Electronic speedometer?

[TurnNBurn]

I'm about done purchasing and building my electric motorcycle, but I have done absolutely no work on the gauges and thus I have a quick question. Does anyone know of any digital/electronic speedometers that are affordable? More specifically, I'm looking for something like a sensor I can attach to the wheel (rfid or infrared?) that will count the rotations of the wheel and output on a display how fast I'm going. Is there anything like this or anything else you guys would recommend?

 

[dogman dan]

A cycleanalyst is what you want for sure. The stand alone model will work off the wheel magnet, or you might be able to just plug it into your controller depending on the model you are using.

You will of course, get lots of other vital functions from it. Grin cyclery is the place. http://www.ebikes.ca/drainbrain.shtml

 

[cal3thousand]

I'm about done purchasing and building my electric motorcycle, but I have done absolutely no work on the gauges and thus I have a quick question. Does anyone know of any digital/electronic speedometers that are affordable? More specifically, I'm looking for something like a sensor I can attach to the wheel (rfid or infrared?) that will count the rotations of the wheel and output on a display how fast I'm going. Is there anything like this or anything else you guys would recommend?

Plenty of bike speedometers out there, how affordable are we talking?

Best thing IMO, is a cycle analyst. You will be able to measure all types of things including your speed and speed related averages.

 

[dogman dan]

You won't regret the cost of a CA. But yeah, a regular bike computer might work ok if you aren't going too fast. I know for sure they work to 50 mph, the fastest I ever went on an ebike.

There are very cheap wattmeters out there, but the CA is the best for over 100v. You could use a 20 buck wattmeter to monitor just half of your pack, to keep it below the 60v upper limit of those ones.

 

[TurnNBurn]

The cycle analyst looks cool, but it's way more than I need. I just wanted a simple speed guage. Possibly in the future I'll upgrade to that or something similar, but for now I'm just looking for a speedometer until I get things up and running.

 

[friendly1uk]

Most $10 units are wireless now. Sensor at the wheel and speedo on the handlebars. I prefer a wire myself as it is just another set of batteries going wireless, and while it might save 12" of wire, the housing gets bigger to hold the battery so there is no gain that I see. Just complications.

You certainly don't want a cycle analyst. It's a totally different bit of kit. It may offer speed, but that is a small part of it's actual job.

You will actually struggle to get something as simple as you need. It will no doubt be a trip computer not just a speedo, but there in my walmart from $10 upwards. Ebay is littered with them.

 

[dogman dan]

Since you said you had done no work on the gauges, I assumed you needed a voltmeter and a wattmeter too. That makes a CA a no brainer choice. I held out for several years on getting one, and once I did, I realized what a dope I'd been. Now I have two, and wish for a third.

You can use a bike computer to 50 mph for sure. Don't get wireless, the motor emf interferes with them. You can get very inexpensive voltmeters on ebay. Look for the two wire type, that runs on your pack voltage. I have some of that stuff, and I'll tell you, I have to stop to read any of it except bike speedo's. But the CA I can read on the fly even on the worst dirt roads.

The CA is what you want, even if you don't think so right now.

 

[rscamp]

...The CA is what you want, even if you don't think so right now.

...and a CA is what you need, even if you don't know so right now. Unless of course you already have other instrumentation that provides a fuel gauge and measures speed, battery capacity consumed, energy consumed, current, electrical power, fuel economy, etc.

 

[TurnNBurn]

The cycle analyst is definitely on the future purchases list, but I can't justify it right now. I just blew $500 on the Alltrax 7245, $680 on the mars ME0913 motor, and I don't have more to blow on a $250 cycle analyst. The next priority is the batteries (going with optimas to start and then upgrading to some thundersky. $3000 on those) So just to start I wanted a speedometer while I take the motorcycle safety courses and get a motorcycle license. Once I get up and running I'll upgrade to the CA. To start, though, the bike is going to be used to get to and from work (half a mile) and quick trips around base (Air Force base.) Maybe down the road a mile or two off base.

 

[dogman dan]

True enough, tracking your range does seem low priority at the moment. That's what I didn't know.

FWIW, less than 20 bucks gets you a wattmeter that goes to 60v, so you can use one of those, and just monitor a portion of the pack, and figure the rest of it is discharging pretty similarly.

I can also safely say with great confidence, once you have it running you will want to ride it as far as your battery will allow.