I've got 3 yosepower batteries, the oldest 4 years old, still going strong, no noticeable drop in capacity. Full 36v kit with 15ah battery is sub £400, donor bike easy to find for £200 or less

Hi guys any thoughts on buying a non-running but fairly new bike on gumtree etc? The first one with the intermittent fault could be an easy fix.

 

 

£400, original price £1000 (allegedly

https://www.gumtree.com/p/electric-bikes/electric-bike-make-is-b-twin-peddle-assist-and-throttle-/1433363986

 

 

£250, original price £750

https://www.pedelecs.co.uk/forum/threads/cheap-e-bike-£600.43526/page-2?view=date#post-653832

The gumtree bike might be worth a punt if you have £400 to spare and can test ride it. One needs to know exactly when and how the bike cuts out so again a test ride. The cutting could be that the set speed limit has been reached or the motors terminal rpm has been reached if the lcd speed limit has been set higher. One can't ride the bike with power faster then the terminal motor rpm winding will allow without increasing the voltage.

The downside is it uses the lishui control system, it depends if it is a speed or current control but personally think the KT is much better and easier to to replace components.

Edited May 31, 20223 yr by Nealh

The B TWIN ad says 'Now bike rides but cuts off '. That's different from an intermittent fault.

 

One possible reason for that is a nearly dead battery. If it isn't looked after that can come with even a fairly new battery, eg if left for a time fully discharged. That would charge normally, but as soon as you try to get any current from it voltage would drop and the motor cut out. If that is the case a replacement would be around £200 up depending on capacity. (The ad doesn't say the original capacity of the current battery.)

 

If you are lucky it could just be a dodgy connection somewhere.

