My Story with the Cab Bike Hawk

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19
Sorry for the English... my German is non existent, but I'm sure Google translate can be very helpful.;)
I hope this forum welcomes all the foreign languages and shares everything about the velomobiles.
 
After more than 150 emails exchanged with Pima, I visited Pima in Poland to try out the Cab Bike Hawk (CBH). I was impressed with the quality of the CBH I tested, the blue one from their website.

During my discussions with PIMA, I made it very clear that I wanted a motor, I wanted to be able to reach 45km per hour, and the CBH needed to be CE certified to get it registered in the Netherlands for a number plate and insurance.

On the 17th of July 2017, I signed the contract to start manufacturing the CBH with a promise from PIMA to deliver latest by 7th of October 2017.

October passes, November also, December I get impatient. I received the CBH on the 19th of December 2017. more than 2 months later. On inspection, I discover that the rear light lense is broken. I was promised to be sent one in 3 weeks. Until today I have not received this. To compensate for the delay, PIMA promised to send me a free trailer for the CBH. Until the time this article is written (November 2018) I have not received this.

A couple of months pass by, and I'm still not very comfortable while pedaling. I'm stretching my legs too much and I'm getting those weird pains in the legs. I need to bring the pedals about 5 cm closer to me. To do this, I need to open the hood. The hood opens only 30° , not enough to work on the pedals. I also remember the nightmare scenario of another CBH owner (gweisser) who tore the same hinge from the CBH body while opening the hood. The front hood needs to be removed completely. So I postpone this major job for a later time.

A couple of months pass by and I notice that there is a missing number on the decal I ordered. I thought I removed it without noticing while cleaning, but then I noticed on some pictures PIMA sent me that the number is also missing on these pictures. So it wasn't me, a small mistake from PIMA.

February 2018, I went to test the CBH at the RDW (the Netherlands Vehicle Authority) to get it certified for a number plate. The CBH failed to pass the test! All the lights (chinese no brand) have to be CE certified. The electrical motor needs to have a CE certificate of Electromagnetic conformity. The seat belt needs to have a strength certificate. The start key has to be only 1 key, not 1 for the electra and 1 for the motor. Everything I asked for to register the CBH to drive at 45 km per hour legally when I was ordering the CBH in July 2017, was not done! Even the maximum speed is not 45 km/h, only 36!

The CBH drives reasonably quiet. It does have some squeaks and odd sounds here and there from the under carriage. A bit of grease and sort of quiets down. For a while... From time to time, I need to readjust the seat because the velcro is not sticking well to the glue.

In April, I ask Pima for how to connect the 2 keys to 1 key so that I can start the electrical system and the motor together. I'm just sent 11 documents, all in Polish. When I ask for more details I get no answer.

Summer comes and all the glued items are falling off from the heat. All the LED strips, all the protection pads, the seat needs to be adjusted more often.

In August I have a few weeks of holidays. I decide to overhaul the CBH. I change all the lights with brighter CE certified lights from Highsider, so brake, signal, front left and right headlights, rear brake/blinker lights and front blinkers. While doing this I discover all the shoddy electrical work. Bad and loose soldering, and unpractical connections.

This is the final result for the lights. Very bright and clear. Please excuse the mess in the garage...
upload_2018-11-9_0-57-56.png

I also decide to change the chainring. I had a 43 on an Efneo GTRO and upgraded it to 65. While doing this I discovered that the chain was not in line with the chainring and the chainring was rubbing against the supporting wall of the crank. So I had to add a 3mm spacer to the bottom bracket (spindle).

upload_2018-11-9_1-5-42.png

I also remembered the story of GWeisser opening the front hood to more than 30°, so I decided to change the “barn” hinge that was holding the hood to the body, to a hinge from Hettich, that opens more than 90°. To do this, I sent an email to PIMA in August 2018 to ask what is inside this box where the barn hinge connects to the body. NO ANSWER!!!

In my quest to find a solution to the opening of the front hood, I open a small hole in the place where the original "barn" hinge was fixed to introduce a camera.
upload_2018-11-9_1-8-0.png

I was completely shocked at what I discovered! and I understood why Gweisser had a problem with the hinge.
  1. The reinforcement half tube that runs around the inside of the CBH is glued on to the body with some silicone glue. This should have be done with epoxy glue.
    upload_2018-11-9_1-9-38.png
  2. The aluminium plate that was holding the "barn" hinge is 1 mm thick sandwiched between 1 mm fiberglass with no other support such as molded hard plastic or even wood to fill the void and to hold the screws!upload_2018-11-9_1-11-40.pngupload_2018-11-9_1-12-11.png
When I sent PIMA this email, all I received from them was a long sarcastic email bitching about how I should buy a VW and complain about it and lots of blablabla, but no asnwer to fix these problems.

