Selector drum end float

S

Stu

New member
Location
South Wales, UK
I am re-assembling an SF1 and have a bit of end float on the selector drum. Please, can anyone tell me what is an acceptable amount of end float?
 
A bit of end float is normal of course.
I can't remember what the values are but as Clem states, neither too much nor too little.

Put the forks and shaft in and then the gearbox shafts with gears. Go through the box, check a) that gears are meshing correctly, b) that there's enough space between gears to allow for thermal expansion.

Not very precise I know but you should see what I mean.

Ciao
Paul
 
The alloy expands more and quicker than the steel drum. I seem to remember up to 0.2mm from other types of motor. Paul?s advice is important.
 
End float is of course important to stop the drum binding when it's all hot on the one part but on the other part as perhaps I didn't mention clearly enough, it is a contributing factor to proper gearbox setup.
The other is that there are different shim thicknesses mentionned in the manual, not because of end float but because of gearbox setup as described in my previous post.

I learnt the hard way, the gearbox of my recently acquired and rebuilt SFC was making nasty grating noises, in neutral! All down to shimming that drum incorrectly.

Endfloat is in fact probably not very important since the drum will get bullied into place by the selector forks, but shimming it up properly is. The drums revenge on the forks!

Ciao
Paul
 
Thanks Everyone for your advice. I have about 1mm float at present. If I use some 0.2mm shim in various combinations/positions I should be able to reduce this to about 0.4mm without too much trouble (famous last words). I take Paul's advice onboard, but I suppose that the acid test is when it is up and running. The gear change was never silky smooth, and there were always a handful of false neutrals too so it can only get better.
 
Stu,
0,4mm seems fine.
Unless you see anything obviously wrong with the gearbox, you'll setup the selection itself out board of the crankcase, under the triangular cover.
Ciao
Paul
 
I know that I am getting old, but if my memory serves me roight the slector drum is a steel pressing carried by an aluminium "drum" riveted together, no countersunk screws, so the expansion of the slector composite drum and the crankcases might be similar.
CLEM

Paul M
mail me the details of Trier
svp,
mon pipe puffing amie
 
CLEMTOG said:
I know that I am getting old, but if my memory serves me roight the slector drum is a steel pressing carried by an aluminium "drum" riveted together, no countersunk screws, so the expansion of the slector composite drum and the crankcases might be similar.
CLEM

Paul M
mail me the details of Trier
svp,
mon pipe puffing amie
Click to expand...

Ok Clem, will do.
Have given up the pipe. Non smoker nowdays!
Paul
 
yes Paul I am aware that you have given up smoking and cut your hair
but you will always be a pipe puffer and any minute, I expect tyo see you on a fully faired air cooled BMW
me/
well my hair is long, but I havent tried fags since the 30 June 1973, too tight, thats my main reason, oh yes and I was in hospital trying ny best to die (unconsous for seven days) and when I came to, I asked for a smoke and it made me puke instantly, and then,I realy thought, that right now I will die, so I stopped, never done it since.
CLEM
 
CLEMTOG said:
yes Paul I am aware that you have given up smoking and cut your hair
but you will always be a pipe puffer and any minute, I expect tyo see you on a fully faired air cooled BMW
me/
well my hair is long, but I havent tried fags since the 30 June 1973, too tight, thats my main reason, oh yes and I was in hospital trying ny best to die (unconsous for seven days) and when I came to, I asked for a smoke and it made me puke instantly, and then,I realy thought, that right now I will die, so I stopped, never done it since.
CLEM
Click to expand...

Clem
The last time I wanted a reasonable bike, BMW (?), I bought a Gilera.
That was over 20 years ago now.
Time flies and the Gilera has become a collectors.
Paul
 
Paul Marx said:
Stu,
0,4mm seems fine.
Unless you see anything obviously wrong with the gearbox, you'll setup the selection itself out board of the crankcase, under the triangular cover.
Ciao
Paul
Click to expand...

Thanks for that Paul. I'll let you know how I get on. I'm away until mid June and I'll get stuck in when I get back. No rush but the bike is 40 next year, so I have a date to aim for.
 
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