Stealthy front hub-drive for ancient Raleigh?

[samsavvas]

Hi Folks,

I'm a reasonably accomplished bicycle tinkerer and have a well equipped bike shed. I've restored and rebuilt many bikes and have already put together a couple of rather eclectic e-bikes so I feel reasonably confident about tackling something novel. So here's my project: I have an ancient, very faded and tired-looking Raleigh men's roadster made for 26 x 1-3/8" wheels, which it has lost along with most other shiny bits, but still has a really nice sealed chain case and original crank and pedals. It has the very slack/relaxed frame angles that sedate bicyclists such as myself covet and value. So naturally I want to give it a bit of electric assistance! Because I want to retain the chain case without carving it up to fit a mid-drive and because I want to install a new 3 speed hub in the rear, I've decided it's going to get a small front hub drive. So I want to ask the forum's advice please.

First, here are my goals:
- it needs to be relatively inexpensive
- I'm very happy to build my own wheel and already have a set of excellent rims
- I want both thumb throttle and PAS
- I'd prefer to use a 36V battery (although I'm not yet sure where it's going to go)
- happy to make up a package from recommended components
- I'd prefer to use my own N.O.S brake levers (using e-brake sensors which I can easily make up myself)
- I don't need to go faster than 25-30km/h with pedalling, happy for 25km/h throttle only and any inclines I'll need to deal with don't really qualify as hills
- would prefer not to have an LCD screen and if I must have some sort of meter or display, for it to be discrete
- I would like to keep everything, including the wiring, as 'stealthy' as possible (I'm happy to make up my own switch box to keep the handlebars free of plastic controls)
- I'd very much like the front motor to be as small as possible and polished alloy (not black). I don't plan to paint this old bike and I want bare alloy parts so they too will acquire 'patina' over time and blend in...

My question is, what small and inexpensive motor and what controller should I get? I've been looking at the Q100 family here: https://bmsbattery.com/31-36v?id_category=31&n=26. Also similar motor kits here: http://www.greenbikekit.com/electric-bike-kit-1/front.html?limit=30. I really like the size of the Q100 but I'd like to better understand how it stacks up against other small hub motors that may be available. It's all getting a bit confusing as neither of the vendors identified is overly generous with information. I'm in Oz by the way and need a vendor in China or somewhere else not too far away. Did I say 'relatively cheap'?

Thanks in anticipation!

Savvas.

 

[crea2k]

You'd be better off running a bbs2 mid drive on it than a front hub motor, as it'll be a lot more stealthly as you wont have to have a controller, plus it will be lighter than a hub motor, plus if its an old hard tail like the Raleigh I have, the front forks on it are like toothpicks, so putting a hub motor in something like that would be a reallllly bad idea. For plenty of power a hub motor is spot on with the right frame thats beefy enough to handle it on the BACK, but I wouldn't go putting a hub motor on the front of an old bike, as its likely to bend something, plus the handling will be ropey as hell with all the weight at the front.

 

[Ykick]

Measure your front dropout width. I've ran into 85mm or slightly less on some 1970's road bikes. That will limit your choice of front motor. I've used Q100C, Q128 motors with good results. Not torque monsters or speedsters but if you help pedal on hills they're a nice, lightweight to go.

How about a picture of the bike? Does it have enough hand brakes to safely do what you want?

 

[green79]

Just to flag that the older Raleigh 3 speeds have non-standard threading so a mid drive might not work. Sheldon Brown has a great website on this. I don't think the dropout width is a big issue - I've been able to squeeze 100mm hubs into the 90mm 3 speed dropouts before. FWIW I would not put a motor with the standard 3 speed brakes - they are very flexy and with steel rims they are horrible when wet (though you'll probably replace the rims with a motor hub). I would recommend Dia Compe centerpull brakes with some kool stop pads.

 

[dogman dan]

I agree, very likely a bike that old will not accept a modern bb sized mid drive. A small hub motor should be possible to cram into the front forks. Might have to bend em up some, but doable.

Want a display, but no plastic shit on the bars, hmmm. Put a cheap wattmeter in the battery bag?