I cut a square opening to this box and removed the aluminium plate and filled it first with fiberglass putty to close the holes of the fortifying frame and then epoxy. This was done for both the hood and the body.
upload_2018-11-9_1-16-2.png

I then installed a Hettich (made in Germany) kitchen cupboard hinge. Solid stuff and does it's work perfectly. Now I can open the hood almost to 80°. I did consider Septomax but it was a bit too expensive...

upload_2018-11-9_1-16-42.png
upload_2018-11-9_1-32-13.png

Sarcasm from such a young company is not very productive or useful when they need all the support they can get. PIMA just buries its head in the sand, ignore the emails and phones calls, and hope that the problem goes away. That is not how to run a business or treat clients.

All in all, the CBH is very beautiful to look at and very comfortable. When it is raining, you are protected. But it stops there. The reliability on the long run will suffer! Only buy this product if you are VERY handy and are willing to forfeit the guarantee (as if that really existed anyway)! For all the problems I had, I refuse to be an advertising board for them, so I removed all advertising signs from the CBH. I am considering getting a student artist to use it as a canvas... but this is for another time.

If a client buys a product from there, he has to be prepared to NOT receive any after sales support. Emails are ignored. Phone calls are not answered. Promises are not kept.

 
Now this is a real eye opener. Thank you!
I got some sympathies for the Hawk because the original Cab Bike was produced not too far from me and it was among the early velomobiles to see serial production, but this one: Hrmph, obviously.
All the velomobiles I have seen so far are built to high quality standards and the customers are a discerning bunch, so Pima probably better rethink their production policy if they want to succeed in the long run...
Cheers, Martin
 
If all those who cheer and some future or potential customers invite Pima to respond in this forum, one might get a response.
If not , why should Pima (and others) change their game plan?
 
Pima did response in the thread "Alles über das Cabbike Hawk" and it was just like CBHWagih wrote here...
 
Excellent idea, I bought one and will pick it up tomorrow...

If you are planning to change your hinge, please consider this in the following picture:
upload_2018-11-9_23-37-6.png

This picture is for the inner side of the hood. I was measuring how big the "block" where the Hettich hinge is supposed to attach. In this picture it is too small by about 25mm.
You will need to extend this so it is about 19mm from the lip of the hood. In the documentation of the Hettich hinge, you can see the correct dimensions.
First I had to remove the flocking because nothing sticks to it. Then I had to build a small wall of plastic or thin wood extending towards the lip or border of the hood, make sure it is level with rest of the actual block and then pour a 2 component resin or epoxy. It takes a long time to harden. Once it is hard, you can remove the "walls".
Then there is the bottom part as shown in my previous post. I can't remember how you fixed your hood, but if the box is still empty, you may need to do the same as I did; I cut a square opening to this box and removed the aluminium plate and filled it with fiberglass putty to close the holes of the fortifying frame and then epoxy.

Then there is a small piece of black hard rubber or plastic cut and sanded to an angle (I think) 15°. This wedge has 4 holes for the screws and is exactly the same size of the door plate of the hinge.
When I was putting everything together, I closed the hood and taped it in position, making sure that I could not see any light coming between the hood and the body when I was looking inside. Then I put some double sided tape on the Hettich hinge on both the door/hood and body sides. Then I placed the hinge in its place from the feet openings. First the body side. While doing this try to come as close as possible to the hood. Once the body part is stuck in its place, I inserted the 15° wedge between the door hinge and the hood, making sure that I slide it in on the hood. Once it is in the correct place it will stick to the double sided tape that was placed on the hinge. Now comes the frustrating part: drilling small guide holes and screwing some stainless steels screws. Take care not to go all the way through!

Now you can open the hood to about 80°, make sure that the lip clears the rubber when opening.

Let me know if you need more info. Have fun!

