Hi, I have a Trek Checkpoint ALR 4 with SRAM Apex 1 40T x 11-42 gravel bike. I use the bike probably ~60% off-road and ~40% on road with 45mm tires. I’m looking into getting a second wheelset for use on road-only rides with 32mm tires. Wondering what would make the most sense for gearing based on my terrain/ride style while keeping the wheel swap as easy as possible.
40T 11-42 is the perfect range for gravel for me, so don’t want to change it if I don’t have to
On the road, I have never touched the 40/42 combo and use 40/36 occasionally
Road rides will be mostly solo and I haven’t been too concerned with needing more top end speed. It’s really only on the slight downhills where I can be spinning 30mph but not fast enough to coast where I have felt limited, but it’s not a major issue at all. I average anywhere from 16-18mph depending on the hills and my effort level for the day.
I’m thinking of keeping the chainring the same and just fitting an 11-36 SRAM cassette. The tighter cassette should move my chain line up a bit (swaps 42 for 12 tooth) and gives me a low enough gear for all my road rides.
Thoughts on this? Any other considerations before diving in? Thanks!
My preference is to keep the cassette the same on multiple wheels and swap chainrings as needed for terrain. A few reasons I like this -
You can often get away with the same length chain for multiple chainrings when they are fairly close in size
If racing, having a spare set of wheels at the aid station with the same cassette makes for an easy swap
Chainrings are cheaper than cassettes
My checkpoint is all I use for road and gravel. I used to swap a bit between AXS xplr (10-44) and AXS eagle (10-52) based on the course profile, but I’ve been on AXS Eagle for the last couple years and love it for road and gravel. Allows me to run a larger chainring on the front while still having nice low gearing for climbs. Zero issues hanging with fast group rides running a 44 or 46 ring and could go larger if I wanted. Obviously the Xplr group has smaller jumps between gears, but I don’t notice that any more and I choose to prioritize the range that I get with the 10-52.
All that said, it sounds like you are fundamentally OK with current gearing, so why not just go 11-42 on the new wheelset? It’s always nice to standardize parts when possible, not have to worry about swapping chains and/or adjusting B gap when swapping wheels, etc.
Thanks for your thoughts here and it is a good point. I could definitely just get another 11-42 cassette. Two reasons I an considering the 11-36 is 1) I don’t use the 42 tooth on the road (but no harm in having it…) and 2) the speeds on the road are higher and I find myself using the 15 and 13 cog quite a bit on slight downhills. The 11-36 will have 11,12,13,15… etc. vs. 11,13,15… etc. so helps to move chain line up the cassette a bit.
I agree the 11-42 cassette could be fine as well especially if it makes the swap easier.
Is this 11 speed? If so, I know SRAM make a 10-42 cassette, which is what I’d recommend. Or I guess 10-36 if such a thing exists? You’ll need an XDR freehub but if you haven’t got the new wheels yet then that shouldn’t be an issue.
The difference between a 10 and 11t cog is pretty significant and I suspect you’ll end up grateful for that extra top end on the road even more than you will be for the tighter spaces between gears. But in terms of swapping wheels, 10t and 11t won’t really be any different.
Oh - and make sure to get some disc rotor shims so you don’t have to align your calipers every time you swap!
UPDATE: Just looked at SRAM website and there are 4x different tiers of 10-42 cassettes for 11 speed but no 10-36. For 12 speed there are 3 different tiers of 10-36 cassette but then it jumps to 10-44.
If you are good with the above, then there is no reason your plan won’t work fine. I’ll just note that you will likely find yourself up against the limits of the 40T chainring more often once you put road tires on because they will be faster overall. But for the average speed noted, you should be OK the majority of the time.
Good ideas. I have considered the 10-42 but it is more expensive and would need to make sure the new wheelset hub could take that driver body, though probably not that hard to find. The 10-42 will introduce some bigger gaps as well (10-12 vs 11-13). I like that the HG driver gives me options to run normal 11-speed road cassettes if I desire
I know the chainring size is big issue for many but I’ve been surprised how good it has been (understand 32mm tires will reduce the speed a bit at same rpm). I find that I like to spin fast on the road, like 90-100rpm, so that helps. The other thing is that if I find I’m getting fitter and average speeds are increasing, I could stand to bump the chainring up a size at that point.
40 tooth seems awfully small for a road setup. I guess it would be fine for endurance rides, but if you plan to do any A group/hammer rides I have to imagine you are going to spin out. You’ll also completely wear out your 11 tooth prematurely. And the steady state chainline will be highly inefficient if you care about these things. As a CAT2 rider, I found 46T with a 10-42 covered me fine in the midwest. Most of my time was spent in the third cog (14). It was sufficient in the mountains on vacation, but if I lived there I’d bump the cassette up to 10-50 to afford a higher cadence on the steep pitches.
Interestingly your setup would be very similar to mine just with one additional (massive) overdrive gear. Assuming 32mm 700c tires, your gear inches are 30-104 (minus the 10 tooth) and mine are 30-99. You are also probably a much stronger rider than me. I do not plan on participating in any fast group rides on this bike.
Also, if you spend most of your time in 46/14, that would be 24mph at 90rpm. That’s much faster than I can push on the flat!
I was thinking about how on gravel I could maybe benefit from a 38 on longer trips or riding more singletrack and a 42 might be slightly better for the road… then I came back to well… the 40T splits the difference and should be fine most of the time haha. Thanks for your input
Yep. I always figure that for me, if I want overall higher or lower gearing, a change less than ~10% is not worth doing. 40 to 38 is -5% and 40 to 42 is +5%, so if I have 40 (which I do) I’d want to go to at least 36 for lower or 44 for higher.
That’s tricky. Essentially, you need to decide whether the convenience of having a single do-it-all cassette outweighs the negative of one missing gear.
Personally, I’d definitely not want to have to think about that. And coming from the MTB side, I don’t mind the jump between the 13- and 15-tooth cogs. The only one that I find a bit clunky is the one between 11- and 13-tooth gears.
Totally agree. But in this case I would still keep the 11-42 on the gravel wheelset and then potentially would have the 11-36 on the road wheelset. The gravel wheels will be my do-it-all set for mixed gravel and road rides where the road set would be for pure road rides.
The 11-36 gives me that 12 tooth to plug that otherwise jarring gap and improves my chain line for road riding (at least, that’s what I’m thinking).