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Old 10-01-08, 03:26 PM   #1
itsajustme
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respacing SA-8 for Brompton

Has anyone tried respacing the Sturmey Archer 8 speed down to a 110mm OLN to fit the Brompton?

I know officially this hub can only be respaced down to 115mm, but I was wondering if there might be any tricks to getting it even lower so the dropouts wouldn't need to be spread.
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Old 10-01-08, 03:35 PM   #2
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Did you see my brommi here (no special widening of the ti-triangle needed, the hub goes quite smoothly into the triangle):
Somnatash's chic Brompton + front Pantour hub pics!

Last edited by somnatash; 10-01-08 at 03:42 PM.
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Old 10-01-08, 03:46 PM   #3
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You will need to remove and replace the nuts on the axle. I think the standard ones are 5mm and they can be replaced with 3mm ones. In any event, the rear triangle needs no modification. Depending on how you lace the rear wheel, the spokes may hit the standard Brompton pump. You will need the 19-tooth sprocket for the SA to avoid any filing of the rear triangle.
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Old 10-01-08, 04:37 PM   #4
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hmmm....so what is the minimum over locknut dimension achievable with the SA8?

I have to admit that I don't actually want to put it in a Brompton, but in the front fork of a Downtube Mini which is 100mm.

I thought the minimum OLN for this hub was 5mm larger than the Brompton's 110mm dropouts. So what gives?
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Old 10-01-08, 05:01 PM   #5
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Originally Posted by itsajustme View Post
I have to admit that I don't actually want to put it in a Brompton, but in the front fork of a Downtube Mini which is 100mm.
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Old 10-01-08, 05:18 PM   #6
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Planning a Recumbent?
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Old 10-01-08, 05:38 PM   #7
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Planning a Recumbent?
Or a Cruzbike conversion? If a Cruzbike, the kit comes with brackets that turns the front forks into 135mm, so you'll have no problems.
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Old 10-01-08, 07:35 PM   #8
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Originally Posted by somnatash View Post
Did you see my brommi here (no special widening of the ti-triangle needed, the hub goes quite smoothly into the triangle):
Somnatash's chic Brompton + front Pantour hub pics!
I have a several of questions?

1. Can you have the shifter installed on the regular Brompton handlebars or do you need the flat bar?

2. Do you know if you can use the Nexus 8 speed or does it have to be SA?

3. How has the SA 8 been holding up? Have you had any problems?

4. Did you need to remove or modify parts like the rear derailluer?
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Old 10-01-08, 07:42 PM   #9
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Or a Cruzbike conversion? If a Cruzbike, the kit comes with brackets that turns the front forks into 135mm, so you'll have no problems.
Yup cruzbike conversion...you know because I made another thread about it, but I decided to make this thread to trick the passionate brompton geniuses into divulging their secrets.

In any case, the SA8 would have to be respaced to fit snuggly in the 135mm cruzbike bracket anyway. So if I have a choice I'd rather just toss the bracket and space it down to 100mm for a cleaner look that saves the weight and bulk of the wheel bracket attached to the fork.

Of course I'd also have to find a way to attach the cruzbike "stays" directly to the fork, but I'm hoping it might be possible to simply put them on the hub axle before adding the axle nuts.

However, the question is can the Sturmey Archer 8 speed be spaced down to 100mm? Official spec is a minimum of 115mm, but the fact that people are sticking them in Bromptons without spreading means it can go lower. How low can it go?

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Originally Posted by Dahon.Steve View Post
2. Do you know if you can use the Nexus 8 speed or does it have to be SA?
Not that I've tried it, but I believe the Nexus 8 is much wider than the SA8 and, thus, incompatible with unspread/unmodified Brompton dropouts.

Last edited by itsajustme; 10-01-08 at 07:52 PM.
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Old 10-01-08, 09:13 PM   #10
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I have retrofitted the SA8 onto my Moulton MK3 which is also 110mm, same as the Brompton. No problems. Just had to get a couple of thinner axle nuts from Harris Cyclery.

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Old 10-01-08, 11:15 PM   #11
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Quote:
Originally Posted by Dahon.Steve View Post
I have a several of questions?

1. Can you have the shifter installed on the regular Brompton handlebars or do you need the flat bar?

2. Do you know if you can use the Nexus 8 speed or does it have to be SA?

3. How has the SA 8 been holding up? Have you had any problems?

4. Did you need to remove or modify parts like the rear derailluer?
1. I have the flat bar, but I don't see why the shifter wouldn't work with the M-bar. I cut my shifter down by about 30 mm to fit it on the flat bar with Ergon grips and the standard brake levers.
2. A Nexus can be fitted, but not without spreading the rear triangle.
3. My SA-8 has been working really well, but it is still fairly new (~200 mi.). I had a few adjustment issues in the first week, but since then it has worked flawlessly.
4. I used a mildly modified Brompton 2-speed chain tensioner and slight modifications to the standard Brompton cable pulley. No other mods to the Brompton. The SA-8 needed the locknuts changed (as mentioned above) and the fulcrum plate trimmed down (since I used the Brompton cable pulley instead).
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Old 10-02-08, 08:35 AM   #12
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Originally Posted by bromptonS8 View Post
1. I have the flat bar, but I don't see why the shifter wouldn't work with the M-bar. I cut my shifter down by about 30 mm to fit it on the flat bar with Ergon grips and the standard brake levers.
2. A Nexus can be fitted, but not without spreading the rear triangle.
3. My SA-8 has been working really well, but it is still fairly new (~200 mi.). I had a few adjustment issues in the first week, but since then it has worked flawlessly.
4. I used a mildly modified Brompton 2-speed chain tensioner and slight modifications to the standard Brompton cable pulley. No other mods to the Brompton. The SA-8 needed the locknuts changed (as mentioned above) and the fulcrum plate trimmed down (since I used the Brompton cable pulley instead).
I noticed that there were some people with track bikes fitting Nexus 7 speed internal hubs in the rear.

http://nycbikes.com/item.php?item_id=665

Just speculating, they take a hub with a coaster brake and remove the apparatus to get 120 mm OLD. Maybe they use different lockwashers and nuts too.

Now that I think about it, maybe they use the hub with the roller brake instead. Anyway, one should get the idea.
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