On Sun, 28 Sep 2003 00:08:57 -0700, "Yumi" <
[email protected]> may have said:
>I recently got an old road bicycle with 12 speed. Before this, the only bike I rode was a cheap
>ATB, the kind you can buy at Walmart. However, I found that I need to work much harder with this
>road bike when climbing a hill even at the lowest gear selection. So, I would like to replace the
>double crankset to triple if possible, but I'm not sure what I need to get.
Swapping to a triple front will almost certainly require replacing the front derailleur; your luck
would be astounding if yours were the exception. It will probably require replacing the bottom
bracket (generally called BB, it's the bearing and pedal shaft assembly) since the triple crank will
most likely need a longer BB in order to avoid having the small ring too close to the seat tube.
Your shifter lever most likely will work OK with the new derailleur, but that's not guaranteed. The
rear derailleur, however, is probably one of the old short-cage types, and may have problems taking
up the slack of the small ring; if that's the case, you'll need to replace it as well. There's a
distressingly good chance that this will end up costing you more in parts than you want to invest in
an old bike, unless the local bike shop has a pile of used stuff that can be had cheaply.
Alternately, you might be able to pick up most of the items on eBay if you know what to look for,
but you're probably still looking at punching a big hole in a hundred bucks, even with much of it
being used stuff.
I would suggest, though, that there's an alternate path which might give you close to the same
result with less hassle. Shimano makes replacement 6-speed freewheels with a larger low gear than
what's probably there now; count the teeth on the big rear cog that's present, and if it's 28 or
less, a $20 (plus shipping) freewheel with a 34 tooth low gear might solve the problem adequately
with a lot less work. You'll almost certainly have to replace the chain or add some links if you
go this route, but there's a good chance that the old chain is worn anyway. In rare cases, it's
necessary to replace the rear derailleur to get enough slack take-up capacity, but the chances
are good that your existing der will be up to the task. A lot of older touring bikes came with
gearing very much like this, so the ders generally had the capacity. You may need to clean it
thoroughly, though.
For the megarange 6-speed freewheel, here's one source:
http://www.sheldonbrown.com/harris/freewheels.html#6
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