steeljunkie

Over the years I've found that my top usable gear on most of my bikes has gotten smaller. Once upon a time I rode a 53x12 and dropped into it fairly often on descents, though to be honest I never used it on level ground. These days my biggest gear is a 48x12, which I hardly ever use. So I'm curious - how big a big gear do other folks find to be really useful?

Doctor Morbius

Come spring I'm going to set up one of my hybrids with 44t/14t top gearing (thanks to a junior road cassette on the rear), which will bring me to 21 mph at a cadence of 85 rpms. I doubt I'll need more than that. If for some reason I want to hit 22 mph I'll need to increase my cadence to 89 rpms. No biggie.

The top gearing on my road bikes is 52t/13t and I'll never use that high of gearing. Since my road bikes are triples, they have a 42t middle chainring so that works out very well. My rear cassettes are 9 speed 13t-23t.

EDIT: Basically 80 gear inches tops is all I can really use on a day to day basis. I live in a very flat part of Indiana, so no hills to contend with.

rms13

50/11 is plenty big for me I'll spin out descending at 35+ but I'm fine coasting at that point

slimyfrog

48/11 is fun enough for descents. At the speed at which it stops being effectual (a bit above 30mph or so), common sense kicks in and reminds me I'm too old to go that fast on a bike.

Leinster

I have 50x12 and 53x13 on my bikes, and only rarely spin out on the very steepest of descents. I never use higher than 50x14 on the flat, and that would only be briefly, with a tailwind.

Bunyanderman

I will drop it into my 50x11 most rides actually.

caloso

53x12. I'm old school, what can I say?

gregf83 

In the winter I ride a 1x10 setup with a 42-12 or 42-11. Lately it hasn't been shifting into the smallest cog and I've been too lazy to fix it. My biggest challenge is spinning down a steep hill where I hit 40mph without bouncing in the saddle. I can be fairly relaxed going down a bridge at 32mph. It's good practice.

catgita

I have a 46-12 gear, but I don't think I have used it, even on fast group rides. My gears are chosen to minimize jumps and front shifting, and pedaling down hill is not a priority. I can go faster in a tuck anyway.

It is very difficult for a non-racer to get gearing that makes any sense. The bolt circle diameter of most cranks is simply too large. Tripple cranks have too many compromises simply to add a redundant chainring.

hueyhoolihan

most people, IMO, use a big gear while descending because it helps to balance against some resistance. IOW, they feel a little intimidated at high speed while having nothing to push against if coasting.

hueyhoolihan

i've got a old worn out derailleur that does that too.

B. Carfree

On a half-bike, a 48X12 is plenty and has been for four decades (when I was actually fast, I had a higher cadence). On a tandem, 53X11 is not quite high enough but is all I can do and still have a low enough low gear.

TrekmanDan

On my usual 20 mile ride, my largest 53x11 is never used. In fact, I've only used it once on a 1/2 mile descent, where I topped out at 40mph. Even then, I still didn't have to worry about topping out...

Sy Reene

This. I recently went to compact, and 50/12 has more than sufficed over prior 53/12. If I need to spin and go 30mph it only means a cadence of 90, and that's more than fine for me. Last ride I still got to 36mph on the downhills which is probably faster than I should be going anyway as there were no prizes being offered.

OldsCOOL

I have a 53/12 max on my Cannondale and only use it for descents. On flat ground sprints and fast rides I'll tap into the 53/14 quite often.

big chainring 

I bought a 55 tooth Campy chainring at a swap meet last year. I'm putting it on an old Schwinn Super Sport. With a five or six speed 14-28 freewheel it will have a nice range of gears for a flatlander like me. Get a nice tailwind and put it in the high gear and pedal 60-70 rpm, that's fun.

PepeM

50/11, which should be able to get me all the way to 40mph. Not even sure I've ever used it, the 50/12 can get me past 30mph and after that usually I rather tuck in than pedal like crazy.

Shimagnolo

Two of my bikes have a top gear of 48/11, which is a little too low for the fast descents.

Another bike has a 53/11, which is a little too high. When that 53 wears out, I'll probably replace it with a 50.

MKahrl

Let's start with how big a gear that Eddy Merckx needed to dominate the world's best bike racers in his time: 52x13 or 107 gear inches. You can argue that you need a bigger gear than Eddie Merckx but no one will believe you.

On a modern bike with a 11 tooth small cog the largest chain wheel needed is 45 T (109 gear inch) (if you are =< than Eddy Merckx.) Some people are either > E.M. or they like to pedal going downhill where their max cadence (let's say 110 rpm) would limit them to 36 mph.

Since E.M. faced the same problem of spinning out (albeit at a higher cadence) he probably used long or steep downhills to tuck in and conserve valuable energy.

DrIsotope

Another 48/11 here. And I use that gear only when descending-- hell, I don't think I've ever used the 48/12 on a flat for that matter. Yeah, it spins out at about 35mph, but I really don't see a need to be pedaling above that speed. The 48 is just a lot more usable across the rest of the gears, I don't worry too much about the tiny cogs.

cosmicfour

I have a 52/11 which is what came with my bike (CAAD 10 5), I live in a flat place so i do use 52/12 when training using intervals and quick speed bursts to build up strength in my legs/muscles. My cassette range is 11-28 and chain rings are 52/36 a good range for me. I usually stay around the 52/15-19 range when on everyday "endurance miles". If I got to a hilly area ill go with a compact chain ring but the cassette usually stays the same.

Lower when pushing during training so really depends on what I am doing which and where I am as to the gearing I use/need.

series1811

I use my 52x11 frequently on descents. It is also fun to use when there is a stiff tailwind. Need? Probably not. Want? Absolutely.

silversx80

It's rare for me to spin out my 50/11 combo, but it does happen and I like to have the option. I'm considering swapping my crankset to a 52/36, and putting my 11-28 back on (using an 11-26 right now).

merlinextraligh

My road race bike is 50/11. Never had a problem spinning out descending, even in Colorado.

Time trial bike is a different matter. On a course with downhill, and downwind sections, 56/11 can be useful, even if your not Eddy Merckx.

kcjc

I have both 53x11 and 50x11 setup, and uses the compact exclusively now. On descents I spin out rather easy on either setup because of my cadence limitation; I find anything over 100rpm rather hard to maintain especially when there is limited resistance. That point is typically around 30-35 mph. On sprints, it's different. I used to spin out on 53x11 just above 120 rpm when I was younger but now it's pretty difficult for me to do with 50x13 or 14 at 120+ rpm. Haven't sprint much recently but the best I can muster is around 30 mph and I find it easier to use 50x11 with a lower cadence. I'm still playing catch up after 23 years hiatus and only been back on the bike for less than 1.5 years.