Seven Fifty cafe-racer chassis adaptation.

Hurray! The parts for Seven Fifty  cafe-racer chassis are ready. I draw all blue prints for these parts good three weeks ago, but there was some minor delay in work of my subcontractor in machine milling, but last weekend I got all parts and that’s awesome good. Here they are:

There were several questions concerning Seven Fifty cafe-racer chassis.

The first was front wheel and brake rotors aligning.  But in fact this question could be reduced to meticulous  measuring and simple calculation. As a result you may see a lower row of parts on photo above, three collars for front wheel and two spacers for brake rotors. The only interesting  point of these parts is brake discs spacers. As they have only 5mm of thickness and 98mm of outer diameter, I ordered to cut them out from steel  on laser cutting machine. Much easier way than machine milling.

The next question was Zephyr swingarm adaptation. Zephyr 750 swing  has 20mm axle whereas Seven fifty one’s has only  15mm. Zephyr swingarm also is designed to work in flatside frame and, what is good in this case, its sleeve  is 19mm shorter  than Seven Fifty one. Seven Fifty frame is not flat in swingarm mounting points:

With  all this input data I designed solution as simple as possible: two side spacers for Zephyr swingarm with inserts into sleeve. In addition, just to make process  of swingarm axle insertion more easy,  I ordered to machine stock Seven Fifty swingarm sleeve. So here is a setup:

The upper part is  Zephyr 750 swingarm sleeve itself, the central construction is CB-750 Seven Fifty swingarm axle with adapters and lower piece  is Zephyr swing axle which I placed  only for comparison. And that’s how it works:

As you may see,  we have custom  swingarm as easy in mounting as original one without help of a third hand to hold the spacers when you push the axle into its place.

The upper row of details on the first photo of this article is a setup for adapting rear wheel and rear brakes, but let it be explained in my next post.

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