help with e bike convertion
 

http://bikeforums.net/attachment.php...hmentid=354164

First hello as I am new to this forum and new to e bikes but I have been a casual cyclist for many years.

I want to convert my Carrera vengeance MTB to an e bike but need some help.

I want to use the bike for my commute to work of about 12 miles each way. I want it to be pedal assist so I am still getting some exercise but will help smooth out those heart burning hills and help keep my average speed up. I am happy to keep within the UK legal limit of 250w and 15.5 mph. the bike has no rear mounting for a battery rack but a bottle mount battery should still give me enough range. I am also going for a front wheel motor as I think it will be an easier fit and effectively give me 2WD in assist mode

This bike has hydraulic disc breaks and I am worried they are not compatible with the electric off break leavers supplied with most conversion kits. I know in assist mode I dont need electric off breaks but with the throttle fitted I know I will use it and I dont want to build a death trap

Any advice will be much appreciated

A front motor on that type of fork is not recommended but at 250~350w it's ok if you install it carefully, would recommend a torque arm....

Don't worry about the e-brakes, stick with your stock levers, your car does not disable the gas pedal when you hit the brakes, it's just common sense.... pedal sensors tend to suck, just get a kit with twist or thumb throttle ( depending on your preference ) and keep it simple, less things to go wrong.

Many thanks for the quick reply

That now makes sense about the breaks.

The kit will be a significant investment for me so I am trying to get as much info as I can so I dont buy the wrong kit. I can not afford a mistake. But I may be able to afford some ads on's if needed later .

Keeping simple sounds like good advice

With out a pedal sensor can I still pedal to assist the motor? What I mean is if my pedal speed does not match the motor speed what effect can this have

The throttle works just like a variable speed adjust, just throttle as little or as much as you want while pedaling, it's obvious within seconds or riding, i usually pedal from a dead stop ( in top gear, never bother to shift ) and throttle on while pedaling, you can adjust as you go easy peasy.

thanks again. without ever riding one it is a little hard to imagine how it handels. I have been in contact with a UK kit suppier who tells me he has converted similar bikes to mine without problems (but they would say that)

But I amnot looking for top of the range performance if it works that is good enough for me. If it works out well it may be worth while buying a dedicated e bike later on but I need to walk before I can run

well it seems I could buy whole bike for not much more than the kit

http://www.ebay.co.uk/itm/Electric-B...item3cd992abdb

no pedal assist

Since you are in UK.
You have very nice ebike dealer in your country who carries quality ebike kits which last - Team Hybrid Ltd.
They are famous for quality. Of course they charge, they do not install cheapo stuff, according to them it must last.
That,s why they carry Heizman and FALCO.
They are dealer for FALCO Motors - one of the best hub kit on the market, USA designed.
As you can see they offer what youare looking for - UK legal kits 250W.

http://www.teamhybridebikes.com/

another option for you.
http://www.electricbike.com/mid-drive-kits/

It is all very interesting

After some more research I have found my lowest cost option would be a direct from china conversion kit through ebay. from the photos it is the same hardware that is being offered from UK bases suppliers. the risk being if there is a problem with it there will not be any after sale support.

I am an electrical engineer so I am pretty confident I can sort out any electrical problems. Any mechanical problems though would be harder for me to fix.

I have seen a few build blogs for similar bikes to mine with both front and rear mounted motors and both seem to have been successful
I am still inclined to buy a front motor as I think it will be much simpler for me to fit and keeping cost down is important to me

I doubt you can get on eBay what TEAMHYBRID is selling in your country - UK.
They do not use China brand parts like PROMAX brakes/example/ but only Western brands .
If you want cheap of course you know where to go/eBay/ but do not expect quality or support for mechanical failures with no warranty practically /do you send back parts to repair/replace to China????/ .
If you are EE you would hate to ride on motor with undersize wires ,
if you read blogs you for sure read about completely rebuilt China motors- phase wires replaced for biggers, bearings replaced for some quality ones and on and on. But cheap.

I agree that simple is good. However, I have a geared front motor kit and always saw those e-brakes as a kind of emergency cut off switch(es) in the event that something went wacky with the throttle or motor and it was "running away" - and with me on it! I would grant that this is quite unlikely, but possible.