50-34 chainrings for Cannondale Super Six
 

I am looking to change from 52-36 to 50-34 on my 2020 Super Six. The crankset is Cannondale’s SI ( not Hollowgram ) I can’t seem to find chainrings anywhere online.
Any thoughts?

Where do you live

Don't the Hollowgram rings fit the Cannondale One crank and spindle? With many things in short supply for new bikes, I'd get on Cannondale's site and push that button that says "check local bike shops" and then call each one.

Otherwise what BB shell is on that frame? If you are willing to have the BB changed and get an entirely different crankset you'll have more options and might find something decent considering the current inventory scarcity.

you can also order a 5 bolt spider for the cannondale crank and then run normal chainrings from any manufacturer

What are the existing chain rings? Are you looking for (a) 4 bolt chain rings, (b) 5 bolt chain rings, or (c) Cannondale Spidering?

I'm pretty sure the SI and Hollowgram SI/SISL2 cranks all run the same chainrings.

​​​​​https://www.amazon.com/Cannondale-Sp...a-574552887732

https://www.biketiresdirect.com/prod...RoCeA4QAvD_BwE

So the photo posted by waters60 in post #7 above shows a 52T/36T chainring set mounted on a 120 BCD 4 arm spider. The problem is that a 36T chainring is the smallest that fits on this spider. A Cannondale 110 BCD 5 arm spider is needed to fit a 50T/34T chain ring set.

Cannondale HollowGram Spider 110mm BCD Road Compact QC693/ (bicyclebuys.com)

Cannondale Hollowgram SL Spider, 110mm BCD, Road Compact, QC693 (cannondalespares.com)

https://cimg8.ibsrv.net/gimg/bikefor...d4badd980.jpeg


50/34 from my Synapse.

https://cimg8.ibsrv.net/gimg/bikefor...d4badd980.jpeg


50/34 from my Synapse.

Any BCD markings? I cannot see. But assuming that both of your bikes use the exact same crank spider, i.e., 120/90 BCD, there is still another difference. On your Super Six, both chainrings are mounted on the outer (i.e., 120 BCD) holes of the crank spider, whereas on your Synapse, the large chain ring is mounted on the outer holes and the smaller chain ring is mounted on the inner (i.e., 90 BCD) holes. So you may want to try an FSA 120/90 setup comprising a 120 BCD 50T and a 90 BCD 34T chainrings, available directly from FSA:

Gossamer PRO 2x BCD 120/90 | FSA (fullspeedahead.com)