25. Assembly: Fork Stops...

A blow by blow photographic account of chopping from stock to chop... This projcet has been given its own forum due to the large number of photos it contains making uploading slow for those of you still on "dial up".
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Prof
Founder, Choppers Australia
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Joined: Sat Oct 22, 2005 3:54 pm
Location: Willunga, South Australia
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25. Assembly: Fork Stops...

Post by Prof » Sun Mar 11, 2007 10:40 pm

Frame is clamped on my bike stand, so now assembly can begin.

First step is to assemble triple trees which includes putting in new head stem bearings. I also have to finish the fork stops as I forgot to do them before I sent everything off to be chromed... in fact things are a bit disorganised in this regard.

I have sent out a second lot of stuff to be chromed and have to wait two weeks for it.

I just swapped wheels with Michael (at his request), so he could have mags and I get spokes. Mags are definitely easier to clean, and allow you to run tubleless which means cooler running tyres and slower air loss in case of punctures. But now I have to clean up mags and give them a paint... charcoal to match engine cases, so assembly is going to go in fits and starts.

Plus gear box and motor top ends have to be assembled yet. By the way, the easiest way to put in a motor is to lay it on its side on the floor and lay your frame over it. Won't happen this time.

Ok bearings first...

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Make sure you clean out any paint residue before installing outer bearing races. Begin with a hammer GENTLY tapping in race. To prevent it jamming by going in crooked, tap at 12 o'clock, 6 o'clock, 3 o'clock & 9 o'clock and keep repeating the process until it is almost level with steering head edge... then use a pin punch to drive it in the rest of the way. Paint is brittle and will chip if you touch it with either hammer or punch so concentrate... Make sure race is seated fully. The ring you get each time you hit punch will change to a noticably tinnier sound when it is fully down.

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Same care taken here when driving bearing down of bottom tree. Use a heavy walled tube that is level on the bottom. Again, listen for the distinct bottoming sound when bearing si fully down...

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Stock bikes steering locks are always too restrictive, usually to protect the tank. Make sure when you mount your tank you keep it back far enough to get in a decent lock without the tank getting damaged by forks.

Choppers with their longer wheel base can also stand a tighter lock than stock bikes. I set mine at 33 degrees of the centre line (as seen here with tree put in upside down). Once your chopper is up and running, with practice, you can get it turned around in a very small space, feet up... and blow everyone's minds in the process!

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I chucked away all the stock fork stop rubbish and welded in a simple triangular stop under the steering head. I am going to use two 1/4" UNF socket heads on lower tree to contact triangular stop. Here the locations of the holes for the socket heads are being measured. Marked paper is the easiest and most accurate way to mark distances on curved surfaces. Top mark is centre when forks are pointing straight ahead, so need an evenly spaced mark each side...

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Red arrow (Michael just showed me how to do this!) shows hole being tapped for 1/4" UNF. A 1/4" bolt has 1 ton shear strength and these are stainless, so more than adequate as stops. Socket head screws all way down to tree but still contacts triangular stop. This is important to retain that shear strength.

Blue arrow points to a "bottoming" tap. When tapping threads into a blind hole, begin thread with a taper tap and finish with a "bottoming" tap. Bottoming tap has no lead ie is flat on end so you can get your thread to the full depth of the hole. I made this one by cutting the end off a spare taper tap with angle grinder.

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Job done... Socket head works a treat and looks really neat... Paint will chip where socket head hits triangular stop. If you want to be really trick, cut out your triangle, send it to the chrome plater and then weld it in. This way when you paint your frame, you can mask off the part of the triangle that will be contacted by the fork stops and voila... no chipped paint!


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Chopit'nrideit... Prof

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