Midmotor & hubmotor combo

[hjns]

Hi all,

I have been lurking for a couple of years after some exciting experiences with a 8kW CroMotor on a Fully as well as a 250W power Bofeilli midmotor hardtail. I'm just not happy with the Bofeilli's low power with 36V bottle pack, nor with the extremely heavy CroMotor + accompanying 20S lipo pack.

My purpose for my bike is the following: get me from home to work along my normal 15km commute (30km/day) but at the same time get me up a steep mountain (20-30% inclination) and down a not-too-dangerous single trail down hill if I feel like it. The Bofeilli doesn't get me up those hills nor down the single trail within one piece. The CroMotor + 20S pack is way too heavy for any down hill attempts.

So I have been looking at relatively light weight Fully solutions, mid-motor preferably. I have pulled the trigger on a Haibike FS RS (45kmh version) with the accompanying licence for these kind of bikes here in Switzerland. That should do the trick, and I will share my experience with the thing in a nice review here. Taling about experience, it took a lot of time to save up for that bike, though....

However, I was just wondering if anyone here has experience combining a mid motor with a relatively lightweight low turn rear hubmotor like a 6t Mac or so?

Getting uphill with such a machine would rely on the midmotor through the gears. On the flat, a high speed hubmotor on a small extra 15S pack should allow me to maintain the topspeed much better than the mid motor alone. At least, in theory. Any thoughts?

Thanks!
KR,

 

[hjns]

I'll pick up my Haibike tomorrow morning....

 

[hjns]

Picked up my Haibike this morning in Germany. It is gorgeous. I will try to post some pictures as soon as possible.

Unfortunately, in order to drive it in Switzerland, competent authorities need to specifically approve it, as proven by a yellow number plate. The approval will hopefully be given based on the EU certificate of conformity. But you never know until you got it.... And of course, they only have time to look at my bike by the end of October....

Anyway, the first thing is to create a nice single (mid-)motor baseline. As mentioned, this bike will be used for daily commutes, as well as for short detours with very steep hills. I want to keep track of this using various technologies, including but not limited to the Cycle Analyst with Data logger. I'm very uncomfortable to hook the CA into the Bosch system, for fear of losing warranty. I also have no idea how the Bosch system is laid out, don't know where to even start measuring voltage and current, and I am not ready to tinker with it. A "stand alone" CA/Datalogger using a dedicated power source will at least give me the opportunity to record speed and altitude. Any other suggestions are more than welcome!

 

[nutnspecial]

Awesome, congrats on the new bike! It will be awesome to see coverage/ learn about it.

Johnbozi of australia is the main guy I know of with a dual setup, and although the hub was a heavy clyte, maybe there's some info there to help you if choosing to supplement with a rear hub.

I have no clue on Bosch mid/CA; I would go direct to ebike.ca and ask their support team about it- they should know better than anyone imo.

Have fun!

 

[hjns]

Thanks, Nutspecial!

And here is the first image:

 

[hjns]

All photos made using a Sony A7ii with a Summilux-R 50mm on a Fotga adapter

Nice little Midmotor. It is driving a 20T gear. The small gear is located exactly at the pivot point of the rear swingarm, resulting in significantly decreased chainslap when managing rough terrain. Very smart solution for what is actually quite a universal problem with many full suspension MTBs. From my single descend I can already tell that it works like a charm. No chain slapping when dealing with smaller bumps at 30kmh. The red cover is doubling as a protection plate.

Power is transferred into a 10-fold cassette with gears from 11T to 36T. When shifting, it is very noticable that the motor temporarily cuts out. Especially when going up a very steep (>25%) hill, this will take some time to adjust to, because the rhythm is slightly different as compared to switching gears on a push MTB. I found this out during my single ascend behind my house, that has 250m of 25-30% inclination in it. I managed that on the Turbo setting and in lowest (36T) gear without a sweat. And remember I am an untrained 40y male with a desk job!! Pretty amazing!

Brakes are Magure MT4 hydraulics. Obviously, they cut the motor when activated. Brakepads are breaking in very quickly, so that is nice. I still need to find the best position for the break handles. I prefer a one-finger approach, but these brakes are not really designed for that. We'll see what can be done. The front fork is a Fox 34 CTD with a remote control on the steering bar. It has "only" 120mm of travel, but considering that these are 27.5" wheels, this should be sufficient from some great XC work. One shouldn't do any major DH jumps with an Ebike anyway... cause you would take the bus or lift uphill and thus don't need a motor in the first place.

The lights (front and rear) can be switched on and off using the console on the steering bar. Nice and bright, but not as bright as my Crays LEDs. Probably sufficient though.

Saddle with adjustable post to quickly and easily change post height depending on climbing or descending. This is not standard, but I find this soooo useful while on the trails.

Obligatory rearlooking mirror. It is in the way when making a very tight left corner, so I may reposition it. Will have to experiment with this.

 

[hjns]

Status update. Meeting with competent authorities only on the 20th of October. Until then I'm not allowed to use the bike on the public road. So, no further updates until after I get my licence.

 

[meelis11]

Looks like really nice bike! Are you really so law-obeying and patient that you just wait until you get your licence?
At least go for off-road or smth!

What brand chain it has? Keep us updated about chain life.

