The hub on our Mistral has broken (it is not the pawls) so that the pedals will no longer turn the hub. As the 36 volt battery, controller, etc are all in good order, and I happen to have a 250 watt Suzhou Bafang 24 volt motor to hand would it be safe to fit that in place of the existing 36 volt motor? In other words would the 24 volt motor be able to handle a fifty per cent increase in voltage?
Can I safely fit and run 24 volt motor on a 36 volt system
- Thread starter rooel
- Start date
Thanks Scottyf,
I did a few years ago over-volt a Dahon motor (the Roo EL) by about 25 % when I changed the battery cells from NiCad to Lithium Polymer, and there was no evidence of melt-down. I just hope that a 50% increase in voltage will not turn the 24 volt motor into an electric fire.
I did a few years ago over-volt a Dahon motor (the Roo EL) by about 25 % when I changed the battery cells from NiCad to Lithium Polymer, and there was no evidence of melt-down. I just hope that a 50% increase in voltage will not turn the 24 volt motor into an electric fire.
Unfortunately I have just discovered that my original request for advice is redundant as the spare motor is for front wheel only. Looks like I may soon be offering a bargain used Mistral on ebay or somewhere with a good re-celled battery, front wheel hub dynamo, B and M lights, Marathon Plus tyres etc, and still able to be driven via the throttle, albeit at no more than 10 mph or thereabouts.
Unfortunately I cannot post photos of the hub fault as it lies inside the casing. I thought at first that the pawls in the block were broken, but a bicycle repair man said they were OK, and that the fault lay hidden inside. When the pedals are turned the chain turns the cogs but the force is not transmitted through the hub which suggests perhaps a split somewhere in the middle. When electricity is applied via the throttle the motor does activate and does turn the wheel. Presumably if the electricity is applied via the pedelec the same thing happens but I cannot confirm this as the wheel has now been removed.
This fault doesn't make sense on your rear motor Synergie Mistral Rooel.
The most likely thing, despite what you've been told, is that the multi-sprocket freewheel mounted on the side of the hub-motor has failed, and that is easily replaceable.
Alternatively, the freewheel mounting threads have completely stripped which is highly unlikely, or the threaded boss on the motor side plate has snapped off or is spinning inside the alloy side plate, again highly unlikely.
No fault inside the hub motor can produce the symptoms you describe, not even a snapped spindle. If the sprockets of the freewheel seem laterally secure in relation to the motor hubshell, it's highly likely to be a failed freewheel.
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The most likely thing, despite what you've been told, is that the multi-sprocket freewheel mounted on the side of the hub-motor has failed, and that is easily replaceable.
Alternatively, the freewheel mounting threads have completely stripped which is highly unlikely, or the threaded boss on the motor side plate has snapped off or is spinning inside the alloy side plate, again highly unlikely.
No fault inside the hub motor can produce the symptoms you describe, not even a snapped spindle. If the sprockets of the freewheel seem laterally secure in relation to the motor hubshell, it's highly likely to be a failed freewheel.
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Thank you flecc. We took a new replacement freewheel to the bike shop expecting to have it fitted but the repairman who is very experienced with mechanically driven bikes said that the fault lay in the hub and only the manufacturer could deal with it.
However I have checked the wheel again and find that the freewheel can be spun easily in either direction, and is transmitting no force to the axle. The new replacement freewheel can of course be pushed round only in one direction.
Back to the bike shop I think. It is only a case of unscrewing the old freewheel and screwing on the new one.
However I have checked the wheel again and find that the freewheel can be spun easily in either direction, and is transmitting no force to the axle. The new replacement freewheel can of course be pushed round only in one direction.
Back to the bike shop I think. It is only a case of unscrewing the old freewheel and screwing on the new one.
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Here's a photo below (click on it) of a typical hub wall and the arrowed threaded boss mounted on it Rooel. You can see that if the freewheel pawls are engaging, when the freewheel turns the motor shell will turn also.
