Oh dear, another quandary on which kit??

colinstone

Just Joined
Aug 25, 2018
4
0
69
Good evening all,
Just joined and thinking of electrifying my trusty 1991 Shogun mtb - pic attached. Hopefully the tea leafs will leave a gopping pink bike alone!!
IMG_20180825_1149582.jpg
I spend the summer boating on the canals and rivers in Europe and only transport is a cycle. Towpaths are easy being flat, but of course it is often hilly to towns and I'd like to venture further. Travel radius currently is about 10 miles. I'd like to extend that to 30 miles.
Shogun has triple chainring 28-38-48, 7 speed cassette 12-28, combined shifter / cable brakes and weighs 16kg.
From reading this and other websites, it seems that crank drive may be the way to go, especially with hills. Although the Pedelec guide is not so certain. But perhaps for a first go, a front hub drive kit? And thinking of kits from Woosh, which seem to be pretty keenly priced and the bits will all work together. Or have I missed something?
I am pretty mechanically minded and handy.
So a few questions that I haven't been able to find answers for:
1. Does the BBS01 crank drive torque sense?
2. Is it feasible to dismantle the supplied brake lever sensors and transplant the bits into my current combined shifter/levers? I have a number of small neodymium magnets that I can attach to the brake levers.
3. How much drag is there from a front hub motor and cd motor when in human pedal mode?
4. The Woosh Krieger, crank drive, had a couple of interesting comments - good for hills but not if you don't pedal fast!
5. And can I mount the water bottle carrier on top of the battery??
So a bit of a quandary??
Any thoughts / advice gratefully received. Thanks.
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
2,460
1,675
69
West Wales
Hi Colin,
1. No, it's a cadence sensor.
2. No, the switches are built in. However you can buy sensor switches which you can mount on your levers, they are normally used for hydraulic brakes. You may want to think about upgrading that front brake to a Magura HS11 anyway. Better able to deal with the extra weight on those hills.
3. If it's a geared hub, none, because there is a clutch in the motor that allows freewheel when power is off or you are over assist speed limit Not experienced BBS but I understand it's the same. You will feel the extra weight of the bike though.
4. Crank drive motors need to operate in their sweet spot to deliver their power effectively and not bog down. This is done by being in the right gear for the motor, this may not be the right gear for your preferred cadence.
5. Wouldn't advise it, it would mean drilling the battery case. Not to be advised unless you are outdoors with the fire brigade in attendance!:eek:

Personally I think front hub is the easiest to do. Can be a bit tricksy on loose steep surfaces but is fine for general road riding and the occasional path. Don't discount a rack battery with a front hub. Battery weight is high but overall weight distribution is OK with the motor at the front. I've done 6000 miles on my conversion with rack battery (even carry a range extender in the pannier these days) it's never been a problem. Well except when I'm stunting:cool::(
 

Derrick Lewis

Finding my (electric) wheels
Jul 20, 2018
21
4
56
Redditch
The switches on the brakes can be popped out, inside is a reed type switch and has long as you got a area on brake flat enough for the switch to press against it can be used, had to cut plug off and resolder I didn't have enough area for switch so put a bit off a picture hanger and glued it on brake and works great.
 

Eagle

Esteemed Pedelecer
Aug 31, 2012
381
134
As Benjahmin points out:

Crank drive motors need to operate in their sweet spot to deliver their power effectively and not bog down. This is done by being in the right gear for the motor, this may not be the right gear for your preferred cadence.

I would recommend that you go for a hub kit as opposed to a crank drive kit. There is also far less strain on the chain and gears etc with a hub motor.

The front hub may be easier to do, but you are less likely to skid on a damp or loose surface with a rear hub.

An alternative is to buy a used electric bike which has most of the basics fitted already and allow, say, £300 for a new battery from Insat International (BGA Reworking).

http://www.pedelecs.co.uk/forum/threads/battery-replacement.32078/#post-450058

As an example, here is a used Wisper Works 905SE:

https://www.ebay.co.uk/itm/Wisper-Electric-Bike-Works-905SE/202415874600?hash=item2f20ed2228:g:Ui4AAOSwuMRbgmjm

Keep an eye on the classifieds here, ebay and Gumtree etc.
 

