naked_draughtsman said:On my old mountain bike I had a shimano 11-34 freewheel, but my new
bike had much lower gearing and I'm planning to change what I have now
for something similar.
The equivalent Shimano cassette (new bike takes a cassette on the rear
wheel, rather than a freewheel assembly) needs a tool to screw the
retaining plate in - does anyone know if this is the same tool that
you use to remove a freewheel? It looks similar but I have a feeling
that they require similar but different tools.
To remove a modern cassette, you need the relevant splined tool (yes it's
different to the Shimano freewheel one), and a chain whip (otherwise the
cassette just goes round and round).
You can make a chain whip from a piece of old chain and piece of steel bar
(I did because I needed one and had the bits to hand, though they are quite
cheap to buy).
On your "new" bike. You need to check that the derailleur mechanism can
cope with the larger size cassette. The derailleur will have a "capacity"
and a "maximum size".
The maximum size is the largest rear cog it can deal with.
The capacity is the number of teeth difference between biggest and smallest
cog, bearing in mind the front chain rings. Longer cage derrailleurs have a
larger capacity than shorter ones. eg. your old MTB was 11-34 rear, and
(my guess) 22-32-42 front, so the capacity needed was (34-11)+(42-22) =
23+20 = 43. In practise, one can get away with slight under capacity as one
should avoid the extreme "big to big" and "small to small" combinations.
--
Nigel Cliffe,
Webmaster at http://www.2mm.org.uk/