 

~~~

p.s. I misread that as £250 for the BTWIN. I'd be very dubious of spending £400 on it.

Edited May 31, 20223 yr by sjpt

Hi guys any thoughts on buying a non-running but fairly new bike on gumtree etc? The first one with the intermittent fault could be an easy fix.

 

 

£400, original price £1000 (allegedly

https://www.gumtree.com/p/electric-bikes/electric-bike-make-is-b-twin-peddle-assist-and-throttle-/1433363986

 

I don't think that bike was originally £550 and certainly wasn't bought from Halfords. A problematic ebike kit is not worth spending that money on, the battery, motor or controller could be faulty and it could be an easy fix the cadence sensor maybe or a very expensive fix like a failing battery pack its a gamble. You can buy a brand new fresh yose ebike kit for less than £400 and its fully guaranteed. That Decathlon bike looks nothing special, you could probably pick up something similar secondhand for £50. The battery could be end of life after 100s of charge cycles. The fact the seller doesn't know that Decathlon bikes don't come from Halfords means the bike was bought secondhand or possibly stolen.

As sjpt has mentioned it might be a battery issue but one needs to ride the bike to see.

It has a voltage read out so one can watch to see if the volatge collapses when using throttle, his saying that PAS is faster then the throttle is not correct, both PAS and throttle will give max current.

The battery depends on the specs and the max continuous current output of the cells, the battery will need to output 25a continuous for the 18a rated controller. If it is a cheap battery then it may not be up to delivering the current.

It's a confusing Decathlon bike, it seems to have hybrid style short travel forks but it has mountain bike tyres and the crankset looks pretty cheap as do the pedals. Almost like its a mix of different bike components. The frame looks like a Riverside model especially as its paired with short travel forks. The ebike kit doesn't appear to be installed very well which is hopeful. The hybrid forks have remote lockout which is more of a premium feature for hybrid forks.

Ok gonna sack off that idea!

 

Bought a new one of these locally for £100

 

https://www.ebay.co.uk/itm/334200005390?hash=item4dcfdf630e:g:E1kAAOSwbuFgPyNd

Edited May 31, 20223 yr by Max1980

Ok gonna sack off that idea!

 

Bought a new one of these locally for £100

 

https://www.ebay.co.uk/itm/334200005390?hash=item4dcfdf630e:g:E1kAAOSwbuFgPyNd

 

OK, so you've bought a 48v battery and cradle with no controller? Not being funny but what is it you intend to do with that?

OK, so you've bought a 48v battery and cradle with no controller? Not being funny but what is it you intend to do with that?

 

Buy bike, buy conversion kit minus battery?

Buy bike, buy conversion kit minus battery?

 

OK, well good luck. Don't forget though you will need a 48v kit (I think).

One can buy dual volatge controllers like Kt with displays the easy bit, what you will have to be careful with though is the hub motor and particularly the winding speed. If you buy a 36v hub it will run 33% faster at 48v so if wanting to climb hills one will need ideally a proper 48v wound hub at 201rpm.

One can buy dual volatge controllers like Kt with displays the easy bit, what you will have to be careful with though is the hub motor and particularly the winding speed. If you buy a 36v hub it will run 33% faster at 48v so if wanting to climb hills one will need ideally a proper 48v wound hub at 201rpm.

 

As far as I understand it controllers are DC to DC converters with speed being voltage and current being torque so when you hit a hill voltage drops but current surges in the controller to give a torque boost but at a slower speed. I understand your point about specially wound torque optimised hubs but still any controller can optimise torque more with 48V than 36V can't it? It has more capacity to drop voltage and produce more current plus of course the batteries being setup for 48V will mean the cells have more capacity for current when needed to get up hills.

 

I've seen some 24V ebike reviews and typically those bikes have very little torque for the hills even with low geared 20" wheel folding bikes which are typically good high climbers because of their low gearing (small wheels). Those ebikes typically have probably only 12-15Nm torque at the motor.

Ok gonna sack off that idea!

 

Bought a new one of these locally for £100

 

https://www.ebay.co.uk/itm/334200005390?hash=item4dcfdf630e:g:E1kAAOSwbuFgPyNd

 

Is it definitely new? I see battery packs for sale occasionally in my area and they may look newish from the advert but many people sell battery packs after they have done 100s of charge cycles and capacity starts to drop. I remember reading a thread somewhere possibly this forum but not sure where someone had bought a ebike for £300, used it for about 18 months with the battery capacity dropping considerably and then sold it on ebay for something like £380 and he couldn't believe his luck it went so high with an end of life battery. Many people don't consider batteries as consumables with a limited life so don't bid realistically on ebay. I've also seen a few threads where people have bought ebikes secondhand only to complain of the short range of the battery many of which were on this forum.

Is it definitely new?

 

Yeah fortunately (or unfortunately!) this one is definitely new. The guy needed the 36v model and was just out of the returns period.

 

I've seen this one but I don't fully understand the freewheel/cassette differentiation.

 

What kind of bike setups work with freewheel motors? Should I avoid this setup entirely?

 

https://yosepower.com/collections/e-bike-conversion-kit/products/48v-1000w-26-rear-motor-kit-for-freewheel

