Latest road and single track weapon.

[oatnet]

<------- CORNER

Some shots of the bike with the new battery case fitted.

People should go back one page and see your latest pictures.

8) Your battery box, side panels, and mounting are slick and elegant solutions, and I really like that the project does not require an extensive toolset so it is accessible to almost anyone - though few will execute it as cleanly as you did. I expect many will follow where your imagination has led!

-JD

 

[teklektik]

Your battery box, side panels, and mounting are slick and elegant solutions, and I really like that the project does not require an extensive toolset so it is accessible to almost anyone.
...
I expect many will follow where your imagination has led!

+1
Kepler's eye for clean design has come through again.

Wow + Mental wheels instantly turning = Inspiring!

 

[waynebergman]

Very nice. Looks real pro. I look forward to hearing updates on the fun you are sure to have on this bike. A light weight & quiet pedal assist mid drive that looks trouble free. Awesome! Makes my 85lb tank look kind of rediculous really.

 

[Kepler]

Thanks all for the feedback. I am really pleased with the overall look of the bike now.

With all the fantastic mid drive emountain bikes now coming out, this has really given me a heap of inspiration to build a bike that can compare to these high end works of art without the constraints associated with a commercially built bike.

The Bafang might not be quite as well designed as Bosch but it but it still ticks most of the boxes. Although I ride with 200W most of the time, it is very nice having 1000W on tap plus the ability to travel at 50kph if I really want to.

 

[Modbikemax]

Looks great! I am not sure I am a fan of the mounts though. I would have opted to hard bolt the case to the frame through the Ali walls of the box and slide the batteries in after through the side panels.
100% for style and I like the picture with bike leaning against the transformer.

 

[Kepler]

Thanks for that.

With the way the slide plate is attached to the aluminum, there is a heap of strength there. The bigger problem would be with pressed bottle mount blind nuts failing as with any of these bottle mount battery systems. This will change once I add the back mount. I think I have settled on a design now that will give me the added strength and stability needed for rough single track work.

 

[Kepler]

Finished off the rear mount. This mount stops all lateral movement of the case and also keeps the case securely mated into the front slide mount.

Also fitted a plastic support plate to the bottom of the case that allows the majority of the weight to be supported on the outer shell of the bottom bracket.

The case is now super secure on the bike but still can be removed in a matter of seconds.

Finally go the BMS but still waiting on the batteries to arrive. Hopefully here this week as its been a month since placing the order.

 

[Samd]

How do you feel about the size of the 29er Kepler? Is the BBS still ok for torque despite the bigger wheels?

 

[Modbikemax]

Nice tidy job but I can't help thinking you are going to get movement potentially flogging out the frame.
How about a clamp instead of the o ring?
How often are you going to remove the battery anyway? I would be taking a nice bike like that inside not just the battery.

 

[Kepler]

How do you feel about the size of the 29er Kepler? Is the BBS still ok for torque despite the bigger wheels?

I think the stock chain ring is too large with for the 29er setup. I am using a 44tooth but the 42tooth Italian CNC'd chain ring would be better.

 

[Kepler]

Nice tidy job but I can't help thinking you are going to get movement potentially flogging out the frame.
How about a clamp instead of the o ring?
How often are you going to remove the battery anyway? I would be taking a nice bike like that inside not just the battery.

Fair comment. I am not too worried about damage to the frame though as the heavy duty O ring squeezes the 2 posts together so there is zero movement. Something I will definitely watch though.

In regards to battery removal, I am actually removing the battery nearly every time I charge. For my situation I typically charge the battery in my office so quick removal and attachment is an important consideration for me. Also I quite often take the bike out without it being powered so taking the battery off then is a must.

 

[--freeride--]

Very nice Build. 29 is the best

I like your Battery.

 

[savaoaknyc]

Hi Kepler,
so what is the weight of the empty box??

 

[Kepler]

The box is 450 grams on its own. About 50 grams lighter than the long skinny box I first made for the bike. Still haven't received the 18650 cells. Unfortunately they are being sent slow post from Poland. Been 5 weeks now so hopefully I will see them soon. I think it is going to come up to a similar overall weight to the LiPo setup I had except 50% more capacity and a lower centre of gravity on the bike.

For the time being I have just shoved 13S 1P 5.8ah LiPo into the new battery case. Gives me 250Whr which is enough for my 30km commute on PAS setting 2. Allows me to spend most of my time traveling between 30kph and 40kph.

