expatbrit

Admittedly, I'm just under true clyde in weight, but I live in the foothills of the Sandia's in NM, and so end up climbing quite a bit.

The new bike is a CX bike, with CX gearing. 46/36 on the front, 12-27 on the rear. Thus far I've been OK with this on the climbing (a fact I find pretty surprising, since I'd use MUCH lower gearing on my old bike to go up the same hills, and the 10lbs of weight difference isn't the thing here. That's a whole different question, however, and one of the reasons I love the bike)

Crank is an FSA SL-K Light, chainrings are also FSA. While I've seen bad opinions on these, they're fine for the level of riding that I do.

I'm not planning on spending money right now, but I'm looking at my 'cycling wish list' for the year. One thing that looks to be pretty common would be to 'upgrade' to a regular road compact set, by someone like Praxis. Not a huge amount of money, but enough that I don't just want to buy it 'just because'.

Checking gear calculator, it'll give me a slightly lower bottom gear on little-big (my primary concern) -- approximately 5%, if my math is good.

It also gives me a higher top gear, but while I get sloppy pedaling at cadences above 120, I can do it and that's a pretty decent clip for me even downhill these days.

There's less overlap between small and big chainrings.

Would this be a 'useful' ride upgrade, in my continued quest to ride up grades? Or am I better off just staying where I am and riding more. (Or, optimally, both?)

sstorkel

My most-used bike has a 50/34 compact crank and 11-28 cassette. That's a pretty ideal setup, as far as I'm concerned. The 50-11 combo will get me going faster than I want on the downhills and with the 34-28 combo I can tackle multiple long climbs on a single ride... assuming I've done the requisite training.

IAMAMRA

I run a 48-38-28 right now but am switching to a 42-32-22 hopefully this year.

IBOHUNT

Which RD do you have? You may be able to use a 30 rear or if it's SRAM Apex or Rival mid cage perhaps a 11-32 which may make a mid-compact a better alternative if you want the top end and don't mind the larger jumps in gearing.
Spin a 52x11 or 52x12 at 100 rpm and you get 37 or 33 mph. If you then ride in a flat area you can use a rear cassette that's tighter allowing you to keep in a closer rpm range.

My vote, and what's on my bikes are a mid-compact.
Climbing cassette is a 12-28 and flatlander cassette is a 12-25

End of the day you need to decide what you need to climb and have the top end you are looking for. That can take some experimentation and can also change with fitness.

Cheers

fietsbob

sounds like it's not getting Actual CX use (.. use the 24" gear, 2 feet, shoulder the bike and Run the hill)

thats OK , My CX frame has the same gearing as my Touring bike.. a 24 40 50 triple crank

and a long cage RD like a Mountain Bike..

jsigone

Your crankset is legit, Just change out the 36T for a 34t, might be like $30-40. Changing the 46t to a 50t might set you back another $50-60

My CX came with the 46/36 front and 11/28 rear. Somehow managed this climb in the 36x28 w/o walking anything, but there was times I REALLY REALLY wanted too but didn't want to dirty my new road shoes on the "fireroad climb" https://www.strava.com/segments/1205524 A 34t in the front would have made it a bit more enjoyable, but 12/32 cassette would have made it really comfy/easy. Option 2 would be $140 Force WiFli Rear D, $30 KMC chain, $70 12/32 cassette vs option one $30-40 for the 34t front ring

IBOHUNT

^
Another option, if it's a SRAM grouppo, is an SRAM X9 RD and use the 36T cassette.

B8888S

My Roubaix has a 50/34 in the front and an 11/32 in the back using a SRAM Apex rear derailleur. While I wish the middle gears were spaced a little closer, I really appreciate that 32 in the back on a long climb. I just shift into that 34 - 32 combo and spin away. Not fast at all but I get to the top. I am beginning to think about getting a new wheelset for this bike and will likely go with a 12/32 rear cassette. This should slightly tighten up the middle usable gears, keep the 32 rear climbing gear, and only loose a little on the top with 12. I don't need to or like to go that fast anyway. The wheels are supposed to be a reward for meeting my weight loss goal of dropping 80 lbs. I have 20 lbs. to go. Who knows, after dropping this last 20 and getting more fit, I may want to go with something like a 12/28? I have plenty of time to think about it.

expatbrit

So. RD is Ultegra. I could probably get to 12-28 on that, I think. But that's not a terribly worthwhile change in my mind. I'm honestly not worried about top speed yet -- my fitness is such that I probably couldn't spin out 50-12 if truth be told, so not a huge amount of point. As to flat? Yeah. We have that -- if I fight my way across town to the river, but that's not my typical riding if only because it's such a PitA to go east-west across 'burque.

The mid-compact is 52-36, yes? That doesn't give me the lower gearing I'm whining about.

That's a hell of a climb in 36-28, and I'm well aware that you're in DRAMATICALLY better shape than I am. That's why I'm considering the 34. (I hadn't thought of just swapping out the little ring. That's a MUCH cheaper option, and I assume bolt up). I'll file that away as a good option.

The Praxis rings I was looking at are more like $160 for the pair, but those aren't the cheapest on the market for sure.

expatbrit

Not so much yet. Maybe next year. A little bit of dirt and gravel, a lot of crappy roads and chip seal. CX bike mainly so I can run 28mm tyres easily to support my fat arse on the agglety-agglety roads.

stephtu

I would recommend going for new cassette & a MTB derailleur, go for 11-32 or 12-32 or 11-34 or something like that. I would not change cranks for only 2 tooth difference, not really enough change for the effort. To me it's good to have smaller difference between chainrings, more overlap, front shifts easier, don't have to shift both front and rear all the time (which is why I run a triple).