GLJoe

Esteemed Pedelecer
May 21, 2017
852
407
UK
As Benjahmin points out:

Crank drive motors need to operate in their sweet spot to deliver their power effectively and not bog down. This is done by being in the right gear for the motor, this may not be the right gear for your preferred cadence.
So what would be the equivalent advice as per above, if you were to be talking about a hub drive instead?
 

Woosh

Trade Member
May 19, 2012
19,406
16,387
Southend on Sea
wooshbikes.co.uk
So what would be the equivalent advice as per above, if you were to be talking about a hub drive instead?
No pain no gain.
ride at a fixed speed, where the motor is at its peak efficiency.
That is typically one third lower than its noload speed, eg, if the noload speed of your geared hub motor is 23mph, then stick to 23 * 2/3 = 15mph.
 

Eagle

Esteemed Pedelecer
Aug 31, 2012
381
134
IMO, a hub motor is far more forgiving and gives plenty of power assistance at all times regardless of cadence. All you need to do is select the right gear for where you feel most comfortable.
 

GLJoe

Esteemed Pedelecer
May 21, 2017
852
407
UK
IMO, a hub motor is far more forgiving and gives plenty of power assistance at all times regardless of cadence. All you need to do is select the right gear for where you feel most comfortable.
While a hub motor can be fine for a number of situations, for people needing to deal with steep hills, I think your logic is back to front, and its the crank drive that's 'far more forgiving'.

bearing in mind that the actual motors themselves are effectively the same technology, let me re-write the initial advice, but for hub drive:

"Hub drive motors need to operate in their sweet spot to deliver their power effectively and not bog down. This is done by travelling at the right speed for the motor, this may not be the right speed for the situation you actually find yourself in!"
 

Woosh

Trade Member
May 19, 2012
19,406
16,387
Southend on Sea
wooshbikes.co.uk
bearing in mind that the actual motors themselves are effectively the same technology, let me re-write the initial advice, but for hub drive:

"Hub drive motors need to operate in their sweet spot to deliver their power effectively and not bog down. This is done by travelling at the right speed for the motor, this may not be the right speed for the situation you actually find yourself in!"
you have greater motor diameter in geared hub and DD motors: CD motor diameter is kept small because of the typical arrangement: it's squeezed into one side of the gearbox, typically 12cm in diameter, 8 poles. Geared hub and DD motors can have much larger magnet ring, more poles. Their efficiency increases rapidly with the number of poles: 16-24 poles.
 
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Eagle

Esteemed Pedelecer
Aug 31, 2012
381
134
GLJoe,

While a hub motor can be fine for a number of situations, for people needing to deal with steep hills, I think your logic is back to front, and its the crank drive that's 'far more forgiving'.

I am not getting into a debate over hub motor vs crank motor.

People must test ride different machines and then come to their own conclusions, bearing in mind that individuals and their specific requirements are often markedly different.

All I will say, on the basis of owning two hub-motored bikes (FreeGo Eagle and an Oxygen MTB), is that both climb extremely well on very hilly terrain in West Wales and I do not have to pedal like crazy to reach the top.

There are 4 ways out of my village and every single one is up a steep hill. Without an electric bike I would have no chance whatsoever.
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
2,460
1,675
69
West Wales
Me too in West Wales. 6000 miles covered and never suffered a motor stall. I try to keep a minimum of 8mph uphills, but have been down to 6mph on the steepest ones. Gets a bit noisy at that speed and the controller gets hot, but sorts itself out on the flat. (For clarity I do have the mighty Ezee Mk2, large diameter and prodigious hill climber Wife has the Bafang bpm - ditto).
Most of my riding is done at 12-14mph which is fine by me. 16 gears allows me to pick the pedal cadence to suite me and let the motor get on with it's thaing.:cool::D
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
19,990
8,172
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West Sx RH
With hub motors you need to select highest assist for hills and then they romp up them easier, much better if you use 48v and 17/20a controllers then they have plenty of power.
 
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Benjahmin

Esteemed Pedelecer
Nov 10, 2014
2,460
1,675
69
West Wales
With hub motors you need to select highest assist for hills and then they romp up them easier, much better if you use 48v and 17/20a controllers then they have plenty of power.
Nah! Always use 2/5 unless I'm on the last stretch home and feelin pluckered, then I might go to 4. Anything higher and the range gets a kicking.
Mind you, I don't mind working. It's great to have a bit of exertion going up, to feel that glorious easing as you come onto the flat and you feel like you've got the legs of a 25 year old again. 'Cors the problem is he always wants 'em back!:(;)
 
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