"Sean M. Cunningham" <[email hidden]> wrote in message news:<[email hidden]>...
Quoted message said:Hello,
I'm trying to put together a road bike. It's my first attempt at building
a
bike from the frame up.
For gearing, I'm looking at using a 32-42-52T crankset, or something in
that area.
Right now, I have two cranksets. Both are geared for a mountain bike. One
is a Shimano Altus 24-34-42T; the other is a Shimano Hyperdrive-C. The
Hyperdrive is installed on my mountain bike right now, and it's covered
with grime, so I didn't want to touch it 🙂 but it looks to be nearly the
same size as the Altus.
I was wondering if it's possible to take either of these apart, use the
large and middle sized chainrings, discard the small one, and add a big
52T ring. It doesn't look like they can be taken apart, but I haven't
tried prying/pulling/twisting anything, as I don't really know what to
look for, and I don't want to break or bend either of these.
Any advice you can give would be appreciated.
Thanks,
---
Sean Cunningham
[email hidden]
Most cheap cranksets, probably including at least the Altus one you
have, have non-replaceable chainrings. Basically, if it doesn't have
obvious bolts that take allen wrenches, it's a crankset with
non-replaceable rings. The other crank you mentioned may or may not
have replaceable rings: Hyperglide C isn't a Shi product line, it's
one of their feature terms that some cranksets have stickers for. Some
of these cranks have replaceable rings and some don't. However, most
(maybe all, not sure) of the ones that do happened to use a bolt
circle diameter (the term for the diameter of the circle which passes
through all the chainring bolt holes on a crank) that road-size rings
don't exist for. So basically what you have won't work. You have some
options for what to get instead, as others have mentioned. I would
recommend making sure you avoid the pitfall of getting too high of a
gearing range - 52 is way too high for most people. 46, 48, or 50 is
usually a lot better. You have to be working really, really hard to
spin out a 50/11 or 50/12.