 

[hjns]

Whatever I am posting is going to be either law abiding or hypothetical, including anything on dual motor setup. And the wait is not that difficult, as I'm currently on a holiday in Italy, without my bike. When I get back, off road is a possibility within the law, but won't provide good numbers on range or durable power.

I will certainly note the chain brand here, and watch chain life.

 

[hjns]

Tomorrow is the official evaluation. With some luck, I get the approval and the number plate right away! We'll see.

In the meantime, I added some carbon mud guards front and rear. Really love these!

(not my picture, but taken from the Rock Guardz website)

 

[hjns]

So, here we are. Licenced and whatever!

My father-in-law and me put the bike in the car, and this morning we drove to the Motorfahrzeugkontrolle (competent authorities). A nice man reviewed again the documentation and found them in order. Then he asked us to wait until the agreed time for the actual inspection. We were 30 min early, so we waited 30 min.

Here in Switzerland they like accuracy. So a few seconds after the agreed time, we were approached by another man who introduced himself as the inspector. He invited me to drive my bike into a hallway with equipment very much like in a lot of garages. However, he only checked whether the serial number etched in the frame was the same as in the European Certificate of Conformity provided by the factory, and if the nominal power description of the motor (printed on a sticker on the Bosch motor) is within the limits. The inspector noted the obligatory mirror and checked the brakes.

All the while, the inspector was smiling and nodding, and making comments like "nice bike", "great frame", "good brakes", "nice mirror". He clearly had not seen anything like it.

Then he put on full motor gear (full face helmet, jacket, trousers, gloves) but normal shoes (imagine pedalling with motor boots...) and asked me for instructions how to handle the bike. I explained the different power settings, the interuption of motor function when activating the hydraulic brakes, automatic speed management when closing 45kmh, and then he took off.

If I ever saw an e-grin it was when he came back after 10 min. Comment: "let's give you the licence"!

We then had to wait another hour before the paper work was done and I got my actual licence. Costs CHF 200. But this was surely worth the wait!

Required documentation:

• Passport
• Purchase bill
• Customs documents
• European Certificate of Conformity

Documents provided by Competent Authorities:

• Bike certificate with insurance document
• Bike passport
• Yellow licence plate

After fixing the number plate on the bike, I took off to work (15km) at "Turbo" level. Topspeed 45khm, average speed 30kmh, exactly 30min, estimated range left (in "Turbo") is another 20km, so I can do my whole commute in Turbo setting. This is what I wanted, this is what I needed! And now I got it! One happy ebiker here!

Next efforts will include creating a good baseline using my daily commutes and occasional hills. I will continue to post the results here.

 

[phalluscopter]

Holy shiet thats a lot of work just to be able to ride. Your bike looks sweet btw. Thanks for all the updates and pictures!

 

[tomjasz]

Yikes! And Americans complain about regulations...

 

[hjns]

Hi all,

Here is a summary of my experience during the first 350km.

Riding
I have done 9 daily commutes (30km/day) and the occasional mountain (twice). My way to work is between 13.5 and 15km, depending on the route. Over the 9 commutes, I found myself in "Turbo" 90% of the time, averaging 30kmh (including stopping for traffic lights) with peaks of 45kmh (not counting long downhill trajectories). Usually, the 15km would take me 30min or less. I think it is important to note that when I was driving my 8kW Cromonster, I was doing this route in exactly the same time (but with much higher power consumption due to crazy acceleration, the thirsty motor and my use of the throttle).

I find that I keep overtaking more and more ebikes, and that I can keep up with most of the other 45kmh speed pedelecs (Strömer, Dolphin, Kalkhoff, and the likes). However, in order to maintain 45kmh (actually 43kmh), it takes really a lot of sweating, because (1) the bike only gives full power when it detects that you are actually pedalling hard, and (2) it starts turning down the power at speeds higher than 43kmh. I do like the first point (but would prefer to choose diferent power settings with different inputs), I don't like the latter. Theoretically, this last issue is easily managed using 3rd party solutions like the ASA speed thing. The first issue can probably only be managed by taking a look at the electronics and find the Rsense (there may be two of them, not counting the ones for the lights). The board is actually inside the motor, so to find out more will take a lot of time disassembling, frolicking, and assembling again. So I will delay this look to probably next spring or so.

Going downhill is really nice! I have adjusted the suspension so that it is firm enough to do some mild jumping. The bike takes to the trail quite well, and I can really take advantage of the added motorpower when lifting the steer to hop onto/over a lump or when coming out of a corner. Brakes (Magura MT4) do feel a bit spongy, but that may also be because I am used to a set of Formula R0. Compared to those, everything else feels spongy....

Maintenance
When I bought the bike, I also got a service booklet, with the first service planned after 300km. I have brought the bike in, mentioning that the rear brake was too spongy (it really was). The mechanics serviced it (brakes, chain, etc) and gave it back to me after a full day working, because they had really trouble bleeding the rear brake. Not sure if this is a Magura issue or anything else. The shop also has Shimano Saint brakes, but I may want to go back to my Formula R0..... Anyway, the mechanics did solve the sponginess, and now the rear brake is working as it should. Total costs for the service was 29 EURO, which is quite ok for an official entry into the service booklet.