I've seen this one but I don't fully understand the freewheel/cassette differentiation.

 

Freewheel: the motor has thread for a screw on freewheel, usually 6-7 speed, like this:

 

 

Cassette: the motor has a freehub and will accept a 8-10 speed cassette, like this:

 

 

Motors with cassette fitting (freehub) tend to cost a little more.

Check your rear wheel and buy accordingly.

If you have 11-speed cassette, check with the supplier before buying.

Yeah fortunately (or unfortunately!) this one is definitely new. The guy needed the 36v model and was just out of the returns period.

 

I've seen this one but I don't fully understand the freewheel/cassette differentiation.

 

What kind of bike setups work with freewheel motors? Should I avoid this setup entirely?

 

https://yosepower.com/collections/e-bike-conversion-kit/products/48v-1000w-26-rear-motor-kit-for-freewheel

 

Oh dear another one who doesn't understand that 1kw kits are;

1. Not legal.

2. Likely not suitable for the inteneded use.

3. Unlikely the bought battery can sustain more then 30a continuous for the kit linked to.

Yeah fortunately (or unfortunately!) this one is definitely new. The guy needed the 36v model and was just out of the returns period.

 

I've seen this one but I don't fully understand the freewheel/cassette differentiation.

 

What kind of bike setups work with freewheel motors? Should I avoid this setup entirely?

 

https://yosepower.com/collections/e-bike-conversion-kit/products/48v-1000w-26-rear-motor-kit-for-freewheel

Well you got a brilliant deal on that battery then but it does restrict you somewhat. Anyway which bike are you aiming to get or are you basing it on the most suitable ebike kit?

 

If you are buying a cheap new bike then its probably freewheel based anyway. Despite that kit saying includes Shimano 7 speed freewheel it is not pictured in the included items. Anyway if you bought a 6 speed freewheel based bike then you can use the 6 speed freewheel no problem and the bike will come with a 6 speed shifter.

 

The issue is the legality of the kit but it does include a display and you will be able to restrict it to the legal limit in the settings I'm sure but it will never be fully legal. You will probably want to remove the 1000W sticker on the hub motor too. This sort of bike would be compatible;

 

https://www.argos.co.uk/product/9308435 or a similar s/hand bike.

 

The Voilamart 1000W kits used to have a physical wire that limited the controller to lower watts and a 15.5mph speed limit but that kit looks like it would be through the display options to restrict it.

 

Don't forget there is a yose discount code if you join their mailing list.

 

Although it looks like the kit is cheaper on ebay and does show the freewheel.

 

https://www.ebay.co.uk/itm/334171987768

 

So you will end up with a spare rear wheel and possibly a 7 speed freewheel to sell to help recover some costs. There could be some bonuses and discounts available due to the holiday weekend. That ebike kit shows as 750 nectar points for me which is about £3.75 in real money.

 

I didn't realise 48V and geared hub motors were so rare. It looks like you are pretty much forced to have a direct drive hub motor with 48V.

 

I bought a kit of amazon sometime ago which I haven't fitted to a bike yet but its 48V 500W 20" wheel and geared, I didn't realise how rare it was when I bought it.

Oh dear another one who doesn't understand that 1kw kits are;

1. Not legal.

2. Likely not suitable for the inteneded use.

3. Unlikely the bought battery can sustain more then 30a continuous for the kit linked to.

 

Not legal of course but don't quite understand the other 2 points why would it not be suitable for the intended use and why would the battery not be suitable. That kit isn't going to need 30A continuous that sounds more like peak figures, 1000W shared by 48V is about 20A but these kits exaggerate their power. Going from the legal mode which peaks around 400W the so called 1000W mode only goes up to about 500W, the 1000W claim must be absolute peak power. That battery will be fine I'm sure but if the display is set to the right assistance speed limit there certainly won't be any problems.

 

The issue is legality really and its a tough one to answer. How Bosch can get away with close to 800W with their so called legal mid-drive motors and yet others are classed illegal that produce half the torque at half the wattage seems very unfair.

Quite simply by checking the spec's of the kit he linked to !

The controller is 15a rated and 30a max, one in general should always select the battery continuous rating to be greater then the controller max out put as you should know.

If one doesn't then these guys start moaning about how crap hub motors are when they don't spec the correct components. Whether or not he uses the 30a max current is another thing but if wanting a moped as most seem to want to for some reason then the throttle will draw max current, the battery simply I doubt will be capable and will cut out.

 

We have seen this many times on here in the past, dissapointed buyers buy cheap motor kits and a cheap battery simply not up to supplying the current or able to climb hills. A £100 or £200 battery isn't going to be 30 or 35a capable.

Bosh and others get away with it because the eu/regulators dislike china hub kits and hub bikes, bosh etal label their motors 250w and they are wholly believed. Also they keep very quiet and don't mention at all the controller current rating or potential max watts output, which most who can do simple maths know are not truly compliant with the law.

They try and diss the china midrives etc ,etc but keep quiet about there false specs for their motors much like the diesel emissions hocupocus going on.

