Newbie

[rajsol3000]

Hi im Raj, i would like to do an electric bike conversion, the bike is to be used for commuting too and from work, i dont have too much money to spend and i was wondering if any of you guys were able to recomend a kit to me, ive seen quite a few on ebay ranging from £100-£350 for a front wheel with electric hub, twist throttle, brake leavers, motor controller and a crank sensor, the one im looking at says its a 1000z 48v, only thing it dosent include is the batteries.
so ive got a ferw questrions
how much power do i need?
should i have the front or rear wheel powered?
are there any sources for cheap kits and batteries?


thanks

 

[Nealh]

How far and how fast do you want to ride and the terrain how hilly is it.

 

[rajsol3000]

well I want to use it for comutinfbto work, 20 mile round trip but I can charge up at work. it doesn't need to be mega quick but I don't want it to be gutless, the terrain is fairly flat but there are a few ups and downs. I've seen a few kits, 36v 500w from eBay seller easylivingus have you heard of them? I think I want a 36v 10-12 ah battery. any ideas?

 

[Nealh]

A link to the products.
I suspect it may be a gear less high speed direct drive hub which will struggle on inclines at 36v.

For commuting a geared 250/350 hub 3- 4kg in weight will offer a relaxed ride and with a decent celled battery last a good few years. 270 - 300 rpm wound hub will offer up to 24mph and should amble a long nicely at 18 with out to much effort, inclines of 10% are manageable albeit at a slower speed.

Woosh bikes sell a legal complete 250w 48v kit for sub £600.

 

[Deleted member 4366]

The problem with those cheap direct drive motor kits is that they're not very efficient so you need a bigger battery than with other types of motor. Also, to get the power out of them, you need a battery that can supply a high current continuously. That means that you need to spend more on the battery than you would for other kits, so the overall price of the complete kit is not so favourable.

Some of the DD kits provide a battery with the kit, but they're mostly under-specified for the job, so you get poor range and the battery wears out very quickly.

Finally, those big DD kits are illegal and it would be difficult to convince anyone otherwise. You can still get enough power with a kit that at least looks legal.

 

[rajsol3000]

cheers for the info lads, I was hoping to spend no more than £400 on the whole thing really, any other ideas? also are there Any online resources for general info on building e bikes, rather than just getting snippets of info from good fellows like yourselves. but generally is what you are saying is that having geared hub is better than a direct drive, tourque and rpm multiplication increases battery efficiency?

 

[danielrlee]

what you are saying is that having geared hub is better than a direct drive, tourque and rpm multiplication increases battery efficiency?

Not necessarily 'better', just more suitable for a low-power, low speed electric bike.