Touring ratios

Robin Norton

My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings are
46/36/26. My bottom gear is 25 ins.
For touring in high mountains I'd like a bottom gear of 20 ins or a bit
less. I don't mind sacrificing gears above about 90 ins.
My local shop has suggested rings of 40/32/22 but this gives a whole heap of
low gears but very little basic flat country gears. For a better spread
what rings should I go for? (Obviously I mean gear that's easily
obtainable). My existing equipment is Shimano Deore. Help would be much
appreciated.
Rob Norton

MSeries

Robin Norton wrote:
> My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings are
> 46/36/26. My bottom gear is 25 ins.
> For touring in high mountains I'd like a bottom gear of 20 ins or a bit
> less. I don't mind sacrificing gears above about 90 ins.
> My local shop has suggested rings of 40/32/22 but this gives a whole heap of
> low gears but very little basic flat country gears. For a better spread
> what rings should I go for? (Obviously I mean gear that's easily
> obtainable). My existing equipment is Shimano Deore. Help would be much
> appreciated.
> Rob Norton
>
>

I have 50/38/28 up front on an old Deore chainset and 13-32 (in 8) on
the rear give me around 23" bottom and 100" top. Its not the height of
the mountains thats the issue its their steepness. 36x32 (~30")was low
enough for Independence Pass at 12096'.

Clive George

"Robin Norton" <rjnorton@iolfree.ie> wrote in message
news:cpsspa$363$1@kermit.esat.net...
> My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings are
> 46/36/26. My bottom gear is 25 ins.
> For touring in high mountains I'd like a bottom gear of 20 ins or a bit
> less. I don't mind sacrificing gears above about 90 ins.
> My local shop has suggested rings of 40/32/22 but this gives a whole heap
of
> low gears but very little basic flat country gears. For a better spread
> what rings should I go for? (Obviously I mean gear that's easily
> obtainable). My existing equipment is Shimano Deore. Help would be much
> appreciated.

First up you can just swap your 26t for a 24t without changing the chainset.
That gets you down to 23".
Then you can change your cassette to a 13-30 (settle sell HG50 7 speed in
that for 12 quid). That gets you down to 21.6" in conjunction with the
above.
Another choice would be a HG40 8 speed 11-34 cassette (settle, 15 quid)
merged with your existing one. That'll get you to 19", and you could have
something like 34-28-23-19-16-14-12 on the back, ie the same top gear.
The 7 speed version of the above lacks the 23t, which I reckon would be
useful.

Or 14-32 HG70 7 speed from SJSC, but that's 30 quid - swaps your top gear
for a new 20.25" gear, new top is 88" - possibly a bit low?

If you do go for the merging cassette route, you might get away with only
replacing the smaller cogs when you change chains in the future, ie only
having to buy one cassette rather than two which would be tedious.

I'd be tempted to go 9 speed though - same chainset, 24t granny, 12-34 XT
cassette, and new wheel and shifters obviously. Hmm - starting to get
expensive. In practice I'd probably go for the merged cassette route.

cheers,
clive

Kenneth Clements

"Robin Norton" <rjnorton@iolfree.ie> wrote in message
news:cpsspa$363$1@kermit.esat.net...
> My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings are
> 46/36/26. My bottom gear is 25 ins.
> For touring in high mountains I'd like a bottom gear of 20 ins or a bit
> less. I don't mind sacrificing gears above about 90 ins.
> My local shop has suggested rings of 40/32/22 but this gives a whole heap
> of
> low gears but very little basic flat country gears. For a better spread
> what rings should I go for? (Obviously I mean gear that's easily
> obtainable). My existing equipment is Shimano Deore. Help would be much
> appreciated.
> Rob Norton

I have 44/32/22 chainrings and 12-34 XT rear sprocket. Rear mech has a
capacity of 43 teeth and I think the Deore is the same but not 100 percent
sure. Fully loaded I still had to do a bit of pushing while traversing the
Pyrenees but any lower gear and it will be hard to get started on the
inclines. On the flat the top gear was high enough.

Ken
>
>

James Thomson

"Robin Norton" <rjnorton@iolfree.ie> wrote:

> My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings
> are 46/36/26. My bottom gear is 25 ins.

> For touring in high mountains I'd like a bottom gear of 20 ins or a bit
> less. I don't mind sacrificing gears above about 90 ins.

