dudezor

What's the benefit of running all even?

Not a good idea if you plan on skipping and/or skidding very much as it will only give you (I think) two skid patches.

I just put on a new 48t chainring and wanted to run an 18t to give me a close gearing to what I used to have (42:16), but because of the skid patches on an 18t I decided to go for a 17t instead. After a bit of riding it's been great, but I'd want it a bit lower if I regularly dealt with bigger hills than I generally do.

Gearing down to around 70 gear inches is a good suggestion. It's a great all-round gear, and as a noob you can benefit greatly from learning to spin a smaller gear faster than you would a larger gear.

Scrodzilla

Jake...thanks for the calculator. It helped a lot in my figuring out gear inches and what chainring/cog does what to increase/decrease them (Sheldon's site, while usually an endless wealth of awesomeness, only made my head spin when reading the section on gearing). I use a brake and don't skid (I know how, just choose not to unless I have to). Thanks to everyone else for their knowledge/comments as well.

I do think I'm going to make the switch down to around 70gi. Either that or I'll just scrap my bike and start walking, as the ever-helpful and always pleasant-to-deal-with timebandit suggested.

melon

70GI is the standard for track bikes on the road, and its a nice comprimise for accleration and hills, but still enough length to be able sprint at speed on the flats. witht his said its more important to choose a gear that fits your level of fitness/strength and the terrain you ride.

i ride 70", but i live in an area wiht undulating terrain, if i lived in a flat city id probably go up to 80".

i recommend getting yourself an 19,18 and 17t sprocket. try the 19 out for a couple of weeks even if it feels a bit spinny. then try the others and see how you feel. remember its better to spin than mash, and riding in a gear thats too high is only going to give you big but ineffcent muscles and maki your average speed low.

Hirohsima

I run a SS 50/16 and a 48/16 in my not that hilly area. My opinion is that if you are at the cruising speed you like given your current gearing and the only issue you have is that hill, then keep your gearing. Gearing down for one hill IMHO is not worth having the wrong gear for 95% of the other riding you may do.

Now if that gear is too tall for other parts of your ride, then gearing down makes sense to me.

a_elephant

I'm running 48:18 right now. I believe this is ~72 GI, which is what I was running on my conversion prior.

It is great for flat stretches and downhills (I have never spun out or felt like I lost control of my pedals), but terrible for long climbs.

Unfortunately, there are a lot of long climbs in Seattle.

Be very careful when switching out your cog, if you choose that route. Some people will say you just have to know how to do it right, but I've heard horror stories of even trained mechanics stripping hubs (believe it was a limited-edition brass Phil Wood hub [edit: yes it was, read about it here: https://mobiuscycle.com/node/299) trying to change out cogs. Chainrings are much easier and idiot-proof to swap AFAIK. Kinda makes you wonder why they don't make bolt on cogs... maybe soon.

I just ordered a 46t chainring, which will put me at 69 GI with 9 skid patches. Many claim 69 GI is the golden number for Seattle. I'm crossing my fingers.

devilshaircut

With your ratio, you also only have 1 skid patch. I recommend 46:16 ... most people seem to like that. It is about 77 GI which is pretty reasonable.

akaio

48/18 a common ratio? That is way steep for the streets. That is like an entry level track racer gear. I use 48/16 for racing not for streets. I ride at least a 17 in the back, if not bigger. Youll tear up your damn knees trying to look tough. In the winter I run 48/19 and work on my spin.

devilshaircut

48:18 is too low for track racing. If you are working on your spin though, that is fine. But that *is* low for the track in a race.

Is it "tough" to run a large gear? I beg to differ. IMO, it is more tough to be able to spin. Anyone can mash. Not everyone can spin.

akaio

Yeah, it is on the low end for the track. Thats why I said entry level, when you should be workin on your spin. I used a 15t in the back last season, and a 14t this year.

I race 48/18 on a mountain circuit race that has a fixed class, low enough to push up hill and big enough keep the downhill spin manageable. And I hate pushing that gear around town for just messing around.