The only things that can stop that are as I've mentioned. The threaded boss snapped off and that would leave the freewheel obviously wobbling about, the thread stripped and the freewheel turning on the boss, but the binding as it turned would make that obvious. Finally, the boss turning in the motor side plate, but I've never heard of that ever happening and it's highly unlikely.
Nothing inside the motor can cause this and I'm sure the new freewheel will fix it.
The only things that can stop that are as I've mentioned. The threaded boss snapped off and that would leave the freewheel obviously wobbling about, the thread stripped and the freewheel turning on the boss, but the binding as it turned would make that obvious. Finally, the boss turning in the motor side plate, but I've never heard of that ever happening and it's highly unlikely.
Nothing inside the motor can cause this and I'm sure the new freewheel will fix it.
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D
Deleted member 4366
Guest
I agree with everything Flecc says. Most likely a broken free-wheel, in which case take it to a different bike shop. Only other possibility is that the threaded boss on the motor is stripped or broken off. If you've already removed the wheel and you can't simply lift the gears off the wheel, then it's the free-wheel
Thanks for all the advice. I have just taken the wheel back to the bike shop where the very experienced repairman who advised my son yesterday confirmed his diagnosis that there was nothing wrong with the freewheel (otherwise, he would have replaced it on the spot). He showed me why the freewheel is not driving the hub: there is something missing between the inside of the freewheel and the outside of the motor casing, presumably some sort of ring or large washer, which has disintegrated and fallen off.
The consequence of this is not only that the freewheel fails to drive the hub it will be a problem to anchor the hub in such a way that the freewheel can be unscrewed. Thereafter where does one find the missing part?
The consequence of this is not only that the freewheel fails to drive the hub it will be a problem to anchor the hub in such a way that the freewheel can be unscrewed. Thereafter where does one find the missing part?
No ring or washer, the freewheel screws onto the threaded boss that I arrowed above. If the shop is correct, either the boss has snapped off the hub shell which will leave the freewheel flopping about loose and falling off the hub with the wheel out of the bike which doesn't seem to be the case, or the steel boss is turning in the alloy hubshell.
I've never heard of that latter fault and I can't see it causing a free spinning situation, there would be considerable friction binding it. I can see the problem with trying to remove the freewheel though, nothing to purchase on.
Alien Ocean e-bikes are now the Synergie owners and parts suppliers.
I've never heard of that latter fault and I can't see it causing a free spinning situation, there would be considerable friction binding it. I can see the problem with trying to remove the freewheel though, nothing to purchase on.
Alien Ocean e-bikes are now the Synergie owners and parts suppliers.
D
Deleted member 4366
Guest
Over to you Flecc. I'm completely miffed. All my 250w Bafangs have the thread directly machined out of the motor housing. Is this a Bafang motor?
Roel. Any chance of some nice photos of both sides of the motor so that we can identify it, and perhaps a detail view of where you believe the problem to be?
Roel. Any chance of some nice photos of both sides of the motor so that we can identify it, and perhaps a detail view of where you believe the problem to be?
It's not a Bafang but has similarities. Main difference is that the end cap and spindle cable entry are on the left and there's doubts about whether it has an internal freewheel since many owners complain of drag over 15 mph. Here's a photo of the rear quarter I've taken offline, and I'm just as baffled by this problem:
If unrepairable, could be worth checking with Alien Ocean the price of a replacement motor. Could be quite reasonable since this bike mainly sold at £499.
Alien ocean contact page
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If unrepairable, could be worth checking with Alien Ocean the price of a replacement motor. Could be quite reasonable since this bike mainly sold at £499.
Alien ocean contact page
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I did try to upload photos of the space between the freewheel and the motor casing, and could also produce photos of the whole motor, but I found it impossible to follow the current site protocol for doing that.
The motor is not labelled so there is no indication whether it is a Bafang or not. The only identification on it is an engraved "CE YPS-01", on the side. There is certainly some drag if the motor is switched off or the battery dead, but I thought that was caused by the brushes as this is a brush motor (which uses only two wires to connect to the controller).
