New Bafang Crank-Drives

High performance claims are crap. A quality bike from today will gain you absolutely no time over a quality bike from twenty years ago. The placebo effect is huge. Look at the hour record. Nothing they have done to a standard bike has increased speed. Only by going to non-standard rider positions, and aero-disc wheels have they been able to beat the 49+ kilometer distance since 1972. Anything which actually increases speed is banned from racing, and therefore is of no interest to the cycling public.

http://upload.wikimedia.org/wikipedia/e ... rd.svg.png
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Hi Warren

I have built a bunch of bike frames also and know lots of builders that live mainly in the past. They spend countless hours trying to justify why things were better back then. Wool shorts, leather saddles and all. Insist that cars were better back then also. Agree to new stuff is hyped to beat the band, but there are legitimate improvements also.

Hour record? Who has attempted that lately. Lots of other records have fallen / been reset in the past dozen years. http://www.ultracycling.com/sections/records/stats/timed/ Aero increases, I agree, have been a big factor also but to say no improvements have been made in twenty years IMO is just wrong in so many areas. Improvements are measurable. Strength to weight, Specific stiffness, Strain numbers, etc etc. You would be hard pressed to find one component that is no better today. I believe you would see the difference more clearly if there were established hill climb routes/ records mixed in and true dope free racers. I would like to see how a columbus SL frame bike mixed into the pack at le tour on one of those killer mountain stages. Seriously, your would be hurting trying to make up the 40,000 -50,000 pound feet you would be handicapped just on added weight of the frame and fork.
 
Chalz said:
This new crank drive looks ripe for liquid cooling. It's already sealed up and sitting lower than the crank bearings. Just drill and tap a low output connection and a high input. Fill with mineral oil, pump and cool with this little computer liquid cooling radiator setup.

http://www.newegg.com/Product/Product.aspx?Item=N82E16835181030

Don't you guys think that would do well?

~Chalz
Click to expand...

Interesting idea. I haven't seen one of these in person, so i can't say. An external radiator to increase the total amount of thermal mass and heat dissipation, plus the forward motion of the bike would help to cool this thing A LOT.

I think it would be worthwhile to make one of these a sacrificial lamb and see.

Then your next problem will be to stop destroying bike chains, lol.
 
speedmd,

"lots of builders that live mainly in the past'

I am not living in the past. I swapped out my Brooks for a light, waterproof plastic saddle in 1972. I traded my beautiful, but functionally crap, Campy Record rear derailleur, even up, for the vastly better Suntour V slant parallelogram, and a set of sweet Suntour bar-end shifters when "real men" knew that you had to bend over to shift. As nice a ride as sew-ups give, modern clinchers are much more practical. Index shifting is great, and thankfully I know how to adjust them, so I don't have to run to a mechanic when they get out of adjustment.

"Hour record? Who has attempted that lately."

The hour is important because it eliminates all the variables that make it impossible to tell anything from roadracing. With the insistence of the rule making bodies to use standard bikes, there is little point in trying. Without drugs, people aren't getting any better.

"Strength to weight, Specific stiffness, Strain numbers, etc etc."

All very impressive on paper, but it doesn't translate to more power getting to the pavement. Show me where any meaningful amount of energy is going into heating up the frame. The biggest problem is air resistance, followed by rolling resistance. Tires are as good as they are going to get, and of course there are more aero positions on a bike. Unfortunately, in a more prone position the ergonomics are so bad, nobody but a masochist will maintain them for more than a few minutes. And in the supine position, while very comfortable, there are measured losses of rider output of 10%, even in highly trained riders.

"You would be hard pressed to find one component that is no better today."

First we would need to define better. But I won't even begin to make a list.

"I believe you would see the difference more clearly if there were established hill climb routes"

Lower weight is definitely an advantage climbing. The problem is that a bicycle is already amazingly light. You have a vehicle that is only 12% of the weight of the rider, and the frame and fork is only 20% of that. As you point out, you have to climb a hell of a lot to see the effect of a 1% difference in gross weight!

I find it funny to be accused of living in the past, when I ride an electric assist recumbent that allows me to ride all day, as far and as fast as Lance hopped up on drugs.
 
Hi Warren

Your are right. We are talking a few percent in overall weight savings, and all it takes to get dropped badly by equal riders on the first significant climb. Agree, no argument, aero makes biggest gains when going much above running speed. Wheels have improved significantly in drag. Lots of data published already on them. Climbing is where you would see huge benefits of a 20% lighter package that flexes 30% less and clearly transfers power better. Don't take my word for it, put a power meter on it and see for yourself. You could ride Cannibal style. All that is required to be measured is Speed vs power. No need to measure body heat. Heart rate a must. No guessing which is better and by how much or not better at all. Cyclocross and cross country bikes would be good to compare also on a closed loop with good riders. You may argue that the newer high end stuff is not worth the cost but at least you can put your theory to rest that it is all no better.
 
Still waiting on Keplers review of the BBS02 and build details..................... :D :D :D

Is anyone using these units PAS only with success, I really don't like throttles but I can the issues with shifting on these units.
 
pjgold said:
Still waiting on Keplers review of the BBS02 and build details..................... :D :D :D

Is anyone using these units PAS only with success, I really don't like throttles but I can the issues with shifting on these units.
Click to expand...

