Greetings from UK, yet to take the plunge, am thinking DIY so far.

kmccune

Well-Known Member
Stick another 250 watt hub motor and wheel on the front, it will have plenty of go and shouldn't attract a lot of attention.
 

Kriis

Member
Region
United Kingdom
Stick another 250 watt hub motor and wheel on the front, it will have plenty of go and shouldn't attract a lot of attention.
Thanks, but will be happy to fix everything on this bike for starters. Battery holding full charge at 45.5 volts so far. Lots to read about testing and possible repair of bike in general. I will go searching on here, but if anyone sees this post - I am looking to overhaul the Bafang motor possibly next as spins up ok with no load, but far less with load sadly so need to diagnose further. It's a brush-type.
 

kmccune

Well-Known Member
Ah, so basically a "universal" motor( brushes eh) lets see the way I used to fix "brush" containing motors was sand armature down regroove commutator and check and lube bushings or bearings( my drills always came back to life after this treatment as well as starters, generators etc.Carry on you will learn a great deal, battery sounds good if it will not crash under light load.
I had a little "Hyper" 700C from Walmart for a while ( it pedaled easily unpowered) that little 250 watt motor was a lot of help as long as you were willing to put in some effort, so all is not lost with 250 watts( check out the actual torque on some 250 watt middrives) Make sure the brushes are not clean worn out and the springs have sufficient tension to firmly engage the brushes to commutator. And good luck( welcome to the club)
 

Kriis

Member
Region
United Kingdom
Ah, so basically a "universal" motor( brushes eh) lets see the way I used to fix "brush" containing motors was sand armature down regroove commutator and check and lube bushings or bearings( my drills always came back to life after this treatment as well as starters, generators etc.Carry on you will learn a great deal, battery sounds good if it will not crash under light load.
I had a little "Hyper" 700C from Walmart for a while ( it pedaled easily unpowered) that little 250 watt motor was a lot of help as long as you were willing to put in some effort, so all is not lost with 250 watts( check out the actual torque on some 250 watt middrives) Make sure the brushes are not clean worn out and the springs have sufficient tension to firmly engage the brushes to commutator. And good luck( welcome to the club)
we sound so similar re: enjoyment in rejuvenating a commutator, drills, angle grinders, wiper motors :) I used to do Slot Racing in my youth, and of course, these were critical, you had to shunt the brushes on the more powerful cars or stuff would start melting.
 

Kriis

Member
Region
United Kingdom
Ah, so basically a "universal" motor( brushes eh) lets see the way I used to fix "brush" containing motors was sand armature down regroove commutator and check and lube bushings or bearings( my drills always came back to life after this treatment as well as starters, generators etc.Carry on you will learn a great deal, battery sounds good if it will not crash under light load.
I had a little "Hyper" 700C from Walmart for a while ( it pedaled easily unpowered) that little 250 watt motor was a lot of help as long as you were willing to put in some effort, so all is not lost with 250 watts( check out the actual torque on some 250 watt middrives) Make sure the brushes are not clean worn out and the springs have sufficient tension to firmly engage the brushes to commutator. And good luck( welcome to the club)
hit the ground running now as motor is brushless so that's a plus. Unfortunately performance normality was short lived and about to learn about the Dorado battery it uses, as getting mixed messages at to whether it's just generally on it's last legs or whether the main output connector is making intermittent contact on one pin connection (or possibly both).
 

Alton

New Member
Region
United Kingdom
Hi All
I, i'm guessing like hundreds of others, have been "hovering" for over a year now, taking ages in deciding which is the best way to go. My main excuse is that I fear that my chosen E-bike might not get the use that my non-powered currently gets. and i'm only really considering this route because my health is slowly changing.

Over here, a logical choice would be a Carrera Hellcat plus a Voilamart (possibly?) rear wheel 48 volt 1000 watt kit plus a 52 volt 17 Ampere hour (or more) set-up, am part of the reason for joining is to bounce this idea off some of you experienced E-Bikers (i've probably used the wrong phrase) to see what others think/have done. I've already decided I want to avoid an internal controller, as it seems to present reliability problems long-term.

