Rockfox BMW 650 Rallye Prototype

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BMW F800GS
Ok,
now we have gone completely mad. :imaposer:  This picture is the (incomplete) prototype frame for Mike's Rally bike.

The geometry etc etc are designed with enduro suspension geometry and checked with Solidworks. We opted for a semi stressed engine to reduce frame complexity with required frame rigidity.  We then built a 'concept frame' to evaluate the spring rates in real life. (Static loading only.)

Next step will be to make the changes to the design as some engine/frame clearances were too tight or non existent once the wiring harness will be plugged in.

Just a few of the design criteria.
1. Centre of Gravity as low as possible.
2. Access to plugs etc within 2 minutes if bike drowned.
3. Access to valve adjustment within 2 minutes (tappet cover removal)
4. Larger water radiator.
5. Oil cooler with extra oil capacity.  (It is a dry sump motor)
6. Air filter access within 1 minute.
7. Balanced fuel load between front and rear tanks.
8. Hydraulic clutch actuation (Still under investigation)
9. All fuel tanks and body panels from high impact flexible epoxy resin.
10. 300mm suspension travel, 350mm ground clearance,
11. Less than 145kg dry weight in full rallye kit. 65F/75R weight balance.
12. 30l fuel split in 18 rear 2x6 front.
13. Aluminium rear subframe.
14. Custom exhaust pipe and muffler.
bla.. bla .. bla.

The next build phase will be to manufacture the 'real' frame and then complete the basic running gear as a 'Plastic' so it can be tested at Dirt and Dust and Zone7 or Quarry for sand.  The rear shock angle will be adjustable during shakedown tests to test the 'linear' spring rate during compression with a standard spring.  We might need to go 'progressive' to simulate the effect of a link suspension design to achieve the 'winding up' of the suspension over the last 100mm of wheel travel.

NOTE: all the braces etc not welded in as this phase was to evaluate the suspension geometry.

Adie
Laat ons Stof maak
rockfox.co.za


 

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