TrojanHorse

People bellyache about the overlap between compact chain-rings all the time. The 50 is kind of an odd duck. It's not really low enough to put you in the lower end of your cassette (for spacing) but it's not really high enough for really good top end. I used to have a mid-compact (52/36) and that plus a 11-28 got me up just about everything I needed to climb EXCEPT for a few really nasty hills near my house, and by nasty, I mean 15%+. That 52 was pretty daggum awesome when the road turned down though.

I have since put compact chain-rings on and it definitely makes a difference on the steeper sections. You could easily just swap out your inner chainring and accomplish the same thing. Depending on your desire to bomb down hills, you could swap out the larger or you can just deal with coasting when you get above 30 mph. As I get older, I'm losing my urge to hit 50 on downhills but that's up to you. That 46 tooth ring probably puts you in a pretty good spot on your cassette when you're riding the flats.

5% less effort is a lot when you're doing 10% grades but what you have now should probably be comfortable for anything up to 8%, especially at your delicate weight. It really just depends on your terrain and desired effort.

Null66

I'm running a shimano deore 591 44/32/22 at 175mm and 11-32 in back.

I like it, sometimes I think I should have gone with the 46/34/24, but not often and not when I'm tired and and the hills get steep...

IBOHUNT

And they are AWESOME.. until the world tilts to 15%

Medic Zero

.

Maybe I'm a wimp, or maybe a lot of the hills around here really suck, but I can't imagine running anything other than 48-36-22 or 46-32-22 with an 11-34 or 11-32 in the rear. I do ride rather upright and on MTB's converted for city use or touring, so there's that. Maybe I'll feel better when I've finally dropped from my current ~280 down to my "fighting weight" of 210 pounds, but even then I wanted an 11-34 in the rear, and at my fittest was running a 51-40-32. I can just manage on that set-up now, but it's tough on the knees and even slower on my several daily climbs than something geared lower.

bigfred 

I'm another that has tried both 34 and 36 tooth chainrings and has decided on 36 being the better choice for me. Currently running 36/50 X 11-26, but, at my currently decreased fitness level wish I had the 12-27 or 11-28 on my primary wheels. May have to make a cassette switch tomorrow.

expatbrit

I see 6% and 7%; there's a couple of long climbs I'd like to be in shape for this summer (this one: https://www.strava.com/segments/1466117 for instance) and while it's 'only' 5.5%, it's a bit of a go. This one https://www.strava.com/segments/712721 is a shorter term goal; shorter but significantly steeper.

Wanderer

I know the hills around ABQ, and would think that a 48,36,26 triple would be more suitable. Im a big fan of triples, because they give you such a huge gear range. With the little ring, you should be able to ride up the side of an arroyo.... especially if you switched to an 11,32or34 cassette.

spdntrxi

I use 50/34 and a 11/27… with my knee issues I might go to 12-29.. I need all the help I can get.. There is little little short road I like to climb with ~20% grade.. it's a slog.

RollCNY

OP, you currently have a 10 tooth gap on the crank, which makes for brilliant front shifting. If you put on a 34 ring, it would still shift lovely.

Compact 50/34 cranks, and this new goofy 52/36, both use a 16 tooth jump which is less crisp than a 14 tooth jump (like a 50/36 or 53/39) and significantly less crisp than what you have. What you will find is that many people with these large gaps try to ride 95% of the time on one ring, and shift the front as little as possible, and recommend wide range cassettes to let them stay in that single ring. With a close gap, you get to use all 20 gears, incredibly easily.

IMO, 34T 110 BCD rings are as common as cats and dirt cheap. Install one, and don't look back.

fietsbob

With the engineers getting work by redesigning stuff ... the shorter teeth

and pins and ramps on the inside face of chainrings, these days

the up shifting is earlier than It used to be.

the High end 3D chainrings of Shimano are laterally stiffer than flat ones,..

but since the small one is right above the mounting bolts , the flat shape is fine..

digibud

I think it would be a very reasonable upgrade. You'd have a better high gear and a better low gear. It wouldn't be huge but for road riding it makes more sense. If you can spin at 120 that's quite impressive. There are plenty of pros that spin more slowly than that. Riding more won't get you a bigger top end or a smaller bottom. Sooner or later you'll find yourself on some ridiculous 20% grade thankful for the lower end and in some race going a few mph faster downhill happy to have the better top end. Seems like a no brainer to me if you're road riding.

expatbrit

Thanks for all the advice.

Looks like it's a mix between 'get a triple' (which sounds expensive, since I suspect it's shifters, front mech, and chainrings) and, honestly, not my cup of tea, and mostly 'replace just the small ring' (which is cheap and easy).

I'm still tempted by a (good) compact set, but (as RollCNY commented) leery of the impact to shifting. I already spend most of my time in the large chainring, but I think that on a 50/34 I'd be in the smaller ring MUCH more.

Decisions, decisions!

sstorkel

With my SRAM Red and Ultegra 6600 drivetrains, I personally can't feel any difference in shift quality between my 50/34 and 52/39 cranks... and I'm more sensitive than most people to stuff like this.

bigfred 

I'm more concerned with the resulting gearing overlap than any difference in shift quality when deciding between a 14 and a 16 tooth front differential.

By the way RollCNY, I believe that 36/52 was promoted as the new "compact" gearing choice before 34/50 became the more popular.