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Old October 19th 07, 03:46 PM posted to uk.rec.cycling
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Default Making a fixed-wheel bike

On 19 Oct, 14:02, Duncan Smith wrote:
On Oct 19, 12:47 pm,

(D.M. Procida) wrote:
Following recent bike misadventures, I'm considering taking up a
friend's offer of an old frame, to turn it into a fixed-wheel bike.

Yeah, go for it. It's fun.

My main concern is that the bottom bracket will be too low and I'll keep
catching the pedals on the ground, something that I've done several
times lately on my old Raleigh hybrid.

Low profile pedals. I gather you're planning to use those new-fangled
clipless thingies- you should be fine with those as far a clearance
goes (though other fixie riders may laugh at you... or maybe that's
just me :-).

What else do I need to consider?

What gear you want- personally I like a lowish one (~64"), most
people seem to prefer something nearer 70). Cogs are easiest to find
around 15-16t, so if you can get a chainring around 42t that can make
it easier to get a likely gear.

I konw it needs to have horizontal drop-outs. What about axle spacing?

This can usually be fettled fairly easily- if you're using a "track
hub" then you can buy to suit, otherwise you'll probably want to
redish the wheel anyway. A suitable combination of dish, spacers etc
can usually be arrived at.

You can always fit shorter cranks (160mm?) if you're worried about
pedal strikes.

These can be quite hard to find. 165mm "track" chainsets are quite
readily available at a price, standard road ones are usually 170mm and
will probably work fine. 175mm ATB cranks are probably best avoided
for this application...

... You might be allright with the drop-outs on an older
frame as they tend to be more diagonal than vertical so you could get
enough fore and aft positioning of the wheel to tension the chain - if
not, you could pop on a tensioner like this one:

NO! Not for a fixie. It'll work on a single-speed (which is what On-
One are listing it for) but won't take the strain from a fixie.

You'll also something like a Hozan C-205 Lockring spanner keeping the cog on - unless
you never brake by pedaling backwards as pedaling forwards will only
tighten the cog.

I prefer to use brakes to stop, as a general rule, though I sometimes
skid-stop the last bit to keep the cranks orientated for a good
launch. I, along with many others, havn't had any problems running
without a lockring. One of my fixies has a 22t cog (ie lots of
leverage) without a lockring and it doesn't unscrew. If not running a
back brake it might be worth ensuring you have one but otherwise I
wouldn't sweat it.



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