My drive has just turned up. Had a quick look in the box and all seems to have arrived undamaged. The test bike is built ready to accept the drive so hopefully should have something to report by the weekend. :)
 
Kepler said:
pjgold said:
Still waiting on Keplers review of the BBS02 and build details..................... :D :D :D

Is anyone using these units PAS only with success, I really don't like throttles but I can the issues with shifting on these units.
Click to expand...

My drive has just turned up. Had a quick look in the box and all seems to have arrived undamaged. The test bike is built ready to accept the drive so hopefully should have something to report by the weekend. :)
Click to expand...

Looking forward to your build and opinion Kepler, i guess it will be another commuter style bike? I want to do a light xc dual suspension conversion. Kinda glad i held off till now. the 350w sounds a bit weak, and the one that melted down is a bit of a worry.
 
With the kit arriving at my work address, the first trick was to get it home. No problems, just lash it to the Fighter and hold it in place with my knees :mrgreen:

photo.JPG

Got the package home safely and unpacked. First impressions: Kit arrived safely without any damage. Looks to be good quality with a well thought out mounting system and nice water proof plug and play connections.

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Stripped out the crank assembly in preparation for the drive to be fitted.

I know, unimpressive frame but this is being built as a test bed more than permanent build.

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Actual drive was installed in less than 10 minutes and couldn't be more simple.

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This bike has a Vee brake rear brake so I utilized the the supplied brake lever and brake switch for the back brake how ever opted for a hydraulic front brake using 180mm rotor

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Went with a 7 speed cluster ranging from 13T to 34T. Not so good for all out top speed but I prefered to keep the tooth count up for plenty of chain wrap.

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Chain line is perfect on this bike even in the tallest gear.

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Fitted my usual handle bar bag to house LiPo's and excess cable however this made it difficult to fit the rather large display which is designed to mount in the same place the handle bar bag mounts. No problems. Whipped up a nice sturdy mount that attached the display the headstem bolt.

photo1.JPG

Very easy to keep the build nice and clean with this system.

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And so that's it. 2 hours of my life and the drive is fully installed. Too easy. 8)

But now the interesting part. How does it perform? Stay tuned. To be continued!!!! Headsup. So far, love it. :)
 
@ Kepler

nice and clean build. I like these Bafang crank drives.
is this the 750W unit or a lower powered one?
what battery are you using?
I'm excited to hear how it performs.
 
It's the 750W BBS02 with the speed limiter removed and the LVC set to 40V. Using tired 6S Turnigy 5ah packs x 2 for 48V nominal. Getting 3.8 ah out of each pack and their internal resistance is over 350 mOhms so they are not long for this world. Even so, managed 17km out of the pack during testing :shock: .
 
Kit came through Aliexpress and GEB. http://www.aliexpress.com/store/group/E-bike-kit/326611_253240667.html

I requested that the speed limiter be removed and LVC re set to 40V to suit my LiPo as a last line of defence cutoff. I also requested that the speed limiters be removed on all 9 available assist settings but have a percentage power for each power level increment be retained.

Looks like I got the speed limiter removed and the LVC set but I think the last request got lost in the translation. Each speed increment definitely as an associated speed limit together with a corresponding power limit. Not exactly what I wanted as I prefer to be able have a low power assist level but not have any speed restriction. However,so far this doesn't seem to be too much of an issue with the limited programmable adjustment I have available.

I has set the speed to to 50kph. It seems the incremented speed limits are a percentage of this maximum so I can set a fairly decent speed with a low level of assist. The number of assist/speed increments are adjustable also. It can be set from 2 - 9. I started off with just 3 but have now gone to the full 9 as like the better resolution in relation to the level of assist this it gives. Available programming on the 9C61 is very simple and straightforward making setup a breeze.
 
But now the interesting part. How does it perform? Stay tuned. To be continued!!!! Headsup. So far, love it. :)

Sounds good. Looks smaller than I imagined. Any issues with your floating bottom bracket. Looks like it sits lower because of that bottom bracket to.

When you do your follow up can you give your views on how it compares to hub motors, advantage/disadvantages. Noise levels, performance. Will you be upping the volts?

Thx
 
It does sit a little lower with the floating bottom bracket but its not an issue. Ground clearance is still fine. The drive obviously pivots with the suspension but again not a problem at all.

Will definitely do a full comparison against hub motors. Voltage will stay stock at 48V. Really no point in going up as the motor is already out spinning my usable cadence speed. Next job is fit a CA with an inline shunt for monitoring purposes.
 
Thanks for the info Kepler - the LVC was the only thing holding me back on ordering - looks like GEB are going to get another order soon :)
 
Hello all. My first post after my first build.
I used the Bafang BBS01 350w 48v PAS only kit. I built it on a Giant Via 1 with a 9 speed SRAM internal gear hub. I am using a 48v 15ah lipo battery.
As built the efficiency is incredible. Admittedly you do need to pedal All the time (duh) but even with just enough pedaling to keep the PAS engaged I am looking at a range of about 70 miles. The range on my Ezee with the same size battery is only 1/2 of that.
I plan to have the drive re-programmed to increase the PAS level. To achieve 20mph takes ideal flat conditions. I am told that as delivered the PAS is only giving 47% of max amps. I have ridden the bike a couple of hundred miles pedal assist and I must say I really like it. The throttle can really get old.
Anyway, I love this drive and can't wait to up the power a bit. The only bad part is I need to send the motor off to get it done :(
 
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