OK, I finally found a bike to convert (an Astra "Tour de France" - $30). It has a 51/40 chainring set up, and I'm not changing them. My problem is that I bought a 16T cog and I think I want 15. But, the Bike Church only has 16 and 14T Dura Ace cogs. Should I shell out the extra $7 to get a 15T Surly cog? I really don't know, seeing as a 40x16 is 67.5 gear inches and 40x15 is 72. The gear ratio of a 42x16 is 2.6, while 40x16 is 2.5 and 40x15 is 2.7. I like the idea of a stronger gear, but money is kind of an issue, and I'm gonna head down town to do the swap pretty soon. Please help.

ride the 16 for a while, if it's really too short a gear trade it with someone here.

agree with dolface. no need to be urgent about this.

I just meant "urgent" because I'd be leaving to swap it soon. Looks like I'll stick with it, though.

go with 40:14.

67" is just fine.

ill swap you a dura ace 15T for the 14T. pm if you want it

That's kinda big, don'tcha think?

no, but i commute with 48:16 and sometimes even commute with my track ratio of 48:14.

Naw, I like the 16T idea. Nevermind, I'm just getting anxious to have this all built up!

give it a try; i personally love it. 48:16 is a perfect 3:1 ratio. 40:14 is just shy of that.

edit: boy oh boy, you're quick! hahaha are you moving to colorado or just visiting? it's ugly and dumb here... i hate it a lot... ;)

When I lived in santa cruz, 42x17 got me up and down any hill I needed.

48x16 only gives you one skid patch though...

gives me two. but yeah, spin that tire.

No, just for vacation, but I'll be gone for 11 days, and I'll miss my fixie project :(. Oh well, I'll just settle for mountain bike rentals...I've got time to decide about the ratio.

sometimes i skip a little, but i never skid. i've never even really try to since it seems more fun than effective for stopping and i am usually riding expensive tires that i don't want to ruin. plus, having fun is stupid. :eek:

for flat philly, whats a good gear setup? 48/18. unsure, no in to good of shape

i've been in philly for about 3 days now...i run a 40-14...i've seen dudes running 52-14...it's all about preference...i prefer control over top speed...your call.

-jason

THREADJACK - Hey iso:
is that a common ratio at 7-11 velo?

48/18 is roughly the same as my 43/16, which i (personally) find perfect for philly. If youre not in too gooda shape, you may find umbria and mannyunk a little challenging, but hey, thats what its all about.

yeah, it is. 50:15 is also another common one, which is a perfect 90 inch gear. i love gear ratios that are even like that... people will gear up or down a bit from there, depending on specific events. a low 90ish gear inch is a good all around gear though. the track is 333 meters long with a 35° bank. dive bombing out of turns is so fun!

sometimes when i want to spin my little banana's off, i'll run 48:16. you certainly couldn't race with that though.

what are you running on the track? your track is long and low banked?

didn't you ride the track here a bit when you lived here? you should still come out. my new house is a whopping two minute bike ride from there. poor me!

That's what I do now, but soon I'm going to switch to 49-18.

<voice of reason>48-16 only gives one skid patch!</voice of reason>

Continuing to threadjack this a bit, does anyone swtich out cogs on a somewhat frequent basis (maybe a couple times a month)? Just wondering if a cog is properly installed if you significantly increase your risk of stripping your hub by switching cogs.

I run 46/16 on the road, but that really doesn't cut it for the track. I'd like to try 46/15 or 46/14 and I don't currently have the funds for either a new wheel or a new track-only bike. I know, I know... I should have just gotten a fixed/fixed wheel to begin with, but I decided to save myself the $50.