Scrodzilla

If I were concerned about looking 'tough', I'd be raising hell around town on a flat-black Harley wearing a German war helmet, not riding a bicycle!

I know this is a discussion forum where threads can take many different turns but what's good for the track is an entirely different story. I'm just seeking a few tidbits of advice from those who have been riding longer than me regarding how to make my bike a little easier on the ol' legs.

I do think I'm going to decrease my gear inches to somewhere in the low 70s, because I feel that even just cruising around on flat ground could be a little easier. Not that I want riding to be super easy...but maybe just not so damn hard. I wouldn't necessarily be gearing down just for one small portion of my daily ride. Like I said before, I don't skid so I'm not overly concerned with how many skid patches certain gearing will provide and spinning a little more will most likely be a treat.

TRaffic Jammer

Staying seated while climbing will help too.

Scrodzilla

Also (I can't believe I forgot to ask!)...how much of a hand does crank arm length have in all of this?
I run 170s now.

a_elephant

Crank arm length isn't going to give you much a difference in terms of mechanical advantage.

Consider: it is 10mm difference between a 165 and 175 crank arm.

Some say you will be able to spin faster with shorter cranks. Clearance is the greatest advantage on a fixed gear.

PedallingATX

i do 48x17 on pretty decent hills around Austin and find it perfect. Don't be too drastic w/ these changes. My advice is to only chance one tooth on the cog at a time. Don't worry about changing your chainring. 48t should give you enough flexibility to do anything. You could go w/ a big, 22t cog and have an easy ratio or you could get a 13t cog and have a seriously hard ratio. I think you would be fine w/ 48x17

Tom88

i didnt think you could bike over that bridge. always seems like heavy traffic

Scrodzilla

Holy crap...you're familiar with the Salem/Beverly bridge? Are you from the area? I think I've seen two other guys riding FGs here. Weird for a college town.

There's a wide bike lane when traveling toward Salem and a smaller one on the return side. there's also a wide sidewalk on the side heading into Beverly on which I've seen a lot of people ride (or at least walk their DUI mountain cruisers up and ride down the other side). I always see two hardcore roadie-type guys decked out in aero helmets and full spandex tearing ass across the bridge like it's nothing. Damn gears.

Scrodzilla

Didn't think so. I've been considering new cranks lately and that's pretty much why I asked. I wasn't sure if I should go for the same or get something shorter. I've never had any run-ins with pedal strike, so I'll most likely stick with 170s.

psirue

use the crank size that's appropriate for your fit (or stick with 165s if you're riding with a low bb). search the forums / read what zinn suggests.

practice your spin.

get a 17t or 18t cog, not a smaller chainring.

I like this calc the best: https://www.sheldonbrown.com/gears/
/thread

jakerock

You need to work on yourself a little bit time bandit.
That was incredibly unskillful.

Scrodzilla

I concur. He's usually better than that.

dudezor

Clearance can be important if you're riding a conversion, but if you're riding a fixed gear specific frame with a higher bottom bracket it's not a huge issue. Faster, smoother and easier spinning is the main advantage to shorter (i.e. 165mm) cranks for many riders.

On my first fixed bike I had 175mm cranks, I then switched to 170mm cranks and noticed a significant improvement in my spinning. I've just switched to 165mm cranks and there's a significant improvement again. The extra clearance of 165s is just icing on the high-cadence cake.

Tom88

yeah im out in gloucester but i make deliveries to that area sometimes for work.

ianjk

Just swapped out from 48x16 to 48x20... riding is much more fun now. I ride much faster overall being able to spin up hills instead of mashing like crazy.

frymaster

and that's the whole point right there: choosing the gear ratio that best for your style of riding, your objectives and terrain.

Sinsemilla

You guys talked me into swapping gears, i have been grinding on my 46/14 for 86gi. I had a serious problem at first but i just kept going and it still wears me out but i see my riding distance and stamina increasing every day.
I am switching to 46/17 for 71gi, just to see the difference. If its too easy i will get a 16T cog.