SV650 Chassis Jig - Part 6 (Completed)

Posted by Amelia Swhizzagers On 1:36 PM 0 comments
Having added a few of the lesser important mounts onto the rear of the mock-up frame, and put some tubing in place to mount the rear shock, we pulled the frame of the jig and set it onto the engine for the first time. Here's how it looks . . .

Everything fits and clears as expected, with the frame being tucked in as narrow as possible. Sitting next to the original frame, its much more compact looking and about 30mm narrower. Cant wait to see a finished version with a nice bright powdercoat finish.

The next stage is to build it up loosely onto the remainder of the rolling chassis and think about making the subframe and swingarm.

Pimping A DH Mountainbike Frame

Posted by Amelia Swhizzagers On 1:46 PM 0 comments
Spent Saturday morning making some new pivots for a Cortina DH frame. The old ones were nasty, worn and could be simplified, so I got to work on some hollow Stainless versions.


The frame broken down into all its parts. Took the opportunity to anodise all the linkage plates whilst everything was dismantled. Can't decide on what colour to powdercoat the frame though - red bull dark blue or clean and simple white . . .

I really love the technical look of this frame with its floating shock linkages. Its a 10 year old design but still offers a really smooth ride. Now its time to test it on some downhill trails at Fort William in a couple of weekends time!

SV650 Chassis Jig - Part 5

Posted by Amelia Swhizzagers On 1:21 PM 0 comments
Some photos showing the progress on the frame over the past few weeks.


Area around the swingarm pivot. Will be adding an additional tube vertically between the two engine mounts to triangulate this area.

The start of the cross-bracing. All these joins are cut by hand and often test fitted many times before they fit correctly.

The frame beginning to take on a similar form to the CAD model.

Before we left the workshop this evening, we took the frame off the jig for the very first time. Very pleased to see how its come out, just like we had imagined it. Even did a test fit onto the engine, but we'll save the photos for the next update!

SV650 Chassis Jig - Part 4

Posted by Amelia Swhizzagers On 2:53 PM 0 comments
Time to crack on making the mock-up frame on the jig! For now, it will just be a few tubes of ERW steel tacked together, as its inevitable that things will need to be altered as the design progresses.

Headtube machined out of 3" tube, with aluminum cups either end to hold the bearing races. The finalised headtube will have pinch bolts to clamp the aluminum cups in place.

Got the old mandrel bender back in action. Having decided to use 1" 3/8 tubing, we needed to machine up some new formers to fit the tubing.

The first few bends. Trying different angle to see what fits the design best. The CAD model says one angle, but things look different on the jig in front of you!

You can see a few kinks beginning to form on the inside. Thanks to some advice by an experienced tube bender, the technique has been dialed. There's defiantly an art to this tube bending business!

This is the stage it was left at tonight. The main structural pieces are bent and positioned, so now just a case of adding the smaller diameter cross braces.