Apaulo

I picked up a new wheelset and am looking to purchase a 9-speed cassette and new chainrings. I haven't the slightest idea what kind of gearing I should get. My cranks are 130mm bcd, so I know i'm limited on what kind of gearing i should get. My other bike has a 50/34 crank and an sram 12-13-14-15-17-19-21-23-26 cassette, 34.4/109.5 gear inches. I like the gearing, but have felt at times i wanted a larger gear, and wouldn't mind having a slightly higher low gear. So what I'm thinking of getting is a 11-12-13-14-16-18-21-24-28 cassette and a 38/50, 35.7/119.5 gear inches. Any thoughts?

Drew Eckhardt 

1) If you need a gear as tiny as 38x28 you lack the strength to do something useful with anything as big as 50x11 or 50x12. Trade the 11 and 12 for useful gears in the middle.

2) The spacing would still be sub-optimal. If you need a gear as low as 38x28 consider trading parts to get a triple like 50-40-30 x 13-14-15-16-17-18-19-21-23 which is even lower.

Apaulo

I'd like to keep a double, as i don't want to spend the money to replace my cranks. Also, I actually don't need gearing that low, on my other bike i always felt i could do aways with my 2 lowest gears.

canam73

[QUOTE=Drew Eckhardt;13320548]1) If you need a gear as tiny as 38x28 you lack the strength to do something useful with anything as big as 50x11 or 50x12. Trade the 11 and 12 for useful gears in the middle.

You should tell Contador he's doing it wrong: https://road.cc/content/news/36163-gi...ador-goes-apex

To OP: as in the above article, you may have to check your derailleurs capacity and swap out to a medium/long cage type. Shimano standard road units can usually handle 28t even when they are not spec'd to, but if you go any bigger on your cassette it may be an issue. Also, if your crank already has rings on it it may be just as easy for you to get an 'apex' like set up with a longer derailleur and wide range cassette.

RecceDG

If the OP lives in a hilly area, those taller gears can be useful on the descents.

Flat areas want tight spacing in the centre of the range. Hilly regions want a wider range (on both low and high ends) which necessitates larger steps between cogs.

DG

fiataccompli

I guess a 39/53 crankset is out of the question? certainly puts a new perspective on all the cogs in the back....

ericm979

The SF bay area has a lot of hills. But few descents here have significant straight parts, so a high gear does not make much sense. I race, and I do ok with a 50x12.

What's on your current crank on this bike? It's probably 53/39. You could get a 38t ring, and a 12-27 cassette. I think that a 53x11 may be more gear than you need, and skipping the 11t would give you an extra cog elsewhere.

cyclezen

your 34/26 is 1 inch lower gearing than a 38/28...

difference in velocity of 50/11 and 50/12 is 2.5 mph (low to mid 30's...) at 100 rpm. If you are in the final stampede of a hotly contested crit sprint, you might want it.

otherwise add a few rpm to your cadence, you'll get there just as quick. If you think you're spinning out a 50/12, that's illusion - you're not spinning...

a new tranny ain't gonna help, rebuild the motor.

spreading the gears out means you'll have less choice in the gearing you'll ride maybe 96% of the time... ?

Drew, what are you thinking? Reason and Sense have no place in the 41 !

adriano 

50x12 to 34x26 is what is thought just reading the title. give the 34x28 a try.