One question I would love to hear answered is, how far have people pedalled their flattened-battery or broken bikes home?! I promise that i'm not a pessimist at heart but certainly a realist and this is a factor that I have to get to grips with as I love the idea of doing 60 miles total or more again before i get too old.
Hi Kriss,
I built my own ebike much along the lines that you mention. It weights 35kg with the battery on board and I can peddle it 20km fairly easily thanks to being generally fit and due to some good gearing. With the battery removed it is much easier to peddle again and I use it that way to go out on non-powered rides with my daughter for up to 30km. I have a 31.5 Ah battery so I've only run out of juice once, on a capacity test. I ride normal road bikes too so know what proper cycling is. If I ever break down and can't do a roadside repair (I carry a compact tool kit and spare chain/quick links but you never know), I am not worried about pedalling home.
 

Kriis

Member
Region
United Kingdom
Hi Alton
Thank you for replying, I forgot to update this thread, partly because of very small response anyway! Your bike sounds great and I still might assemble a special eventually but meanwhile I took the plunge which was quite a gamble, and bought a 3 year old OXYGEN mtb in need of repair and after working through several issues I have a really excellent package. It's only a 250W Bafang rear wheel drive but by pure chance i've discovered that it's all I need as more than capable of sustaining legal speed. I got a 21 Ampere hour battery for it, and that will last for 40 miles with pedalling. Last week I decided to test it long distance (and test my health) by covering 66 miles which involved me cycling for 33 miles without motor! This is not as bad as it seems and could manage 15 mph without much effort due to the low gearing. It was utterly reliable but I got caught out 200 yards from home mainly due to being so tired. In short, there is a danger of writing off the rear derailleur and distorting the chain if the latter slips between the lowest gear and the hub during a gearchange. The only safe answer is to set the limiter screw on the derailleur to block it from changing to "1st gear" on the rear wheel (which I have now done). I haven't discovered a thread that lists all the teething problems on this particular bike, but I guess I could create one. Overall it's an excellent package and the bespoke frame is really well made, and just to confirm - it's perfectly fine to ride without motor assistance which has been my biggest concern pre-purchase, if caught out with a flat battery or inoperative motor.
 

Kriis

Member
Region
United Kingdom
Although posting in the wrong place I suppose, I forgot to add that I can help anyone out now with re-wiring a thumb operated throttle, as learnt the hard way. I bought same* for a Bafang mid-drive with matching 3 pin plug (even the colour (orange) was correct!) hoping it would work but for some reason the wiring was different for this particular controller/Bafang motor set-up in that the red and black wires needed reversing.Once done, it now works a treat.

*it's the most popular type with multiple listings on Amazon and EBay.
 

Alton

New Member
Region
United Kingdom
Hi Kriis,
Well that sounds like you made a good start. Congrats for taking that first step and making it work for you. It's particularly good to read that you can pedal good distance without power and still enjoy the ride (and your health).
There are always technical and teething problems and drivetrain issues are common. I set the H limit screw to block the smallest cog since I really don't need to go THAT fast and reckon an 11 or 12 tooth cog does not bode well for chain longevity on a high powered ebike. I also set the L limit screw to allow lowest gear engagement (36T) only if I really hold back my twist grip gear shift all the way. That's so I can use it for a really steep hill if I need to. By avoiding the extremes of the 9 speed cassette I am hoping to preserve better chainline. 7 cogs are more than enough.
Is it flat where you live? Given the motor you have chosen in a hub format and the range you describe, I am guessing there are not many steep hills in your area or am I wrong?
 

tomjasz

Well-Known Member
Region
USA
City
Minnesnowta
Although posting in the wrong place I suppose, I forgot to add that I can help anyone out now with re-wiring a thumb operated throttle, as learnt the hard way. I bought same* for a Bafang mid-drive with matching 3 pin plug (even the colour (orange) was correct!) hoping it would work but for some reason the wiring was different for this particular controller/Bafang motor set-up in that the red and black wires needed reversing.Once done, it now works a treat.

*it's the most popular type with multiple listings on Amazon and EBay.
Google is your fastest support access.
wiring and testing an eBike throttle
SHAZAM!

 
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Kriis

Member
Region
United Kingdom

Kriis

Member
Region
United Kingdom
You MAY have a problem! Lithium batteries are ALL dangerous when overcharged. If you in fact have a 36V battery, top voltage is 42V. Either you have a problem 36V OR it's not a 36V. !!!PLEASE BE CAREFUL!!!
Thank you tomjasz, I appreciate what you are saying, I used the Oxygen approved charger so hopefully all ok and maybe voltmeter optimistic even.
 

tomjasz

Well-Known Member
Region
USA
City
Minnesnowta
Thank you tomjasz, I appreciate what you are saying, I used the Oxygen approved charger so hopefully all ok and maybe voltmeter optimistic even.
Fella! IF it's a 36V you HAVE A SERIOUS PROBLEM! An overcharged battery is DANGEROUS! FFS!!!
 

