upgrading grip shifters to triggers

My sister has twist-grip shifters on her bike and wants to swap them for
'trigger' type shifters. I said I'd take this job on for her, but I'm
wondering if I'm really up to it - I've got the Haynes Bike Book to turn to
for assistance but it says nothing about twist-grip shifters so I don't have
a clue how they work.

Has anyone got any experience of this kind of job? Any tips? How difficult
is it to set up the indexing when the new shifters are installed? And is it
better to fit integrated brake/shift levers or separates? Any
recommendations for particular make/model of shifters - Wiggle seem to have
a good selection of SRAM and Shimano stuff but it all looks much of a
muchness to me.

cheers,

d.

"david kenning" wrote in message
...
Has anyone got any experience of this kind of job? Any tips? How difficult
is it to set up the indexing when the new shifters are installed? And is
it
better to fit integrated brake/shift levers or separates? Any
recommendations for particular make/model of shifters - Wiggle seem to
have
a good selection of SRAM and Shimano stuff but it all looks much of a
muchness to me.

Two helpful sites:
http://www.sheldonbrown.com/gearing/index.html
http://www.parktool.com/repair_help/FAQrindx.shtml

Setting the indexing is not difficult, it's more about patience.

I've never used Sram trigger shifters so can't comment on them but if you're
using Shimano mechs I'd stick with their shifters.

Fit seperate shifters and brake levers, this keeps options open for the
future and it will be cheaper and easier to replace worn or damaed items,
although IME these items will probably last as long as the bike wear-wise.
--
Regards,
Pete

Peter B wrote:
I've never used Sram trigger shifters so can't comment on them but if
you're
using Shimano mechs I'd stick with their shifters.

I've not actually seen the bike so I don't know, but I suspect it's more
likely to be some cheapo generic own-brand set of components - I'm sure it
won't hurt to upgrade it a bit.

Thanks for the links and the tips,

d.

BenS wrote:
It's a pretty straightforward job.

Cheers for the in-depth instructions! I shall print them out and keep them
by my side when I do the job.

For 7 speed I'd suggest the STX shifters:

http://www.wiggle.co.uk/?ProductID=5110000034

Sounds perfect. Thanks.

All of the above was written on the assumption it's either a mountain
bike or mountain bike style bike.

Yup - more a bog-standard hybrid, to be honest, but that basic shape.

Thanks for the advice,

d.