A guy I know had this rather expensive carbon fibre MTB and wanted it converted. He's the sort of guy that says. "where there's a will, there's a way". His forte is converting road cars. His Nissan Quashqai can do a no bullsh!t 230 mph, and it drives on the road like any other car even though it has 1800 BHP, which is nearly twice as much as a Bugatti Veyron:

 

http://i1228.photobucket.com/albums/ee457/SevernValleyMotorsport/Autosports%202016/qashqai%202_zpsh9p9iibo.jpg

 

The bike is top of the range Trek Pro Fuel 9.9 with carbon fibre frame and every nut, bolt and screw made of titanium. It's very light for a MTB, something like 10kg.

 

It has lots of problems when it comes to conversion:

Through axles means a hub-motor wion't fit.

Carbon fibre frame is virtually impossible to fix anything to and can't accommodate any torque applied.

BB90 bottom bracket is the wrong size for a crank-motor

 

Not withstanding the non standard BB, It looked like there would be insufficient clearance around it to fit a Bafang BBS motor. We decided to take a chance and hope that we could shoehorn it in, so I ordered the 1000w BBSHD and a 50v 19Ah triangle battery from Em3ev.

 

In the meantime, I disassembled the BB and found a web on each side that would prevent the motor shaft from passing through, so I removed them with my dremmel. It really worried me hacking this frame, which probably cost £3000 on its own. I then sketched up some special inserts that would fit exactly to the profile of the bit of the BB where the bearings were with a inner diameter to fit the motor shaft.

 

The motor arrived, but the shaft wouldn't go through, even without the inserts in place. The gear cable and rear brake cables go through the frame and exit at the BB right where the motor would go, so we decided to run then externally and remove the terminal plate, which added a bit of thickness to the BB. With all that out the way, the motor just fitted with about 1 micron to spare.

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160613_123247_001_zpsrm1qqxdu.jpg

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160720_135014_zps0nofi4nn.jpg

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160720_135027_zpsddc5odqc.jpg

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160720_135154_zps6dugtuus.jpg

 

The next problem was to find a way to resist the torque from the motor. Bafang provide a clamp plate that stops the motor from dropping down and relies on the motor resting against the frame to resist the torque, but the shape of the frame around the BB meant that as soon as the motor twisted, it was giving a massive crushing force to the thin carbon fibre moulding. The only anchor point for a torque plate was the suspension pivot bolt, which turned with the suspension, so we couldn't clamp anything to it/ We therefore took out the pivot bolt and made our own with an extra arrangement on the end to locate the plate without clamping it.

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160722_135523_zpsxpoczjrv.jpg

 

That was all the hard work done. After that, it was only a question of switching connectors on the throttle for a left hand one, which fitted in the space left after the front changer was removed; modifying the bag that came with the battery because it was miles too big for the battery and frame; and rerouting the brake and gear cable down the outside of the frame. here's the finished bike, pending further battery bag mods. I kept the front derailleur to stop the chain jumping off. I used the end-stop screws to hold it in position.

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160730_100802_zpsvdzqbxx8.jpg

 

http://i451.photobucket.com/albums/qq236/d8veh/Trek%20Top%20Fuel%2099/20160730_100744_zpsi9uoiqz3.jpg

 

What's it like to ride? Well, it was a bit of an anti-climax. it seemed very docile considering its power. The power was programmed to increase with increasing speed/time, so it was very easy to manage and easy on the gears, but if you kept the throttle open, it got faster and faster. 30 mph was pretty easy. I fitted the gear sensor that cuts the power when you change gear, It worked very well, much better than OEM systems I've tried. It's probably the most user friendly crank-drive bike I've ridden with no crashing from the gears, and it's totally silent. All-up weight is a mere 25kg, which is very light considering the size of the battery.

 

I've now returned it to the owner who seems happy with it. His mate has an ordinary BBSHD with a 48v battery. In a side-by-side test, he said that this one was noticeably more powerful, so it's worth getting this one set up for the 14S battery from Em3ev.

"where there's a will, there's a way"

I take the same attitude at family funerals...

 

Good to see your post Dave!

