Latest road and single track weapon.

[Samd]

Lovely work John. Well done.

I had always wondered about 15s tripping the HVP, didn't know about the 61.5 volt limit!

We should do an evening ride when the days get longer. Whilst I'm still not a fan of the bbs for offroad, been having the time of our lives with the the kids on the back of my wife's Mundo. It pulls up our hill like a mule, four people onboard 8)

 

[tahustvedt]

Nice and clean ride. I would definitely put some fatter slicks on the road wheels. Fatter tires have lower rolling resistance and better comfort. Road racers use slim tires for reduced air resistance.

 

[oatnet]

Hey Kepler - another elegant build, light, clean, and stealthy, well documented with descriptions and pictures, thank you for yet another major contribution to the sphere. Your microswitch on the shifter is genius. When I finish my current EV project and return to ebikes, you have inspired me to try a BBS02 build.

-JD

 

[Kepler]

Thanks Jd. Glad I could help with the decision on your next build project Been watching that EV project of yours with great interest. Makes any of bike projects look fairly lame in comparison. Great work on that one.

 

[Kepler]

Lovely work John. Well done.

I had always wondered about 15s tripping the HVP, didn't know about the 61.5 volt limit!

We should do an evening ride when the days get longer. Whilst I'm still not a fan of the bbs for offroad, been having the time of our lives with the the kids on the back of my wife's Mundo. It pulls up our hill like a mule, four people onboard 8)

Look forward to catching up for another ride in the near future. Maybe I can convince you that the BBS is the track weapon of choice when applied to the right bike. I am now quicker around my Lysterfield trail circuit on the BBS then my BPM powered Fighter 8)

 

[Kepler]

Nice and clean ride. I would definitely put some fatter slicks on the road wheels. Fatter tires have lower rolling resistance and better comfort. Road racers use slim tires for reduced air resistance.

I have some 32mm, 38mm, tires and 48mm ries for the bike and will have a bit of a play over the next few weeks. I dont think it is correct that fatter tires have lower rolling resistance though. Stands to reason a larger contact area with the road equates to a greater rolling resistance. Whether the difference between a 25mm and say a 32mm tire is discernible is probably more of a point of conjecture.

Between the two setups pictured, the road version rolls way better then the track version but of course that is one extreme to another. Comfort wise, 120mm of suspension travel back and front even makes the road going set up an extremely compliant ride.

 

[Allex]

Damn nice as always, looks factory built! Would like to try this kit someday...

 

[morati]

Beautiful work Mr. K!

 

[PRW]

As usual, an inspiring build, Kepler.

This is tempting me to take the BBS-02 off the Iron Horse, and put it on a 700C commuter - although without the very clever power cut-off. On 15S, is the motor spinning at around 100rpm?

thanks

 

[Samd]

I am now quicker around my Lysterfield trail circuit on the BBS then my BPM powered Fighter 8)

This sounds like fun

Regarding PRW's point above, I've always assumed that the software compensates for change in voltage with the RPM sensor - but I may be wrong here.

 

[Kepler]

Going 15S, I was a bit concerned about the higher crank RPM but its proved not to be an issue at all. At the end of the day your cadence is governed by the load on the bike and the gear you are in. It feels no different to 12S except that the lowest PAS setting is now about 150W as opposed about 120W on 12S. My up and coming CA3 conversion will fix that.

 

[PRW]

that's excellent, thanks Kepler

 

[tahustvedt]

Nice and clean ride. I would definitely put some fatter slicks on the road wheels. Fatter tires have lower rolling resistance and better comfort. Road racers use slim tires for reduced air resistance.

I have some 32mm, 38mm, tires and 48mm ries for the bike and will have a bit of a play over the next few weeks. I dont think it is correct that fatter tires have lower rolling resistance though. Stands to reason a larger contact area with the road equates to a greater rolling resistance. Whether the difference between a 25mm and say a 32mm tire is discernible is probably more of a point of conjecture.

Between the two setups pictured, the road version rolls way better then the track version but of course that is one extreme to another. Comfort wise, 120mm of suspension travel back and front even makes the road going set up an extremely compliant ride.

There have been done tests that verify that fat tires have lower rolling resistance. Pro cyclists are starting to use 25mm tires as well now instead of <23mm:

http://www.schwalbetires.com/wider_faster_page

http://velonews.competitor.com/2012/03/bikes-and-tech/technical-faq/tech-faq-seriously-wider-tires-have-lower-rolling-resistance-than-their-narrower-brethren_209268

 

[hjns]

very very nice! My dreambike now, and I am already planning to do something similar.

 

[teklektik]

Amazingly clean and elegant build.

There are many dazzling builds on ES that are extreme exercises in fabrication, but for most they are as unachievable as concept cars. This is a build that owes its appeal to elegant and functional design using readily available materials and clever solutions. As always the devil is in the details and all seem to have gotten your attention - from the battery mount end caps to the the electric speed-shifter.

Imitation is the sincerest form of flattery and I'm sure this build will inspire many...

 

[Reflector]

Hi Kepler,
I've been watching the forum with great interest over the past few weeks. The BBS02 750W drive seems to be just what I need in the KV4 aluminium velomobile kit which will be arriving soon from Dutch Speed Bicycles.
My emphasis will have to be on weight and distance and hill-climbing assistance, (rather than popping monos). Do you agree that the 750W (as opposed to the 350 or 500W) teamed with a similar LiPo setup to yours would deliver better PAS for NSW hills?
I intend to also run LED strip indicators, brake lights (thanks for the details and pictures) and headlights and horn off these batteries.

