Misc: Speedometers No Speedo

[powella]

If you need one of these VERY EXPENSIVE instruments and like an engineering challenge then read on.If not hit the delete button..The Vin uses a L433 ( or S603 ) speedometer and can be in excess of £300 to buy. Both instruments turn at 1600 revolutions per mile.
Indian made EXACT copy ( have handled one and they are well made ) and DO FIT. The copy turns at 1350 revolutions per mile and is £30 .YES JUST £ 30 GDP.
To use the copy it needs to turn faster.
To do this there are three ways 1 Send it away for the internals to be changed BUT the repairer / restorers do not like this since it involves changing a lot of gears.
2 Change the drive gear ratio in the front wheel OR
3 Change the gear ratio in the speedo drive gearbox on the front brake plate.
Consider option 3 The gear ratio as we know is 1 and a half to 1 using a 9 tooth Driver ( driven by the speedo ring on the hub ) and a 12 tooth Driven.
These are " Crossed Axis Helical Cut Gears" and can be found in the HPC Gears ,Derbyshire ,U.K. catalog using the internet.
SO someone who is good at sums can work out the Quadratic equasion 1600=1.5 and 1350= x and choose two suitable cogs using the x ratio.
From a autojumble / swapmeet obtain a Speedo Drive gearbox ( PR32 ) from any machine .With the internals knocked out, remachine the shafts , fit your new ratio gears and job is done.
The new gears need only to be Nylon ( Delrin ) since they only driving the speedometer Cable - the instrument takes very little torque .
Done one and is a mornings work BUT buying a L433 is easier!!!

 

[oexing]

Delrin is NOT nylon/PA , but POM I say. And at 30 Pounds you don´t get a chronometric Smiths copy , these are the cheap magnetic types, deeper than the real thing. Unless you can post photos or links to the copies you found. Yes, they look good but just a cheap copy .

Vic

 

[erik]

Dear Powella! For saving money I think there are better ways than driving a Vincent.For the price of a black shadow instrument you can buy a BMW K100 ! Doing this you can save a lot of money and having a reliable motorcycle with complete working instruments. Erik

 

[powella]

Thanks for your replies - at least someone is reading these post`s.
I stand corrected and am TOO OLD for a K100 !!!

 

[oexing]

Would you post a link to these Indian Chronometrics you found ? I do not believe they are chronometric but magnetic copies.

Vic

 

[Alyson]

I did sell my '83 K100 for C$1,500 so almost cheaper than a nice 5" speedo

 

[powella]

Note to Vic - would you tell the difference ( chrono or magnetic internals ) if they both worked ?
The magnetic instrument turns at 1350 revs per mile which was the whole point of the post.
Did you work out the mathematics - 23 % faster on the driven cog.?

 

[oexing]

It is not a concern to me about total original Smiths or not, just wanted to know what you meant by
"Indian made EXACT copy ( have handled one and they are well made )"
so these are not EXACT copies as they are magnetic. You can see they are deeper than the originals and the weight is less. But certainly they are great value. Talking about Chronometrics I think you can get some with stepper motor inside and the typical indication in little steps well-known from real Chronometrics. It is everybody´s choice what they want to spend their money on, I don´t care much about matching numbers, cannot , as my collection of pieces comes from unknown bikes.

Vic

 

[vibrac]

Dear Powella! For saving money I think there are better ways than driving a Vincent.For the price of a black shadow instrument you can buy a BMW K100 ! Doing this you can save a lot of money and having a reliable motorcycle with complete working instruments. Erik

I have a K100 in the garage haven't used it for 2 years speedo does not work.....

 

[Alyson]

I don't usually look at my speedo, always my eyes are on the road. Only time I did look at my speedo was on my S1000RR and that was for.... two... seconds... top speed on that bike is 300 KPH and I was clocking it. I looked back up and everything I saw two seconds earlier was now way behind me. Learned a fast lesson that day. Don't look at the speedo !!