Wed 10 Feb 2010
Spent all day making a batch of tensioners for the 8-speed Brompton kit – it’s more efficient making a batch, but very boring! Especially when you have to completely dismantle the tensioner, machine off a bit of it, and reassemble using different bolts and different washers.
This is a new improved design, though – it has fixed instead of floating pulleys, which keeps the pulleys further away from the spokes, and it now uses standard off-the-shelf jockey wheels which can easily be replaced if they wear out.
February 24th, 2010 at 4:45 pm
Hello,
1) Do you use the last sturmey archer x-rf8 (w) wide 325% hub for your “Brompton 8-spd Kit”?
2) The gear table for the Brompton 6 speed is :
1-2,63m
2-3,23m
3-4,11m
4-5,06m
5-6,45m
6-7,94m …. What is the gear table with your Kit?
3) Is there a “non-plastic” way for the chain tensioner? A 100% metal chain tensioner?
Thank you very much for your time.
Kind regards,
Rémi (from France).
February 24th, 2010 at 5:29 pm
Yes, it’s the X-RF8(W) – the newer wide-range version.
I haven’t worked out all the ratios yet, I’m afraid, but it goes from 29″ to 95″ in inches – that’s about 2.3m to 7.5m I think.
The problem is the tensioner needs to take up a lot more chain than a standard tensioner – I don’t know of any metal one that will work.
February 28th, 2010 at 1:31 am
Thank you for your quick answer!
Could you modify the ratio to 31″ to 100,7″ in inches?
If so, how much would be this special 8 speed kit?
March 3rd, 2010 at 9:48 am
That would be easy enough – just fitting a larger front chainset would do it. It wouldn’t cost any more to do this.