Bafang BBS01 350w vs Dillenger 250w front hub

[Samd]

I've done a raft of full carbons, this 29er might look familiar! be prepared for at least a little BB surgery if you go the middrive route :wink:
One 29er came up a treat, ran like a steamroller!

 

[Scotty T]

I gotta say, I've noticed my little 26" wheels on the MTB compared to the hybrid which feel massive comparatively. The 29er MTB would be the ultimate commuter.

 

[byebyepetrol]

Schmicko little rig Sam.

No-Spark Tip
Tip for those getting sparking when the charger is plugged-in to the battery; turn your charger on first then plug it in.

FYI
There's a start-up on Indiegogo that's looking at getting support to "build" an all-carbon 27.5 bike @ 17Kg (no suspension).
I reckon what we're doing here matches what they're doing.

http://www.pedelecs.co.uk/news/carbon-e-bike-seeks-funding/

 

[Scotty T]

They could lose a few hundred grams with the chainring upgrade

 

[2old]

Zan, little late to the game, but your gearing is 46/(number of teeth on smallest rear cog, probably 11 or 12); number of speeds doesn't matter.
Too bad (for me) that Storm killed any chance I'd ever get involved in a crowd funder since some look enticing.

 

[zan5hin]

New Drivetrain

New KMC 10-speed chain, new XT 10-speed cluster, new 48T chainring and new SLX RD has made it smooth and quiet.
The clunk from the battery pack is gone.

If you are ok with imitation being the best form of flattery, I would really like to copy what you have done, on my Giant Innova.

What I really would love is the NuVinci Harmony, I am lusting after it: http://www.ebikereviews.com.au/electric-bike-reviews/bosch-gepida-reptila-1000-review/

However, they are only doing it on OEM ebikes, there are no aftermarket kits planned, and after reading about the new tech the old N360 kits look like boring old tech.

In the meantime, I was reading and watching youtube about the clutched version of the SLX and your setup looks like the best option to improve the performance of the Bafang for speed and reliability.

I am still pretty n00b to bike maintenance so I will have some help to get it installed, but I have a few questions. I have a Shimano Deore LX 9 speed derailleur so I assume that the cassette and chain also have to be replaced?

Are these the parts you got?

Long cage or Medium cage for the SLX? http://www.chainreactioncycles.com/au/en/shimano-slx-m675-shadow-10-speed-rear-mech/rp-prod83164

36T cassette or something eles? http://www.chainreactioncycles.com/au/en/shimano-xt-m771-10-speed-mtb-cassette/rp-prod52281

This chain? http://www.chainreactioncycles.com/au/en/kmc-x10-sl-silver-10-speed-chain/rp-prod23963

Total is $160 AUD.

I was reading this informative piece about Bafang kits and chainrings https://electricfatbike.wordpress.com/bbs02-chainrings/ and he writes "One thing to keep in mind when picking custom chainrings to use is that the lightest chainrings will often be made of softer alloys. If you want to maximize your usage and minimize your replacements there is really only one choice for material, chrome plated steel. The same holds true for the cogs in the rear. Lightweight cassette will wear quickly especially if you are using higher speeds on the smaller cogs. A 11T cog running at 30 mph made of lightweight alloy is not going to last very long at all."

Is the M771 a lightweight aluminium cassette or steel? I can't find the information.

Would this Surly 50T stainless steel chainring work with the rest of the gear? http://www.wiggle.com.au/surly-stainless-steel-46t-to-50t-chainring/

• Incredibly strong and durable!
• 
  No ramps or shift gates
• For use with 6-10 speed chains, 1/2"x3/32" pitch
• Use of Surly rings with 9 and 10 speed chains will have a tight fit and require a short break in period
• Made from 304 stainless

With this chainring adapter? http://california-ebike.com/product/ba130-bafang-chainring-adapter/

Thanks for helping out the n00b

 

[byebyepetrol]

Hi Zan,

Dunno why I bought the long cage. Habit I guess.
In hindsight the short cage would be fine. I don't use more than 4 cogs at the rear and I could have saved a few links in
the chain (from memory I'm using 116).

As for chainring I got the cheapo steel Shimano 48T one. That's as big as I go on this rig.
IMHO the motor torque wouldn't cope with anything bigger.

Too early to gauge wear.
The XT M771 cassette is the one I got. 11 to 36T.
For your hub you need to work out if it can take a 10-gear cassette.
If it can, get a 10 speed chain. 10 speed chains are thinner than 9-speed.
The KMC one I got was relatively expensive (AUD75).

Chainring adapter? Mine was 104mm BCD which allows me to use 104 chainrings. Of which there are plenty.
Cheapest I've seen are from here in OZ (Ballarat Bikes). The one I got is mint; very precisely made and from emax.com.au

 

[eMax]

I recommend the clutched XT or SLX Shimanos also but nothing beats the fixed chainline of an IGH with these mid-drives. The Nuvinci and Alfine 8 I have used with great results.
Always use some kind of cutoff to stop shifting under load. So many times I've seen beginners snap chains or worse with these mid-drives because they think its ok to shift under load.

