New Crankset for Schwinn World Tourist 12 speed?

On 21 Feb 2005 13:46:35 -0800, "pedantus" may
have said:

Hi All,
Does anyone happen to know if I can put a compact crankset on an old
Schwinn 12 speed. I picked up a Ladies World Tourist because my wife
has had her hip replaced an needs a step-through frame. She just liked
that old thing when we saw at a rural second hand bike shop, it is just
her size, and it has probably never been ridden or left in the weather.

Oddly enough, I picked up one in similar condition about a month ago
for less than the cost of a tire to fit it. I bought it to scavenge
the aluminum rims from it to upgrade an old Bridgestone that came with
the now-dreaded chrome-plated steel rims of yore, but my daughter
appropriated the bike intact instead. Rats.

It does seem that a cartridge type bottom bracket could be used to
replace the original, the tubing there at least looks like the same
size.

The BB shell in the frame is able to accept common sealed BB units,
but why bother? The original is probably in good shape, and uses a
regular square taper.

This would of course probably allow me to fit a MTB type triple
crankset on it, but I'm not going to take it apart without knowing what
I'm in for here... I suppose that would mean I have to replace the
rear wheel--put a 7 speed freehub in a 27" rim, I guess. Any one got
any suggestions?

Putting a triple on there might mean swapping out the front der; if
yours is like the one here, it won't have enough throw. There's no
reason to swap out the rear just because the front is changed, though.

The cable routing on that model's a bit novel; the cable guides are
metal brackets above the BB instead of a plastic piece below it, so a
dab of grease (with all of its wonderful ability to grab and hold
grit) may be needed to achieve smooth cable motion.

The other option is to stay with a double in front and (as Sheldon
Brown suggested) swap up to a freewheel in the rear which has a larger
low-gear sprocket. I haven't tried that with this one, so I can't say
if the der (which might not be the same anyway) will accommodate that
jump, but even if it doesn't, the der swap wouldn't be hard or
expensive.

BTW, if your World Tourist has the same setup as this one, the front
sprockets are riveted to the crank; to change the front gearing, you
would indeed need to replace the cranks, but the BB should be OK
as-is.

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"pedantus" wrote in message
oups.com...

So many responses...thanks everyone...

I couldn't find the freewheel tool I thought I had, so I had to take the
bike to a shop anyway... Wife took the van, so I had to bungee the
partially disassembled Schwinn onto the back of my Xtracycle, and entertain
the motoring public.

As described the BB comes out in pieces, the shaft is octagonal, the
grease cups are removed using the splined freewheel tool. A BB cartridge
threads right in: a square tapered one fits the cheap compact MTB triple
crankset, (and, yes, now I need to dig up a front deraillure with enough
throw). The FF freewheel was replaced by a standard freewheel.

Now if only I had actually had that @#$% shimano freewheel tool...

Thank you all for your help.

Rog

Wow. I pulled one of these (well, mine's a 10-speed) out of the trash and
it works great for taking the kid for rides.
I'm an inveterate tinkerer and just learned more about the bike than I
thought possible, thanks!
Now I can plot and plan ways to 'modernize' it.....