to establish the number of arms (easy) and BCD (slightly harder) of the chainset and then search for suitable rings.

At a guess it will be 5 arms and 110BCD. BCD is Bolt Circle Diameter, the diameter of an imaginary circle passing through the centre of the chain ring bolts. There's a useful table here.

110BCD rings should be easy to find at Spa Cycles made by either Stronglight or TA.

[gaz]

BTW I run a 38T outer on a "compact" triple using a standard 52/3T road double front mech.



I've been running that set up for over 20 years without problems but I don't use front indexing. I have tried front indexing but as the front mech wasn't index compatible it was very harsh. Nevertheless it did work.

[djnotts]

Any good?

http://www.dealtime.co.uk/xPO-Full-Spee ... ad-Cycling

[Ray]

Thank you both for your help.
I measured the bolt centres and it is indeed 110BCD. Both Spa and SJS do TA 9/10 speed rings in 44/45 teeth, which look as if they should work. Having successfully run a triple mtb-type chainset in the past with a double road front changer, I would expect there to be more tolerance of 'mis-matched' components than manufacturers would have us believe.
Next time I'm near Harrogate I'll call in on those nice people at Spa Cycles and ask their advice.

Happy cycling

Ray

[mr riff raff]

Get TA rings over Stronglight if longevity is an issue.

TA are also very shiny!