Chainring help

Dear all,

I hope that I don't incur the wrath of the general fixed-gear/fixed-wheel populus on account of my being a newbie.

I have a mainstream fixed-wheel bike (model name rhymes with "Wangster"), running a 42x16 gearing. Like any sane person, I aspire to a stable of bikes comprising classic old frames built up lovingly, but for the next couple of years, my current bike will have to do.

I'd like to move up to a 46/16 gearing. My LBS (Apex Cycles in Clapham) are very friendly, but don't seem to have a clue when it comes to fixed stuff, so I was thinking for something as simple as this I could swop chainring (+/- chain if absolutely necessary) myself. I'm looking around online for a 46t chainring and am not quite clear what will fit and not. Could I just buy any chainring expecting it to fit, or is there something in particular I should be looking for.

Thanks folks,

Arn.

PS: sorry for jumping on your subcultural bandwagon/contributing to the death of the fixed-wheel phenomenon by buying a Langster/etc.

measure the BCD of your current chainring: http://www.sheldonbrown.com/gloss_bo-z.html and you're set.

Like tick.tick.tick said - make sure you get the right BCD (bolt circle diameter).

I'd like to move up to a 46/16 gearing. My LBS (Apex Cycles in Clapham) are very friendly, but don't seem to have a clue when it comes to fixed stuff, so I was thinking for something as simple as this I could swop chainring (+/- chain if absolutely necessary) myself.

You want to make your gear ratio bigger, so if you change your chainring to a larger size you will probably have to buy a new chain (the old one may be too short to go around the larger chainring).

But . . . why not increase your gear ratio by dropping the size of your rear cog ? Cogs tend to be cheaper than chainrings and you can use the chain you have (might need to shorten it).

Here is a gear calculator to work ratios out on . . . .

http://software.bareknucklebrigade.com/rabbit.applet.html

PS: sorry for jumping on your subcultural bandwagon/contributing to the death of the fixed-wheel phenomenon by buying a Langster/etc.

If you are that ashamed or self conscious of your Langster then simply don't mention what bike you have. No one here is really that bothered about what you ride.

[URL="http://software.bareknucklebrigade.com/rabbit.applet.html"][/URL]
If you are that ashamed or self conscious of your Langster then simply don't mention what bike you have. No one here is really that bothered about what you ride.

+1

Welcome to the mayhem :-)

Tighten up the saddle, and get a smaller sprocket since youre in deep south to head brixton cycles.
yeehaa
Stoopsombitch!

about 1/3 of the forum have owned a langster at some point, including me. Don't mistake the self-hate for hate :-)

The standard chainset with the langster is the Sugino messenger, with 130 BCD and a 1/8" chain (there are two sizes, 1/8" and 3/32"). If you buy a new cog, you'll need to ensure that it's 1/8".

Adding or removing teeth to your drivechain at front or back and keeping same chain length will move your rear axle back/forward by 1/8 inch per tooth added or removed.

Depending on where the axle is sitting in the dropout you might need to lengthen or buy a new chain as you would be moving axle 1/2 inch forward by adding 4 teeth at front.