Assembling the engine

Engine cover and mounts sprayed ready for assembly.

The metallic black looks great on the engine cover.

Engine cover located, gently gently don’t want to scratch anything.

Engine assembled.

Metallic drive sprocket, yeah, why not.

Rear wheel complete, now lets get that engine on.

I cut up some rubber strip to protect the paint on the frame. Engine mounts on, and on goes the engine. Perfect.

Next step, brakes and gears.

Assembling the motorcycle - first fix

Pressed the headset cups into the newly painted frame.  Then in go the springer forks.

Both wheels go on.  There’s not a lot of clearance on the rear, had to let the air out of the tyre to locate the hub in the dropout’s.  I guess that’s what you get when you opt for balloon tyres.

Pressed in the bottom bracket cups, and in go the bearings and spindle. On go the cranks and pedals.

Petrol tank on, just need to make some spacers and retainers for the leather straps.

Brooks saddle on, and we’re starting to get somewhere.

Next step, I need to paint the engine and mounts, and fabricate a stainless steel exhaust.  Right, I’m going in, it’s bloomin freezing.

Prep and spray

Plenty of paint stripper was required to get the frame back to bare metal.  I then smartened it up by sand blasting.

A little bit body filler here and there to get rid of the water bottle and badge holes etc, and its ready for the paint.

Popped to the local paint supplier to check out some samples, and opted for Alfa Romeo Nero Black which is a nice rich metallic with silvery / gold metal fleck.

Paint applied to the tank, quite a few coats of clear lacquer to add depth.  Thanks to my Dad for the cracking spray job, great end result, well pleased.

Engine mounts next, and I’ve got to sit and design the art work / pin striping for the engine cover.

Pressed in the bottom bracket and head set cups, and I’m almost ready to start assembling.

Re-engineering the forks

Headset in, fits like a glove.

In goes the handle bar stem, and on go the North Road bars, upside down of course. I think they look much better like this. Not sure yet if it’ll make the riding position too agressive, I’ll have to wait until its rideable to know for definite.

On go the forks, but…..

Looks like I’m going to have to make a custom spring hanger bracket, as there’s no way the standard one will fit, its in line with the head tube.

Fire up SolidWorks, and get that kettle on, click.

Right, lets mark out this bracket and start cutting metal.

Rough it out on the milling machine, and I’ll shape the rest on the linisher.

It’s 8mm thick, so I’ll throw a bit of heat at it, and bend on the fly press.

Holes in, before I assemble with the headset I’ve got to find 8mm from somewhere, as I’m already using the full length of the steerer tube, and there’ll be no room for this too.

I’ll turn 8mm off the bottom step of the steerer tube, and that should do the trick.

Sand blasted the bracket, re-assemble the springer forks and head set, and we’re done.

Perfect fit.

Springer Forks

Imag0085 OK, back to the bike again, and onto the front end.  Originally I intended to go for a nice old fashioned brazed lug style fork, but I was a bit concerned it’d become a bit of a bone shaker.

So, in keeping with the period look, I’ve opted instead for a set of ‘springer forks’. Hopefully that’ll soften the ride in style.

There seems to be a lot of variation here, the steerer tube length, OD, ID, and thread length being rather important.  Quite a few phone calls, emails, and a bit of umming and arring and hopefully I’m good to go.

Length: 8”, OD:1”, ID:7/8”, Thread length 3”.

Imag0087 Wheel in, and fotunately all seems to line up nicely with the front Sturmey Archer hub.  Brake arm fits nicely, might need a bit of gentle persuasion when the tyre goes on. Imag0089 Hmm, the steerer tube has got a step at the base, and the lower bearing track on the headset doesn’t fit.  Back to the machine shop.

Drive chain complete, wheels on

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Finally finished off the rear drive.  After taking apart the rear Sturmey Archer, and rapidly putting it back together before the whole thing collapsed into millions of pieces (woh, theres a lot going on in there). I split the sprocket boss and clamp into three, so you can assemble everything whilst keeping the Sturmey untouched, probably best…

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Now that’s what you call a flip flop hub.  The sprocket fits snuggly underneath the brake arm, but there’s still enough clearance for it to do its thing.
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I was a little concerned that the drive sprocket would foul the chain stay, but everything’s looking good so far.  Well this is going rather smoothly.

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Onto the front forks, the front Sturmeys in, and the wheel aligns nicely.

Well, I might as well start assembling the handle bars and stem so I can get the gear shift working.

Hang on, the new handle bar stem doesnt fit inside the front fork?  Aww, I’m sure I ordered a 22.2mm and not a 25.4mm, where’s my vernier?….

Stem’s right, seems I have a fork with a 21mm I.D.?

Kettle on, Click.

Rethinking the drive chain

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The ideas factory did its thing this morning, and a solution to the drive chain was born.

Sprkt

Quick mock up in 3D, just to check.

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Engineering drawings produced.

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On to the lathe, lets cut some metal.
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Steps done, now for the boring bit (quick joke for the engineers) - I’ll try and think of some funny ones for future posts.

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Turnings done.

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It fits, horay.

Thoughts turn to the drive chain

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My new Sturmey Archer AWC rear hub is a lot larger than the hub on the old wheel I used to align the engine.  A bit of modification is therefore required.  I might just get away with the PCD of the mounting holes if I’m lucky.

Hmmm, head scratching and a bit of chin rubbing ensues….  It’s a bit too close for my liking.  Looks like I’m going to have to fire up SolidWorks and have a little bit of a rethink.

Kettle on, ‘click’.

First lot of parts start arriving

Finally the first lot of parts start arriving.

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Cream tyres, lots of toing and froing, but settled for the 26” Schwalbe fat franks.

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North road handle bars.

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Brooks sadle, in honey of course.

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Vintage style pedals.

Making the petrol tank

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Sourced a great aluminium filler neck (beautifully modelled by my daughter).

 

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Created the tank template.

 

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“Measure twice, cut once.” Then promptly onto the TIG welding.

 

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Tank welded and starting to look the part.  Clearly not as interesting as Peppa Pig though.

 

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Filing down the welds.

 

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Mmmm, blended welds, looking pretty.

 

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Tank done.