derail3

I have a 2003 Brompton 6 speed with a SACHS 3 speed hub. There are two sprockets 13 & 15. The hub runs great but the sprockets are just about wore out. Tried to have my local Brompton dealer replace them. But was told they could not find a source for replacements.

The hub has a 3 spine mounting. Shimmino have 9 and will not fit. Does anyone have a source for these sprockets? I live in the USA but willing to go outside the US if need be.

Blackstrida_A_

Found at cyclechat.net
https://www.cyclechat.net/threads/br...-speed.261765/
2 + 2,2 + 3 = 7,2 mm

Considering this (and hoping my calculations are correct) I'd say that a spacer with 1,8 mm thickness, combined with these two sprockets, might work, too.
https://www.clevercycles.com/brompto...-spline-f.html
https://www.sjscycles.co.uk/sprocket...lat-cp-hsl850/

3/32" => ~ 2,4 mm
3 + 1,8 + 2,4 = 7,2 mm

Please check by yourself

Winfried

As SRAM (which bought Sachs in 1997) stopped manufacturing gear hubs in 2017…it won't be easy finding cogs for that hub:

"Sachs/SRAM IGH parts are no longer made. You can still find spares online, especially in Germany (but good luck post-Brexit, many shops won't ship to the UK)." (Source)

gear hub = nabenschaltung
cog = ritzel

tcs

If they are non-dished sprockets and have only been run in one direction...flip 'em over.

The 'three spline mounting' has been used by Sturmey-Archer and Fitchel&Sachs (a.k.a. Sachs a.k.a. SRAM) since the early 1950s, and used by Shimano for hub gears since they started making hub gears in 1957. It's been used over the decades by many single-speed coaster hub manufacturers, too. These sprockets are one of the rare universal fit items with bicycles. Seriously, any ubiquitous Sturmey, Sachs (SRAM), Shimano or off-brand three tab sprocket* will fit that hub. You can achieve the spacing you need with either flat cogs and spacer(s) or dished cog(s).

You know those Shimano nine-spline cassette hubs? Yeah, they're the same diameter around the outside of the splines as a three-speed IGH driver, so spacers in all sorts of thicknesses for between the cogs are pretty much a ubiquitous item, too. In fact, this is the same diameter spacer needed to adjust a bottom bracket's alignment in a BB shell.



Pathetic.

Fun fact: Those sprockets are offered in sizes from 13T to 24T, plus 27T and 30T, in flat and dished for 1/8 chain and 3/32 chain.

*The rare, 'non-ubiquitous' three-tab sprockets for the S-A 8 and newest S-A 5 hubs will not fit.