Probike Mercury (with lead acid battery and twist grip throttle)

[AlanRHB]

Further to my post in “Introductions”, some more details of my Probike Mercury, and possibly some questions for the knowledgeable here eventually.
Although at first I didn’t actually care for the look of this “Dutch type” step through, I am learning to love it, the step through helps my arthritic body to mount and dismount easily, and even though heavy, it is a very strong steed indeed, and relatively well balanced with a fairly low centre of gravity

I do not know the age of this bike or very much info available on 'tinternet, but I was lucky to find an accurate picture and specsheet...
Perhaps a clue to age on the controller label (about 8 or 9 years old) but no sign of the Probike brand online anymore,

 

[AlanRHB]

Hub motor and controller details

P

 

[Nealh]

Depending on your usage if you ever need more range then you can currently get from the replacement SLA's, you can in the future if you keep the bike go for a retrofit 24v silver fish battery to fit behind the seat as yours is. A new lithium 15ah battery would come with a charger and new battery mounting plate/kit for about £150, range would be much better as well as power from the battery.
Another advantage is a weight saving of a few lbs.

 

[vfr400]

That looks very similar to a Cyclamatic Power plus, but with a lead battery instead of Lithium. the battery could easily be converted to lithium. I've done a couple of similar ones myself.

The controller rating of 12A is very low. You can get a lot more torque out of the motor by a simple trick of adding a bit of solder to the shunt in the controller to take it up to around 18 amps. Those motors can handle a lot of power. You can even go up to 36v, which will make it much faster and more powerful.

 

[AlanRHB]

I only took off the end opposite the loom entry vfr400, but don't recognise the shunt
in there



Perhaps the shunt is at the other end.
popped it back together for now, but can check at the weekend

I wondered about 36v, would this controller take 36v when modified to your instructions, or maybe an upgrade ?

 

[AlanRHB]

I checked out the Cyclematic Power Plus as well vfr400, yes very similar and around the same era 2010/2012 ? perhaps the same motor and controller.
I am going on the manufacture date on my controller label, but of course the bike itself may be a little later.

I find the history of ebikes very interesting, even though only scratching the surface so far.
Presently reading about Neal's Swizzbee ... a good read ... (note to self, thank Neal for the link) ...

 

[Nealh]

It is possible the shunt might be on the underside of the pcb.

 

[vfr400]

I only took off the end opposite the loom entry vfr400, but don't recognise the shunt
in there

View attachment 32499

Perhaps the shunt is at the other end.
popped it back together for now, but can check at the weekend

I wondered about 36v, would this controller take 36v when modified to your instructions, or maybe an upgrade ?

If it's the same as a Cyclamatic, which it looks like it is, the shunt is under the big capacitor on it's left side behind that red wire. You have to take the pcb out, which means all the other seven screws.

 

[AlanRHB]

Thanks vfr400 and Neal, I will strip at the weekend and let you know what I find if I may.

 

[AlanRHB]

I took more photos of the pcb out of the case vfr400 and Neal...



Underside of pcb

Top view pcb


Capacitor details


Under large capacitor

 

[vfr400]

See the thick red wire, then the thick black wire. The next thing in that line is the shunt, grinning at you from under the black wire. Pull the wires out the way, then add a blob of solder about 25% of its total length. Give it time for everything to heat up so that the solder fuses.

It looks like you have the white wires for the speed limit. IIRC, it's disconnected for no speed limit and connect for limited, though it might be round the other way.

I've just noticed that you have some burnt tracks, one of which has been repaired by the green and yellow wire on the back. You should cover the other ones with solder, otherwise they'll corrode. I'd say that that was caused by a short on that yellow wire, which seems to carry battery voltage. Do you know where it goes? The Cyclamatic has that wire, though red, but it isn't used for anything. Maybe somebody tried to use yours for lights or something.

 

[AlanRHB]

Wow! It certainly is when you know what you are looking for...

The legs are very short, so is the blob actually on the legs from the pcb, around each bend onto the horizontal section, measuring 25% of the whole length.
or is the blob of solder restricted to the horizontal length from the bend towards the middle from one or both sides of the shunt for a total of 25% (2 X 12.5%)
Or



After sorting the shunt and other soldering that you advise, I will Road test then if speed is limited, will pick your brain further regarding the white wires if I may.

Many thanks for the advice so far.

