Gary Britton's  Fifth BSA Trials Bike build.


This time Gary starts from Scratch.




Gary Britons “Number five”.


Hello Charlie, thought i'd drop you a line about number 4. Actually that should be number 5 as there is also a


1971 b25t in the garage now, but that’s another story.


I always fancied making my own trials frame so this


Winters project is sorted.

I stole the dimensions off your site and off the Faber Mk1.

I drew the frame out on


the dining table and set about making a jig.

I used some 4 inch box for this (should be ridgid enough).


For the frame I used 1 3/4 inch for the top tube, 2 inch for steering tube and 1nch for the sub frame.


All 2mm wall, I know that’s a bit thick, but it was easy to get hold of and should be easy to weld.


The steering head has machined inserts for tapered bearings.

The swinging-arm is off a BSA B25 all the way from


the USA.

I made slugs to lengthen it by 1 inch to make like the competition swinging-arm it was sold as.


Well that’s as far as we have got.

I'll keep you informed of progress. By the way ,bikes 1,2 and 3 are still going well


Nigel is winning everything on Mk2, Jay rides Mk3 now, and then (he beat me on the weekend) and I’am still wobbling


around on Number One.




Like the barrel Gary.


All Photos Courtesy Gary Britton.

Yes Always built yourself a jig.



Good Swinging arm box Gary.


A tip to others contenplaiting building their "Otter" Frame ,

is dont make the swinging arm to shallow or the  swinging arm will have restricted movment. and if you build it too wide, that many people think the Faber one is, you will have trouble with the chain fouling the top and bottom of the box.




I this one will just be Ok.

Looking a bit like a "Bariel" build to me Gary.




Hmmm, the primary drive is going to be interesting then?




Are that's better but it is still a square barrel Gary.?



B25 barrel C15 head




Explanation from Gary,

Your right Charlie, that cardboard box will never work, so I got one of these.
Only problem is I wanted to use a C15 cylinder  head.
First problem, the valve drain holes are different, so I had to make up a plug and drill a new one.
Problem number two, how to seal the push rod tube, umm.
Problem number three, how to make it look a bit nicer.
Oh well it would not be fun if it was easy.
 Charlie> Your doing a good job, keep plugging away.



Faber "Bariel", Frame, this one for a Triumph Cub engine,


An "Otter" frame with longer top tube Like an Ariel HT frame.

And 1" top suspension struts.


 Hi Charlie, thought I'd give you an update on number 5.
As you can see the basic frame is welded.... of sorts, (i don't think the Harris bros will be on the phone any-time soon) .
All the angles are close to what I wanted and there is not to much distortion.
The steering head bearing seats have gone a little out of round but I think I can fix that with the dremel.
 The swinging arm has rubber bushes so the next job is to make some proper ph-s bronze jobbies. Some nice aluminium 14" shocks are on the way.
The plates under the engine in the pics is just an engine stand, i'm going to extend the engine plates front and rear down below the motor so i can fit a nice 6mm bash plate.
The motor is a B25 with a C15 head.
I know lots of people use B25 barrels on a C15 and i'm not sure how this is going to pan out.
As well as the drain hole not lining up the studs are to short and the C15 ones, are the wrong thread.
I have made a  3mm compression plate to take some of the bark out of it and someone suggested using C15 cam followers to make it a bit softer. But that's long way off yet. All for now G.B.
Pic's below.
All Photos Courtesy Gary Britton.
And the Barrel named "Shawn".
The "Bariel? build. is looking good Gary.
 Hello Charlie, as you can see its nearly finished,not.
This weeks problem has been the exhaust system.
First take one perfectly good very shiny very expensive chromed exhaust pipe and cut it up with the angle grinder.
The fit of the pipe in the head was like throwing a nail bar into a empty warehouse.
First I had to machine the port so its round then turned a plug to take up the gap,
looks aright I think.
For the silencer this time I thought I would buy one at the show but when I got it home it just did not look right so this one was bought on ebay.
Some Triumph Tiger-Cub hubs were bought and cleaned up and made wider.
I also made some brake pivot cams.
Forks are four-stud as per the others.
I think the material used for these yokes was more cheese than aluminium,also all the tooling must have been worn out as the burs around all the machining was really bad.
Charlie.> Gary I am just getting some New yokes made as they are getting imposible to find now and the price you have to pay is up to New billet ones.)
As you can see the rear mudguard and seat have that Ariel look about it.
Do you think it needs a brace across the  mudguard?
While asking for advice what about bracing for the swingarm box?
Charlie.> Gary you could rivet a alloy plate on the underside of the mudguard this would keep the look but make it stronger.
Swinging-arm box should be OK with the large diameter tube. but you could brace the footrests to the engine plates which would strengthen it and the rests!
All for now. G.B.  
'BARIELS ' I do like its basic design.
The exhaust modification looks very good, a lot better than the standered push into the cylinder head that always leaks.
This hub modification by adding 1 1/2" into the width is a must for good spoke line with the off-set you need.
And still works out cheaper than buying Billet hubs if you can do the work. 
You can turn these brake cams on a lathe and then cut and file the flats. so you dont need a milling machine.
All Photos Courtesy Gary Britton.
More Photos and update later.


There is a New Page in Construction about The labelled "Bariel" Machines.


Due shortly.



More Later.