 

[Drunkskunk]

The Andana Cute Q100 is the about smallest, weakest, most gutless motor you can buy. It's also a very good motor, and has enough power to meet most people's needs. If you want stealth and simplicity, this is the motor to get.

A few suggestion for added stealth. Forget the front motor. while a Cute is small and will look not much different a than a brake hub, the wires sticking out and strapped to the side of the fork and along the frame won't be even remotely stealth.
Instead, use a rear motor, and mount the controller down under the bottom bracket. it will be partly hidden by the chain ring, and the cable routing will be easier to the motor, battery, and throttle.

If the bike has an old weathered look, try Ebay for an old leather bag or briefcase. you can mount the battery in that on a back rack or panier, or use the leather to make a frame bag.

 

[samsavvas]

Thanks for the ideas and helpful comments,

The front forks are a shade under 90mm - I could try spreading them but I am aware that there is less leeway to do this at the front end. The brakes I had in mind were a Sachs drum in the rear (part of the Sachs 3 speed I was going to install) and a long reach dual-pivot Tektro calliper for the front - have one in the parts box.

Rims would be a new set of Sun CR-18s in the 26x1-3/8" size this bike requires. So I have no concerns about rims or brakes but the comment about the strength of the front fork has me a bit concerned. They are indeed fairly slender and curved - I'll have to give that some thought if the forum thinks they may not be strong enough. I had indeed thought about a BBS01. The BB is the standard Raleigh 73mm which I think the BBS can be adapted to. However the bike has a chain case which I'd like to retain, so some surgery would be needed. I'd have to put the BBS on the bike and line the case up to see if it will still mount OK (the mid-drive will probably have a wider chain line than the original crank). Also, I'd have to chop out a circular section on the back of the case to accommodate the main gear case and then figure out how to mount it securely at the front end. See - I said it was a 'project'!

Apart from the 'stealth' aspect, one advantage of the BBS route is that I'd be able to maybe use a Sturmey Archer 70mm combined dynamo/hub brake at the front which might be nice and more in keeping with what I'm aiming for. Someone asked for a picture - I'll take one as soon as I can. In the meantime, just picture something pulled off the scrap heap and you'll have an accurate idea of what I'm working with!

Thanks again for the thoughtful responses folks. I think I need to go back to the drawing board on this one.

Savvas.

 

[Ykick]

You may have to give up the enclosed chain case which is a mild trade-off if the BB otherwise works.

Here's my old Ross with the narrow, (83mm, IIRC?) light forks:


This one uses a Q128H rear motor on 16S RC Lipo - 900W. I built the wheels with CR-18 rims which greatly improved braking performance. While they're not as firm as more modern V brakes it's plenty of brake wet or dry, even towing a load of stuff in the trailer.

 

[motomech]

Thanks for the ideas and helpful comments,

The front forks are a shade under 90mm - I could try spreading them but I am aware that there is less leeway to do this at the front end. The brakes I had in mind were a Sachs drum in the rear (part of the Sachs 3 speed I was going to install) and a long reach dual-pivot Tektro calliper for the front - have one in the parts box.

Rims would be a new set of Sun CR-18s in the 26x1-3/8" size this bike requires. So I have no concerns about rims or brakes but the comment about the strength of the front fork has me a bit concerned. They are indeed fairly slender and curved - I'll have to give that some thought if the forum thinks they may not be strong enough. I had indeed thought about a BBS01. The BB is the standard Raleigh 73mm which I think the BBS can be adapted to. However the bike has a chain case which I'd like to retain, so some surgery would be needed. I'd have to put the BBS on the bike and line the case up to see if it will still mount OK (the mid-drive will probably have a wider chain line than the original crank). Also, I'd have to chop out a circular section on the back of the case to accommodate the main gear case and then figure out how to mount it securely at the front end. See - I said it was a 'project'!


Apart from the 'stealth' aspect, one advantage of the BBS route is that I'd be able to maybe use a Sturmey Archer 70mm combined dynamo/hub brake at the front which might be nice and more in keeping with what I'm aiming for. Someone asked for a picture - I'll take one as soon as I can. In the meantime, just picture something pulled off the scrap heap and you'll have an accurate idea of what I'm working with!

Thanks again for the thoughtful responses folks. I think I need to go back to the drawing board on this one.

