clones2

Currently ride a 50/34 crank, with 172.5mm arms. Upgrading the crank and going with 175mm crank arms. I am wondering if I should stick with a 50/34 compact, or should just ride the standard 53/39?

I do race - so shouldn't it benefit me for sprints to have the 53 big ring? (I run an 11-28 in back)

Most hills around here aren't more than 6% - 8% and are a mile or less in length - which means the 39 should be just fine I would think.

Thoughts? Am I missing something. I'm a bit more of a gear masher than a spinner if that factors in at all.

thechemist

If you are already running an 11 cassette and still need more speed than yes I would get the 53/39.

Homebrew01

When do you actually wish you had a bigger gear than 50-11 ?
Get the gears you need. But no point having higher or lower than you'll use.

Sprinting doesn't usually involve huge gears.
When racing in CT, I don't think I have needed more than 53-12 (smaller than 50-11). If I had long downhills trying to bridge, then maybe, but in most situations you can hang with the group even if you have slightly smaller gear. Plenty of strong juniors win senior races.

If the 34 is useless for you then go up to a 36 compact or the 39 option.
Your 34-28 low gear is tiny so you could also consider a tighter cassette. Get a gear chart or calculator and map out your options.

clones2

I was kind of thinking the other side as well... Would I ever need less than a 39-24 or 39-28? Was just considering the "standard" size as it may keep me in the middle of my cassette for climbing.

Right now for 5% grades...which are typical around here...I end up crosschaining alot. Running 50-21 or 50-24... or 34-14... Thanks for the insight.

I have been using the gear calculators etc... which is why I made the statement right here thinking that my climbs would keep me in the middle of my cassette. Nothing really severe around here where my 34-21,24, or 28 are going to be needed.

mkadam68

If racing, get the 53/39. I find the 53 strengthens my legs during training. Now, in the crit & road races I do, I don't always get to the 11. Usually sprint in my 53x12 or 53x13 or if we're really strung out at 30+mph. But, since you're near hills, a 53x11 will be really nice to have if racing down those hills!

Dean V

53/39 and a 12-25 or 11-23 cassette.

Brian Ratliff

1+

Racers definitely mostly choose 53/39 crankset. Yes, yes, a 50/11 is "bigger than a 53/12" but a 53/11 is bigger still (for downhills mostly), and having a larger big ring gives you better gear ratio resolution which helps with fatigue. I tend to shift less when I have a smaller ring on the front.

HMF

52/36 is also nice.

carpediemracing 

I have all the respect for Homebrew as I even vetted him as one of the instructors at the clinics I run.

However

I've been thinking about the whole compact vs standard crank thing for a while. Here's the big limiting factor with a standard - you can't go smaller than 38T inner ring. With a compact you can always go bigger - a new standard for compact cranks is to use a 52x36. This gives you a good top end gear without sacrificing the small ring. You can still run a smaller cassette than if you had a standard, and a smaller cassette has closer ratios for better jumps in gear.

Smaller rings/cassette-cogs means more wear, but, honestly, I don't think that's a huge thing. It also means less efficiency - more teeth is more efficient, and TTT squads used to use huge chainrings in order to use larger cogs - but again, I think it's a minor part of the whole equation.

I do think that a higher high gear is good. You may not use it in a sprint but you may use it in a hard tailwind or on a slight descent. At Bethel, basically a flat course, the first straight is a slight downgrade. It's rare to go down that at less than 30 mph, and on fast laps it's more like 38 mph. If you're limited to a 50x11, versus a 53x11, and you're doing 30 or 50 laps, that's a lot of extra spinning. On courses with even sharper downgrades you'll easily hit 50 mph in a bunch, and the bigger the gear you have the smoother you can pedal. I used my big gears not necessarily for sprinting but for moving up when the pace was fast, usually on either a downhill/downgrade or when the group is winding up for the finish.

An example where I salvage a place due to moving up at speed (last lap of race):

Another, more dramatic example (I was literally at the back of the field with half a lap to go; the rain helped the situation):

foresthill

Where are you? If somewhere with steep climbs like I am, I can't say enough about how awesome 52/36 is. Otherwise 53/39 is fine.

deacon mark

I would not worry about hitting 50 mph this is beyond pedaling speed. A standard is fine unless you have bigger grades. One thing about a compact is it all on the big ring if the course is reasonably flat, and 50/11 is a big gear if you can spin it out you are not asking the question you know the answer.

Homebrew01

I'm not against anyone running big gears if that's what they need. Personally, I don't recall needing more than 53-12, even in fast races. If I had an 11, I would have to give up a middle cog I use all the time for an 11 that I would rarely use. But cassettes are cheap, so you can have several on hand for different events. I have a 12-23 on my race wheels and 12-25 on my training wheels. (I don't do hilly races any more)

jsutkeepspining

i use a 53/15.

rho

Hello Clones2,

I´ve been riding 53/39, 11-25 for about 2 years and it works just fine on the flats for me, when I do +13% climbs that are longer than 2 km I really beg for the lazy gearing. I was curious about getting a 11-28 on the back as the one you have, as I don´t like changing cranksets...

You should try to use one of those on-line gear calculators, they are just great because you just input your prefered gearing componentry and a specific cadence so you can now how fast you m8 go with each gear. There are plenty of gear calculators out there, but I´ve found this one that I like the most, as it graphs the speed for each sprocket/ring combination.

https://home.earthlink.net/~mike.sherman/shift.html

Have fun with the new gearing.

99Klein 

53-11 or I spin out down hill. No problems finding the right gear ever