Singlespeed & Fixed Gear - Chainline and the quest for perfection.

Hey all :) Recently discovered the forums, and this thread, and I'm quite plussed that there's a good community out there. And, as with all mere mortals building their first fixie (and first bike in 10 years I might add), I find myself compelled to ask for a bit of help.

Chainline and the quest for perfection. I'm running a quando low flange flip-flop (the wheel I bought came off a recent fuji track bike), set up with no dish, 120mm spacing. The frame I'm building my mean machine around is a 126mm spaced road frame, late '70s or early '80s I suspect. I'm nearly finished building the bike, but I find myself getting stuck in the details pertaining to the drivetrain... I've done some initial rough measurements using Sheldon Brown's instructions, and to my perplexion I keep coming up with a chainline of about 38mm. From what I gather from the research I've been doing, most track cranksets, and the inner ring on double chainring setups tend to sit around 42mm when mounted to a bottom bracket with an appropriate spindle length. I haven't bought cranks yet, as I want to sort out a solid plan before I start chucking any more money around (this project's already $150 over budget!).

Short of re-dishing the rear wheel what can I do to balance the 4mm difference between my front and rear chainlines? I've never heard of a wheel needing to be dished TOWARDS the drivetrain... But then... I'm new to this! Additionally, wouldn't dishing the wheel towards the drivetrain mess up my ability to take advantage of my flip/flop by throwing the opposite side completely out of line?

Any insight would be hugely appreciated oh mighty fixers!

Thanks!

I'm thinking, you might need a different bottom bracket. Slightly shorter.

One the other hand - the Quando hubs are weird - I picked up a rear wheel with one cheap a while ago and I can't use it, the chainline is way in there with it, and the hub is a lot shorter than any other rear wheels I own.

Personally, I'd get a better, standard hub/wheel. Though that doesn't help in the budget area...

Heh! Yeah, this is rapidly turning from my 'Build a cheap fixie project' into my 'build an expensive bike' project. Yeah, bottom bracket is definitlely in my sights as a place to try to make this work. but this raises a few questions:

If I use a shorter BB I run the risk of not having enough clearance for my cranks/chainwheel, no? I understand that this varies from crank model to crank model, and that all have reccommended BB spindle lengths, but is there any reference available that quotes internal chainline measurements for a variety of 165mm cranksets?

Unfortunately (or fortunately, depending on perspective) the quando was cheap and cheerful, and I'd like to get it running for the duration of the winter (I live in Toronto and i'd feel bad slapping on that miche hub I've been coveting through the salty, slushy hell that will soon be coating the ground).I figure that I'll recycle the quando if it lives through the winter, and throw sommink better on come fairer days :)

And yeah - while I'd rather not go this route, is re-dishing the wheel towards the drivetrain an advisable idea if I can't sort out the chainline at the crank/bb?

Thanks again,
Tim

P.S. Thanks for the heads-up on the quando... good to know that I'm not nuts, and that I was probably measuring correctly :)

Update: Mechanic's insight saves the day!

So I spoke to one of the toolmeisters over at Urbane in Toronto who has experience with the quando hubs. Turns out (and it would make sense that this may be true of other flip/flop hubs now that I realize why) that the Quando flip/flops need to be dished about 4mm on the freewheel side to provide about a 42-45mm chainline, depending on the cog. This should also bring most freewheels into line on the opposite side.

Saved! Hope this is useful to anyone else using a Quandopoop hub.

glad to hear you got your problem solved. post some pics when you're done.

Hehehe - it's only conceptually solved as yet - we'll see what happens when I get home and break out the spoke wrench tonight ;) At least I can go and get a set of cranks now with relative certainty that they'll work out without much further catastrophe.

Any recommendations on good low-q cranks that won't break the bank? i'd like a set of sugino mightys, but... can't find any as yet.

I'll definitely be posting the bike once it's done.... and whatever other mongrel bikes arise from the part pile that's now rapidly accumulating in my abode!

as for cranks, i guess it really depends on what bb you go with. for iso square taper, maybe some shimano 600's or maybe some dura-ace 7400 or 7410's... i have some 7410's on a fixie and i love them. i think they're the best looking dura-ace road crank ever made.

chucksbikes.com has some brand new 105 octalink cranks for 72 dollars. i'm sure you can find a better deal on some used cranks off of ebay though.

maybe look for some dotek bmx cranks as well.

Been lurking around Ebay for the past few days, but no joy so far. The LBS puts RPM (acronyms a-go-go!) cranks on their homebrew fixies... a messenger friend of mine rides them and says they're fine... anyone have any experience with these? I can't find any information on them online at all.

Thanks for the suggestions - I'll definitely snap up a set of older DAs if I see them.