Misc: Everything Else Brampton Coil-Over Damper

Oldhaven

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By the way, in the photo of the rear Thornton above, and also on the front one,it shows the rubber bumper in an orientation the way I got it. I kept it that way, but it seems it would work better the other way around on the shaft, since now the small end of the bumper hits the seal when the travel bottoms things out. Am I wrong on this?
 

Bill Thomas

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Robert's "Works" one , Above , Seems the same, So they must have thought of something !. Cheers Bill.
 

davidd

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By the way, in the photo of the rear Thornton above, and also on the front one,it shows the rubber bumper in an orientation the way I got it. I kept it that way, but it seems it would work better the other way around on the shaft, since now the small end of the bumper hits the seal when the travel bottoms things out. Am I wrong on this?

Ron,

I think the seal is is supported on the inner side, but I will have to look the next time I change the oil. The rubber bumper is said to give .25" of travel before it prevents further movement. I think if you hit the bumper it will slide over the lock nut on the rod which is holding it proud of the screw on end. Carleton hit a hay bale dead center once and the damper appeared untouched. It was not Carleton's crazy riding that was at fault. Another rider snagged some material that the bale was cloaked with and spun it onto the track.

David
 

hadronuk

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Ron,

I think the seal is is supported on the inner side, but I will have to look the next time I change the oil. The rubber bumper is said to give .25" of travel before it prevents further movement. I think if you hit the bumper it will slide over the lock nut on the rod which is holding it proud of the screw on end. Carleton hit a hay bale dead center once and the damper appeared untouched. It was not Carleton's crazy riding that was at fault. Another rider snagged some material that the bale was cloaked with and spun it onto the track.

David
I thought AVO had the bump stop the wrong way round as it would contact the seal more. They said it was fine, the scraper outboard of the seal is easily tough enough.
 

flxible

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Nice ride Ron-
Is that a 20' or 21" front tire?
And how are you liking the front brake?
Best-
George
 

Oldhaven

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Thanks, George. It is a 21. I used it because they are easier to find tubes for, and I think it compliments the vintage look of Brampton forked Vincents. The front brake is quite nice and I don't find it too "fierce", which might have been a problem. It stops me as fast as I feel comfortable with. I have only had one panic stop and didn't break the tire loose, which pleased me.

Ron
 

Oldhaven

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Hi Alyn,

Not to worry. Here is a picture of the bike with half a tank of fuel, and me not on it. As you can see, everything is good and agrees with recent findings about Girdraulic lowers. I am not sure how Bramptons are affected by slight down inclination, but mine is fine and slightly up with me on it. I could probably preload the spring a bit more, but I mostly ride solo and no luggage. As you can see in the center stand photo and this one the long travel allowed by the forks now renders my front stands useless except for tire changing unless I carry a 2 inch tall stone slab along with me. I miss that and will probably fit a V3 type stand. I already fell over once trying to start it in loose gravel after a stall with only my left foot to hold things up.

I also included one showing remaining Thornton travel with the bike in this semi loaded condition. It's not a lot, but handles things fine. I did not measure with an original spring, but it is probably about the same.

IMG_0480.JPG
IMG_0481.JPG
 

timetraveller

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Just to note that the recent comments on front forks and modified steering heads concern only guirdraulics. The geometry of the Bramptons is different and it would be interesting for any bike owner with Bramptons to remove the front spring and to trace out the front wheel spindle movement as I did. Publishing the track either here or in MPH would educate a lot of us.
 

Oldhaven

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As an interesting note, and I hope I am not getting too far off track, When I ordered my Dave Hills center stand, I measured the rear pivot bolt distance as he specified, and got 12-3/4 inches. Dave commented that this was about an inch taller than typical, and was the second longest stand he had made, let alone for a B. I think my stand is a bit long now that things have settled in a bit, but the combination of the front and rear Thornton's and the Justin Mackay-Smith rear springs and spring boxes put the thing up in the air a bit. That is probably why my front stands are vestigial appendages now. B's should be lower than C's and a comfort to shorter inseams. Anyway, that is something to consider if you want to change to a Brampton coil over.
 
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