Commuting - Fixed NYC Commuters: Advice, please!

O.K. I received a windfall I wasn't expecting, and so I'm going to convert the 1981 Fuji 12-speed to a fixed gear. (Looks fun, and I'm amazed whow these guys can fly up hills. Example: I outmaneuver the fixies all through downtown Brooklyn, or we keep even. But once we hit the bridge, they just vault into Manhattan. I don't understand. Must experience this firsthand.)
Here's what I'd like help with.

1. What's a reasonable gearing for someone who's pretty strong but who's never going to race? This bike will be for New York commutes/around town.
2. The bike has 27" wheels with sidepull brakes. I'm keeping the front brake. I'm resigned to buying a new wheelset for the conversion, but will the brakes still reach 700c rims?
3. What's the biggest mistake you can make in a conversion like this?

Thanks for your input.

1. My bike has 44/16 gearing, which I really like.
2. 27" and 700C wheels are *almost* exactly the same size. The brakes should still fit.
3. I don't know, never converted one. Mine came this way :)

You will need to be able to move the brake pads down 4mm to go from 27" to 700c. Either that, or get long reach calipers. You could just pick up a back wheel in 700c, and forget the back brake. Then keep the front wheel 27", and therefore the brake too.

Do a search in the Fixed/SS forum. A plethora of questions about converting bikes have been asked many times over.

Mchaz: So no great deal to run a 700c rear and 27" in front? Good to know. As for going to the source on fixed questions, I thought I'd play to a friendly crowd first. Frankly, I didn't want to get chewed up and spit out in the SS/F forum.

Mchaz: So no great deal to run a 700c rear and 27" in front? Good to know.

I have seen it done, I don't think there's any problems with it. I don't actually have a fixed gear bike though, I have just done the research because I want one.

About the SS/Fixed forums, I understand. That's why I recommended a search. ;) I really can't answer your other two questions because I don't have any solid experience.

I run 46/17 and I'm not particularly strong. The usual consensus is to go around 70 +/- gear inches. As for climbing quickly, you can either be slow and mash or try and keep your spin up. One feels better than the other. Don't forget to run clipless or clips & straps.

I don't know about NYC itself but for anybody, around 70 gear inches is a good starting point. That means 42/16 or the equivalent. See http://www.sheldonbrown.com/gears to play with the numbers. Fixed gear is TONS of fun and it is great for commuting since its so simple and reliable.

Hope this helps!

3. What's the biggest mistake you can make in a conversion like this?



Crooked chainline!
Make sure your rear spacing accomodates the wheel so that your chainline is nice & straight.

Also, getting cheap parts is another mistake.

I too recommend using the 27" front wheel and a new 700c rear, that is exactly what I did for my conversion.

I really like 48x17 (~75g") for flat commuting (but have taken it on a 1100' 5mi climb)
Depends though on your cruising speed and top speed needs. Basically I like a ratio that lets me grind/stand up long hills at 50rpm, cruise into a headwind at 100rpm and hit peak speed at 150rpm.

Al

I run 42x16 fixed/18 free (flip-flop hub) on a Fuji 12-speed (Fuji Sport) conversion. I switched both wheels to 700c for easier tire selection and picked up long-reach single pivot side-pull calipers. The rear dropout was a little tight but steel frames can be cold-worked to fit. The rears brakes reach with some margin (I probably have the wheel further forward in the dropouts than if I was using a derailluer). The front brakes did not quite reach - I used a dremel tool to lengthen the slots for the brake pads a few mm. You will not (probably) be able to use double-pivot calipers due to lack of reach (today's long-reach is not 1970s/80s long-reach) and use of recessed nuts. Sheldon Brown's site has info on this and other fixed conversions. The fixed gear and bike repair forums are good sources, too. Best may be a fixie-friendly LBS with a good parts bin and helpful attitude; mine helped with the wheel swap and had suggestions for a few other things.

27" front with the original brake (get new pads) and 700 rear (brake/no brake depending) may be the easiest way to get fixed quickly.

This is great to hear. All right, so I may not need the LBS for this? I'll buy a rear track wheel and a cog of around 17 teeth. I'll need spacers, probably. Plus a lockring, yes? Plus a new chain. Anything else? Shorter chainring bolts when I get rid of one. Can I do this for less than $150? Oh, yeah, plus a tire and tube. Bottle of Maker's Mark for the assembly.
How the hell does Redline sell the 9•2•5 for only $500?

You'll need a wheel, cog, lockring, chain tool (for shortening the chain), single chainring bolts, tire, tube. Depending on where you get the parts, it CAN be done for <$150. The biggest expense of course will be the wheel itself.

When you install the cog and lockring, lightly grease the threads and tighten them good. I use the rotafix method of installing the cog, and then I use a hammer and flat blade screwdriver to tighten the lockring. Oh the humanity! Just get those suckers on there TIGHT and after you've ridden it a few miles, tighten down the lockring again.

On the chainline: get it within 2mm or so and you should be OK. You can measure the chainline with a metric ruler. Just measure from the middle of the chainring to the middle of the seat tube. That's your chainline. Track wheels have a 42mm chainline. If yours is too far off, then just get a bottom bracket that is appropriately shorter or longer for your cranks.

Lastly don't forget pedals. You'll need caged pedals or go clipless. I skipped the caged pedals and went clipless and love it.