Its been interesting to see the highly varied results people have reported using these motors from boisrondevens highly unlikely claim of 0 to 60 in under 2.5 seconds to very far from it with poor hall placement and even after adjustment, overheating even at low power levels. A few years ago when the Rv120 first came out i got one to try in a bike to race in 125cc category with flattrack gassers and within reasonable budget and tested it just for torque output to work out the gearing for 200-250Nm to the wheel, it came out pretty well -a little better than the BHT and is also lighter.
It never got to compete though as it got above 220deg c pretty quickly in use and would not really accelerate any better than a cro motored version of the bike, even when geared low for about 65kph. By then it seemed like i had maby cooked the magnets although i dont think the KV went up much so i dont really know why its performance dropped from what was initially a very reasonable test result for the money.
The results of this basic test are below with a BHT '1000w' motor for comparison, its a simple locked rotor torque/saturation test like Justin has done a while back and is likely the best way to measure the ability of a motor to produce torque and tells you the 'cost' of producing it in Watts from the battery, 1kw to 1.5kw is around the level of waste heat motors of this size run open are capable of shedding short term or sustain with a bit of fan cooling so the Revolt was capable of 26.2 and 30.1Nm respectively, but remember the test was done before running it on a bike. :wink:
Curious if they have changed to better magnets and thinner laminations than this early (.5mm lam) Rv120 that was before the pro's came out, the guys who made them were good to deal with and were prepared to make improvements to hall positioning and phase wires etc and now with the newer Rv160pro long im thinking i might offer to buy one, test it on a dyno and IF (at 9kg) it can come close the output power of the Joby jm1 (at 2.7kg) then ill keep it and merrily race it alongside the Joby bike and hopefully find that 6 kg's extra is not really a problem, however if not then ill post it back and ask for a refund. TBH even 15kw measured output for 30 seconds would be enough, and i think it could likely be capable if they have made progress since the early stuff and it then to me becomes a perfectly viable and cheaper motor option.
The same requirement/test for a 120 pro (at say around the 7.5kw output level?) could also be offered and to me seems like the only way to clearly show where the truth actually sits, it would require many hours of work to set up and multiple efforts to get the best result possible with tuning and various controllers etc but im more than happy to put the time in because i want to know.
Ive had a few pm's back and forth with most of you guys on this thread on this type of subject over the years so you probably know that im plenty keen for measured truth and have a fairly low tolerance for bullshit, so sure when people are laying it on a bit thick online with claimed power levels etc, the facts are often not what people want to hear, but for this job its the sole requirement.
So what do folks reckon? Once we settle on a fair and reasonable expected output figure (and max temperature
) on any motor that we are interested in, instead of 10, 20 or more of us buying a motor and pissing about without any quantifiable result, we put the offer to the manufacturer/seller that we want to buy a motor and if it makes the grade then were all good and i send it to whoever wanted it and paid for it, and if it doesn,t then it goes back and you get refunded. Upon purchase a manufacturer who says NO to the option of refund for a motor that does not meet their own spec saves us the trouble and reveals their true confidence level, ones that prove their metal will build buyer confidence and sell more as a result.
Im half keen to go first on this with the rv160, as i have a use for it, but either way i think this stuff clearly works better when done publicly, and im a big fan of getting the power (in both forms) back to the people :wink: and moving forward on good EV gear whilst reducing the stockpile of useless stuff that we often blow our hard earnt money on, i reckon paypal would be our friend here and a simple written agreement before purchase. its a game we can all play a part in and get a benefit from so any thoughts and ideas on this general idea are welcome, if there's enough interest here ill start a new thread on the EV dyno etc and maby offer to test any motors people want to send for free initially and the results go up on ES. SplinterOz and myself are planning on using this closed loop dyno control and software;
http://dtec.net.auInertia%20&%20Brake%20Dyno%20(Dynamometer)%20Software%20-%20Kart,%20RC,%20Bike%20&%20Car-%20Engine%20&%20Chassis.htm (main screenshot pasted below) -but tweaked for dedicated EV use with extra inputs for phase current and battery Amps/Volts to display efficiency and saturation. - So do folks want to help make this happen? Do you think we can create enough interest to keep the manufacturers honest? and is the Rv120/160 offer reasonable?
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