Can I add a granny gear to an existing Ultegra double?
 

I'm thinking about building up a CX bike for various purposes. I'm thinking about using a triple up front. I already have an Ultegra 39/53 crankset from an old roadie. Is there a way to add a granny gear to convert it into a triple?

Have you looked into a compact crank 50/34?

I don't think you can because with the BCD of the 39 it's about as low as you can go for those rings.

yopu can't turn a double crankset into ab triple crankset and, as jfmckenna points out, the smallest chainring that you can fit on an ultgera crank is a 38t. there rea other optins, however: ad acrtic hawk says, you can install a compact crank that accepts smaller chainrings, and you can also install a casette with a bigger big cog.

You can get a tripleizer that bolts onto the inner ring and gives you a smaller BCD for the granny.
Specialities-TA may still make them
www.peterwhitecycles.com/chainrings.asp

You can also get those at Harris Cyclery.

avoid the triplizers. if you want a triple crank, put up the cash and buy a triple. personally, i think your better off with a bigger cassette and 38/48 chainrings.

Yea it looks like by the time you get all that stuff you may as well just get a triple crank. Then you would have two cranksets and if you wanted to go more road race set up just swap out the Ultegra double though I am not really sure how that wors out with the front triple shifter? I second the compact crankset though.

I got a tripilizer that works just dandy. I don't think a triple is the hot setup on a real cross bike tho.

i just think that retrofitting a triple on a double crank should be a last-case scenario. the triplizer works in theory, but i imagine it would require more than just the chainring -- longer cage rear derailleur, new bb, stuff like that. the other thing is that, ny adding a nother bolt on, you're adding another weak point. not a great option in my mind.

It works in reality. Just like the website says "you'll need a 74mm bolt circle ring for the inner or "granny" chainring, a longer bottom bracket axle, a triple type front derailleur, and probably a long cage rear derailleur."

The guy is building up a bike from spare parts and those are the cranks he has but wants a triple. If he has the parts to make it work, it is the perfect application of the triple conversion ring. Sure a granny is the last thing you need in a cross race, however, my cross bike doubles as an off-road touring bike and I sure like that triple when hauling loads.

-s