road biking: front chainring question

[upallnight]

i just bought my first road bike, and the compact crankset has 50T/34T rings. i've been riding around, and i've noticed on flat terrain i am on the big ring - 2nd or 3rd smallest rear cog.

at about 40mph downhill, i've definitely run out of gears.

only on a few climbs (still in the saddle), i've been in the small front/big rear granny gear.

this could be a total roadbiking JONG question...but i'm wondering if i should consider switching to a 53-39 setup.

my concern is that I'm not in tip-top roadbiking shape yet...and I'm worried that i'll be maxed out on the higher gears -- so getting the 53T ring would solve that problem. however...would the 39T be too high a gear for those climbs?

sorry if these are dumb questions...i'm trying to get the setup dialed.

if it's relevant, i'm in pretty good shape and enjoying the first week on this ride, but i don't expect roadbiking to ever be #1 in my stable.

also...if you had to put a price on it, how much is it worth to upgrade from shimano 105 shifters & rear derailleur to ultegra? what about a cassette upgrade?

(i've been doing some price checking, and i think i might've overpaid for those couple upgrades...and it's causing a little pit in the ol' stomach. that said, i'm super happy with the fit and feel of the bike. fun sport!)

[Hicks]

The regular rear cassette is 13/25 if that is what you currently have. I got an optional Shimano cassette with 12/27 but that's just one tooth on the small end. Cost is about 60 bucks. I have the same problem but since my emphasis are the climbs I decided to stick with the compact.
Next step would be 39/52 which you could consider in conjunction with the 12/27. This would give you both options of steep climbs and pushing it downhill.

We are talking regular Shimano possibilities here since most custom rear cassettes are incompatile. On a side note the regular Ultegra front crankset is pretty heavy,that's why I'm using Raleighs for example. Not sure about price right now. Hope that helps a bit.

[ulty_guy]

probably the best thing to do is to switch the cassette to a racing one (11-23, about $70). that would give you as big a gear (50x11) that 53x12 gives you, but also allows you to keep that granny option. do you ride really long climbs, or short ones? steep ones or gradual? you could swap your inner ring to 36 which would get you a better chainline too as the 16 drop from 50-34 can cause rub sometimes. on the flip side, do you ride solo or in groups on the road. if you're often drafting, you can ride much bigger gears which would make a 53-39 more useful.

[Plakespear]

If you do decide to go 53-39, I would be willing to buy the compact crankset from you.

[Cornholio]

Most compacts are sold with at least a 12 for a small cog, no?

Anyway, the range of gear ratios is really what's important. Do you know (or will you go count) your cassette size?

[Vinman]

I agree, get a 11-23 or 12-25 rear cassette and work on your fitness as well as your pedaling style. A compact setup is best suited to someone that can spin all the way around the stroke with a high cadence vs. someone who typically mashes on the down stroke and then coasts up the backside of the stroke.

[upallnight]

probably the best thing to do is to switch the cassette to a racing one (11-23, about $70). that would give you as big a gear (50x11) that 53x12 gives you, but also allows you to keep that granny option. do you ride really long climbs, or short ones? steep ones or gradual? you could swap your inner ring to 36 which would get you a better chainline too as the 16 drop from 50-34 can cause rub sometimes. on the flip side, do you ride solo or in groups on the road. if you're often drafting, you can ride much bigger gears which would make a 53-39 more useful.

thanks for the input, everyone.

it's a shimano 105-10 rear cassette (hg-5600). i counted 12-25 (although from what was posted above, maybe it's 13-25 as the 'standard').

i guess i pretty much maxed out on the bike in terms of $$ spent, so i'd be bummed to have to spend more. i definitely wasn't expecting to bump into the upper limit of gears in my first week of cycling, though.

so far, i've done mostly level rides, or ones with some decent hills (e.g., 2,000' of el gain in 25 miles) -- but nothing major. i do live at the base of teton pass (up to 10% grade -- around 2,500' of gain in under 5 miles), but i haven't ridden it on my road bike yet. i do ride the adjacent 'old pass road' on my heavy MTB.

i'm not into racing (only myself), and i generally ride solo.

does that info help?

maybe i got a little taken on the shifter & rear derailleur upgrade, which wound up being $150 over the shimano 105 shifters & rear der.

thanks!

