Speedometer mods?

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zarlor
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Speedometer mods?

So, I've got an XM-3500Li on order (probably the end of September shipment, but we'll have to see) and I think we're all pretty well aware of the speedo (and odometer as well) issues with pretty much all of the scoot models. So I've been thinking that maybe I should start a thread on mods so we can bang out heads together to find ways to get these closer to real world numbers.

For example, I think some folks here have mentioned putting some of the readily available bicycle speed/odos on their scoots. Any tips on installation and how those are working out? Do they seems to be getting closer to the real world values when compared to GPS or Radar gun speeds?

How about being able to open up the casing and gluing in a printout of a better calibrated readout over the one that's in there? Is that even possible?

Is there a tire size that would fix the issue (like I've read about being done on the XM2000s) and what would the problems be with changing out one of the tires(and presumably having to deal with different sizes), or would it be better or even possible to put the same size tires on both wheels?

Or is there a way to modify the current speedo/odo to better calibrate it?

Of course if folks could provide pics of their mods (and installation pics, too!) I think that would be a lot of help. So if folks have some more ideas or actual mods they be willing to share, please do let us know!

reikiman
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Re: Speedometer mods?

Good idea to use bicycle speedometers.... though perhaps there's a way to "fix" the speedometer to be accurate in the first place. For example the Xebra has a similar problem (inaccurate speedometer) and those people have developed ways to fix the inaccuracy.

Anyway .. about bicycle speedometers. I'm really fond of the Cycle Analyst for my bicycle. It includes a speedometer in addition to excellent voltage/current tracking. I've gotten a couple to attach to my motorcycle projects and ran into a problem with mounting on a motorcycle. The speedometer part has a magnet that you attach to a spoke on a bicycle wheel, and then you attach a sensor to the fork. The setup is highly centric to bicycles and with the motorcycles/scooters in my possession they won't work. For example when the fork has front suspension it's difficult to attach the sensor to the correct place on the fork because the suspension is going to travel through the same place the sensor mounts.

zarlor
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Re: Speedometer mods?

It looks like the R. Martin EVD-3000 (same body design at the XM-3500li) has a replacement dash, supposedly with a mor accurate speedo even, as can be seen here: http://visforvoltage.org/forum/4841-evd-3000w-wlithium-batteries#comment-29423.

I wonder if there is someplace to get that dash. Anyone know?

Lenny Zimmermann
Metairie, LA

richardb
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Re: Speedometer mods?

For anyone who wants to try using a bicycle speedometer, I installed one on my XB-500, and am very pleased with the results, and the accuracy is great. I wrote up my instructions on my own website. You are welcome to check it out at:
http://www.bergerweb.net/xb500

Installing a bike speedometer is so simple you don't really need any instructions other than the ones that come with the speedo, but my method of calibrating the thing is more accurate than most, and is a lot more accurate than a GPS reading.
Dick B.

Dickey_b
Waste Not, Want Not

PJD
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Re: Speedometer mods?

Conventional mechanical speedometers work by having the speedometer cable spin an aluminum cup that surrounds a magnet - the magnet is connected to the needle of the speedo which has a watch-spring (spiral-type spring) attached to it. Due to eddy current induction, the spinning cup causes a twisting force on the magnet and spring-loaded needle proportional to the RPM's of the cable (and therefore the wheel). So the speedo can be calibrated by bending the tab the watch spring is attached to (offset adjustment), or shortening or lengthening the spring where it is anchored to the tab (gain adjustment). It is delicate work. I knew a guy who earned a living doing this in his basement - auto mechanics sent him speedo's from all over the country to get fixed, calibrated and adjusted. This will only fix the speed reading, not the odometer reading.

If both the speed and odometer readings are off, the gears that drive the cable at the wheel hub need to be changed - there are different gear sets for different wheel/tire sizes - but they are probably impossible to find for a Chinese scooter. Finally you can change the tire size - a bigger diameter tire will make the speedo read slower. I put bigger tires on my e-max for other reasons, but an added benefit is that the speedo and odometer now read correctly.

founder
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Re: Speedometer mods?

I put bigger tires on my e-max for other reasons, but an added benefit is that the speedo and odometer now read correctly.

Same here. I put Urban Master Snow winter tires on my E-Max S. The odometer is now within 1% precise.

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