Misc: Everything Else Brampton Coil-Over Damper

Albervin

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I forgot to mention that the Woodhead Monroe setup required some cutting and brazing to the fork, which these days is sacrilege!
The lower link on my Rapide had been "filled in" prior to my purchase. This obviously strengthened the link but I believe it was done for sidecar work.
 

vibrac

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I thought I would share the bottom fittings of my alphabet twin Brampton damper its one I bought from the USA (I think at the first St Helens NA rally) no longer available but made in California it picks up on the main coil spring anchor point.
I was going to get Bens suspension gurus make some but it proved too costly
BDparts.jpg
BDbottom.jpg
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greg brillus

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Has anyone come up with a pair of suitable coil overs that can be used at the rear of an original series "B" where the forward through bolt tube is still in it's original "Un-cut" state.......? I know most over the years have been modified to fit a shock absorber between the spring box's, but I know of some that aren't. I remember Craig had a set on his early "B" and I asked him about them, but never got any reply...........How could anyone forget those bright yellow springs............o_O
 

hadronuk

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Has anyone come up with a pair of suitable coil overs that can be used at the rear of an original series "B" where the forward through bolt tube is still in it's original "Un-cut" state.......? I know most over the years have been modified to fit a shock absorber between the spring box's, but I know of some that aren't. I remember Craig had a set on his early "B" and I asked him about them, but never got any reply...........How could anyone forget those bright yellow springs............o_O
The basic problem you are up against is that the B series was not designed for a hydraulic damper so the available space is severely limited. Hence the fairly major re-working for the D series that created space for a much longer damper.
I have just had a look through the Armstrong catalogue, and I don't see anything suitable, they are all too long.
I can't see anywhere if the listed minimum length is including or excluding the bump stop. Anyone know?
In the intro, very interestingly it says
"Our SB units are made in two in sizes. SB 3 and SB 4 with nominal stroke lengths of 3" and 4" respectively. (Figs. 2 and 3). For most machines these allow too much movement and stroke restrictors are employed to reduce it in the particular way needed for the individual models. The extended and compressed lengths in the list show this."
So there may be scope for the Armstrong replica suppliers to assist.
 

greg brillus

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Thanks Rob, I think that's why when I was looking for something to use on the racer, I ended up buying something just for experiment off Ebay which was actually a coilover to suit a "Pit Bike" if you know what they are. It was longer than standard which is what I wanted, had adjustable spring pre load and adjustable rebound on the shocker, all very well made, and only $100 Australian dollars or about 50 pounds sterling. All I need to do then was get some other springs made to get the spring rates I needed. Problem also is trying to find/use something that doesn't look too modern which spoils the look on an old bike. That is why I suggested being able to refit the original spring box's to hide the looks of the coilover. The Thornton unit has a spring diameter of about 63 mm which meant I had to space the original spring box's outward about 8 mm either side, and this set up looks good and works well. The only other idea I had was to use a shroud over the forward end which would hide most of the spring. Just me thinking outside the square if you know what I mean. People seem happy enough to make practical changes to their bikes, but still want it looking standard if possible.
 

Goffy998

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John
I have a file with some dimensioned drgs. for the Thornton Brampton coil over unit, I can't upload them here.
Go to my website & send me an E mail I will return this + some other photos of similar units.
Paul Goff
 

Oldhaven

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Here is the Brampton Thornton setup on my B. I posted some pictures during my build, but here are some more recent ones. I had to do a bit of fabrication of mounting points by modifying commercially available clevis components to make it work, since the damper was supplied as a standard rear non coil over configuration. It is internally modified by Dave Molloy to reduce travel for this application. I am not sure if it is still offered. The specifics of the mounting details were suggested by Ted Leno and Dave Molloy, based on Ted's B adaptation, and a drawing was available from Dave that shows one way of doing it. I departed from that a bit because I did not want to mount the bottom head light stays on a pivoting mount, as was suggested. I made an extension from the balance beam pivot. This lowered the headlight by about an inch which has other benefits such as clearance for the speedometer and switch, and I like the slightly different look of the lowered light. My balance beam is not being used since I have the Vincent Speet's brakes and is just there for appearance and as a place to route the cables. I don't see why this mounting could not be done with a functional balance beam. Anyway, it simplified the lower mount by not requiring the headlight stays to cope with the slight rotation of the lower damper mount. the lower clevis mount has to be long enough to clear the fork spring lug through the range of travel. All in all I am quite pleased with the way it works and I find it comfortable and it eases the harsh action a lot on bumpy roads.

I have a Thornton non coil over on the rear also. I did cut the UFM tube to use it, which mortified me since it was unmolested, but that could be easily undone if some future purist want it correct.

damper install 1.JPG
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