Kriis

Member
Region
United Kingdom
Hi Kriis,
Well that sounds like you made a good start. Congrats for taking that first step and making it work for you. It's particularly good to read that you can pedal good distance without power and still enjoy the ride (and your health).
There are always technical and teething problems and drivetrain issues are common. I set the H limit screw to block the smallest cog since I really don't need to go THAT fast and reckon an 11 or 12 tooth cog does not bode well for chain longevity on a high powered ebike. I also set the L limit screw to allow lowest gear engagement (36T) only if I really hold back my twist grip gear shift all the way. That's so I can use it for a really steep hill if I need to. By avoiding the extremes of the 9 speed cassette I am hoping to preserve better chainline. 7 cogs are more than enough.
Is it flat where you live? Given the motor you have chosen in a hub format and the range you describe, I am guessing there are not many steep hills in your area or am I wrong?
Hi Alton
It is fairly flat here, but the gear spec on this bike is ridiculously in favour of steep hills anyway, even more so than my non "E" mtb so missing 9th is hardly noticeable but more importantly, is yours a rear drive Bafang with a 9 speed block? - if it is, then unless different to mine then you could also be perilously close to a chain-snag plus derailleur damage were you to select 9th cog "in a hurry". I totally take your point about the 11 tooth, and I can see from inspection on both bikes (have two identical Oxygen now) that owners appear to have just left them in this gear or 12 tooth, the rest of the gears looking almost unused.
 

Kriis

Member
Region
United Kingdom
Fella! IF it's a 36V you HAVE A SERIOUS PROBLEM! An overcharged battery is DANGEROUS! FFS!!!
I will double check, but after charging both batteries they nearly always show at least 42 on average, and battery case cold. Even the one time at 45 volts battery case was cold, but I thank you for your concern and have taken it onboard.
 

Kriis

Member
Region
United Kingdom
Google is your fastest support access.
wiring and testing an eBike throttle
SHAZAM!

Further to this tomjasz, could you please help me find this link? I have just searched using the specific words you included as the one you supplied doesn't work* - prior to working it out myself, I swarmed all YouTube tutorials I could find, and none went into the detail of identifying which wire suited which on each existing controller/motor so I will be impressed if this one does.

*Even a "non-YouTube" search has not found your link using your specific words/Shazam, - this is is possibly as good if not better:-


as said, immaterial for me now anyway, but if you think it is a definitive guide, then worth finding and linking properly for others, will leave it with you. :rolleyes: :)
 

Alton

New Member
Region
United Kingdom
Hi Alton
It is fairly flat here, but the gear spec on this bike is ridiculously in favour of steep hills anyway, even more so than my non "E" mtb so missing 9th is hardly noticeable but more importantly, is yours a rear drive Bafang with a 9 speed block? - if it is, then unless different to mine then you could also be perilously close to a chain-snag plus derailleur damage were you to select 9th cog "in a hurry". I totally take your point about the 11 tooth, and I can see from inspection on both bikes (have two identical Oxygen now) that owners appear to have just left them in this gear or 12 tooth, the rest of the gears looking almost unused.
I used a BBSHD (mid drive) on an old MTB frame and built the bike up around that to work well. 200mm brake disc rotors with Avid BB7 calipers. Designed and built the battery box myself. 46T Lekkie Bling Ring up front and a 12-36 9-speed Shimano steel cassette takes care of all road hills near me (fairly steep) and can get up to just over 60kmh on the flat. 31.5Ah battery gives a range of 80km on full power (average speed around 37kph) with no range anxiety. 1.75" e-bike road specific tyres. I weigh 170lbs. Front shocks on the forks and a parellelogram suspension seat post (not shown on this image) make for a comfortable ride (which could be made more plush with a larger tyre and tube on the back). I use it to commute to work every day. I made another for a friend of mine.
 

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Kriis

Member
Region
United Kingdom
I do apologise Alton, it looks as though I didn't read your earlier reply judging by my last question, but I did - it's just a combination of age and painkillers with me. Your bike looks excellent, and more mental enjoyment when riding knowing you did it all yourself unlike me.
 

Alton

New Member
Region
United Kingdom
No problem. at all. I am very careful maintaining, monitoring it and built it to be secure, reliable and safe.
Mind you, downhill I still go faster on my leg powered road bike on skinny tyres, no suspension and wearing far less clothing protection!
The risks are relative.