I don't get what gear inches are

Sheldon Brown:
You could multiply by pi to get the actual distance traveled per revolution of the crank in inches.

For what it's worth, I have done a lot of long distances fixed (multiple hilly 1200k's, 1000k's, etc) and have ridden with a number of other people who made a habit of doing the same thing. I ride a 42x16 with 165mm cranks and 25mm tires for everything, IOW, about 70". Most of the other guys I've ridden with who were experienced distance riders on fixed used gear were using gears between around 64" and 76". What I have found is that getting comfortable and efficient over the long haul requires a couple of things: the first and more obvious is spinning fast, smoothly and comfortably downhills. It takes some time to get really smooth and comfortable so you aren't slamming your butt against the saddle on every stroke and so that it doesn't wear you out too quickly. The other thing is figuring out how to find a comfortable rhythm at really low RPMs. On short hills you can afford to just power up, but if you have longer, sustained climbs you have to be able to figure out how to get up slowly enough that you aren't going to just blow up, and easily enough that you don't over-strain your knees, achilles, etc. Which one of those two things you're better at might also inform your gearing choice - for example, if you have a hard time getting over the top of the pedal stroke at really low RPMs but you can spin fast comfortably, go with a lower gear. If you can keep it going at really, really low RPMs but spinning fast is uncomfortable, go higher.

My commuter bike has the same gearing (slightly wider tires though), and although I am too lazy to change it, if I were to do anything I'd go lower. I often carry heavy panniers on that bike, and I ride it with street shoes and toeclips which don't give as much leverage as being clipped in. I also let the drivetrain get a WHOLE LOT skankier before doing anything to it maintenance-wise, and I ride it through snow and stuff in the winter. All of those things add up to making it harder to pedal, so that's another reason to go with a lower gear (although as I said, I am too lazy and it's ok the way it is).

so im 15 and weigh 126, would pushing a 50/18 ratio be good

It'll stunt your growth.

Not too sure about the scientific merits of the above statement but we can't speak for you for that question.
However, you are ultimately limited by how strong your lower body is, how fit you are, and the topography of the area you plan to ride in.

In such a case, the old saying holds true, you won't know until you try.

i weigh 105lbs. 50/18 iz so gud.

do you live in an area with alot of hills?

i am currently riding 50/16 is this ratio good

Not if you enjoy using your knees when you get older, 69 through 72 gear inch is a good area to start

Everyone said its better to spin then mash.

I just switched from 46/14 to 53/16 today. I haven't ridden it enlighten yet to notice a huge difference. That's going from 86 GI to 87 GI.

I'd also like to add that gain ratios are probably better for comparing bikes with different crank lengths because they take into account the crank lengths. Gain ratio for my fixie is 6.5.

This was the absolute most helpful thread I found when researching how to set-up my own gearing...

Perhaps if it was pulled out of the sticky index at the top of the forum and made a separate sticky, maybe even renamed something like "Official Gearing Thread Thread", it would get some action and you wouldn't have the steady stream of repetitive questions about gear ratios we've seen here lately :crash:

Report it to the Mods if you want your idea to get attention.

And people still wouldn't read it :bang:

What is wrong with the name of the thread ?

It should have been called "Europa's really really useful guide to gearing", but you wouldn't use it ... and just because I didn't write it too :(


We are hijacking this thread a bit, maybe you should consider asking the mods to lock it ... but only after someone posts a clip of "Bicycle Repair Man" (I think that's the name of the character in your avatar, I can visualise the skit in all it's horrendous glory)

Great thread. I just browsed it, learned a lot. Just getting into SSFG riding, and have a lot to learn.

Kudos to you Beardogger for finding and making use of this very informative thread, instead of starting a new "What gear ratio should I run?" thread like all the geniuses here usually do...

LOL! Every once in a while, even a blind hog finds an acorn!!

muscular adaptions with high rpm
 

I used to ride centuries and with groups a couple decades ago when not running and typically rode around 95-102 rpm when pushing it. Since then I've not ridden at all as it was too dangerous around here. I want to ride the indoor wind trainer now for conditioning, and made a mistake this past year riding at too low (53-61) rpm with high resistance (52/12x27 117gi). Now I am changing, and have a question about adapting to high rpms.

Currently the fastest I can seem to go (4th day) is 84 rpm in a very light gear (40/17x27 63.5gi) this morning, but feel like I'm not really pushing it. My legs are just not used to moving any faster, although each day has been slightly higher. However I'm wondering if pushing it now, instead of just giving time to adapt, might be putting a strain on my legs, i.e. hamstrings. My goal is to average 100-110 rpm for an hour, perhaps in a year from now.

Can someone comment on the muscular adjustments that occur when training for high rpm, and how best to adapt to this gradually, without excessively straining the muscles or causing some injury? Thank you.

That's not such a low gear. By my calcs it comes to about 65 GI with a 700x23 tire, which is a totally reasonable road gear, especially for someone just getting back into the sport.

Riding a single gear means that effort and cadence are tied directly together. If your fitness won't let you ride faster than X mph, and your current gear has you turning the pedals over at 80 rpm at that speed, you have two options to increase cadence: gear down or pedal harder. IMHO, you're better off gearing down now to something like 42x19 or even 42x20, rather than grinding it out while you wait for your fitness to improve enough to let you spin 110 rpm in that gear for long periods.

Do what seems comfortable. The best way to get better is just to spend time in the saddle. As your fitness increases you will be able to up the rpm comfortably. 84 rpm is probably a good starting point. My advice would be to just get used to training for an hour and once you are there, spend time doing intervals. Do things like 120 for two minutes, 85 for two minutes for 8 repetitions. I wouldn't commit to just going out and riding at 100 rpm for an hour, even if you had a lighter gear.