 

[AlanRHB]

Just before I covered the bike up for the night, I followed the two thin white wires to this adjustable terminal (rheostat?) ?.
I wonder if I leave this item accessible after reassembly if It may allow me to adjust the power/speed cut off.
My maximum without pedalling on the flat, is 12mph at the moment.

Soldering and reassembly tomorrow I hope ...

 

[vfr400]

That adjuster is for the speed limit. Turn it each way to see which way increases the speed. You just have to use your judgement for the solder. It's difficult to see in the photo whether that's solder or the coating on the shunt has fallen off. I would start with a blob on each end up to the middle of the bend.

 

[AlanRHB]

It was coating on the shunt vfr400. I cleaned it off completely, then soldered both legs to just after the bends ... a good blob on the inside of one bend, but just tinned the other as not so accessible


I think nearer 35% rather than your advised 25%.

I reassembled temporarily, and tried it down my road towards towards town which is an incline for half a mile which I need assistance to climb back again.
The motor is certainly more “gutsy” and accelerates far faster than it did even uphill, I also left the speed limit adjuster all the way one way, and there seemed to be a small increase in top speed also uphill, but the test cut short when an insect flew into my face, was trapped under a helmet strap near my eye so stung me The eye socket and cheekbone area are aching, but washed well and took anti histamine.

I am very pleased with results so far, in fact considering the bike is using 24v lead acid batteries ( now 2X 12v SLA agm 33ah) a pretty fair result.

Thank you again vfr400 for sharing your extensive knowledge with me. ... will keep you posted with further developments.

 

[AlanRHB]

A more extensive test today, near me is a stretch of road about one mile long and fairly level. So a few runs along and back as quiet this time of day, trying the “speed limiter” adjustment all of the way clock and counter clockwise, but no difference in top speed or acceleration, so have now left it disconnected, as they have done in the “Beastamatic” topic about tuning the Cyclomatic, I found on here last night ... .
You were correct vfr400, there are similarities between my Probike and the Cyclomatic, particularly the controller, which may prove very useful for the future .

The result is more than I hoped for with 24v SLA batteries, fast acceleration pedalling from a standstill, then holding 23mph on the throttle without pedalling both ways along this flat road, slowing to 10mph then accelerating back up to 23mph without pedalling.
mph checked using my phone with GPS speedometer, after the equivalent of four miles using motor only, the hub was quite cool, and the controller only warm.
Need to check temperatures on a long climb next, but as the object of this bike is for exercise, I will not be “pasting” it on a regular basis, but useful for carrying me home when my legs have run out of steam... more anon. ...

 

[vfr400]

Thanks for letting us know the results. Don't forget that the increased current runs down the battery quicker. If you find that you don't have enough range, you can take your lead batteries out of the case and wire in a cell-pack from Ebay or Aliexpress. 24V ones aren't very dear, but you want one that can give at least 20 amps. some of the very cheap ones can't do that.

 

[AlanRHB]

Thank you for all of your help vfr400, I am over the moon with this distant cousin of the Beastamatic, and of course thanks to your reference to the Cyclamatic now have access to lots of useful information relevant to my own Probike Mercury.
Not so much raw speed that I need to use, but the improved hill climbing abilities are worth their weight in gold.

Yes, 36v li-on in my 24v case eventually, then even a replacement controller with led and additional power options ... then find a decent full suspension frame to build a more modern replacement bike using these electrics. As you said, this is a decent hub motor with the capacity for further upgrades ... budget e-biking at its best ...
It certainly hits those bumps hard currently on poorly surfaced roads. but a good “test bed” to enjoy learning more about these e-bicycles.

Many thanks once again vfr400 for sharing your valuable knowledge, and also to Nealh for his tips, and links to such interesting material
Alan.

 

[AlanRHB]

To comply with UK regulations in order to continue to qualify as an e-bike rather than a moped, I have now readjusted the speed limit control to allow a max of 15.5 mph, and sealed it back into the controller housing below the frame bottom bracket shell as per manufacturers spec.
As this bike prior to work on the controller, struggled to eventually attain 12 mph on the flat and quickly lost momentum on hills even with pedal assist, I am pleased that even with the correct speed restriction now in place, the torque of the motor has improved markedly and now tackles fairly steep hills with only moderate pedal assistance and without a dramatic drop in speed.