This is my first post, so if some of these topics are in the wrong forum, I'll learn to split them up in future.
Nice work on the latest machine and I should add that until I saw it I was about to outlay on an outrunner and run a friction drive on my Greenspeed trike.
cheers,
Reflector

 

[Kepler]

Hi Reflector. Welcome to the forum. Go with either the 500W or 750W version especially the hills of NSW. They are physically bigger motors then the 250W / 350W versions so they can handle being pushed harder for longer. Good luck with the build.

 

[Kepler]

Amazingly clean and elegant build.

There are many dazzling builds on ES that are extreme exercises in fabrication, but for most they are as unachievable as concept cars. This is a build that owes its appeal to elegant and functional design using readily available materials and clever solutions. As always the devil is in the details and all seem to have gotten your attention - from the battery mount end caps to the the electric speed-shifter.

Imitation is the sincerest form of flattery and I'm sure this build will inspire many...

Thanks tek, much appreciated.

I think the the CA3 conversion will be the last piece of this puzzle and will have the potential to turn the drive into something very special. Using your invaluable guidance through the beta stages of the CA3 development I think I now have a pretty good handle on how to integrate display and get the get the most out of it for this drive. Looking forward to the challenge.

The drive currently is off the bike at the moment undergoing some routine checks and wiring conversion for the CA3 integration.

 

[Kepler]

With the drive removed for conversion to CA3 control, I quickly converted the bike back to stock so I could go for a pleasant 60km trail ride with a group of riding buddies yesterday. Conversion to stock took about 45 minutes. As the trail was just gavel paths (Warburton Trail Victoria) fitted a set of 48mm Big Apples to the road rims. Will leave these on for the time being for commuting duties once the drive is re installed.

 

[Kepler]

CA3 Integration is coming along with the job of mapping out the wiring now complete. I have tried to keeping disturbance to the original drive's wiring to a minimum so that it is always a quick and easy conversion back to stock.

I wont go into too much detail on this thread in relation to the CA3 Integration as it deserves its own discussion and will post further details on the CA3 dedicated thread and electricwheels.de starter thread.

Anyway, here is the integration map I have come up with so far.

 

[Hyena]

Tidy work as always Kepler!
I'm curious if you've pushed power beyond the rated 750w and if so how much they can take ?
I'm still a fan of 'large' geared hubs for light weight power as the last middrive I tried (full throttles GNG) didn't really blow my skirt up but I'd be keen to try one if you could get the power up to around 2kw. If these are as quiet as a hub that's a real bonus. I guess I'm looking for cyclone sort of power without the noise.

I had always wondered about 15s tripping the HVP, didn't know about the 61.5 volt limit!

There'd be a HVC resistor you could probably mod in the controller to bypass this. Back in the very early days of ebike building (when hobbyking was still a baby!) I was running 15S on the old golden motor controllers and they had the same issue where they'd not work over 61v. A quick resistor mod and (and a splash of solder on the shunt while in there) it was cheap power and happy days

 

[Kepler]

Thanks Hyena. The 750W version peaks at about 1150W stock but wont last long under that load. 750W is about the safe continuous rating for the drive so 40kph to 45kph is about the drives best sustainable speed.

I am tipping the BBS02 would be a little underwhelming for your tastes also. In comparison to the GNG we both tested on that group ride, it feels about same in relation to power but more refined and much quieter.

Problem with going to a 2 kW+ mid drive is keeping the drive train together. With the power output of the BBS, drive train failures are rare.

You still should consider giving one a serious go. They suck you in and reward you with I truly satisfying ebike experience.

 

[Hyena]

More refined and quieter over the GNG is a good thing, and the sealed/modular aspect of the BB02 making for less chain/belt alignment headaches is certainly appealing. A little over 1000w peak through the gears is not to be sneezed at I guess. I'm definately keen to try one.
How far are you from the airport again ? It's cheaper to fly down to Melbs for the day than investing more $$ in testing gear and then having it cluttering my workshop

I know you have the 2 wheelsets, but would you say you prefer it over the BPM more for offroad or onroad or both ?
Obviously there's the handling benefits for technical singletrack but how would you compare it for plodding along on a regular commute ? This is one area I'd be happy with less power and I'm actually trying to keep my power usage to a minimum these days in the interest of health and losing a few kg.

 

[Kepler]

I am an hour from the airport. $100 eachway by cab. Always welcome to come over for a test ride Jay but if decided to purchase one and didn't like it, re selling it would be a snack.

In regards to its best use, I originally got it for single track and just love it for that type of riding. However, I then started commuting on it also and found it really suited me for that purpose. This why i decided to invest in the second set of wheels.

Don't get me wrong though. The Fighter is far from retired and i love riding it still. I just ride it in a completely opposite way with no regard to economy or exercise :lol:

 

[Zwarst]

Greetings Kepler,

Im a light weight weinie nut 250w keyde front hub commuter on a 7-8ahr battery on13kg 2 speed kick back 700c bike, I love both your carbon ebike effort & this latest design which falls inline with my long held dream to make an all terain interchangable road & offroad bike.

Two things I wanted to share with you.

1- With the issue - "Problem with going to a 2 kW+ mid drive is keeping the drive train together" - could it be solved by this mid-mounted internal hub peice of genious from Zerode? http://www.zerodebikes.com - Awesome down hill bike on its own indeed, the inventor built the first prototype in carbon in his garage!!

Listen to interview here
http://www.vitalmtb.com/photos/features/Zerodes-Full-Carbon-Gearbox-Trail-Bike,7113/Slideshow,0/sspomer,2


2- Whats your thoughts on the latest offering from HPC? Is it an improvement on the 8fun mid drive??
HPC Custom 8fun Mid Drive Conversion System
http://www.ebay.com.au/itm/181409439049?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
http://www.hi-powercycles.com/hpc-custom-8fun-mid-drive-conversion-system/