Great post D8VEH, and nice to see you back on the forum. Could I be so cheeky as to point you at this post for your opinion ....

 

http://www.pedelecs.co.uk/forum/threads/cyclotricity-stealth-no-pas-but-throttle-ok.24564/#post-313414

What's it like to ride? Well, it was a bit of an anti-climax. it seemed very docile considering its power.

That can only be a good thing Dave. I programmed my BBS02 for 100% Start Current and it lost traction too readily in the lower gears.

 

Now back to 50% for a nice compromise on acceleration, traction and drivetrain longevity.

I too prefer slow ramp up on power, much kinder to the chain.

well done as usual and great work.

 

For the kind of money this guy is happy to throw, I'd gave him the best in class available rather than a BBSHD.

 

Tangent drive is 7lbs for 4kw:

http://tangentmotors.com/ascent

https://endless-sphere.com/forums/viewtopic.php?f=31&t=70098&hilit=tangent+sale

Nice report - which gear sensor did you use? Does it just go between the cable and outer?

It's this one. I'm not sure if you can buy it direct from the manufacturers. I got mine from Em3ev for only $45 with the rest of the stuff. I think many of the retailers that sell BBS01/02/HD kits stock them.

 

http://gearsensor.com/products

 

http://dillengerelectricbikes.co.uk/enthusiasts/misc/gear-sensor/mid-drive-gear-sensor.html

 

It's extremely simple to fit. it works in both directions, so you can put it on the gear cable where you want. My kit had a separate connector coming out of the motor. I don't know if that's standard or if it was a modification that Emv3ev did. Possibly, it would normally be fitted to one of the brake sensors, so you need to consider the cable length when deciding on a place to fit it.

well done as usual and great work.

 

For the kind of money this guy is happy to throw, I'd gave him the best in class available rather than a BBSHD.

 

Tangent drive is 7lbs for 4kw:

http://tangentmotors.com/ascent

https://endless-sphere.com/forums/viewtopic.php?f=31&t=70098&hilit=tangent+sale

Apart from desperately needed a torque sensor instead of cadence, the BBSxx series are actually pretty top class in my eyes. Bafang are listening to their customers and improving the units all the time

Bosch make washing machines and fridges, Bafang make motors for e-bikes so they have to listen

Apart from desperately needed a torque sensor instead of cadence, the BBSxx series are actually pretty top class in my eyes. Bafang are listening to their customers and improving the units all the time

 

I purchased 2 bbs02 so far and they both developed some defects after few thousand miles.

 

I sold one of them and the other one is still for sale, it has some noise while pedalling I never managed to fix:

http://www.pedelecs.co.uk/forum/threads/mountain-bike-with-bbs02-750w.23531/

 

And I didn't even overvolt the bbs02 or changed the controller.... so for me they are far from top class

After reading a number of threads on the Endless Sphere forum concerning the Bafang BBS motors they are far from reliable.

CD kits are overpriced and since controller can be integrated to battery cradles, there is absolutely no reason to be stuck with an internal controller.

I purchased 2 bbs02 so far and they both developed some defects after few thousand miles.

 

I sold one of them and the other one is still for sale, it has some noise while pedalling I never managed to fix:

http://www.pedelecs.co.uk/forum/threads/mountain-bike-with-bbs02-750w.23531/

 

And I didn't even overvolt the bbs02 or changed the controller.... so for me they are far from top class

In Bafang's defense, I have mates who have purchased BMWs and Mercs and have had no end of niggly little problems with them.

 

Like a lot of purchases in life, you can end up buying a lemon...

 

Unfortunately cwah, you bought two :p

After reading a number of threads on the Endless Sphere forum concerning the Bafang BBS motors they are far from reliable.

I think a majority of the problems come from owners not knowing how to ride a crank drive bike. They expect a twist and go, just like a hub.

 

Unfortunately, crank drives are unforgiving if not used through the gears correctly, and in turn this puts undue stress on the internals and controller.

 

They are getting better with the design though, and it does look like the BBSHD has ironed out a lot of the BBS series earlier problems.

 

*** Disclaimer... I don't in any way shape or form work for Bafang ***

After reading a number of threads on the Endless Sphere forum concerning the Bafang BBS motors they are far from reliable.

