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[simon]

http://www.flickr.com/photos/77012441@N08/6906713210/
http://www.flickr.com/photos/77012441@N08/6906707498/

Two pics to show my solution to the perennial gearbox cover flex issue.

Interestingly I discovered that the cover will actually interfere with the change down and required additional washers to push it out further than it naturally wanted to sit in order that the "stiffening rib" (inverted commas intended)on the inside of the cover didn't interfere with the mechanism. The flex has been reduced from around .080" to .005".

If anyone is interested I'm happy to proved measurements.

S.

[PeteF]

A rather more elegant version of my version, and it looks like it brings the extra fastening closer to the centre of the cover.
I've not measured mine accurately but it definitely reduces flex and has improved the gearchange.


http://www.whfolk.co.uk/REOCHUMBER/Articles/flex.htm

[simon]

Yes no question it was inspired by your posting which I read a while ago. The advantage of having a lathe and a four jaw chuck is that you can make things out of more substantial chunks of steel. What I did find interesting is that the gearbox on first reassembly wouldn't change to second and after a lot of head scratching i worked out that the case was actually impeding the gear change arm. I had to put extra washers behind the cover to actually push it out and then it started to work properly. I didn't finish until late so I haven't given it a test run of any length but I'm looking forward to having a clutch that clears!

[simon]

BTW The additional fastening is via the mounting bolt for the neutral finder stop so there are no additional holes in the cover although I did drill out the thread in the cover so it would pull up tight.

[another Allan]

Not really a solution to gearbox outer case flex, but I improved the lift of my clutch by changing the clutch lever. I bought one from a breaker (might have been from an early Honda) which did not have the 'dog leg' of the original Minda lever. The clutch lift was increased by about 5mm because there was no 'dog leg' to hit the grip before the clutch was fully lifted. Might be a bit awkward for someone with dainty digits, though!

[Midge]

Following many questions about clutch problems you will now find new pages in the Technical Notes relating to this. See also the news section

[simon]

Enormous improvement in the clutch with no dragging when stationary and in gear which was a problem before whatever the adjustment. No false change to second which was another major issue before with the bike jumping out of gear on the take off which can be embarrassing if you've pushed to the front of the queue!
I don't know how many of these ultra thin covers were made but I believe that most of the early 90's era were blighted with them but this is a cheap and low intervention repair that leaves no visible trace on the outside of the machine.

[PeteF]

Interesting article midge but it doesn't address the case flexing problem (not even to mention the special "no flex" cover available as a special part)

[another Allan]

Hi Simon. Is there any possibility that you could make another of your support blocks, for a suitable remuneration?
Allan.

[simon]

I don't see why not. It's a bit of lathe practice. I don't want to tread on Mr H's toes so I'll whip you up one for gratis but I reckon they should be a stock item as it would be two minutes for the skillful engineers at our hosts establishment. Let me know your address and ill send one over.