Just remembered: There is also an 3mm aluminium plate under the body part of the hinge. This is to spread out the torsion weight of the hood when it is open.
 
regarding the top speed problem, I could imagine several reasons:
- the controller is not programmed correctly.
- the battery volts drop due high internal resistance, at high current demand.
- you have a 'slow wound' motor, good for hill climbing
- motor has not enough power or you don'd pedal enough
- you've got a 48Volt motor but a 36V battery
 
Thanks a lot for the suggestions, I have the hinge now and will check the situation tomorrow. How did you limit the opening angle? If the angle between the two plates is 90° with a closed hood then the hinge opens more than 120° in addition. Since you only open to 80° the you did block the opening somehow?

Looks like you also closed the original holes of the front lamps? Or is it just the reflection of the covers?
I changed the lamps, I created a new mount for two IQ-X e and also removed the front covers of the holes, they created too much reflection.
Old mount with weight 466g:
IMG_2221.jpg IMG_2223.jpg

Front with removed covers and new lamps, weight 351g.
IMG_2284.jpg IMG_2285.jpg IMG_2224.jpg

Sorry for the impaired image quality, it was dark outside and the foto from the inside is not as good as intended.
Driving through the darkness is a pleasure now, great light.
 
How did you limit the opening angle? If the angle between the two plates is 90° with a closed hood then the hinge opens more than 120° in addition. Since you only open to 80° the you did block the opening somehow?

Looks like you also closed the original holes of the front lamps? Or is it just the reflection of the covers?

I'm assuming that the angle between the 2 plates is 0° with the closed hood. When you open the hood it should stop at 80°. If you go further than 80°, you risk damaging the lip of the hood cover of the body. On the Hettich hinge you can adjust the opening angle. I changed the original screw for a longer one so that it would block the arm at 80°. You will also need some sort of support to keep the hood open, like an old fishing rod cut to the right size.

There used to be plastic covers for the lights on the outside. I had to remove them because it caused a danger of injuring/cutting someone in the event of a frontal crash. I replaced them with 4 mm poly-carbonate covers glued to the inside of the hood with clear silicone. The covers have a 2 mm recess so that the cover fits inside the hole and is flush with the hood from outside. When I took the picture the covers were still with their protective sheets.

I know there is a bit of reflection but I can live with it instead of water coming inside the CBH.

I was also looking at the IQ-Xe but couldn't find enough information on them so I got the
LED low beam and high beam spotlight SATELLITE from HIGHSIDER from brands4bikes.de.

All the lights and blinkers had to be CE certified to be able to drive on the road when the bicycle path is too small.
 
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regarding the top speed problem, I could imagine several reasons:
- the controller is not programmed correctly.
- the battery volts drop due high internal resistance, at high current demand.
- you have a 'slow wound' motor, good for hill climbing
- motor has not enough power or you don'd pedal enough
- you've got a 48Volt motor but a 36V battery

- How do you program the controller correctly?
- The only high current demand happens when at complete stop and just starting.
- I don't know if the motor is slow wound or not. It's a GoldenMotor Magic Pie 5 1000W on the 20 inch back wheel.
- The motor has enough power. I changed the chainring on the Efneo GTRO gear to 65T and since I have 3 gears I have 65T, 93T and 116T with a Shimano 9 gear at the back. I pedal about 90 cadence.
- Motor is 48V and battery is 48V 23A

With this info would appreciate some ideas on how to improve the speed.
 
so your motor should have ample power. However motors are made for a certain optimal speed respectively RPM.
Is there a label on it, or did PIMA say anything?
Controllers often have a speed limit programmed, normally there's a sub menu for that.
If the controller limits your speed, power falls off quite abruptly. If it's the motor RPM, power ceases a bit more smoothly.
Maybe you can check at the GoldenMotor Website what they have in the 20'' department?
 
Motor is 48V and battery is 48V
Ich denke, da ist das Problem.

Beispiel: Golden Motor

Im Leerlauf und 20" HR dreht der
48V Motor: 370 rpm bei 48V = 7,7 rpm pro Volt = 35,5 km/h

36V Motor 370 rpm bei 37V = 10 rpm pro Volt = 35,5 km/h
aber auch
36V Motor 480 rpm bei 48V = 10 rpm pro Volt = 46 km/h

!!! rpm im Leerlauf !!! unter Last sind es nur um 90% davon
 
36V Motor 480 rpm bei 48V = 10 rpm pro Volt = 46 km/h

If you overload the 36V motor with a 48V motor, you will fry the mosfets and the controller.
You can use a 48V motor with a 36V battery to bring down the speed but not the other way around.
A 48V battery is charged to 70V, I think???

