Kemp Starley Dutch Town Bike - out of hibernation.

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
Hi folks, and welcome to a project I've just picked up to keep me occupied.
It might get brought back to life as electric or non-electric, or could become a parts donor - a lot will depend what I find when I get started.

First impressions :
It's a Dutch town bike by Kemp Starley, high build quality with lots of nice touches.
3 speed Sturmey Archer rear hub, 24v front hub motor, neat battery / rear rack. It came with fabric panniers so it's not obvious it's powered unless you look closely. Nice !
Front tyre (700 rims) had 0 psi but seems fine after I've blown it up.
To do: Remove seat, front shopping basket, pedals (tbc) for use on daily transport mtb.
Front forks are snapped, front wheel is off the bike.
Led controller 790 shows 4 bars power when battery key is turned on.
Battery is badged 24v 8ah, 3/4 bars lit on built-in battery gauge, 28.3v on meter.
Dutch sales website has others for sale if anyone is curious https://www.veilingstart.nl/search.aspx?keyword=kemp+Starley
Some parts are dated 2007/2008, bike has Halfords Netherlands stickers in places. If anyone has info about Kemp Starley bikes from then can you let me know.

Testing the 5-way hall sensor feed to front hub, black/red reads 4.8v (unexpected) when key is on, reads 0v key is off.
This seems to confirm the battery switch & controller (& scrap led display) are energising the system - good news!

The led 790 controller shows 5/5 power LEDs ok, severe internal water damage. Buttons do nothing, mode LEDs are never lit, shorting the pins on the buttons does nothing. It's scrap but ok for now.
Voyage from black earth - key on all 3 wires show 28.3v (internal short circuit?), key off all wires show 0v.
So it's (accidentally !) energising the controller which is good.
I'm not sure the effect of putting 28v to the speed wire (normally 4v max?).

Front hub was near-seized with all wires disconnected, the problem was traced to corroded internals from water damage.
Motor is now unseized (rust cleaned etc)
Satellite gears are now free, teeth undamaged, bearings ok for now (2 gears were stiff, 1 siezed).
freewheel hub is still seized (rusted pawls, or a non-freewheel version?) but is fine for testing.
All phase wires have been cut, 5-way plug for hall sensors is undamaged.
Phase wire tests : All pairs of show 3ohm, insulated from ground - test passed !
Hall tests : connect wheel to bike & turn on power, red/black shows 4.75v. Each hall to earth - 2 (yellow & green) are good and change when hub is turned. Blue is always 4.75v - failure on blue hall (or wiring)

Not even looked at yet : sensors on both brake levers, pas (it's hidden behind an enclosed chain guard), controller (built-in as part of the rack battery mount - I'm hoping I don't need to break it open)

I'm wanting to use this as a cheap way to learn what goes on inside an ebike, would be great if I can get it usable again but also happy to strip it as a donor if needed.
The other problem is I'm temporarily in Portugal which is now under lockdown. I have very limited tools here, no useful shops nearby, and it is difficult to receive post so ordering parts online is not an option.

Photos to follow;)
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
Photos - As delivered (front wheel tied on!) - battery voltmeter - led 790 display - motor internals - hub ID - battery test using 12v+12v car fog lights - controller
:oops:
 

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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Looks like you retrieved the bike from a dutch canal …..

The fully charged battery should be 29.4v, it has 7 cell groups in series each one 4.2v max. 28.3v is 4.04v per group it might just be out of balance, without surgery it may re- balance better after several charge /discharges or try leaving the charger connected for several hours to see if that helps (but outside somewhere safe).

The hub needs all the rust cleaning off back to nice metal if poss and the planet gears and the hub casings sun gear needs a hefty slop of dark moly grease. The electrics in the hub and LED needs a good clean and spray of dielectric spray, the rust tracking between the electronics will cause shorting.

The motor wire really needs replacing completely rather then re -soldering, motor cables are cheap to buy and can be eased in and out through the axle with good lube, I find dairy spread to be very good and slippery and better then grease .

The two white wires are/should be speed wires.
The other 3 hall sensor wires should show about 5v switching when the hub wheel is rotated slowly.
 
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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
@Nealh - thanks for the info.

Some progress today, it’s alive (sort of) :)

The front fork is scrap so I can’t make it any worse, have re-cut the snapped axle drop-outs so the wheel is now bolted in place (not safe but ok for testing).

