November 24, 201312 yr Hi all again How do I find out the code for Bafang motor? I have a Bafang CST with the following on the side CST 36V250W 26 1305 0948 Does it help to find out the how fast does it spin? Thanks Pat
November 24, 201312 yr I have no idea but I wonder if the 26 in the first line is a 26" wheel ? Probably a wild guess and I am sure those who do know will chip in shortly. Jerry Edited November 24, 201312 yr by jerrysimon
November 24, 201312 yr There should be a number in brackets after the 26if it's a BPM but they only do one version of the CST. The CST is about 19 mph st 36v for the 250w and 350w versions. The 500w is 270 rpm, so about 24 mph no-load or 22mph on the road. All of them respond well to the high position of the 3-speed switch on the KU series controllers, so you can get at least 10% extra.
November 24, 201312 yr Author There should be a number in brackets after the 26if it's a BPM but they only do one version of the CST. The CST is about 19 mph st 36v for the 250w and 350w versions. The 500w is 270 rpm, so about 24 mph no-load or 22mph on the road. All of them respond well to the high position of the 3-speed switch on the KU series controllers, so you can get at least 10% extra. Thanks Dave, I will be using it for 29er probably to get a bit speed gain for bigger wheel. Do you think this motor has enough gut to put it on bigger wheel? considering this motor is for 26 or I will need to solder the shunt to give me a more grunt? Thanks Pat
November 24, 201312 yr It would make more sense to get the 500w version, which is the same size and weight, then you definitely have enough power. If you already have 250w version, which I think is the same as the 350w on, it doesn't repond well to a lot of current. 22 amps is the sweet spot.
November 24, 201312 yr Author It would make more sense to get the 500w version, which is the same size and weight, then you definitely have enough power. If you already have 250w version, which I think is the same as the 350w on, it doesn't repond well to a lot of current. 22 amps is the sweet spot. Thanks. I will be not going very fast on this motor possibly around 18mph. Would that be ok? I have a 36v lifepo4 which can do 2C Pat
November 25, 201312 yr With 29" wheels, it'll do about 21 mph. Ideally, you want a controller that can give at least 20 amps. Which one do you plan to use?
November 25, 201312 yr Author I have a ku65 and S06S to choose I think the max amp output is 15 but if I can solder the shut hopefully can give 18 for the motor. Do you think that will be ok? Pat
November 25, 201312 yr It should be OK. Give it a go, and let us know the results. I'd try the KU65 first because the larger S series controllers are rated lower than the KU series.
November 25, 201312 yr Hi all again How do I find out the code for Bafang motor? I have a Bafang CST with the following on the side CST 36V250W 26 1305 0948 Does it help to find out the how fast does it spin? Thanks Pat I think you have the standard CST 36V250W - 205 RPM, manufactured in May 2013
November 25, 201312 yr Hi If you use a 48 volt battery and controller the motor will be 350 watts and spin 25% faster Hope that helps Frank
November 25, 201312 yr Author I think you have the standard CST 36V250W - 205 RPM, manufactured in May 2013 Wow. How do you know that? Pat
November 25, 201312 yr Hi So your 205 rpm motor is 205 div by 40 v 5.125 rpm per volt so 52 v x 5.125 = 266 rpm All motors Give RPM per volt ( Rev per min ) so a 36 volt battery runs at aprox 40 volts so 432 rpm a 48 volt battery is aprox 52 volts so same motor 561 rpm This dont take into acount the extra Grunt Link below great for infomation note the 10. 8 rpm per V The Grin Cyclery http://ebikes.ca/store/photos/MOutrider_Fst.jpg Hope this helps Frank Edited November 25, 201312 yr by banbury frank
November 25, 201312 yr I think You've got the right idea Frank, but I can't quite understand your calculation. To clarify: 201 rpm =15 mph for a 26" wheel. A 36v motor actually spend lot of time around 40v from the battery, so the actual speed on the road is given by: Speed = (motor rpm/201) x (actual voltage/nominal voltage) x (wheel size/26) x 15 mph = 205/201 x 40/36 x 29/26 x 15 mph = 19mph I know the 350w one is about 230 rpm. I thought the 250w is the same. Where did you get that speed from, Trex?
November 25, 201312 yr Where did you get that speed from, Trex? I googled 'CST 36V250W 26' then: Bafang 36V 250W CST Click on the dropdown 'Voltage Motor Code RPM' - select the CST 36V250W26 then read the specs. Just to avoid single-sourcing info, I repeat the same with 3 more links. They all say 205RPM.
November 25, 201312 yr Hi sorry to confuse i was refering to the motor in the link below 10.8 rpm per volt Frank
November 26, 201312 yr Author Hi Pat dont understand ERD Frank Hi Frank It is Effective rim Diameter. I need this information to calculate the spoke length. Thanks Pat
November 26, 201312 yr TN 317: ETRTO: 622 x 17 ERD: 600 http://www.tech-mavic.com/tech-mavic/technical_manual/data/docs/themes/2_16.pdf
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