[Yak] Converting NWT from 8 to 24 gears

[alex wetmore]

On Thu, 13 Dec 2007, Frank Mattheus wrote:
> I will soon be the proud owner of a new 8 gear NWT.  Unfortunately,
> due to powers out of my control, I couldn't actually order a 24 or 27
> gear NWT from Green Gear.  So, I'm just going to have to do the
> conversion myself.
>
> What am I all going to need?
> Front shifter

I'd get a friction or semi-friction one (meaning many steps) if
possible.  For drop bars that means a barend shifter, for flat bars
you can get thumb shifters and GripShift shifters that will do the
job.  Gripshift shifters come in models with only 3 indents and ones
with 9 or more, get the latter.

This will help you with trimming the front derailleur and let you get
away with larger chainrings that don't have matched shift ramps.

> Front 3spd derailleur ( should it be an up or down pull?  tube diameter?)

Down pull.  It should be a brazeon model.  There is a brazeon for the
front derailleur on every NWT that I've seen (although I think John S. 
Allen has noted that his NWT doesn't have one).

> New chain or chain links ...

I'd buy a new chain.

> Anything else I should be looking out for?

What size chainrings are you planning on running?  If they are larger
than around 50t you made need to remove the crank to pack the bike (it
also depends on your suitcase) so you should put self extracting bolts
in the crank.

> If I wanted to switch to a 9 speed cassette, would that work on the
> existing hub?

Yes.  Shimano 8sp and 9sp cassettes have the same spline pattern.

Does your crank already have mounts for the third chainring?  The
stock crank on the Tikit does not, I don't know if they use this same
crank on the 8sp NWT.  If not you'll need a new crankset or will need
to run a double chainring setup.  A double wouldn't be bad, standard
road double gearing of 39/53 combined with an 11-34 cassette gives you
gears from 22" to 91".  Plenty of range, easy to find chainrings, and
a lower Q-factor.  If I owned a NWT I'd be tempted to run it that way.

alex