Hi,
I recently bought a new bike for IRL rides. It’s a SuperSix Evo and has a 52/36 front ring with 11-34 at the back (doing some very hilly sportives this year). My previous bikes have had 50/34 front rings (Shimano) or 48/33 (SRAM).
With the 52/36 my average cadence has dropped from about 90 rpm to 80rpm and my power output is a lot smoother, and generally higher. Also smashed several climbing PRs using the new bike 
so all good news!
Really surprised to see the difference in cadence and power though. Surely it can’t just be down to the 52/36?
Now thinking of changing the 50/34 on my indoor trainer to a 52/36 and see if that has the same effect. Interested to know if anyone else has had this sort of experience changing front rings however.
Only had the new bike a couple of weeks so maybe it’s all just new bike day enthusiasm , but I doubt it really. The new bike and 52/36 is simply a completely different ride from my previous bikes (Emonda Etap, CUBE Attain).
The bigger gearing does have a tendency to slow your cadence, and pushing that resistance will make you feel smoother. I wouldn’t necessarily say a drop from 90 to 80rpm is a good think though.
In theory the gearing shouldn’t make much difference to your power output, but just alter the cadence you would need for the fastest and slowest speeds ie with the 52 you can maintain a comfortable cadence at high speed but might feel you are spinning faster at the same speed with the 50, equally when climbing you can spin easier with the 34 but might be grinding more with the 36.
Has your riding altered? You mentioned more hills, that would likely also be the reason your cadence has dropped.
I’d put the extra power down to some good old indoor Suffering!
Are the cranks the same length?
(Between bikes, not between sides, that would be odd 
)
I opted for a semi compact on my last bike. I have a 32 on the back against 28 on my older bike, so I have both easier and go faster gears now
With the range on your cassette, you have added some big gears, but still have most of the middle range. Since you’re probably not using the new big gears that you didn’t have before to climb, that suggests that either the particular gears available are causing you to ride in slightly higher gears than you were before while climbing (but that wouldn’t lead to the size of your cadence drop), or you’ve subtly changed your shifting pattern (perhaps because of new gear jumps) and downshifting later, or that you are using the big gears downhill and generating more power there.
Or the power meter is different (if you just swapped power pedals, that’s not it).
Or the bike fits you better.
Or you just really like riding the new bike. When I got a new bike last summer, this was a really big effect.
Hi,
Thanks, maybe the 52 just makes me push a little harder and therefore smoother as you suggest.
Regarding routes/riding I’ve been doing pretty much the same hilly routes on the new bike as i did using the old bikes. Certainly I’m spinning a lot less on the climbs than before!
The new bike is a better fit for me, too (smaller frame) and the whole balance/weight distribution of the bike suits me better. So it is probably a combination of factors. I’m still getting used to the new bike, and switched it to
Semi-automatic shifting on the Di2, so will play around with the cadence.
Definitely loving the new bike
Yes, both 172.5 mm cranks 
Yes, bike definitely fits me better. Im sitting further back in the saddle on climbs and maybe generating a bit more power that way?
I’m using the same power meter pedals.
The SS Evo just seems to asking me to push on with the power and makes the other bikes I’ve ridden seem more sedate. I’m not on commission for Cannondale (or anyone else for that matter) 
I would go more with the fitting you better as reasoning.
Unless you are on the easiest or hardest gears, it should not make much of a difference, as you should have a close enough gear ratio on the other bike.
Probably the change in fit gives you more stability on the pedals, so you can apply more torque/for longer (more power throughout the pedaling circle) therefore the lower cadence feels good.
Lower cadence usually is easier on the heart and lungs, so it could all play a part in it.
The difference from chainring sizes may have a slight impact on chain efficiency (larger chainring means chain is not so tight, so slightly better efficiency), but being a new bike, new chain, etc will probably have much bigger impact.
Im thinking of moving back to a 52/36 when I get a new road bike. I was thinking about going gravel much more than I am and thus the SRAM AXS gravel front gear. I find that I’m running out of gear on some minor downhills on the road, which I wouldn’t do on gravel. One thing of note: You will find that you have to move up gears to maintain that 90 RPM cadence. One or two should put you where you were as the gearing is longer (more meters per turn of the crank). You might find that you will be switching to the small ring quicker on significant climbs (>5% grade).
I switched to 52/36 from 50/34. Not sure of the metrics but it just ‘feels’ better. (same cassette)
I train with a sub-compact 50/34 and ride on 52/36 most of the time on roads. I have not noticed any difference in cadence between both bikes, I just let the legs tell me where the sweet spot is. I can put almost the same power in big gear on both, but yes, a bit more on the 52 big ring.
Just enjoy your ride!
A great (edited) tool to compare chain ring and cogs, give it a try!
Ouch…I think you meant to use great! (injecting humour into a correction). It is a fantastic tool to find out how far you go for each turn of the crank.
Was the 34 a stock cassette or did you have it put on? Stock gearing was lower on mine but having a 125 mile / 16,000’ + ride in June I went with compact and 11-34 I know I will be glad!
Hi,
I asked for the 11-34 cassette, a bit like you I guess, because I do a lot of hilly sportives/events. 125 miles and 16,000 feet climbing is a monster!
Food for thought!
https://garrettcountygranfondo.org/
I think of it as a great way to see western MD…
Just checked out the ride profile on RWGPS, that’s one tough day out on the bike! I’m based in SW London, UK, so not one for me.
Still plenty of time for suffering before the event 
Stock on most bikes with the 50/34 is 11-28. I would love to move to a 34 tooth rear, but that means a new rear derailleur with SRAM.
Shimano has an 11-34 cassette, but you might need a new derailleur.
https://bike.shimano.com/en-EU/product/component/ultegra-r8000/CS-HG800-11.html