You have to provide context to what you read.

 

Many of the guys on ES play about with the programming, which can have disastrous consequences if you don't know what you're doing.

 

Many of the guys have old versions of the controller, which was not as robust as the present one.

 

The motor itself has had several internal updates to improve reliability.

 

Forums always give an unrealistic view of product reliability because it tends to be only those that have problems that make posts.

 

Many problems are more a matter of misunderstanding and ignorance rather than anything wrong with the product.

 

If the product was truly problematic, word would soon get around and nobody would buy it. On the other hand, if its relatively problem free, the OEMs soon pick it up. There's hundreds of OEMs using that motor at present.

 

Endless Sphere is a different type of forum to this one. It's more about how to do what. If you filtered out all the "I went for a nice ride on my bike", "I got a new bike and I think it's fantastic" and similar threads from Pedelecs forum, then did a search for Bosch motor, you'd probably get a similar picture to what formed in your head when you read about the Bafangs.

You have to provide context to what you read.

 

Many of the guys on ES play about with the programming, which can have disastrous consequences if you don't know what you're doing.

 

Many of the guys have old versions of the controller, which was not as robust as the present one.

 

The motor itself has had several internal updates to improve reliability.

 

Forums always give an unrealistic view of product reliability because it tends to be only those that have problems that make posts.

 

Many problems are more a matter of misunderstanding and ignorance rather than anything wrong with the product.

 

If the product was truly problematic, word would soon get around and nobody would buy it. On the other hand, if its relatively problem free, the OEMs soon pick it up. There's hundreds of OEMs using that motor at present.

 

Endless Sphere is a different type of forum to this one. It's more about how to do what. If you filtered out all the "I went for a nice ride on my bike", "I got a new bike and I think it's fantastic" and similar threads from Pedelecs forum, then did a search for Bosch motor, you'd probably get a similar picture to what formed in your head when you read about the Bafangs.

 

A long string of assumptions and guesswork portrayed as fact.

 

If you can do it, so can I.

 

The Bafang motor is a relatively obscure product for hobbyists.

 

The Bosch motor is mainstream.

 

Many times more Bosch motors are in use on ebikes than Bafang motors.

 

There are a handful of reliability problems reported for each motor, therefore the percentage of Bafang motors with problems is much higher.

I don't get it. What's your point?

 

Is there something that I wrote that you don't agree with?

let me guess, RobF is bored and looking for a keyboard fight.

Bafang reliability has been falsely undermined by people messing about with over volting and controller programming.

 

I think that people might be surprised by the number of motors they have sold compared to Bosch. Remember Bosch isn't very popular in the USA because limited to 350 W it is very much a European motor.

I don't get it. What's your point?

 

Is there something that I wrote that you don't agree with?

 

The point is that no one - apart possibly from the manufacturers - has reliable failure rate information.

 

Your post - and mine - is little more than guesswork.

 

It does appear the Impulse motor is prone to fail, not least because Derby Cycles has all but coughed the job.

let me guess, RobF is bored and looking for a keyboard fight.

 

Not in the slightest, just pointing out the post is guesswork portrayed as fact.

 

As indeed was mine, the difference being I introduced it as such to prevent any reader being misled.

The point is that no one - apart possibly from the manufacturers - has reliable failure rate information.

 

Your post - and mine - is little more than guesswork.

 

It does appear the Impulse motor is prone to fail, not least because Derby Cycles has all but coughed the job.

 

I'm not trying to guess failure rates. I'm just trying to point out that it's easy to get a false impression of what the failure rate is by reading a forum.

 

I still don't get the bit about posting guesswork as fact. can you be more specific by way of quote from my post?

All the bafang motors I purchased failed without exceptions:

- 3 bpm failed within 3 months only... but I have to admit I did overvolt them.

- the 2 bbs had defect under normal condition without programming or overvoltage.

 

Its enough for me to have my own opinion on the motors reliability... independently of the forum member posts

Yes, but again you have to put that into context. Am I right that you had problems with every motor you ever had - Bafang or not?

 

What are you using now? Is it OK?