kbarch

Still trying to figure this out. Is this an issue in CX because radical changes in grade associated with the switch between chain rings are more common in CX than on the road?

Jakedatc

You mostly want to avoid shifting in the front.. most are 1x now but the ones that are 2x you don't need less than a 36 because you're probably running below that.

my CX/gravel has 46/36 and an 11-36. I'll put a 34 on for this Vermont gravel ride i'm going to do but that has extended hills

Maelochs

Rigtht. CX (real CX) bikes are set up for racing not casual riding. 46-34 would make a lot more sense for casual riding, but fir racing they don't need that wide a range of gear options.

Probably though, making a 46-36 into a 46-34 would involve removing four or fiver bolts, swapping a ring and replacing the bolts.

Jakedatc

Yep, swapping chainrings takes 5 mins. I do it once in a while to give them a good cleaning on my road and cx bike. Some of them need a little tool that holds the back of the bolt. my Shimano crank does.. Rival crank is just Hex on both sides.

DaveLeeNC

I am not sure exactly what true flatland rider is and whether the OP is one or not (his county has a high to low elevation change of around 400 feet). But it had occurred to me a while back that in all the riding that I have done since I returned to cycling in 2014, there probably isn't a single time where I actually needed anything lower than around 50/30. But I can't imagine limiting myself like that as maybe I will end up riding longer climbs some day.

I guess if you had multiple bikes maybe, but I just wouldn't ever choose to do that just for the simplification/weight of a second crank/shifter.

dave

Jiggle

My road bike on flat to rolling terrain has a 36/46 11-28. I ride with fast groups and very rarely spin out. When I do, it's for a short time and I'm drafting to keep up. Total non issue.

What I like about the 46 is the chain line is perfect for my usual speed - 18-24 mph. When I had a 39/53, going below 18 would mean a front shift. It was terrible.

Now it's more like 13-14mph where I front shift, and since the rings are closer together, there's no double shifting involved.

Gear overlap is totally irrelevant.

noodle soup

I wasn't saying that the OP should ditch the little ring altogether, but simply pointing out that it will almost never see any use.

DrIsotope

I ran 48/36, then 46/36, then 46/34 all on the same cranks-- that 46T is just a gateway drug to ditching the front derailleur altogether. And yes, it's just a matter of taking out the chainring bolts, swapping the small ring and putting the bolts back in. I ran a CX70 46T with an Ultegra 34T for many, many miles.

noodle soup

I would ditch the front derailleur on the TT bike, but there aren't any 53t 1x chainrings.

DrIsotope

Wolftooth makes as narrow-wide 52T in 130bcd, which is pretty close...

noodle soup

this is true, but irrelevant to a flatland rider. With a 12-25t cassette, there are single tooth increases from 12-19. Things get wonky when people use 11-32t cassettes on flatland because of the gaps between gears.

noodle soup

..but sadly not one for a 4-bolt asymmetric(Shimano).

Racing Dan

I dont think its irrelevant. I find the 4-5 cog shifts, when changing chain rings, highly annoying.

noodle soup

that part is true, but a flatland rider with a 50t big ring + a 12-25 cassette, won't be shifting the chainrings.

Maelochs

I ride (among others) 50-34 with 11-28 ... first off, it is three cogs between the rings, and second, that is there instant clicks on the lever. Maybe you guys are using downtube friction shifters, but the deal with brifters is that I can jump several ratios almost instantly.

If your particular setup involves four or five shift (really? Half the cassette?) .. you must have a cassette wider than 11-28, or .. . whatever. I am not trying to invalidate your experience, but i certainly trust my own.

If you find the jump annoying .. well I can understand that. it doesn't bother me, but everyone is different. maybe it won't bother the OP. Maybe it will ruining his riding experience. Only one way to tell.

As noodlesoup notes, with a 50-34 and 11 cogs, the whole idea is not to jump between rings ... the cogs are generally close enough that a rider can avoid frequent front shift .. not like it was back in the day of five, six, or seven cogs, when swapping rings and cogs was essential to get the right cadence.

But, I repeat ... if it bothers you, it does, and thank you for sharing that and warning the OP that it might be an issue.

Racing Dan

" ... first off, it is three cogs between the rings,"

50/34 + 12-25 is 5 cogs.

"... you must have a cassette wider than 11-28,"

Its combining a wide crank, like a compact, with a narrow cassette, like the 11sp 12-25 that does it. Not a wide cassette.

https://ritzelrechner.de/?GR=DERS&KB=...&SL=2.3&UN=KMH

Maelochs

Well, like I said ... i ride 50-34 and 11-28 and it sure seems like three gears up or down to get the next ration when I jump rings. Counting shifting rings that is four shifts, i guess.

yeah, I was kind of poking fun at you there.

As i noted, the whole idea of the tight cassette and big jump in chainring teeth is to Not shift so much between chainrings, and to use the one-step differences on the cassette. For those who need .78 or .83 of a tooth difference, they might need to move to the other ring and move much further up or down the cassette ... but I haven't fond it happening to me.

The OP has 50-43x11-28, just like I do so hopefully, it will please him. if not, we have offered him a wealth of options.

Racing Dan

"Well, like I said ... i ride 50-34 and 11-28"

We (noodle and I) were discussing 50/34 +12+25. 50/34 + 11-28 is 3 cogs but that is (was) not the topic.

No one is talking about 0.75 toots jumps, and I have no idea why you argue with me. Do you?

Maelochs

Dang, i didn't even know we were arguing.

zoom26

I'd say get used to the gearing and try high cadence lower gear or high gear lower cadence and find out which one appeals to you more. For mostly flats, you can do middle gear then play around 50 or 34 chainring.

black_box 

My cross bike had road tires on it most of the time, with either 48/38 or more recently (and preferred), 46/36 (and 11/28 cassette). I just got a road bike with 52/36 (11/28) last summer and I've used a 50/34 before. I'm a bit north of you, but along the fox river you probably have a few short hills if you seek them out? Check strava for your local climbs and popular routes. A few short climbs of 6-10% aren't hard to find further north (Barrington, Crystal Lake) and you can string them together.

A 36/28 will likely tackle the short hills around here once you have a bit of riding in your legs. I think it's easier to leave the bike in a 36 and not run out of gear when you're going from stop signs to cruising speed with a decent group (16-22mph up and down the rollers?). To me, as compared to the 34, it felt like the difference between being able to GET to cruising speed before needing to shift, vs. needing a shift to get there at a comfortable cadence.

That said, if you enjoy riding and head up to Wisconsin for the popular centuries, they have bigger hills and you may want a 34. I would suggest finding the steepest hill nearby and see how it feels spinning in the 34. If you're miserable, then maybe stick with the 34 (but you'll get faster as you ride more, of course).