Savvas.

Here's how I would proceed, if I were to electrify your bike. But first, a couple of points.
First, the electric motor wheel requires a double-wall rim and the supplied wheel ASM from BMS Battery would be just fine for your application. There can be a small savings by shipping a motor only, but it is small and really only worthwhile if a wider/stronger rim is needed from what BMS B. can supply. You do not need such a rim.
Secondly, you will have a battery, so there is no need for a dynamo. And a decent cantilever with the formentioned Cool Stop pads will be all the brake you need at the speeds you will be traveling.
Rather than spread your forks 10 mm, go with the Q85 kit and use spacers(washers) to take-up the 6 mm space(3 mm on each side).
So this kit;

https://bmsbattery.com/ebike-kit/595-q85-36v250w-front-driving-v-brake-e-bike-motor-wheel-ebike-kit.html

Order the "201" wheel and put in your wheel size.

For a controller, I understand that you are not wild about a display, I don't care much for them either.
BUT, if you are serious about PAS, you owe yourself the pleasure of using the SO6S w/ the SLCD-3 display. With this combo, you will have available 5 levels of PAS controlled "torque", not speed! This feature is unique to this price range system. Once you learn how to use all the features of the SLCD-3, you will like it.
https://bmsbattery.com/ebike-kit/546-s06s-250w-torque-simulation-sine-wave-controller-ebike-kit.html
https://bmsbattery.com/ebike-kit/546-s06s-250w-torque-simulation-sine-wave-controller-ebike-kit.html
For a battery, order the largest capacity of this style battery as you can afford;
https://bmsbattery.com/ebike-kit/595-q85-36v250w-front-driving-v-brake-e-bike-motor-wheel-ebike-kit.html
36V Li-on! That battery with the "201" motor will put you in the 17 to 18 mph range with decent climbing ability.
Extra items you will need are;
https://bmsbattery.com/ebike-kit/595-q85-36v250w-front-driving-v-brake-e-bike-motor-wheel-ebike-kit.html
https://bmsbattery.com/ebike-kit/595-q85-36v250w-front-driving-v-brake-e-bike-motor-wheel-ebike-kit.html
https://bmsbattery.com/ebike-kit/550-speed-sensor-ebike-kit.html
https://bmsbattery.com/bicycle-parts/511-spoke-wrench-bicycle-parts.html
https://bmsbattery.com/ebike-parts/459-hwbs-hidden-wire-brake-sensor-1pcs-parts.html

Good luck

 

[d8veh]

I would go for the Q100H, which is 100mm wide. It packs a fair punch for its size and is very cheap. i don't know the width of your forks, but if they're too narrow, they will easily spread to accommodate the motor. 201 rpm version gives 25 km/h, 260 rpm 32 km/h.

You don't want an LCD, but the controllers that have them give much better control over the pedal assist - enough that you don't even need a throttle, although you can still have one if you want.

I'd use this battery:
https://bmsbattery.com/ebike-battery/730-36v10ah-bottle-09-e-bike-battery-charger-battery.html

and a S06S controller with S-LCD1. You also need a wheel-speed sensor and a PAS. The S06S is a sine-wave controller, so it makes the motor very smooth and quiet. It also has "torque simulation" (current control) that makes the pedal assist really nice compared with normal square-wave controllers.

If your frame doesn't have the fixings for a bottle cage, you can install some yourself using rivnuts. I use three for extra strength. They're very easy to install. You just drill a hole, put them in and tighten a screw in them while you hold them down. There's youtube videos showing you how to do it.
http://www.ebay.co.uk/itm/151470688046?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

[samsavvas]

I would go for the Q100H, which is 100mm wide. It packs a fair punch for its size and is very cheap. i don't know the width of your forks, but if they're too narrow, they will easily spread to accommodate the motor. 201 rpm version gives 25 km/h, 260 rpm 32 km/h.

You don't want an LCD, but the controllers that have them give much better control over the pedal assist - enough that you don't even need a throttle, although you can still have one if you want.

...and a S06S controller with S-LCD1. You also need a wheel-speed sensor and a PAS. The S06S is a sine-wave controller, so it makes the motor very smooth and quiet. It also has "torque simulation" (current control) that makes the pedal assist really nice compared with normal square-wave controllers.