I still think there may be something wrong with the free wheel although it is obviously not the pawls. When I spin the freewheel in either direction the motion is slightly eliptical (not a wobble caused by slackness). If only I could get the freewheel off I could test the whole setup with the unused substitute which I have.
As a further update I do not think the space (about 5mm) between the inside of the freewheel and the motor casing has anything to do with the problem or that anything has fallen out of there. The problem certainly arises from a fault in the freewheel indicated mainly by its failure to drive, but also more subtly by the that slight eliptical motion when it is spun on the axle.
The motor is not labelled so there is no indication whether it is a Bafang or not. The only identification on it is an engraved "CE YPS-01", on the side. There is certainly some drag if the motor is switched off or the battery dead, but I thought that was caused by the brushes as this is a brush motor (which uses only two wires to connect to the controller).
I still think there may be something wrong with the free wheel although it is obviously not the pawls. When I spin the freewheel in either direction the motion is slightly eliptical (not a wobble caused by slackness). If only I could get the freewheel off I could test the whole setup with the unused substitute which I have.
As a further update I do not think the space (about 5mm) between the inside of the freewheel and the motor casing has anything to do with the problem or that anything has fallen out of there. The problem certainly arises from a fault in the freewheel indicated mainly by its failure to drive, but also more subtly by the that slight eliptical motion when it is spun on the axle.
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The freewheel centre and/or bearing might be breaking up, these are more frail than cassettes.
If you wish, mail me the photo(s) if they aren't too large and I'll post them here, it's mainly that freewheel area and freewheel to motor space I'm interested in.
flecc@tinyworld.co.uk
If you wish, mail me the photo(s) if they aren't too large and I'll post them here, it's mainly that freewheel area and freewheel to motor space I'm interested in.
flecc@tinyworld.co.uk
I have been to check my free wheel mounting on my AURORA which is a bafang motor and have found images of the free wheel mounting but I cant post the images either, it appears that the threaded part of the motor end plate has sheared off thus causing lack of drive. I am continuing to search for more info for you. John
Endless-sphere.com • View topic - Bafang motor weight reduction Check out these hub photos (fifth one down) to give you a better idea of the free wheel mtg
and some more
http://www.google.co.uk/imgres?q=rear+hub+motor&hl=en&biw=1366&bih=643&tbm=isch&tbnid=GaQ4-xDOR-B3cM:&imgrefurl=http://www.czbrushlessmotors.com/electric-bike-kit-rear-drive-brushless-hub-motor-h05-p-6.html&docid=M6Z9ObqGPgDLGM&imgurl=http://www.czbrushlessmotors.com/images/Youe/H05/H05_2.jpg&w=700&h=363&ei=BIatTrmLO4SJ8gPD7-yLCw&zoom=1
and some more
http://www.google.co.uk/imgres?q=rear+hub+motor&hl=en&biw=1366&bih=643&tbm=isch&tbnid=GaQ4-xDOR-B3cM:&imgrefurl=http://www.czbrushlessmotors.com/electric-bike-kit-rear-drive-brushless-hub-motor-h05-p-6.html&docid=M6Z9ObqGPgDLGM&imgurl=http://www.czbrushlessmotors.com/images/Youe/H05/H05_2.jpg&w=700&h=363&ei=BIatTrmLO4SJ8gPD7-yLCw&zoom=1
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Thanks for the mailed photos Rooel, here they are:
If the shiny boss behind the freewheel isn't turning with it but is fixed to the motor, I'm sure it will be the freewheel that's failed.
The removal tool you have is probably the cassette version which is slightly different in size, the freewheel one is specific for those.
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If the shiny boss behind the freewheel isn't turning with it but is fixed to the motor, I'm sure it will be the freewheel that's failed.
The removal tool you have is probably the cassette version which is slightly different in size, the freewheel one is specific for those.
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