> My local shop has suggested rings of 40/32/22 but this gives a whole
> heap of low gears but very little basic flat country gears. For a better
> spread what rings should I go for? (Obviously I mean gear that's easily
> obtainable). My existing equipment is Shimano Deore.

You've had some good answers covering most of the bases already. Here are a
few more.

First, eight ninths of a nine-speed cassette will fit your freehub without
modification. If you buy an 11-32t 9-speed cassette (make sure the second
sprocket is a 12 - most larger sprockets won't work in the first position)
and discard the 11-tooth sprocket, you have a 12-32 8-speed cassette with
9-speed spacing. You'll need a 9-speed chain, and if you want indexing
you'll need to replace the rear shifter. In combination with a 24t
chainring, that gets you close to 20" at the bottom, keeps all the top end,
and nets you an extra gear in between. It also opens up a future upgrade
path to a full 9-speed setup.

Here are a couple of pages listing the various Shimano cassettes available.

http://www.m-gineering.nl/cassettg.htm

http://www.sheldonbrown.com/k7.html

I'm not 100% certain that your old Deore derailleur will handle a 34t
sprocket. The biggest sprockets Shimano made in those days were 32t. It
might go, but it could be a stretch.


Second you could go with the new chainset your bikeshop suggested, but ask
them to change the chainrings. The French company Specialités TA (among
others) makes rings up to a 50t for Compact Drive cranks, and down to a
20t. You'll need a new bottom bracket.


Third, you could consider an adapter that will allow you to mount a smaller
small chainring to your current chainset, either in place of, or in
addition to the 26 you currently have.

Here's one:

http://www.sjscycles.com/store/vIndex.htm?item4199.htm

and here's a page listing others:

http://www.abundantadventures.com/quads.html

I haven't used any of these adapters, and I can't guarantee that any will
work in combination with your chainset and front derailleur. You'd need to
get advice from the sellers in each case. I don't know a European source
for the Mountain Tamers, but postage would be inexpensive on such a small
item, and the US dollar is very weak at the moment.

Hope some of that is helpful.

James Thomson

MSeries

James Thomson wrote:
> "Robin Norton" <rjnorton@iolfree.ie> wrote:
>
>
>>My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings
>>are 46/36/26. My bottom gear is 25 ins.
>
>
>>For touring in high mountains I'd like a bottom gear of 20 ins or a bit
>>less. I don't mind sacrificing gears above about 90 ins.
>
>
>>My local shop has suggested rings of 40/32/22 but this gives a whole
>>heap of low gears but very little basic flat country gears. For a better
>>spread what rings should I go for? (Obviously I mean gear that's easily
>>obtainable). My existing equipment is Shimano Deore.
>
>
> You've had some good answers covering most of the bases already. Here are a
> few more.
>
> First, eight ninths of a nine-speed cassette will fit your freehub without
> modification. If you buy an 11-32t 9-speed cassette (make sure the second
> sprocket is a 12 - most larger sprockets won't work in the first position)
> and discard the 11-tooth sprocket, you have a 12-32 8-speed cassette with
> 9-speed spacing.

Thats what I have done but I made a custom 14-32 cassette to get closer
midrange sprockets. My hub is a late 1980s Deore XT one originally
accommodating 6 sprockets. My cassette is a mix of an LX one and a 105
one, shifters are Dura Ace downtube ones.

Steve W

Kens answer sounds fine to me, but why not play with the gear calculator
charts that are available free on either Kenitic's or Sheldon Brown's sites.
Try http://www.kinetics.org.uk/html/k_gear.html
or http://www.sheldonbrown.com/gears/
Hope this helps

SW


"Robin Norton" <rjnorton@iolfree.ie> wrote in message
news:cpsspa$363$1@kermit.esat.net...
> My Galaxy has rear sprockets 28-24-21-19-16-14-12. My chainrings are
> 46/36/26. My bottom gear is 25 ins.
> For touring in high mountains I'd like a bottom gear of 20 ins or a bit
> less. I don't mind sacrificing gears above about 90 ins.
> My local shop has suggested rings of 40/32/22 but this gives a whole heap
of
> low gears but very little basic flat country gears. For a better spread
> what rings should I go for? (Obviously I mean gear that's easily
> obtainable). My existing equipment is Shimano Deore. Help would be much
> appreciated.
> Rob Norton
>
>