I have always used a 53T chainring and considering an upgrade to etap ads (rival) but the biggest chainring is 48T. Has anyone else made the with and felt like they were giving up speed?
You can always swap out the crank for Red, and get more teeth if you need to. My Red bike came with 48/35, and I picked up 50/37 for most purposes (crit bike), kept the 48/35 rings for super climby days. I rode for a month or so on 48/35, and it was honestly pretty hard to notice. Just a ST’er, beingan ST’er it bothered me thinking about being in the less efficient 10-11t cogs more often. Giving up speed? Not noticeably, though in theory giving up a Watt or so here and there.
Check out https://www.bikecalc.com/speed_at_cadence
At 90 RPMs a 48x10 on a 28mm tire should give you 34.31 MPH
At 90 RPMs a 53x11 on a 28mm tire should give you 34.45 MPH.
The speed difference at 90 RPM is about .14 MPH.
A 53t chainring is slightly larger (and so is the 11) which means it will be slightly more efficient, so technically it is “faster” than the 48x10, but i’d call it a marginal gain.
“A 53t chainring is slightly larger (and so is the 11) which means it will be slightly more efficient, so technically it is “faster” than the 48x10, but i’d call it a marginal gain.”
I agree 100% with your analysis and will add that most (all) of us spend very little time in 48 x 10. 48 x 13/14 which in a very nice chain line is 26/24.2 mph - that or below is where I spend 90+ % of my time. I was skeptical of of the 48/35 chainrings when I first got them, but they are now a non-issue. AND, I love narrow jumps in the back.
I had the same debate when switch to axs, as an alternative option you can mix a d match Force abd Red a bit.
I ended up using a Force crank arm and Red 50t chainring.
Costs a bit more, but the larger chainring helps with friction loss and means I’ll be spending more time in larger cogs on the cassette, again helping reduce friction loss.
As the others pointed out, it is marginal gains but I’m happy with the setup.
It’s not just about the 10T cog though. With a smaller chain ring, you will have more drivetrain losses across all gears. I do agree that it is mostly marginal.
I’ve got a new bike with Red AXS on the way. Planning to run a 50/37T chain rings. First time on SRAM… hoping I don’t regret this.
Previously also mostly used 53x39; switched to 48x35 last winter and have had ZERO issues wrt speed (note all my rides are flat around here).
On solo rides this won’t be an issue anyway; but in fast-ish group rides I haven’t noticed any negatives either. Looking at my AXS app I only rarely use the 12T, let alone the 11T or 10T.
Actually I’m even thinking of going to a 1x 46T front (if this fits my frame, 3T exploro Racemax) to allow for wider tires
I run the 50/37 with 10-26t on the back and find it feels great, with good spacing and excellent range in gearing. Add in some bigger pulleys and the efficiency ‘loss’ of the 10t goes away! haha
One thing to note in this discussion is that the 48t chainring is becoming popular with the 12 speed gearsets. These rear cassettes usually have a 10 for the smallest ring, which at 48/10 puts you at a similar speed/rpm as 53/11 that we are familiar with. I wouldn’t run a 48t with a 11/whatever rear cassette unless you want to spin like crazy.
These rear cassettes usually have a 10 for the smallest ring, which at 48/10 puts you at a similar speed/rpm
Just to be clear, only SRAM 12sp cassettes have a 10t. The Shimano and Campy 12 speed cassettes do not.
I’d stay go 52 or 53 and keep it out of the 10t. The weight to drive train friction is probably worth the regular sized chainring.
I wouldn’t run a 48t with a 11/whatever rear cassette unless you want to spin like crazy.
like crazy is relative
48-10= 34.1 mph
48-11 is still 31.1 mph @ 90 cadence
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I run the 50/37 with 10-26t on the back and find it feels great, with good spacing and excellent range in gearing. Add in some bigger pulleys and the efficiency ‘loss’ of the 10t goes away! haha
I rode the Kona course in 2006 with a 48/34 and 12-25 in the back. I basically never took the bike out of the big ring other than on Palani getting out of town. When I “spun out” I just got into a Sebi Kienle tuck before Sebi was doing it coming back from Hawi and on zero watts was passing all the guys pedaling like crazy sitting on my top tube :-). I just had the 48 tooth back then because locally I have a lot of rolling hills and I hate going back and forth, so I wanted to just stay in the big ring (it was also when larger cassettes were not so common).
Keep in mind that Jacques Anquetil won several tour de Frances on a 52x13 large gear (that’s the same at 48x12). Most of us are not riding faster than him on all our new tech. The large gear thing is somewhat overrated. It is not totally overrated, but it is less important than most of us think. A good zero watt tuck often can get us close and the benefit of the zero watt tuck is those joules are saved for later, meaning we probably can ride other parts of the course faster using up some more joules on uphills rather than using up a ton of joules to heat up the wind going fast. There is a massive energy cost of pedaling hard at high speed when you can pedal “not at all” and go almost as fast.
How many have made the switch from say 53/52 to 50 or less? I live in a flat region of the country and went from 52 to the newer sram 12 speed 46 and moved up to the sram 50. Felt like the increased rpm’s wasn’t fun on the 46.
As a cyclist there are times when a 50x10 is very useful when not on descents, and in a flat IM, that is a perfect gear for rolling along at 50kmh…
As a cyclist there are times when a 50x10 is very useful when not on descents, and in a flat IM, that is a perfect gear for rolling along at 50kmh…
So you are saying that when riding in the draft packs at the flat IMs its a good gear to have? Fair point.
As a cyclist there are times when a 50x10 is very useful when not on descents, and in a flat IM, that is a perfect gear for rolling along at 50kmh…
Dang, you have a pretty good “rolling along” speed. Jens Voigt’s hour record attempt was 51km!
53-13 is a faster gear than a 48-12, even if they’re equivalent ratios. Regardless, the biggest gear isn’t really the point. If you’re using either extreme of your cassette for a significant duration in a triathlon, you’re doing it wrong. Really not sure why this is so hard to understand.
I need a big gear like 53 / 11 for training in order to keep power on on down hills and avoid chunk miles without padeling.
I used to ride a 50 on a 650C bike which is like a 47 on a 700C bike.
The only time i noticed it was on fast downhills with a tailwind.
I would regularly do threshold intervals with spikes up to 26 to 28 mph without issues.