Girders

[tbone]

The brackets are then cut to shape and welded between the legs, then another 8" long piece of tube is inserted through the holes, leaving a 6mm overhang on the outside edges and welded in place.

[tbone]

and apart from a bit more tidying up....thats them...for now
Next i`ll make up the link rods and something to attach them to.

[bitzman5]

Thy look the job will follow this with intrest

[tbone]

The girders are held to the yokes with links, basic dogbone shapes made up with more of the same tube will do, although they can be made fom flat plate.
Two short bits and a longer bit,will be mitred then welded.

[tbone]

And when finished they will sit like this.....

[tbone]

you need 4 of these in total, 2 for the top yoke and two for the bottom, so i`ll pick this thread up again when i`ve done the other 3

[morrag]

Some WW2, BSA M20 forks which might assist in your deliberations Mr. T, and they do in fact use flat "dogbone" links, Morrag

[panthershaun]

me I love girders 

[ByzMax]

I love Girders too

Made a few sets of these and they require great accuracy

A handy hint when making girders is to self template.... Make one side and then use that with shafts fitted to make an identical one for the other side as 1/4mm out at the links could transpose it to a large problem at the wheel end!

[hornet6]

Great thread,as ive been interested in making some myself.Just a couple of questions. A. Does the tubing need to be made from a special material,and whats the size of the tube diameter and the wall thickness.
B. How do they feel,as opposed to normal forks.Could you still crank your bike right over and power out of a long bend?

[morrag]

You have very obviously never ridden a machine equiped with old style 'Girders', but the answer is NO.......unless you have some kind of death wish. They are ok for 'Show' but don't even come close to a modern, telescopic,fork,in performance. I am of course excluding the modern, 'Beamer versions of the type!which I have never tried, Morrag

[ByzMax]

Morrag is right for sports/racing bikes but for Trikes and Custom bikes you cant beat em.

The original custom girders back in the 60's and 70's where often made from bent solid bar and had really crude links that flexed.

This got them a bad reputation but if well designed and built they work great. Because the headstock and fork legs don't have to run on the same plane you can set your trail and have an easy to ride machine with a lunatic rake on it   

The last trike I made handled better than any other that I have made or ridden, The problem is they have to be made to fit each machine and are labour intensive too! Translate that into about  £1200 -£1500 a set for one offs and you can see why you don't see them used much.


I still love em though!

[Plasticpig]

What wall thickness are you using?

Cheers.

[Manky Monkey]

Not sure, but TB's made scaled down models of parts before -are these full size or miniature?
Taz's trike build uses chunky girders, built for us by FLC, (Mick), from Yorkshire. I'm looking forward to trying them out. 

[dracken1]

have to disagree with the not handling as well as teles bit.
teles are like vhs video, an accident of history, betamax was better than vhs, so same with teles.  tele forks have a spring inside a tube anlong with some oil which runs back and forth through various sized holes giving ithe front end damping. good rear shocks have the same set up but the spring on the outside, adjustable damping etc. mate that shock(s) to a girder front end which by it's very design, being trangulated is a very strong  structure, plus the trail changes very little in operation. yes the bmw idea is good as is upside downs. but a properly set up girder will handle with the best of them.