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Cheap 500w ebay kit good for hills

Posted: Nov 26 2020 11:24am
by finitecube
Hi All,

I'm looking to get a cheap ebay kit with a 500w front motor to retrofit on my disc braked halfords mountain bike that is optimised for hills (i.e. geared lower). Its not for regular or serious use but will be something of a backup vehicle as the nearest shop is 15 miles away and I can only trust my twelve year old van so much. I see kits for around the 150 mark and a 17ah 36v battery for £200 - I'd be buying in the UK. I can go a little higher to ensure quality but I'm not looking at some crazy build with like manganese chromium carbon fibre spokes, ceramic bearings or a motor from some nasa lunar rover.

I used to have a 1000w rear wheel kit that I got second hand. As cool as it was blasting 35 to 40mph down the B roads it was total crap on hills due to the higher gearing. It was also a pain in the arse with the wheel bending itself out of shape due to the power and it ate a few spokes.

The hills here are contionous and pretty serious

I am buying from the uk btw. Thanks in advance :bigthumb:

Re: Cheap 500w ebay kit good for hills

Posted: Nov 26 2020 12:15pm
by Tommm
https://www.aliexpress.com/i/4000047529411.html

High quality 500w geared rear hub. I would go with this one to keep it simple. They pay tax for you.

I have the bigger, 1000w and 1kg heavier version of this but I think in normal riding it is unnecessary. Geared hubs behave much better up hills. The controller is 22a so you are getting 1000w effective if used at 48v.

Re: Cheap 500w ebay kit good for hills

Posted: Nov 26 2020 5:43pm
by markz
One thing to note is that when you buy a complete hub motor wheel the rim, its spokes and nipples are usually of lowest quality. Its best to buy the motor hub alone and lace that into a quality rim, using quality spokes and nipples. Its easy to lace, countless videos on youtube, just takes time, take it slow.

Cheap batteries are really a gamble. Its best to buy a quality battery, em3ev, grintech, osnpower, unitpackpower, luna.

Re: Cheap 500w ebay kit good for hills

Posted: Nov 26 2020 9:43pm
by Tommm
markz wrote:
Nov 26 2020 5:43pm
One thing to note is that when you buy a complete hub motor wheel the rim, its spokes and nipples are usually of lowest quality. Its best to buy the motor hub alone and lace that into a quality rim, using quality spokes and nipples. Its easy to lace, countless videos on youtube, just takes time, take it slow.

Cheap batteries are really a gamble. Its best to buy a quality battery, em3ev, grintech, osnpower, unitpackpower, luna.
I agree with this generally, but if you have a 2.4 tire and some working rear suspension it has to be quite a hit for it to deform. On a hard tail yea, it is just a matter of time.

Re: Cheap 500w ebay kit good for hills

Posted: Nov 29 2020 7:21am
by dogman dan
Hmm,, helps if you define hill.

In general, a geared hub will do better on short hills, with the internal gearing, than a DD of similar 500w motor rating. I don't mean the random number they put on the kit to sell it, but the actual motor rating.

However, the geared motors do have smaller motors inside, less copper, smaller magnets. So if the hill takes you say, a full hour to climb it, it may melt a geared motor, while a dd may survive to the top.

The problem here is the slow. Both types of hub motor are in general, designed to run efficiently at about 15 mph to 20 or 25 mph. Any slower, they get hot if the load is high, as in the guy is fat, the bike is towing, or the hill is quite extremely steep. So really, very few hub motor setups for a 26" wheel or larger are all that good for slow up a hill. Power up some, and they do excellent at fast up the hill though.

Talking very generally here, so what good is this? I'm just trying to make the point that if you buy a very small geared motor, it will just be too underpowered to make it up the hill relatively fast, and it will get hot on any long hills, or short ones repeated enough. Furthermore it really does matter what you weigh, and how hard you pedal.

But here is the good news. If you weight is typical for a healthy male adult, say 220 pounds or less, and you are able to pedal hard, you can ride up quite steep hills quick enough to keep the motor happy, using a 48v powered, larger geared type hub motor. It will have nice torque, and if you pedal briskly, you will maintain close to 15 mph up very steep hills, and get up steeper ones quick enough.. The smaller diameter motor will allow the longer spokes that really help the wheel last a bit longer.

The bad news,,, a shitty version of this wheel on the cheap, with a crap rim and crap spokes will still tend to have problems later, especially if you like to ignore loose spokes and kill it.

But if your budget dictates it, you can still buy another cheap ass DD motor and ride. Its just not going to be as nice, especially on the front wheel. Do not go front wheel if you must ride this bike on dirt though. It can be done, but really, rear wheel for dirt.