Battery just needed charging (led on charger went green after about an hour, voltage was 29.1 I’ll leave it connected again today and see if it increases).

Hub has been cleaned and put back together, hub wires are frayed - I had to splice hall sensor earth as it was chewed through.
Blue hall (see photo) has no visible shorts but still always reads 5v.
Hub wire should be replaced but with no tools, no way to receive post and no suppliers locally my options are limited.
Would like to know if the hall problem is the sensor or a short in the hub wiring - will look into this.

Also cleaned the led display, some sections are so rusted a led & capacitor dropped off - oops ! Other LEDs are discoloured so are also rusted out.

I put it back together and it runs !
Very uneven due to the faulty hall but battery, controller, phase wiring, brake cutouts, pas etc are ok. Shame it cuts out after a few hundred yards (it tries the halls and shuts down when they don't work?)
Hub gears are very smooth, bike rides nice but feels very tall - circus bike tall :p

Then tried it with the halls disconnected (sensorless?) but it’s no good, the motor kicks then dies immediately.

A new 790 display, hub wires (and hall sensors?), and new front fork and it will be fine :) Now I just need to find the parts and a toolkit so I can fit them :oops:
 

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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
Things I found useful when I was fault finding (thanks to everyone who posted info!) :

* get a basic multimeter, and learn how to read voltage and resistance/continuity (to check broken wires etc).

* check battery voltage when you first get the bike ( does it have built-in led gauge?). Does the battery have big + & - terminals? Use multimeter (battery key "on" is needed)

* if voltage is above cutoff level ( eg showing 25+ on a 24v bike), its OK for initial testing.

* fit battery, turn on system, any signs of life on handlebar controls etc?

* for testing, its fine to then the bike upside down on carpet. Turn on system, spin motor wheel, turn pedals 2 full turns.

* if not, find the battery controller ( *not* the handlebar display), on the connector to the display (4 or 5 wires, red+black+blue+??) bridge red & blue to bypass the display - see post #2


* disconnect brake switches etc in case they are faulty, retry.

* inspect hub wiring, expect 3 large (phase) wires + several smaller hall sensors etc. Any voltage between red & black hall wires when system is on?

* if yes, you can test hall sensors - see post 8


* a battery that has been unused for a while may improve after several charge/discharge cycles, but for testing anything above "nominal" voltage should be fine to check the system is alive.
 
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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
The bike is now up & running but still has some issues.

The clutch has been stripped, cleaned & free’d off. Now back together and working fine.

Throttle connector works (using a potentiometer/ vari-resistor)

There should be 3 assistance levels but I suspect the shorted 790 display has done something to the controller as only assist level1 works. Maybe a good excuse to upgrade to digital display and new controller once our lockdown ends.

I’ve been testing it on a 5 mile circuit to a nearby village, the battery is getting better every time.

As a fun educational project, it’s working great :D
Many thanks to every one on this site - its been invaluable source of information !

EDADE756-FC16-4838-8C8E-C3F323C469A6.jpeg
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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29.1 v is good and not far off fully balanced , it may get better with more cycling charges.
The hub looks much better/cleaner hopefully you used a good dob of grease on the gearing ?#
The led looks like it is all but toast.
Hall sensors are cheap get ss41's from ebay for a quid or two.
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
Latest update : this has been a fun and educational project but I've decided not to take it any further.
The bike works and rides ok, everything is fixable but replacing all the bits that aren't quite right will cost more than the bike is worth.

Shopping list :
New controller (this one only works on level #1 assist even when given 2v/3v signal to trigger more assist)
New display (led 790 or upgrade to digital as part of the controller upgrade?)
New hub wire (working ok but torn insulation / exposed cores)
New hall sensors (confirmed - the blue hall is short circuited, it's not a wiring issue, replace all as a set)
New clutch unit to replace the repaired one, with new planet gears to fix the noisy bearing.
Hub bearings have slight play (not bad but not ideal)
New battery (it's OK for testing 29.2v/29.3v but struggles to complete a 5 mile circuit on assist level 1, new controller & halls etc might improve this but I'm not willing to invest to find out)
New front fork to replace snapped original, and a couple of broken spokes in the back wheel.
The deciding factor - riding position is very comfortable at a standstill but gets worse as speed increases (it's very upright, lots of wind drag - my 6ft+ / 100kg shape won't help), on the move I prefer my other bike.