Thanks for that concise set of recommendations D8VEH - much appreciated. Plans have changed a bit. I'm now considering much the same combination but applied to my commuting bike, my old Moulton APB. I'm thinking of a rear wheel installation using the Q100CST at 328rpm.

A couple of further questions:
- will the S06S accept a 3 speed switch? Is there any pint in having such a switch on a small motor?
- I note the Q100CST motor seems to have a sealed wire, multi-pin lead and plug, carrying I presume the power wires and the Hall sensor connections. Should I also buy the BMS motor connector which appears to have a similar matching socket and lead? Are there any other small bits and pieces I'd need to connect everything up?

Despite the APB having multiple 'vacant spaces' within its space-frame construction, I'm having considerable difficulty in figuring out where to stash the battery and controller, mainly I think because I don't want to compromise the carrying capacity of the front and rear platform racks. I have a 36v/10ah Ping brick - would this be a satisfactory power source for this motor and 6 fet controller?

thanks,

Savvas.

 

[Ykick]

Definitely listen to d8veh but a couple comments - the Q100CST will come with a waterproof connector motor-controller wire so I'm not sure what you're referring to there?

I would avoid the 328 RPM motor unless this is going into a 20" or smaller diameter wheel. Mini motors will heat considerably if you lug them in inefficient RPM ranges. 26"-28" wheels should use 201 or maybe 260 RPM motor if you strongly pedal.

Triangle frame bags = the best way I've found to carry batteries. Your ping should be fine to power a mini motor but what's the physical dimensions? Can it go in the frame triangle?

 

[d8veh]

328 rpm is too fast for a 26" wheel or bigger, unless you do something special.

You don't need a 4 speed switch with the S06S. You should get a pedal sensor. It will then give you 5 levels of power with throttle override. The power from the throttle depends on how much you twist it.

The Q100s all come with a cable that will fit to their controllers.

Your Ping battery would probably have to go on a rack, otherwise get one og the BMSB downtube batteries.

 

[samsavvas]

328 rpm is too fast for a 26" wheel or bigger, unless you do something special.

You don't need a 4 speed switch with the S06S. You should get a pedal sensor. It will then give you 5 levels of power with throttle override. The power from the throttle depends on how much you twist it.

The Q100s all come with a cable that will fit to their controllers.

Your Ping battery would probably have to go on a rack, otherwise get one og the BMSB downtube batteries.

Thanks Ykick and d8veh,

Apologies - I referred to my APB in the previous post but I realise that not everyone shares my enthusiasm for strange small-wheeled bikes! The Moulton APB is a suspended 20" wheel bike, hence my nomination of the 328rpm motor. It has a low triangulated 'space' frame made with tiny little steel struts. It has no down-tube or frame triangle in any conventional sense and limited room on the seat tube (where the bottle mount eyelets are) so battery mounting using one of the convenient 'bottle' or rack mount packages is proving difficult to imagine. It has flat platform racks front and rear (as are popular on 'cargo' or 'porter' bikes). I use these flat racks constantly - the rear has a big wire basket on i - and am reluctant to take up room there with a battery. There is an awkwardly-shaped trapezoid space immediately behind the seat tube which I think I'll end up using. Otherwise I'm left with putting a battery in the base of the rear basket, which would somewhat curtail my 'commuting' space.

My APB is now quite ancient but going strong. I think it's going to be a more practical candidate for a hub motor than the Raleigh mentioned at the start of this thread. I'll follow up the recommendations you have all given me and maybe come back with a picture of the results when I've finished. I note in some other threads that some believe small-wheel bikes may not be good candidates for electric-assist because they are thought to 'wheelie' on hills. The APB has quite a long wheelbase so I'm hoping this won't be a problem. I've ridden a Moulton TSR with a BBS01 fitted and not noticed any such problem, and I suspect the BBS01 has quite a bit more grunt than the Q100 I'm planning to use.

Thanks all - inputs have been very greatly appreciated! There's always more to learn...

Savvas.

 

[docnjoj]

Check out Miles thread on powering a Moulton.
otherDoc