Tuesday, December 21, 2010

Tim's Triumph bobber build.

Tim has asked us to build him a Triumph pre-unit bobber.
With a vision in mind and some parts at hand Tim is excited and we are ready to get the show on the road.

Above is the front loop of a pre-duplex swingarm frame that will be the base of this project. We have removed the swingarm, knocked out the steering races and checked the frame's condition. Tim wants a conical front end (71-72) so there will be some modifying involved here to start with.

Rear hub built up from spares, blasted and painted 2 pack black with some Von Daz pin stripes. 16" rim re-chromed and ready to be laced up to hub. New bearings and shoes also fit.
The front wheel is of the conical type. We stripped down the hub and brake plate to prepare for Hydro-tech cleaning. As done for the rear, new bearings and shoes were fitted. Front rim chromed and ready for lacing.

We are fitting a 1971-72 front end to a pre-unit frame so we have made up spacers and sleeves to fit tapered roller bearings. This is not an easy task as the later stem has a smaller OD compared to the early.

Top and bottom races now press fit into the headset. The 71-72 trees had to be modified because of clearance issues and we also made our own top and bottom dust covers.
Front end mocked up and everything is working well.

The wheels are complete and ready to fit. Front wheel is 19", rear 16" and both laced with SS spokes. Avons front and rear.

The bike is now a 'roller' and it's slowly coming to life. Rigid section is TFMW and it's excellent. Saddle is genuine aged Bates that Tim found. The tank is a late 60's Triumph slimline. We are pleased with the ride height and the lines look good. We will continue to mock trial everything and weld tabs etc as we go.

Strong and not to mention great looking welds by The Factory Metal Works.

Stay tuned, we're going all the way into the new year with this one!

Back to work and we have mounted a genuine Bates headlamp along with some very cool alloy brackets. Also, 7/8" alloy risers satin polished and modified to fit.

Engine and gearbox mounted using stock Triumph brackets. We now begin the alignment of the engine sprocket to gearbox and rear drum sprocket.
Once this is done we will double check the overall alignment of the frame to wheels and running gear.

We are preparing a set of drag pipes for Tim but while we're waiting i couldn't help but try these high pipes we stock from TFMW. I think they look awesome and those bends are real trick.

Petrol tank hard mounted, SS brackets up front and we modified then welded slugs with threads to take a custom rear bracket.

Keeping things raw as possible, we fabricated this SS bracket to suit the old Bates saddle.
We also fabricated our own rear saddle to frame mounts.

Frank fires up the TIG and proceeds to marry those saddle lugs to the frame.


We removed the standard flimsy lugs off the oil tank, fabricated our own and re-positioned them for a better fit. The frame lugs for the oil tank are spaced enough for rubber buffers. We also fabricated a bottom support bracket for the oil Tank.

Oil tank and saddle now in place we move further towards the rear.
Tim has asked for a ribbed fender so we have chopped and modified it for good tyre exposure.
It will be mounted with one bracket and a sissy bar.

Good news, the high pipes are staying!..
Still to come, rear brake lever, tailight, exhaust mounts and much more!

Tim has picked a nice old Dodge stop lamp and asked to have it side mount. We fabricated these brackets and fit them to the frame.


We positioned the headers and 'molded' them into position using heat. We then fabricated this neat little bracket and welded it to the rear frame. These headers now run a 0.5mm gap between them from start to end!

Rear brake lever fitment on pre-unit Triumph hardtails can be done a number of ways. We fabricated a small but strong bracket to support the lever and also the stop light switch.
Both lever and switch are adjustable.


Primary cover and left peg all play a major role in setting up the rear brake system on modified pre-unit frames.

With all the major components aligned and brackets welded we are now ready to strip down the motorcycle to a bare frame for painting. The guard and fuel tank will also be painted. The colour Tim has chosen is that of an old 1971 Arthur Fulmer helmet with an unusual green metal flake paint job.


To get this colour match was quite some work. There are five colours and tints over a black base. Six coats of clear with flake built up until the final two heavies. Photos don't do justice to paint jobs such as this!
The next move was to highlight the new paint with some pin stripes. We asked Neo Dutch to get those creative juices flowing and make it happen...

...and happen it did. Neo came up with this all out design, kinda reminds me of a Tiki tattoo. 

We also designed and fabricated some nice stainless steel parts to set the Trumpy off. Highly polished rear guard stay with dummy coils, hand made dice on the kickstand, twisted brake rod and some turned brass parts just to name a few.

 Header pipes ceramic coated satin black with a stainless heatshield we designed and made to fit on top of some heat wrap. It actually works very well and should stop Tims leg frying.

We made sure everything was right before the bike was handed over to Tim. He is happy with the end result and we are too. This Triumph is awesome to ride and everthing works the way it should. Many hours spent designing, fabricating, aligning and fine tuning this one of a kind machine. And it's all worth the effort!

Period parts make builds like this stand out in a sea of clones.

 Oil pressure gauge, every Triumph should have one. 

Big thanks to Frank for Tig and Fab work, Neil wiring and teething, Nick for parts, Neo Dutch pin stripes, Lucas at TFMW, Gabby for matching the color and losing his sanity and Tim for letting us build this bike for him!



Anonymous said...

Great work, Tim must be over the moon.

Hairy Larry said...

Was just searching the web looking for a pic of a swingarm frame...and wandered in here. I'm currently going the other direction, making a swingarm bike out of an old '57 chopper. Having to build a frame from two, to restore the swingarm pivot that was chopped off. Looks like you have saved that mount and incorporated it into the build. Thumbs up, in case you ever want to go back it'll be a lot easier. I might build a chop someday with all my left overs. Carry on.

Anonymous said...

Nice stance, can't wait to see it finished

smith623 said...

what is the stretch and drop on the rear section

Anonymous said...

They have the hardtails on there Trojan website, stretch 4" drop 2.5"

Anonymous said...

i luv it!!!!!!