FF: Forks Breaking the bank

[vibrac]

Now that I think I have solved the multiplate problem (see multiplate buying thread) its time for winter improvements to the fleet. One of the things I worry about like many others is stopping power for the alphabet twin in modern traffic, I think I have exhausted all the racing, pivot point, clamp up with brake on, turn linings on lathe, etc fiddles that adorn the VOC scene and need something better. Now I know the 8” or the TLS from Holland is the answer but flagship or not I have the fleet to maintain and finances are always strained, so perhaps a disc brake is the answer. (and keep fingers crossed about roadworthiness testing) That solution however while fine for Girdraulics is exacerbated by the fact I have a Brampton front end (No I wont change it) and as I have said before I have seen the bend in the tubes just above the lower forging on Ron Kemps racing Grey flash with standard brakes on AM4 so I worry about going too high with retardation forces

I have seen many small disc units on dirt bikes, which leads me to think perhaps a small disc on both sides might spread the load I also think that if the anchor point(s) were spread further up the tube work, that might help as well. Has anyone with bigger brakes on Bramptons or discs any comments to give? What is the relationship between disc size and retardation force and how do they compare with a 7” standard set up? I am in contemplation mode

 

[timetraveller]

Thinking aloud and not having a pair of Bramptons to play with I wonder if the distortion of the tubes might be eased by having the anchor point a long way up the tubes and having a restraining strap in tension, not compression. Of course stopping the bike rolling backwards would put the restraining strap into compression, but hopefully only at essentially zero speed.

 

[Chris Launders]

The trouble with smaller discs is there is less room for the callipers nearer the hub due to spokes.
Callipers mounted off the axle and torque arms anchored further up the legs would help spread the load a bit.
You could use the "normal" discs with smaller callipers to "soften" the braking

 

[Marcus Bowden]

Stop pussy footing around, rim disc on WM4 rim giving more space for calipers, that could be operated by cable as the mechanical advantage is so much greater , after all we are trying to stop the "Tyre" not transmitting all that torque to the wheel hub then back out through the spokes, rim to tyre ! Giro effect ? save weight yes I think.
1966 Liverpudlion called Philips had a band saw blade cut down to a diameter that fitted to his spoke nipples and wired ? ! it looked very crude but said only use a couple of fingers cause I'm afraid of damaging my forks (Girders) at the TT Later that year in Motorcycle Mechanics there was an article on him.
bananaman.

 

[vibrac]

Stop pussy footing around, rim disc on WM4 rim giving more space for calipers, that could be operated by cable as the mechanical advantage is so much greater , after all we are trying to stop the "Tyre" not transmitting all that torque to the wheel hub then back out through the spokes, rim to tyre ! Giro effect ? save weight yes I think.
1966 Liverpudlion called Philips had a band saw blade cut down to a diameter that fitted to his spoke nipples and wired ? ! it looked very crude but said only use a couple of fingers cause I'm afraid of damaging my forks (Girders) at the TT Later that year in Motorcycle Mechanics there was an article on him.
bananaman.

My Stars Marcus! you certainly are avant garde, I thought Bill and I pushed what was acceptable modifications but you are as bad as that guy in 1928 experimenting with spring frames that nobody wanted .... now what was his name?

 

[Marcus Bowden]

1911 NSU had a rear mono shock system that I saw in Lowland museum DK , nothing new, we all try to improve what we have and things are made from what we have lying around at the time !

Here we are, isn't easy to get the pictures onto the forum.
FOOTREST HANGER STOP TO FRICTION SEAT DAMPER THICK S/S FLAT BAR WITH DAMPER BOLTS SCREWED INTO IT, Bowden cable clamp, this is the limiter for the right hand brake arm. When brake is applied the right arm is moved first then the left is taking up slack and then both sets of shoes get same force application.

CABLE STOPPER IS A SLOTTED BOLT WITH TWO WASHERS GROOVED OUT FOR WIRE,, NOTICE COCK UP THE REAR STAND PADDOCK BIT CUT AWAY WAS MEASURED BEFORE I SHORTENED THE BRAKE ARMS,

RIGHT HAND SIDE CABLE ANCHOR IS THE SAME ARRANGEMENT AS L.H.S. ALUMINIUM SLEEVE HOLDS THE ACTUATOR FOR THE BRAKE MICRO SWITCH FRONT END IS CLUTCH SPRING

R.H.S. SHOWING CUT AWAY OF STAND TO ALLOW STRAIGHTER RUN FOR CABLE

L.H.S. SHOWING CABLE CLEARING STAND // PANNIERS REMOVED THIS RUBBISH IS NORMALLY HIDDEN

 

[Marcus Bowden]

OVER ALL VIEW .
PANNIER BOTTOM FRAME RAILS 28 INCHES WIDE 26" AT TOP OF BOXES , LEAVE BMW's BEHIND WHEN FILTERING

 

[vibrac]

One thing I like about your panniers (and I am not a pannier man) is, (as far as I have seen) that all the support system consists of basically are two tubes fixed longitudinally under the seat and the panniers as a fixed set have forward pointing matching tubes that just slide in and are secured. Irrespective of the huge size of your "picnic table" panniers the system could be adapted for 'normal' size panniers and makes a mockery of all the scaffolding that normally accompanies Vincent pannier fixings

 

[Bill Thomas]

1911 NSU had a rear mono shock system that I saw in Lowland museum DK , nothing new, we all try to improve what we have and things are made from what we have lying around at the time !

Here we are, isn't easy to get the pictures onto the forum.
FOOTREST HANGER STOP TO FRICTION SEAT DAMPER THICK S/S FLAT BAR WITH DAMPER BOLTS SCREWED INTO IT, Bowden cable clamp, this is the limiter for the right hand brake arm. When brake is applied the right arm is moved first then the left is taking up slack and then both sets of shoes get same force application.

View attachment 17273

CABLE STOPPER IS A SLOTTED BOLT WITH TWO WASHERS GROOVED OUT FOR WIRE,, NOTICE COCK UP THE REAR STAND PADDOCK BIT CUT AWAY WAS MEASURED BEFORE I SHORTENED THE BRAKE ARMS,

View attachment 17274

RIGHT HAND SIDE CABLE ANCHOR IS THE SAME ARRANGEMENT AS L.H.S. ALUMINIUM SLEEVE HOLDS THE ACTUATOR FOR THE BRAKE MICRO SWITCH FRONT END IS CLUTCH SPRING
View attachment 17275

R.H.S. SHOWING CUT AWAY OF STAND TO ALLOW STRAIGHTER RUN FOR CABLE
View attachment 17276

L.H.S. SHOWING CABLE CLEARING STAND // PANNIERS REMOVED THIS RUBBISH IS NORMALLY HIDDEN
View attachment 17277

Thanks Marcus, Trouble is I unbrazed my seat fixings, When I built my "D" type Special in 1975, But I might think of something along your lines. Cheers Bill.