[Cornholio]

I think 12-25 is standard on compacts.

If you're at the budget limit, just deal with it for a while. I had a compact last year and it's not really that big a problem to spin out at 35mph. Next year, get the big rings.

I would definitely ride the pass (or some other monster climb) before you decide anything, though. You'll learn a bit about what that little ring is for, I bet.

If you're dying to change right now, your cheapest bet is to get a new cassette. You can get an 11-25 in both 105 and Ultegra. The 105 cassette is 50 bucks or so, right? You won't need a new chain with this option, either.

[upallnight]

confirmed: it is the 12-25 cassette.

i think right now it would be kind of weak (and something i probably can't afford) to swap out any brand-new parts....i think anything i would do would have to involve going back to the shop and asking if they can work anything out. not sure how they'd react. (they are really nice, but this could be beyond the norm.)

we are talking about a $2k bike....

and, yes, cornholio you're right...i definitely will be in the granny gear on the big climbs. so far, even for the steepest climb i did i was still in the saddle. it was definitely steep, but it wasn't as long as, say, teton pass. i wonder with the 53-39 i'd still be in the granny gear anyway, but maybe i'd be out of the saddle a bit more.

[pechelman]

This year take it easy since you're rehab'ing.
In your case id rather have less gear than not enough.
If it wasnt for the knee, Id say to sack up and get the big rings and smaller cassett as it would only make you stronger.

Youll still get a workout up a 5 mile 10% in a 34-25.
I can garuntee you wont run out of gearing going up that.

Next year upgrade to 53-39T.

[comish]

For me, on a long climb, I still want to be able to be in the saddle in order to keep my cadence rather high. If I'm forced to get out of the saddle that means I'm gonna redline it pretty quick which if you rode Teton Pass and you redlined it ha 2/3's the way up or something would really be brutal.

Give that a try before making a decision because the longer you ride, the bigger the hills you ride, the more you might actually like that granny gear.

That having been said, I haven't ridden the compact crankset as I'm on a standard double, but with a 12/27 in the back for climbing just so I can complete those big climbs in the saddle with only an occasional stretch out of the saddle to vary it up.

[upallnight]

For me, on a long climb, I still want to be able to be in the saddle in order to keep my cadence rather high. If I'm forced to get out of the saddle that means I'm gonna redline it pretty quick which if you rode Teton Pass and you redlined it ha 2/3's the way up or something would really be brutal.

Give that a try before making a decision because the longer you ride, the bigger the hills you ride, the more you might actually like that granny gear.

That having been said, I haven't ridden the compact crankset as I'm on a standard double, but with a 12/27 in the back for climbing just so I can complete those big climbs in the saddle with only an occasional stretch out of the saddle to vary it up.

all good advice. sounds like a 53-39T front / 12-27 rear might be a good compromise... but it's not worth making any change right now.

i will deal with maxing out in the higher gears...i don't expect to be going over 35-40mph *that* often (simply because i feel a sketchy at the point on the light bike...the bike won't be the limiting factor) -- and worse case is that i just sping a little bit faster, which, as pechelman points out, is not bad for my knee.

[homerjay]

all good advice. sounds like a 53-39T front / 12-27 rear might be a good compromise... but it's not worth making any change right now.

I run 53-39/12-27 and climb a ton, good setup. You're obviously too much of a badass for compact gearing.

[upallnight]

I run 53-39/12-27 and climb a ton, good setup. You're obviously too much of a badass for compact gearing.

no...not a badass at all.

