FF: Forks Difference Between Series 'B' and 'C' Balance Beams

[MichaelOrgzey]

Hello everybody!

What are the actual differences between the B and the C beams? Is there a difference in shape or length?
Cheers, Michael

 

[Peter Holmes]

I am unable to give dimensions, but with the Balance Beam used with the Girdraulic Fork the back edge edge of the beam is essentially flat across the back edge, with the balance beam used with the Brampton Fork the tapped adjuster ends are gently curved forward, starting around the halfway point between the pivot point and the adjuster thread, difficult to explain, but once you see one you will understand what I am trying to describe.
I have just checked Know Thy Beast, Edition 2, Page 29, it states the beams are the same, but on the Brampton fork the outer ends are bent forward by 15 deg. to clear the bottom fork links.

 

[vibrac]

And of course the definition is between Brampton and Girdraulic fork not B & C as the two definitions are not synonymous

 

[Peter Holmes]

Yes Tim, I was very careful not to fall into that trap when wording my reply, although as a general rule it is correct to make that assumption, with a few exceptions.

 

[MichaelOrgzey]

Thanks for your replies. Off course you're right, I obviously meant the difference between Brampton and Girdraulics. I have the curved one on my Bramptons, so that seems correct.
My reason for asking is that my right hand side adjuster is just rubbing on the end of the bottom link when I apply the brakes. My short brake cable is on the right hand side, and I think on the Brampton it should be on the left. The problem with the long brake cable being too long has been discussed here before. I just wanted to make shure I have the correct balance beam, I will have to work it from there.
Cheers, Michael

 

[Robert Watson]

Early pictures show the short cable on the RH side of the machine, opposite to later and more common practice. Also, you would be amazed at how easily a balance beam can have the curves in the horizontal plane "adjusted" to move the cable abutment points a little further forward to help clear them from contact with the bottom of the lower friction links. Makes you wonder how much of soft front brakes is from the beam flexing in the vertical plane. I am just looking at a Comet in my driveway with a balance beam I made from a nice piece of high tensile flat bar when one was not avail from the Spares Co. I bet it is harder to bend!

 

[MichaelOrgzey]

Hi Robert, bending the beam slightly forward didn't even cross my mind for some funny reason. I somehow assumed the problem would be anything being not quite right. So careful bending it will be. It will only take a tiny amount anyway...thanks a lot for that!

 

[Peter Holmes]

I presume it will need heat.

 

[Robert Watson]

You would be surprised!

 

[Peter Holmes]

And concerned!