Acewell Speedometer Questions

To those who have an Acewell, I am having troubles with the wheel circumferance setting. I did a wheel roll out, measured and converted to mm per the instructions so my setting is 2032 (80" * 25.4 = 2032mm). However, when I use this setting it shows that I am doing 70mph while idling in 2nd gear. I knew the kz650 was fast, but this is ridiculous. Anyways, I am trying to figure this out. I reduced the setting by a factor of 3 so now it is at 678 and that seems a bit slow. Is there some trick to the conversion that I am not getting?

Also, on a positive note, I put in resistor type plugs and the tach works great. I am using a tach setting of 1 signal = 1RPM. Prior to new resistor plugs the tach was all over the place and rarely consistent.

I would appreciate any help that you can give as I would like to use the bike to commute in the morning. I've been wanting to ride so much that I took it out at 1:00AM just to get a ride in.

KC

Kawiconvert,
Sounds like you did everything correct. I believe from past posts you are using your old Speedo gear on the front wheel with the conversion cable from Electrosport. If you’re using the reed sensor maybe it’s vibration doing the dirty deed. However if not then maybe it’s a little EMI issue from the high voltage generated by the coils. I can’t get a DVM any closer than 2 feet from my bike when it’s running or the meter goes crazy. Try shielding the cable with foil. Maybe a ferrite bead or two. Try removing the meter but leave it hooked up and see if moving it away from the bike will help. I think its EMI personally.
Good luck

I use this setting it shows that I am doing 70mph while idling in 2nd gear

Something can't be right here....

Acewell speedometers use Hall Effect sensing for the speed sensing & measurements.

en.wikipedia.org/wiki/Hall_effect_sensor

Basically what happens is this... The sensor is placed in position on the front fork for example and senses a magnet (earth magnet or magnetic rotor bolt) as it rotates around the brake rotor.

So unless you have this senor too close to the magnet/rotor and is picking up motor/frame vibrations, you should measure 0 mph regardless of the rim programmings.

An 18" rim for example equates to 457.2mm...
You may want to check your inch to conversion process or just use basic math for it and see what happens.

OMR

Acewell has speedo driven adaptors also

www.electrosport.com/street/speedometers.php

(click on the "more info" Links)

I would assume you would need to know the Speedo ratio (how many times the speedo cable turns per each wheel revolution) and then do some kind of calculation to figure it out (I'm not much help on that :dry: )

I'm surprised that the installations instructions dont have more precise directions/ calculations for setting it up.

I think he is already using the gear drven adapter from Electrosport. That is why I'm sticking to my guess of EMI issues. I do EMC testing as part of my job and I have seen all types of electronics effected by EMI RFI.

Ok, sorry for not putting in more information.

It is cable drive, no sensor. As for EMI, the plugs are resistor types and I am getting no signs of EMI in the speedos behavior. I did get some with the tach and it would bounce all over (bounce is a relative term), but the speedo is consistent and behaves like everything is fine except for the ridiculous speeds I was hitting.

I think the Fish may be right. Does anyone know what the wheel turns to speedo revolution is in the front drive? That may explain it. I'll try a 3:1 reduction and recheck as that seems close.

Try removing the cable and mark the wheel and mark a spot on the gear drive and rotate the wheel and count how many wheel revs to gear revs.

Please keep us posted on your findings for the 4000 series is what I'm looking at.... Granted, different models but interested just the same...

Thanks

OMR

I paced a guy from work on the way home and found my latest WAG is pretty close. Instead of the original value, it turns out that I am at about 700 somewhere on a 2.85:1 ratio for my bike. If I have time tomorrow I am going to take it out with the GPS (gotta find a way to attach) and compare the two.

I'll let you know. One thing I am running into is electrical interferance at low RPM's, but I think this may be related to the way the system charges and the fact that I get an odd behavior right off of low idle. According to the Acewell my bike likes 1200 RPM's as an idle. Something else I get to look at.

Ok, at 700 I compared it to the GPS and found between 40-60mph that I am off by 1mph from the gps. If I get my handheld hiking GPS working again I can get a more accurate measurement. But for now, I am using the following equation to get a new value.

(51/50)*700 = new value

So I am putting 714 back into the bike. My first roll out was 79.875" so a value of 2029. So my final adjusted ratio is 2029/714=2.841 . Not a set ratio, but it works compared to what the Acewell was putting out at first.

Also, at low speeds I had minimal error which led me to believe that it was in the value as an error there would grow with increased speeds compared to some offset that would always be off.

Lastly, use some dielectric grease when you do the connections on these. It has been raining here and that seems to effect the RPM's after a bit of time on the road.

Overall I am happy with the Acewell other than the mount that I had to bend to be able to see the screen. Their mount is for flat mounts, not the angled stock ones on the Kawi. But a little bend in the mount and it works just fine now and is easy to read day and night.

KawiConvert,
Glad to hear you got your problem ironed out. I took your advice and bought the cable from electrosport and modified it to fit the old speedo gear drive. Now if the weather here will get above 0F one of these days I can put some gas to her and try out the new speedo.

I'd love to see if yours has the same problem mine did with the rollout conversion. Still though, it does work pretty well now that I know how fast I am going.