Front or rear hub motor?

[Hermann]

Hi all,
what would be the best option for mounting a hub motor? I was thinking to take one of my old bikes and mount one of these hub motors you get in ebay- complete sets without battery for about 150-200 Euros.
I would feel more comfortable with a rear hub motor, because then the motor pushes and not pulls, like the BionX system, and I guess that should be safer, especially on gravel and forest roads. However, most sellers sell front hub motors only (there are some where you can get an rear hub motor, too).
Best regards
Hermann

 

[The Maestro]

Hi all,
what would be the best option for mounting a hub motor? I was thinking to take one of my old bikes and mount one of these hub motors you get in ebay- complete sets without battery for about 150-200 Euros.
I would feel more comfortable with a rear hub motor, because then the motor pushes and not pulls, like the BionX system, and I guess that should be safer, especially on gravel and forest roads. However, most sellers sell front hub motors only (there are some where you can get an rear hub motor, too).
Best regards
Hermann

I'd instinctively say (i.e. with no scientfic evidence) that a front hub motor would be safer on gravel and forest tracks. RWD tends to be rubbish on loose and slippery surfaces. I also like the front hub system because you could tun it back into a normal bike in a matter of minutes.

 

[Jeremy]

I've only used front hub motors, but based on my experience I'd suggest that it's the better option. Unless you go for an extremely powerful (~1kW or so) model, then there won't be any traction problems.

The reason I'd go for a motor in the front wheel is very largely to do with convenience. It's a bit easier to fit and less hassle to play around with, if you don't need to faff around with the chain etc when fitting the wheel. I know that I must have had the wheel on and off my bike a dozen or more times when I was trying to get it set up properly, with the right length wires etc.

I can't tell that the power comes from the front wheel when riding it at all, which probably indicates that it doesn't matter too much which wheel is driven.

Jeremy

 

[john]

One big disadvantage of using a rear motor on an existing bike can be the space left for cassette. I've not seen any which allow more than 7 gears, so if you already have 8 or more then changing to 7 would be a lot of hassle and expense.

 

[coops]

Hi Hermann,

There's a concise but detailed post by flecc somewhere which answers this - I'll try to dig it out... here it is, see the first reply .

Stuart.

 

[flecc]

To which I add that with plenty of experience of both, I prefer rear hub motors, these being more stable under most conditions, and better for most of my usage. As a result both my bikes are rear motor, one started that way, the other converted to it.

Weight distribution requirements on conventional bicycles are very different from many other vehicle types, and front/rear balance isn't possible anyway.
.

 

[frank9755]

This comes up from time to time.

Personally I prefer rear. Main reasons are:
Better steering - feels more bike-like
Avoids the hammering effect though the handlebars that a heavy front motor can have on rough roads. My old Powabyke felt like a pneumatic drill on some poor surfaces, and Torq users reported theirs was even worse!
Looks better

I agree front kits are easier to fit, mainly because getting the wheel dished correctly to accomodate the gears requires additional skill. This is why I believe most kits are front wheel only.
I think a 7 gear freewheel is adequate for an electric bike, so the other reason often cited for prefering front motors - better gearing - isn't really valid any more.

When I fitted a Tongxin kit to an old bike, I intended to fit it to the rear wheel but, although Tongxin offers a rear wheel motor, there is not enough length of axle on the right to fit a freewheel, so it is not usable. I therefore had to fit it in the front. Suzhou Bafang and others do sell motors suitable for rear wheel installation with gears.

 

[oldosc]

One big disadvantage of using a rear motor on an existing bike can be the space left for cassette. I've not seen any which allow more than 7 gears, so if you already have 8 or more then changing to 7 would be a lot of hassle and expense.

Can you tell a bit more on this please, I know Flecc did alude to it in another post which I shall persue, apparently cassette is not an option? I am in the middle of buying bike for J and it looks like I have one choice the Silverado, but it has 8ah battery The black star has 10ah but no gears there is talk about a Black Star with gears, but we know how long talk takes to translate to 'first impressions of the black star with gears'
I've dun a bit of mechanic stuff, but mostly backed up with my MIG and a cutter, not an option here I believe

 

[oldosc]

and often gearing limitations. For example, no hub gears possible, and derailleurs limited to using freewheel sprocket clusters. These are much more limited in range than cassette systems and are weaker as well.

This quote from Flecc..my post above applies,

 

[coops]

Hi oldosc, an illustration of freewheel gears & rear motor can be on flecc's Qbike pages, if that helps else there is more on it on the forum threads... somewhere...

Stuart.

 

[oldosc]

Oh my word,
We have fitted a head gasket to a 250hp cat engine whilst anchored on a lee shore, and thought that was as hairy as it got but that Bike wow.
Thanks for that thread, I was going to blindly buy the Black Star and fit gears, thinking how bad can it be.....
I have taken on the thinking behind the battery replacement, Flecc other reply, but feel this is probably an easier fix than the gears, and a much easier fix than swopping the lady in question.(Jove she's a brillant cook)

 

[flecc]

Oh my word,
We have fitted a head gasket to a 250hp cat engine whilst anchored on a lee shore, and thought that was as hairy as it got but that Bike wow.
Thanks for that thread, I was going to blindly buy the Black Star and fit gears, thinking how bad can it be.....

You might be interested in the T bike on a similar theme with a different way of dealing with the problem:

Torq Radical
.