 

[jesset33]

Kepler do you know any one who has confirmed that we can squeeze more power out off the 750 w bbs02 system ?

 

[Kepler]

I have run mine up to 1500W by using 15S and the drives max voltage of 61.5V. Fine for small bursts but no way the drive will last. IMO for best reliability, limit the drive to 18A and go no more than 13S LiPo or 14S LiOn. This still gives you plenty of power (about 800W) and should allow the drive to go the distance. I am up to around 4000km on mine now using these settings.

The latest stock 9 FET drives are 25A so they do about 1250W out of the box but is not proving to have great reliability with quite a few of them having controller failures.

 

[jesset33]

Is it hard to replace a controller
My last bbso2 needed new bearings as I have had mine in a lot off water and that make them crunchy

Trading up from a phasor to some thing light weight and practical. :lol:

 

[Kepler]

A quick update on this bike. The Bafang has just passed the 5000km mark and is still running strong and quite. Just in the process of carrying out a service and inspection of the drive at the moment. This will entail a tear down just of the final gear drive section. This section of the drive isn't particularly well sealed and tends to pick up a lot of road grime. Will degease and re pack this section of the drive.

The new battery box has done quite a few miles now including rough single track work. The mounting system has proven to be super secure but still a 10 second process to remove from the bike for remote charging. Still running LiPo in this battery box but now have the 18650 cells ready for install in the near future. The 18650 cells will double the range on this bike so looking forward to that.

 

[Samd]

Is it hard to replace a controller
My last bbso2 needed new bearings as I have had mine in a lot off water and that make them crunchy

Trading up from a phasor to some thing light weight and practical. :lol:

Very easy to change, Jesse.

 

[Allex]

great machine Kep!
I would like to build a similar bike.

 

[kfong]

One of the few bikes that has caught my eye for single track, since that is all I ride. Makes me want a bbs setup. I'm not sure I would trust the water bottle mounts over time. Especially the abuse I put my bike through. I tried a 29 last year, felt very floaty over the trails, the 27.5 seems the ticket for me. I like the qiuck response of the 26, but the bigger tires really go over obstacles well. I usually do between 15-20 trail miles per ride, pedaling as much as I can. Going to install a torque sensor this winter to force more effort on my part. GNG was something I was going to really concider, the noise eventually turned me off it. You seemed to have found a combination that is as good as the Mac/BMC for torque and stealth.

 

[Ozziebike]

Man I love it! Would really make me consider going for the Bafang!

 

[pendragon8000]

Clean build bench mark... Again

 

[John Bozi]

Envy your skills wow!

I got sent here because I came to the same conclusion about the throttle being a push button and needing somehow to connect the kill switch to stop the after lag, and of course you have the solution

It looks a bit too difficult for me what you have done but still wonder if I can just swap out the throttle for the button first.

I saw your diagram but looks confusing. Is it possible to just wire the button to the throttle wires and which colours match in what way? I haven't cut back the sheath to see yet...

Also on your build how do you fabricate things so well? Do you own a load of expensive machinery, is this your occupation? Where do your source your alu etc.? I wish I could fabricate stuff so well without the arm and the leg I'd have to sell.

Finally looking at your use of the maximum 61.5v do you think in my situation I should just stay at 12s because I am running this through crystalyte 4065 freewheel hub?

Thanks Kepler, your work is inspirational.

 

[Kepler]

Thanks John. To do just the button throttle is quite simple. Just forget about the microswitch in the diagram and connect the red wire directly to the one side of the button. Also forget about the 10K resistor. The colour coding in the diagram is as per the wiring colour on the Bafang throttle wire.

In regards to fabrication, I have a hobby lathe with an overhead mill attachment and a variety of hobby quality tools and equipment. Nothing too special. However, being a Mechanical Engineer by profession, it allows me to design in a way that makes fabrication possible without the need for a lot of fancy equipment. Being able to visualize your design is very important when it comes to fabrication which is why i like to use drawing programs to model the design followed by mockups and finally the end product.

In regard sourcing materials, I have a number of suppliers close by to me that provide me the materials I need in small quantities and very reasonable prices. You just need to find them close to you.

In regards to voltage, 61.5V has little advantage with the BBS drives. Stick with the design 48V nominal voltage if you can.