53-39/12-27 would be perfect...but i didn't know this before getting setup with 50-34/12-25, and therein lies the problem.

[vinnay]

semi-hijack,
anyone read anything online that does a very good job of explaining gear ratios? i obviously understand it in principle, but these recommendations you guys are throwing out make no sense to me.

[upallnight]

Hey, vinnay...

The simple answer is that you can divide the number of teeth on the front ring by the number of teeth on the rear wheel. This means that for every revolution of the cranks, your rear wheel will turn n revolutions.

For example, a 34T-25T combo means a 1.36 gear ratio. If I switched to a 39T front ring and 27T rear cog, that is a 1.44 gear ratio (= slightly higher/tougher).

Folks that are talking about losing gears or parity are basically doing this calculation. If the gear ratio comes out the same, then two gears are equivalent, regardless of how many teeth the rings have.

Another example:
If I have a 50/12 combo, that is a 4.17 ratio. If I switch to a 53T front ring, I'd need a 12.72 (roughly 13T) rear cog to match the gear.

Does that help?

(Correct/educate me if I've misstated or poorly stated something.)

[glademaster]

Swap out the small chainring on the compact for a 36t one, and maybe drop down to an 11-23 too. I've found that if I'm descending a big enough hill to spin out my 53-12, its faster to not pedal and just get aero. Thats just my $0.02 though.

[rideit]

semi-hijack,
anyone read anything online that does a very good job of explaining gear ratios? i obviously understand it in principle, but these recommendations you guys are throwing out make no sense to me.

Sheldon Brown is your huckleberry.

[mike_h]

I had the same issue a while back. 50 was nice for training, but useless if the speed went up. You can move up to a 52 / 36 set up on a compact which would give you a 50km/h gear and a good range of climbing gears. I don't think you'd be able to find a 53 ring to fit the compact cranks, but things might have changed.

[rideit]

BTW, UAN, keep your cadence in mind. You will want to average 85-90 rpms...If you can do this in the valley in your highest gears, you are a monster! I think you *might* be pushing too tall of a gear, a bit too slowly for maximum effinciency. Show up on a tuesday night group ride after the 'TdJackson, you will learn a ton. Hey, Ya wanna ride to Idaho Falls today? I'm leaving at two if my truck is ready! Only 70 miles from victor!

[CantDog]

If you swap the rear to a 11-23, you get nearly the same ratio as running a 53/39 and a 12-27. Plus you get a tighter cogset so the bigger rings dont seem like much of a jump.

Or, you could keep your crank and run a 'semi' compact, meaning a 52/36. That way you wouldnt have to buy a whole new crankset.

Get an 11-23. You'll be happy with the compact then I bet.

[rideit]

Get an 11-23. You'll be happy with the compact then I bet.

FWIW, I run 30/40/50, with a 11-27 on my cross bike around here. I live at the base of Teton Pass, and damn, there are many days early season that I dip into the 30/27!
The whole deal for me is cadence. I also like to hit trails on the cross bike, so I am not ashamed. Often times the small ring ends up being much faster over the long haul, as fatigue is not as crippling.

[Cornholio]

Because I am a huge dork, and thought about this a lot before upgrading to my current setup, I happen to have some data handy...



Gear-inch development is how many inches your 700c wheels roll forward with each pedal stroke given a specific gear combo.

A development of 100 inches will allow you to pedal at 30mph at 100rpm.
A development of 39 inches will allow you to pedal 9.2mph at 80rpm.

Not shown, but a 53 with an 11 in back gives you 130in development, just fyi.

[Cornholio]

A much cooler and more complicated gearhead calculator can be found at http://www.soulbikes.com/gears/, which even Sheldon Brown concedes is the best.

[upallnight]

I forgot to add (above) that gear ratio also factors in your crank length and wheel size -- but asssuming those are equal, the front ring/rear cog method that i described above works as a quick approximation of relative gears.