Help please!
I am looking for a tensioner nut and washer set for the SRAM hub on my 2002 Brompton bicycle.
(The bit the adjuster cable feeds through on the end of the axle. It also holds on the black plastic unit on which the chain tensioner wheels are mounted.)
.
Do you have one lurking in an odds and sods jar or on the axle of a disused wheel - or have any idea where I might find one?
Thanks
Shivaji
Looking for: a tensioner nut for a Brompton SRAM hub
-
- Posts: 6
- Joined: 20 Jan 2017, 8:50pm
-
- Posts: 3028
- Joined: 9 Jun 2008, 8:06pm
Re: Looking for: a tensioner nut for a Brompton SRAM hub
If you get the SA version it should, with difficulty and cutting oil, thread onto the SRAM axle. I would be surprised if the washer is actually any different between SRAM and SA, since they are somewhat oversize. Generally SA nuts are far softer than the axles but Brompton may not have realised this should be the case when commissioning them, so ideally use a spare FG 10,5 axle to convert the thread, just in case Brompton made their nuts too hard. Not all SRAM hubs are FG 10,5 but the old Sachs models often are.
Better, get an FG 10,5 tap - easier said than done in the UK - and run that through an SA nut to convert it to a SRAM nut. The pitch is the same but there is 0.2mm difference in diameter.
You could also buy a plain FG 10,5 nut, since there isn't anything very special about the Brompton one. Yes, it has a narrow bit at one end to centre the washer, but that's easy to work around. Unlike the SA nut, you don't need a "porthole" to adjust the cable.
For what it's worth, FG = Fahrradgewinde, or "bicycle thread". Like classic Campag hub axles, it's an unholy mix of metric diameter and threads per inch.
Better, get an FG 10,5 tap - easier said than done in the UK - and run that through an SA nut to convert it to a SRAM nut. The pitch is the same but there is 0.2mm difference in diameter.
You could also buy a plain FG 10,5 nut, since there isn't anything very special about the Brompton one. Yes, it has a narrow bit at one end to centre the washer, but that's easy to work around. Unlike the SA nut, you don't need a "porthole" to adjust the cable.
For what it's worth, FG = Fahrradgewinde, or "bicycle thread". Like classic Campag hub axles, it's an unholy mix of metric diameter and threads per inch.