Thanks for the help, I'll be back at some point (I'm already considering a bolt-on kit for one of my other bikes, but not for some time... )
 
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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
I've converted several of those sort of bikes to 36V, which gives a massive improvement to all performance characteristics. The extra voltage will have no harmful effect on the motor. It just gives the option of more speed.

36V batteries and controllers are more common than 24v and often better. This controller is 24v and 36v, so you can use whichever battery you want. You have to buy an LCD and speed sensor to go with it (recommend LCD3), and it might be an idea to get a PAS and throttle (if allowed in Holland) for connector compatibility.

 
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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
^ thanks @vfr400 - I had already looked at those kits and was wondering if I could run my 24v hub at 36v. Good to have it confirmed !
I like the idea but its a fun project being done on a tight budget, I'll see if I can find a cheap used 36v battery before deciding.
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
Things are moving forward as I've just found a place selling off new forks at bargain prices. Order has been placed, I'm happy.

The next priority is to fix the failed hall sensor (and the others), I'm looking for a UK supplier and I've seen a few posts saying "SS41F" is fairly safe option. I couldn't make out any markings when I had the hub apart and don't want to strip it again if I can avoid.
Before I comit, does this look ok (6 for £5 gives me some spares in case..)
Comments welcome
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
Th progress on this project is continuing (very slowly)

New forks for a bargain £25 (+ new stem to convert to threadless) is now fitted, very smart and a much nicer ride. https://www.amazon.co.uk/s?k=bankrupt_bike_parts+forks&ref=nb_sb_noss


4AD5276D-48EB-41CB-9465-C8C7B6C00831.jpeg

The problem now is the failed hall sensor. I bought the SS41F’s above, replaced the failed hall and I’m confused.
The 2 original halls switch between 0v - 5v, the replacement only switches between 0v - 0.5v, the bike sees this as a dead hall so it work no better than the failed original.
Wiring has been checked for breaks and shorts and all seems ok.
Is this a known problem or have I bought the wrong halls? :confused:

A8B2DD6D-7E04-47FB-9BB8-29497D074D5D.jpeg
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
7,938
3,153
Basildon
If you test halls with an independent power supply, they often don't switch properly because they need a pull-up resistor between the signal wires and 5v.

I noticed that your motor cable was badly damaged where it comes out of the axle. Did you repair that?
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
@vfr400 Hi. The hall was fitted then tested on the bike so I was expecting the controller to treat it the same as the original (working) ones.

The wiring is still badly damaged but it tests OK using the multimeter so I thought it would be OK to prove the new hall works OK.
Shame I'm heading back to the UK in 2 days so I think I've run our of time to do much more for now, will bring a new axle cable with me next time and see if that makes a difference.
On hold for now but thanks for the help !
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Did the old halls have any id on them ?
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
@Nealh The larger face (the back?) is clean and has no ID, the smaller face has glue marks but I see no lettering.
 

Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
I’m now back and working on this again. My plans changed a bit when I got offered a basic 36v kit. It's a rather sad story as a good friend had paid somebody to convert her bike - what she got was an incomplete and mismatched conversion - including a new 26” electric mountainbike wheel fitted to her 27” road bike :mad: We decided to put her bike back to non-electric and I would get all the bits she had - to be used on this project.

First job, check the 36v kit works on the bench. It does but only using the throttle (some PAS problem?)

I hoped I could just swap the motor internals from her 26" wheel to my 27", they were close but not close enough.

Plan B: take lots of photos of the spoke layout of both wheels before stripping them.

60D65A07-E192-45FF-8A2E-AB2CE041134F.jpeg

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329DC278-F354-4A41-8D4A-E4905F131024.jpeg
 
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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
I then spent a rather pleasant afternoon with beers and music, lacing my 27” rim & spokes onto her hub.

Part-way through my first wheel build :p
609261BB-55A1-45F2-AE3A-905D07FE1B9E.jpeg

The finished wheel :)
6B974D81-5D67-4587-9AD8-D252F9593B82.jpeg

The wheel was fairly straight once the spokes were nipped up, the final truing took a while but I'm very happy with the end result, looking forward to trying it out tomorrow (weather permitting)
 
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Scorpio

Pedelecer
Apr 13, 2020
165
63
Portugal Algarve (temporary)
I’m still making (slow) progress, the bike is now in regular use. I still need to tidy the wiring at the controller (in a bag behind the seat for now). It's all good fun :cool:
9A3660E1-E88F-4763-8677-0FC4B9042A79.jpeg
 
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