We know that a 36v system reputedily said by many to output 800w can't have a docile legal current applied, so the current rating must be circa 11/12a nomianl with a 22/23a max output rating.

Going from the legal mode which peaks around 400W the so called 1000W mode only goes up to about 500W, the 1000W claim must be absolute peak power. That battery will be fine I'm sure but if the display is set to the right assistance speed limit there certainly won't be any problems.

the disadvantage of those direct drive kits is clear when climbing a steep hill.

Imagine doing that with your car stuck in fifth gear. The motor will not run in its sweet zone, the more you try to compensate for the lack of torque, the more current it will pump until the controller reaches its maximum current. A geared motor with a typical 5 to 1 gear reduction gives you the torque you need while weighing a lot less.

There are very few or no non oem 250w 48v hub motors but one can buy for instance the AKM 48v geared hub but it is 500 or 800w rated. This rating seems to fit the US market perfectly but not the rest of the world.

The wattage is whatever the maker puts on the motor and tbh they can put what ever marking they wish on a motor to suit the market, but most are directed to the US market.

the disadvantage of those direct drive kits is clear when climbing a steep hill.

Imagine doing that with your car stuck in fifth gear. The motor will not run in its sweet zone, the more you try to compensate for the lack of torque, the more current it will pump until the controller reaches its maximum current. A geared motor with a typical 5 to 1 gear reduction gives you the torque you need while weighing a lot less.

 

I don't think its fair to generalise like that, I've seen cheap 24V ebikes with tiny geared hubs and even with the small wheels the motors are only producing a peak of around 12-15Nm, some of the direct drive hub motors are delivering maybe 30Nm in restricted mode 250W(400W peak) and 40Nm in unrestricted mode maybe (400-600W and peak of 1000W) or something like that and then you have geared hubs at up to about 45Nm typically as a maximum. Obviously those who use direct drive hub motors at 1500W and beyond go significantly beyond those figures. A huge part in addition is the gearing, you can gear a bike for climbing.

 

I totally accept that direct drive hub motors are not the ideal hill climbers but still offer huge assistance going up hill and certainly beat many smaller geared hub motors going up hills. They are by far the most reliable of all ebike motors, you have the ability to use regen which if you only use power for going up hills can be a significant boost to range and they have the greatest weight capacity and easiest cooling due to their greater amount of material. There are a huge amount of positives to direct drive hub motors. In fact when you look at Grin Technology its clear its their favourite motor type by far. For long commutes, touring and low maintenance it could be the optimal ebike.

 

This is essential viewing for anyone wanting full info on hub motors and how actually efficiency doesn't vary that much between different motor types as all have areas where they are more or less efficient over normal use. That could be related to energy losses through internal cogs and belts or through the drivetrain (mid-drive) or through heat loss and poor thermal properties.

 

Quite simply by checking the spec's of the kit he linked to !

The controller is 15a rated and 30a max, one in general should always select the battery continuous rating to be greater then the controller max out put as you should know.

If one doesn't then these guys start moaning about how crap hub motors are when they don't spec the correct components. Whether or not he uses the 30a max current is another thing but if wanting a moped as most seem to want to for some reason then the throttle will draw max current, the battery simply I doubt will be capable and will cut out.

 

We have seen this many times on here in the past, dissapointed buyers buy cheap motor kits and a cheap battery simply not up to supplying the current or able to climb hills. A £100 or £200 battery isn't going to be 30 or 35a capable.

Well the battery spec isn't clear on what this battery outputs on that ebay listing but does clearly state compatible with 1000W 48V motors and personally I have no reason to think that is wrong. I don't think these controllers peak at anywhere near what you think they peak at. These 1000W kits rarely go to 1000W more like 500-600W with occasional peak output of 1000W just so they can sell them at 1000W but 30A at 48V is 1440W. I think you are being overly cautious about pairing batteries to controllers or don't realise how over-stated the wattage is on some of these entry level direct drive hub motor kits are. The same direct drive motors are paired with 1500W and 2000W kits just those kits have more capable controllers. Basically the direct drive motor gets what is given, if you can't climb that hill with the provided power then you don't climb it basically.

 

I guess occasionally I might read a posting on a battery pack where a internal fuse has blown but I think maybe one of the occasional issues with direct drive hub motor kits is the controller not handling the sustained level of current, i.e. the controller box over-heating, sometimes they are housed in a provided bag that doesn't assist at all with heat loss and so the controller gets too hot but that would surely indicate the battery is actually coping very well and providing ample power. Typically then people may replace the supplied controller with a higher rated controller and then I can see a battery issue if they haven't thought about the controller demands on that lower spec battery.