The controller limits the RPM to 380.
I believe there must be a way to increase this to 520 with the software of the controller without overloading the controller and the mosfets.
But how?
 
If you overload the 36V motor with a 48V motor, you will fry the mosfets and the controller.
einen 36V Controller an 48V Akku: ja
Einen 10 rpm pro Volt Motor (Golden Motor nennt den 36 Volt): nein
:)
A 48V battery is charged to 70V, I think
4,2V pro Zelle max
Li-ion 13S = 46,8V Nennspannung, 54,6V Ladenschlussspannung.
Li-ion 14S = 50,4V Nennspannung, 58,8V Ladenschlussspannung.
:)
The controller limits the RPM to 380
Nein
:cool:
I believe there must be a way to increase this to 520 with the software of the controller without overloading the controller and the mosfets
Ja und nein, es gibt Controller die den Motor schneller drehen lassen (sollen), die habe ich aber noch nicht getesten.
:confused:

Mach mal bitte Fotos von Motor und Contoller
 
If you overload the 36V motor with a 48V motor, you will fry the mosfets and the controller.
You can use a 48V motor with a 36V battery to bring down the speed but not the other way around.
No. On all accounts.
There are no '36V' or '48V' hub motors. They are similar motors with different windings and hence, different speeds. Thats all.
A '36V' direct drive hub motor will work with a 72V battery. It just turns a lot faster. ;)

For instance:
I have two Bafang SWXH. One is the 24V/28" version, the other is the 36V/20" version. They are exactly the same motors, both turn with the same speed at 36V, the only difference is the sticker.

The controller doesn't mind if you plug a '24V', '36V' or '48V' hub motor to it. You definitely don't fry the Mosfets doing so.
I fried some controllers and hub motors (by other means). :D

You fry controllers, if you raise the battery voltage above the voltage the controller components (Mosfets, Capacitors) are designed for.
For 36V and 48V controllers, the max voltage is usually 63V. If the controller components of your 48V controller have 100V specs, chances are good you can use them up to 90V just fine.

The controller limits the RPM to 380.
I believe there must be a way to increase this to 520 with the software of the controller without overloading the controller and the mosfets.
The battery voltage limits the max RPM of the motor, not the controller.

You can get some controller that use field weakening to speed-up the motor, but not by that amount. Realistically (on the road), the controller with field weakening speeds-up the motor by 10-15%. Since the controller uses additional power to speed-up the motor, the motor will get noticeably hotter, though.
 
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Thank you Marc and JKL for clarifying my knowledge about the motors.

I'm guessing you will be a great help for solving this next issue.
I'm trying to connect my 48V battery to the 12V electrical system so that I can use only one key to start the motor and the electrical system together.
At the moment, I have 2 keys, one for the motor only and one for the electrical system.
I do have a DC to DC converter Orion-TR 48v/12-9. I chose this model because it can be connected to an on/off switch so when ON the connection between the 48V battery and the eletrical system is closed and the electricity passes. OFF the electricity does not pass.
When the motor switch is on, I measured 0V on the 2 pins/wires of the switch. I don't know if it will measure higher if the motor is running.
On the switch of the electrical system, I can see 4 pins/wires coming out.
My idea was to connect the 48V/23Ah battery in to the DC/DC converter and from there out to the 12V battery out connection. Remove the 11.7V/7Ah battery. Connect the motor switch to the DC/DC converter on/off green connection.
This should work, but what should I do with the switch of the electrical system?
How can I keep this switch on all the time and just cancelling the key?
Thanks
 
Thank you Marc and JKL for clarifying my knowledge about the motors
Nicht dafür und sorry, das ich in deutsch schreibe.
So gut wie @Marc hätte ich das nicht mal in deutsch erklären können
;)

Die Frage ist, ob der Schlüsselschalter die Ampere des 12V System vertragen kann, vermutlich nicht.
Ich denke, das einfachste ist es, den DC/DC Converter direkt an die Batterie anzuschliessen und beim verlassen des VM die Batterie zu trennen.
 
On the left you can see the switch for the motor:
upload_2018-11-15_12-7-12.png

This is the switch for the electrical system:
upload_2018-11-15_12-6-59.png

The question is whether the keyswitch can handle the amps of the 12V system, probably not.
The keyswitch is already handling the 12V. The motor keyswitch will be connected directly to the DC/DC converter. This must be less than 100 mA. The big question is how calculate this?
 
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