Off-road fixed / Monster cross bike

[Speedy611]

Hi all,

I posted previously in this thread:
http://yacf.co.uk/forum/index.php?topic=48430.0

And since then the bike has undergone a fixed conversion and gained some new bars- On-one Midge, dirt drop style. I'm surprised how comfortable they are, and practical to, on bumpy stuff. I still need to add a second brake lever mount for the resting on the drops position.

The fixed conversion...after some scratching around on Sheldon's site, and trying to keep to the low budget theme (the bike itself was about $100 AUD), I decided to try epoxying the freewheel. What could possibly go wrong...? It's been very educational. I'd not needed to fully dismantle a freewheel before, so much googling ensued, and once I'd realised that the thread for the top of the freewheel left handed (i.e opposite), all went well. Everthing got degreased and cleaned, then there was much fun with 2 part epoxy and tiny ball bearings. Getting everything back together on the 'freewheel', whilst still leaving the threads intact for cassette locknut, and hollow axle bolt took a bit of fiddling, but I got there in the end. It seems pretty solid - skid stops are fine so far, so fingers crossed.

The advantage to this approach, rather than a proper fixed hub is that I can change the ratios easily, as the original cassette splines are preserved. I've got some spacers that usually go between gears, and these allow me to position precisely for chain line. Given that the bike has vertical dropouts, the ability to tune the sprocket size makes getting chain tension a bit easier.

One downside so far - the sprockets from the cassette have ramped sides, so back pedal braking causes the chain to catch these sometimes, which makes a slightly disturbing graunching noise. We shall see.

Left to do: Lots. The whole bike needs a good wash and brush up, brakes need new cables, and I might indulge in some bar tape rather than old inner tube. But, so far, for pretty minimal outlay I've got a rough, tough do it all bike which I don't mind getting dirty, scratched and bruised.



duck optional.



Cheers,
Mark

[Tail End Charlie]

I'd watch out, someone's trying to nick it already.

Good write up, BTW.

[Speedy611]

Yep, the thief-to-be is in fact my lovely daughter. Still photos didn't record the 'Daddy, my arm's hurting, can I let go now' which rather spoiled the tranquil-pootle-by-the-lake ambience I was aiming for. Still, she did ride 10km so not too bad really.

[PaulF]

As you've got a normal geared hub you can use single speed sprockets. That's the set-up on my signle speed MTB: a DMR spacer kit (essentially a set of washers of different widths that allow you to move the chain line in or out) and a splines sprocket. New sprockets cost about 4 quid and should help overcome the catching problem.