I’m a flat crit racer. I would consider myself a sprinter.
I recently purchased a new bike and I went from a 53x11 11 speed setup to a 46x10 12 speed setup. I’m thinking about going 1x and switching to a larger chainring. The current cassette is a 10-33t. I’m a CAT 2 so typical race speeds are 25-30 mph and my self selected cadence tends to fall in the 95-100 rpm range.
I’m worried about spinning out of the 46x10 combo during a sprint and I’m also worried about general chain line efficiencies during normal riding. I’m leaning toward a 1x 50t or 52t setup and was wondering if anyone has gone through a similar experience.
According to bikecalc.com, I’d likely be moving from the 46x13 gearing combo (current setup) at 25-28 mph 90-100 rpm to the 50x14 or the 52x15 combo at similar speeds and cadence. The cassette then drops to a 17t cog and that drop off has me worried with the 52t chainring.
My own recent (last 12 months) experience of swapping out chainrings has been positive.
I didn’t go to a 1X setup, so I appreciate this response doesn’t entirely answer your specific query, albeit I think the principle of what I experienced is relevant.
I was running a 50-34 up front and an 11-32 cassette (11 speed Shimano) and moved up to a 52-36 and an 11-34 cassette.
Things I found (some anecdotal or could be placebo so take with a pinch of salt):
I was faster - on the flats I felt like for the same level of effort I get higher average speeds and this was measurable - because I noticed segment PRs on flat segments that didn’t feel like I’d been pressing for a PR on the ride
climbing was easier (slightly) in the easiest gear - the 34-36 ratio is actually easier than the prior 32-34 and I didn’t expect to notice any difference but I did
I didn’t spin-out on descents as much - which for me is a better scenario
Time spent in the smaller front ring increased as a percentage on rides (lumpy undulating terrain where I live) which actually made for less cog-swapping and surprisingly felt easier to just modulate cadence, given the slightly bigger jump between rear ratios
I was initially a bit concerned that I’d messed up my setup because I perhaps would find that I was over geared for too many situation, but in fact this hasn’t happened.
When sprinting, I feel like I’ve got a much better ability to push harder into the wind-up, more so when already travelling at speed before pressing on, and this translates into more confidence and less chance of spinning out too soon / plateauing the progressive acceleration.
So overall I’m happy I made the change as described. I think some of this translates over to the option you’ve set out that you are considering.
Thanks for your response. I’m not at all concerned about hills in my current riding location but I’d save my current setup to put back on the bike if I needed to go climbing.
Appreciate your insight. I’ve definitely committed to a bigger chainring, just can’t decide how big. I’m even open up to something crazy like a 54!
We will average 24-25mph on lumpy road rides here (lumpy, not hilly) and I found on my 1x road setup that a 48 - 10/33 was not enough but a 52 - 10/33 was too much (struggled on the slightly longer stabs). I settled on a 50 - 10/33 for those conditions. I would say for a crit in the 25-30 array, a 50 “could” be okay, but a 52 may be better.
I find that if you dont have to use the 10T… the better, thats just my opinion
Considering you probably don’t want to rely on the 10t cog too much, I’d say you want at least the same as before, 53t. I’d go with a 54t chainring and see how you get on.
The other thing to look out for is if your derailleur is good for 1x. It will work with any derailleur, but afail one with a clutch is much better at keeping your chain on.
If you are worried about the 2 tooth jump to the 17 you could also change cassette to the 10-28. That has a little bit closer ratios: 10,11,12,13,14,15,16,17,19,21,24,28
I’ve have a 2019 CAAD 13 that I converted to a 1x. 52 Sram Force up front and Shimano Dura Ace 11-30 cassette in the rear. Been a great combo for flat crits and even some with kickers. I also get it out for group rides and training rides without long steep climbs. 52 up front has been perfect for the crit racing I do. 50 may offer a bit more options for general riding.
I’m a sprinter and converted my road bike to 1x about a year ago. Besides racing or fast group rides I also use the bike to ride through mountains, so I ended up using the 48T SRAM aero chainring and my factory 10-33 cassette. In a sprint it is very much possible to spin out the 48-10 gear if you go for a long sprint, in shorter sprints it’s ok. Here’s the math:
At 100rpm with a 48-10 it tops out at about 38mph. You can obviously spin faster but it’s not something you would want to do too long. I plan to go to the 52T SRAM aero chainring, which will bump up a 100rpm sprint to a little over 41mph. I’m also going to go to the 10-36 Red cassette because I often ride in the mountains but since you live in a flat area I’d stay with the 10-33 or even go with the 10-30.
Edit: Forgot to add that I think you should go with 52T or even a 54T chainring. I’m choosing a 52 because I ride in the mountains. If I lived in a very flat place I’d probably go for a 54. Note that a 52-10 is bigger than a 57-11 (I know there are no 57T chainrings, I’m just pointing out it is a decent size gear)
