Brompton gearing

Steve Watkin <[email hidden]> wrote:
: Anybody fitted a double with a big difference between
: the two sizes? I am thinking of trying a 22 and a 50.
: will it work?

No. Though have a look at Sheldon Brown's site and
this thread:

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Sheldon runs 28/50. 22/50 isn't going to work though.

Arthur

--
Arthur Clune clune.orgclune.orgOpen ↗ "Technolibertarians make a
philosophy out of a personality defect"
- Paulina Borsook

Steve Watkin said:

Anybody fitted a double with a big difference between
the two sizes? I am thinking of trying a 22 and a 50.
will it work?

Dunno, though a neater way (albeit /much/ more expensive)
would be to put in a Schlumpf bottom bracket gear. Have
words with Ben at Kinetics for more details, I'm pretty sure
he's done a few.

Pete.
--
Peter Clinch University of Dundee Tel 44 1382 660111 ext.
33637 Medical Physics, Ninewells Hospital Fax 44 1382 640177
Dundee DD1 9SY Scotland UK net [email hidden]
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Steve Watkin said:

Anybody fitted a double with a big difference between
the two sizes? I am thinking of trying a 22 and a 50.
will it work?

I know little about Bromptons (but a bit about gears).
First of all, can those rings be fitted to the double
crankset? Do you know the BCD*? Note. 24-tooth = smallest
size possible for 74mm. Or are you considering changing the
whole chainset?

If the front derailleur can't cope, you could do without
one! Just manually change gears like cyclists did in the
days before front derailleurs were invented. Seriously, that
could be reasonable if you only used one of the chainrings
very occasionally, say the 22 up the odd long steep hill.

* sheldonbrown.comgloss bo z.htmlOpen ↗

~PB

Quoted post said:

Originally posted by Steve Watkin
Anybody fitted a double with a big difference between
the two sizes? I am thinking of trying a 22 and a 50.
will it work?

SW

A passing aquaintance has a double fitted on his Brommie but nowt like as extreme as you're thinking of. Doesn't use a front changer, just shifts the chain with a length of bent spoke using the two chainrings for two wholly seperate ranges of gears, normal and for hilly terrain.

69 days until the Eco-Trip
Is that a Trice you'll be on?

Pete Biggs said:

If the front derailleur can't cope, you could do without
one! Just manually change gears like cyclists did in the
days before front derailleurs were invented.

Wot front derailleur? ;-) A pal used his Brom with a double
just like this, downhill to the station in the morning,
uphill going home, one ring for each direction (he wore that
bike out completely, it's just been replaced with a new L6
though with a smaller than standard chainwheel, IIRC a 43)

Pete.
--
Peter Clinch University of Dundee Tel 44 1382 660111 ext.
33637 Medical Physics, Ninewells Hospital Fax 44 1382 640177
Dundee DD1 9SY Scotland UK net [email hidden]
dundee.ac.uk~pjclinchOpen ↗