PR: Proprietary Items Acewell speedometers

[vibrac]

Does anyone have any experience of Acewell speedometers? this was set up a year ago on my Egli Comet when I rebuilt it. I have not had a good speedometer reading it seems mostly to just show 1 or 2 MPH and I know I am not that slow! I have checked the pickup and the magnets and the distances between which are correct) and when I started to run the engine in around the local roads I kept trying to find a cause but then I just gave up. I have just got round to checking everything out as the bike has sat in my garage for a year and I am thinking of selling it at auction and 18 miles is hardly an accurate measure to quote! Putting it on the lift I noticed that the lead from the sensor is long (I suppose for rear wheel applications) and I had coiled it round behind the headlamp in a lazy 7" or 8* diameter coil (aprox two turns) would that have caused my problem? all the other applicable functions, winkers etc work OK and I have the same type of unit on my trail bike and that works OK

 

[Pete Appleton]

Some pickups are sensitive to the orientation of the magnetic field. Can you try flipping it over?

 

[vibrac]

so rotate it 90 or 180deg in its mounting will try both

 

[Pete Appleton]

Sorry Tim. I might not have been clear. You need to swap North pole and South pole.

 

[vibrac]

No its me being thick
the magnet is a small coin size item about 3/16-1/4" diameter you can see it mounted in an alloy arm on the edge rib of an akron rim in the above pic. I guess its poles are arranged like this (I course I have no idea which way round)

So does this disc need to be reversed?

 

[John Appleton]

No its me being thick
the magnet is a small coin size item about 3/16-1/4" diameter you can see it mounted in an alloy arm on the edge rib of an akron rim in the above pic. I guess its poles are arranged like this (I course I have no idea which way round)
View attachment 36793 So does this disc need to be reversed?

Tim, this is Pete's busy time of day so I will jump in and steal his thunder. Yes, the coin sized disc needs to be reversed, at least, it did on my one. John.

 

[BigEd]

No its me being thick
the magnet is a small coin size item about 3/16-1/4" diameter you can see it mounted in an alloy arm on the edge rib of an akron rim in the above pic. I guess its poles are arranged like this (I course I have no idea which way round)
View attachment 36793 So does this disc need to be reversed?

I don't have any actual experience of the Acewell units but when using a Boyer unit as a basis for a home made custom race bike installation, changing the magnet North/South orientation gave some "unexpected" results. In this instance pole orientation could be the problem, it depends on the circuitary in the unit. Looking at your photograph it is possible that your magnet is on the wrong path as it crosses the sensor.
Acewell give this advice:

 

[vibrac]

Yes Eddie I have seen that diagram I understand what it shows except that the sensor is shown as an oblong presented to the magnet path. But the sensor in my case is a single circular point about 1/8" across

 

[oexing]

Looks like an ordinary proximity switch, not necessarily dependend on magnets but on metal in correct distance from it to trigger it. Three wires on it ?

Vic
Proximity sensor

 

[Pete Appleton]

You can get, and we have got, both types. Simple Hall effect needs a magnet, the right way up.

Balanced Hall has its own internal magnet and a pair of sensors, all in one tube. That only needs something ferrous. Both types have three leads.

Here they are, although described incorrectly https://www.demon-tweeks.com/uk/aim-motorsport-wheel-speed-sensor-pick-up-magnetic-or-hall-effect

Just flip the flipping thing and see if it works