Strange Question !

[slice]

Ok boys and girl's here is an odd one for you to think about, I had to change the original speedo on the bike for a recon one, fitted straight in no probs and all seemed well till the other day when I noticed on my way to the MOT that the speedo was stuck or not working, long story short I have just discovered that dumb arse here has only fitted the thing with the needle on the wrong side of the stop post !! I mean FFS.

Anyway I have run the bike for about 60 odd miles with it like this and want to know if I have damaged it before I put it all back together, or better yet how do you test it on the bike BEFORE you put all the fiddly screws and whatnot back on? Seems an easy problem but can just turning the font wheel by hand give any indication that the thing is actually working let alone correct.

Any comments solutions appreciated even ones about people who are to stupid to check that the needle goes round DOH !

[jimmy]

Try connecting the speedo cable to a drill and give it a wee turn. That should confirm if you have stripped the internal drive mechanism or not

[slice]

Ah never thought of that I am without doubt starting to lose the plot.

[jimmy]

Sometimes we all get task focussed mate, and it takes another to see the obvious

[NE0]

You won't have caused any damage,...

The drive cable turns a mechanism inside the speedo, which in turn creates a magnetic field,

The needle part is attached to a coil (like a clock spring and as thin as one) which responds to the changes in the field, whilst the needle will be up against the stop, it won't be being wound up by the mechanical parts! it will survive.

[jimmy]

Well Done NEO

I never knew that, I always assumed it was some form of worm drive.......Everyday a school day and all that

[NE0]

Had them apart jimmy in the past,

My first one was a 1961 lambretta unbelievable how it worked as there was hardly any parts inside!

surprised it worked at all just a coil, needle and one magnet, Talk about simplicity!

However, you're not wrong in your assumption as the odometer is a worm drive which turns the number cogs over and that is driven by the cable and a gear or two.

------------------------------------------------------------------------------------------------------------

And before anyone says about putting a drill on the end to wind the clock on, its an old wives tale!

At best you could make the speedo go up to 40 mph! if you're lucky!

which also means it will take one hour to advance the odometer 40 miles, ie 40 miles in one hour!

Even if you could make it do 100mph it will still only advance the clock by 100 miles after an hour!

You can't 'clock it' with a drill, it will take years!, the only thing you can do is take the number cogs out and reset them back into 0000 line!

[slice]

Ok lads all fixed, Jimmy your a star mate, Neo your info is spot on tried the drill and managed 42 MPH at 1800 RPM so think I would die of old age before I got to 000000 !