46/33 chainrings on Campy 10 speed?
 

I'm building up a new Mercian frameset and I have Sugino Alpina cranks, TA 46/33 chainrings, and a 12-29 cassette. I was wondering if anyone could foresee any issues with this gear range - I mean, intuitively, I don't see any problems, but I thought I would tap into the collective wisdom here and double-check. :)

The only potential problem I can imagine is if the frame has a braze-on for the front derailleur. I believe some people have had issues with the FD being low enough for a 46, even resorting to a file. The 29 should not be a problem for a short cage RD.

As to the gearing, only you know the areas you ride and what range you need. It seems to me that your combination will have a lot of overlapping gears.

It should probably be fine. But where did you get a Campagnolo 10spd 12-29 cassette? Campagnolo only made 13-29 and 12-30 10spd cassettes.

(As a point of reference, I've used 48/32 and 44/28 Sugino chainrings on a Sugino OX crank with Campagnolo 10spd, and 48/32 TA chainrings on a Rotor crank with Campagnolo 11spd.)

This is a good point. Modern frames are designed for compact cranks, and have the braze-on lower, but classic era frames will probably be designed for "standard" size cranks, and have the braze-on mounted higher. There are ways to deal with this, including adapters to lower a derailleur on a braze-on tab.

Thank you for the guidance. I misspoke. It's actually a 13-29 cassette.

There are numerous posts all over the internet that the 13-29 cassette can be used with a short cage Campagnolo rd. I couldn't make it happen. The mid length cage did the trick. But again, some people seem to be able to make it work with the short cage...

I have run a TA 46T chainring on a 4 arm Chorus crankset with a matching 2015+ FD. FD shifted perfectly, in fact the lower position opened up a better angle to the cassette and I got a completely trim-free setup across the board.
Problem is that you cant fit a 34- small ring and the small jump upset my upshift/downshift habits so I changed back to compact.
But the 46 front shifting absolutely no issue.

I went to a triple 10 speed Campy Chorus, and have a 24t ring/30 cassette setup. Works peachy. Had to get the 'triple' (mountain) rear derailleur though. My CSI with a 21 gear-inch climbing gear is happy-happy now.

A 30 Campy cassette? Yep, ordered a Miche 30t cog from BikeInn last year, $7, and dropped one of the Campy cogs, can't remember which, and put the 30 in as top dog.

Yep. Even if the front derailleur works OK in the bike stand with a larger than optimal gap to a smaller chain ring, it's a matter of time before the chain will get dropped, at least damaging the frame/paint or worse (injury). Get one of these, I have one, works well (Shimano D/A 7400 front derailleur, Sugino 34-46t crankset).
https://www.fsaproshop.com/products/...illeur-adapter

Threads like this should be banned without pictures. Let's see the Mercian in whatever state it's in! I hope it's BR green. Or another color...

Cool stuff. Fortunately, I don't have to contend with a brazed front derailleur hanger. I'll post pictures as soon as I complete the build.
:)

Is 46-13 enough gear for your riding? Or maybe you just plan on freewheeling down hills?

That's equivalent to a 39T big ring with an 11T, or 35T if you go down to a 10T (or 32-9 in Ekar speak).

I intend to use this bike as a sort of an "all-road" bike (it has clearances for 35mm tires, etc.). I think the 46t will suit my needs - I live near the base of the Sierra Nevada mountains and the surrounding foothill areas. So, it's pretty undulating terrain with paved roads in poor condition and quite a bit of mixed surfaces. I'm not really looking for speed on the descents with this bike - BUT I'm keeping my 48t chainring just in case! :)

I was dialling in my perfect gear range on my training bike recently. I worked out I hardly ever used the 50/12 so I'd drop it down to a 46. (running a 50/34 front with 12-25 rear). The experiment didn't work out as I found I did need the 50/12 more than I anticipated and the smaller double-shift jump threw out my shifting habits.
While I couldn't stick a 33 on the small ring the 46/34 combo worked perfectly as far as shifting. You can get an aftermarket 33T for the Ultegra/DA 11spd cranksets mind you but the Campagnolo BCD is just a bit bigger.
For anyone contemplating this watch out for the chaindrop ferrule on TA branded big chainrings - it is too long and digs into the crank arm. I had to remove it to fit the ring. I'm talking the 4-arm post 2015 Chorus.

I have encountered this also, and just take a file or Dremel to it as needed to shorten it to fit

Finally Built!
 

I posted pics of the built under another thread. https://forums.thepaceline.net/showt...41#post3372641