Customizing my compact crankset

[shekie777]

I switched over a few years ago from a 53/39 standard crank to a 50/34 Shimano Ultegra compact crankset. I didn't like the 16 tooth gap between the chainrings, so I took off the 34 tooth chainring and put on a 36 tooth chainring from Sram. Despite being warned by the shop that did the work that my shifting would suffer mixing Shimano with Sram, it actually worked fine.

I've now reached the ripe old age of 60 and even having a 50 tooth large chainring has me mostly sitting in the 19, 21 & 23 of my 12-25 rear cassette. I'm considering dropping down from the 50 to a 48 tooth large chainring and keeping the 36 as the small ring.

Is there any issue with the front derailleur shifting a 48 tooth chainring as it was originally designed for a 53? Both Sram & FSA make 48 tooth rings, any reason to go with Sram as the smaller chainring is a Sram? Another brand to consider?

Thanks

[fogrider]

I had a 48 for a while and it was great! Since I had an 11 cog, the gearing was fine on the top end and it was good with flat terrain and rollers and I would only need to drop into the small ring for climbing. I don't think it's going to make a big difference which brand as long as the they are made for modern drivetrains.

[aramis]

You'll have to adjust your front derailleur down to get everything to work right, but otherwise you'll be fine.

[cachagua]

Braze-on front derailleur, or clamp? I couldn't use smaller than a 50 (without compromising shifting) with the braze-on mount on my bike, but if you have a clamp-on model there's nothing to stop you going lower.

Some nice 94mm BCD cranks on eBay just now. Could give yourself a smaller low gear, too. . .

[oldpotatoe]

I switched over a few years ago from a 53/39 standard crank to a 50/34 Shimano Ultegra compact crankset. I didn't like the 16 tooth gap between the chainrings, so I took off the 34 tooth chainring and put on a 36 tooth chainring from Sram. Despite being warned by the shop that did the work that my shifting would suffer mixing Shimano with Sram, it actually worked fine.

I've now reached the ripe old age of 60 and even having a 50 tooth large chainring has me mostly sitting in the 19, 21 & 23 of my 12-25 rear cassette. I'm considering dropping down from the 50 to a 48 tooth large chainring and keeping the 36 as the small ring.

Is there any issue with the front derailleur shifting a 48 tooth chainring as it was originally designed for a 53? Both Sram & FSA make 48 tooth rings, any reason to go with Sram as the smaller chainring is a Sram? Another brand to consider?

Thanks

No such thing anymore as 'compact' front ders...plug and play. Put on 48t, lower FD a wee bit(hopefully you can if braze-on)-go ride. I would suggest some other chainring tho, like TA..longer lasting. No reason to 'match' chainring maker tho, as you found out when ya put a sram small ring onto an otherwise shimano crank.

[Spinner]

No such thing anymore as 'compact' front ders...plug and play. Put on 48t, lower FD a wee bit(hopefully you can if braze-on)-go ride. I would suggest some other chainring tho, like TA..longer lasting. No reason to 'match' chainring maker tho, as you found out when ya put a sram small ring onto an otherwise shimano crank.

... TA rings shift cleaner/faster than DA rings that I have replaced.

Cheers.

[EricEstlund]

The Shimano CX70 derailleur is designed for CX ring sizes (such as 36-46, 38-48). Lots of folks using "standard" double front's, but it is an option.