Sub compact gearing on a road bike

I am currently running a 50/34 chain set with an 11/34 cassette on my road bike and really like the extra range of the bigger cassette. I don’t often need the 34t cog in the back but when I do it’s much appreciated. My only issue with the setup is the larger jump between cogs. I just recently saw that Cannondale and FSA make a replacement spider and rings that can be used on my existing Cannondale SI crank to change out to sub compact 48T / 32T or 46T / 30T gearing. I’m considering getting the 48T / 32T combo and then switching my rear cassette back to something with smaller jumps that will also give me a similar low end to match my current setup. I don’t race, and almost never use the 50T / 11T combo on my current set up. I don’t think I would be loosing much too end speed if I did start using a 48T / 11T combo.

Anyone see any downside to this setup that I’m missing?


Makes complete sense.

My weight weenie bike has a converted triple FSA k light crank with 46-30 rings and a lightweight 11-25 cassette.

Nice close ratios, a super low bottom gear, a top end close to 50-12, short cage derailleur and lots of saved grammes!

I live in a hilly area. I laughed at all the nonsense about “is the compact dead?” When 52-36 cranks became fashionable. I’m a reasonably strong rider. A 50-34 is ideal for me. But so is a 48-32 or a 46-30.

I’ve been using a 46-34 on my winter bike for years. I love the small jump on the front rings.

Just choose ratios that work best for you and ignore fashion and naysayers.

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Obviously depends on you and where you ride but I think it’s a good idea.

The only thing I might add is that if you’re going lower, why not just get the 46-30? 46x11 is still a substantial gear for most people who aren’t racing. I use my cyclocross bike on the road with a 1x drivetrain. My biggest gear is 40x10 which gives me approx 30mph at a cadence of 100. Its not often that I need anything faster

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I might give the 46/30 some thought. I could then use an even tighter spaces cassette with a similar low end. I will need to do some calculations on this.

One thing is that my current setup has a round 50T ring and an oval 34T Absolute Black inner ring. I really like the feel of the oval, never made the jump to a 50T oval because I didn’t want to compromise shifting. AB doesn’t make an oval inner ring that would fit the 120/90bcd spider I would be using for sub compact gearing. So going down this path I would have to go back to a round inner ring. AB does make there own sub compact ovals for Cannondale cranks in 48/32 and 46/30. It they have to be used in pairs. Maybe it’s time to give a large oval ring a chance.

I’m also planning on upgrading to Ultegra DI2 this winter, anyone have experience with DI2 and oval rings?

Praxis also sells a crank with sub compact gearing (48/32). They also use a 110BCD so you could use an AB oval like you are used to.

Also if your set up shift fine with mechanical shifting then i don’t see why it wouldn’t shift fine with di2.


Before you buy, please check your bike that your front derailleur can actually go low enough to engage the small ring.

I have a super compact 48/32 chainring on my allez sprint disc and it’s about as low as I can go. Any lower and the derailleur will not be able to go low enough to activate the small chainring.

Apart from that, I’ve been super happy with my super compact as I like to spin up climbs. I have to admit that on spirited group rides, it requires much more gear changes and it does top out at 50 km/h.

On the plus side I use my 32 front 34 rear much much more than my 48/11. The climbs around me have a max gradient of 15% and I weight 62 kg for reference.

Hope it helps.