The Gearsensor from Radim in the Czech works really well. It is the best (with a premium price) option and available for IGH and derailleur.

 

[byebyepetrol]

Hi Ewan,
That sounds like an effective combo.
They do a DI2 version as well.

It's 1.7Kg vs the weight of the cassette and RD and omitting a few chainlinks so the weight penalty
wouldn't be that much.

Extra cost might be $300-350 above a RD set-up.

 

[mfj197]

I'd like to see a 16.5AHr battery on a 29er with slick tyres and around 18Kg, that would push 50kmh and 90-100km range I reckon.

I can pretty much do that, except it's only a 11.6Ah battery. Cube SL Road Pro with BBS01 250W conversion, 18Kg with Vittoria Voyager Hyper tyres.

I've modified the programming to give 100% assistance via PAS and removed the throttle. I have 5 levels of assist and use it almost exclusively in level 3 for my commute, averaging about 35km/h and 55-60km range. If I drop to level 2 I average 30km/h and 80-100km range. Level 5 (max) gives me a cruising speed of around 45km/h but I don't really like riding that quickly! That's with the motor programmed for 15A maximum which is the 250w setting. I could up that to 18A which is the same as the 350W motor but I don't see any need myself.

Build thread here

Michael

 

[byebyepetrol]

Hi Michael, that looks like a proper stealthy road rocket, congrats.

 

[Scotty T]

Hi Michael, that looks like a proper stealthy road rocket, congrats.

Indeedy! This morning I learned why hub motors don't compete with mid drive for overall speed. A dude older (appeared mid 50's or more) and seemingly not as strong as me cruised past me on the flat, the motor kept pushing him along past 33km/h, mine tops out about 29-30. He held about 32-33 on the flat, I tried to draft but lost him after about a km. Then we hit a hill, I think the combo of my small MTB wheels, a bit more strength, and the huge torque of 350w on the rear hub I screamed past him on every hill, he couldn't get near me and seemed horribly slow when I had to hang behind up anything but a slight rise, on one pinch which had lots of flat after where I knew it would be useless to pass he was very slow. I pull minimum 23km/h up all the hills on my route. The first pass where I saw how much faster I was up hill he would have been under 20. I assumed he was on 250w, and that the motor turning the gears +700c hybrid wheels was capable of a higher speed on the flat.

I chatted to him for about 30 seconds the second time he got me on the flat and he said "it's great, not fit enough to otherwise ride" and he appeared to be travelling about 4-5km less each way judging where he turned off. I will have to ask him exactly what the setup is (both our routes had about 12km of common cycle path so we'll meet again), the mid drive motor sat much higher than the Bafang and appeared to drive the normal crank. He was stopped and putting his lights on coming back home, and I was motoring, pulled my faster home leg yet but only 25.5 km/h avg. It took him 7km to catch and pass, there were small rises all the way from where he passed me so I held close and again hit a hill and felt like I was crawling up it.

Interesting observations, it all adds up to the need to make a mid drive 250w bike now, like that lovely one Michael has posted

 

[Scotty T]

Oh I've put down ~80km on PAS 8/9 but with a 1 hour squirt of charge after 40km because I did a couple of small trips to add the 10 k over my normal commute. I ran 9 for over 50% of the both legs today (20km).

I'm pretty confident that on PAS 7/8 I can easily get two commutes or 72km. Battery indicator shows 2/4 right now. Dropped to 1/4 on the last couple of hills when I was having to back off the pedals because of the slower ebike dude in front.

 

[byebyepetrol]

Hi Scotty, It sounds like you have a serious ebike rival on your route. All you need now is a pocket em pulse device and he'll be toast.
Or a mid-drive ;0)


Brass Monkeys Factor
Took the bike for a 60km round trip in 5-10 deg celcius (below 50 faranheit) conditions and no wind and it J U S T made it back home.

Normally in milder temps 80-90km is easy.

I had to resort to turning it off, cycling for a minute or so then turning it back on which enabled me to get home under power.

I guess the temperature had an impact. This pack is from bms battery.

It could also mean that the higher 48x11 ratio and subsequent higher speeds has had an impact too.

 

[Scotty T]

Brass monkeys apply here nearly every day in winter

My son managed to run his 8Ah battery out the other day (about 90% charge at a guess, all LEDS on battery were lit, 24km trip) and he said it rapidly dropped below half about 3km from home on the way in, it was -2.2c with apparent -4.3c! On the way home he had it cut out about a km from home, switched off, pedaled a few hundred meters, switched back on and it got him home (11c). I think he earned his brass monkey badge.

I found that my battery charge is what really affects the top speed too. Roughly each 20% of battery loses about 2-3km/h top speed, so a totally full battery is hauling me along until about 32, between full and 75% battery I lose about 2km/hr and any lower than 75% it's another 2km/h. I bit the bullet and decided to do two commutes on one charge (second one today) so we'll see how I go getting home tonight, and that will be 75km in one charge, with average of ~7c temperature. I dropped about 3km/h average speed coming in with PAS running on 7/9 and battery starting out under 75%.

 

[byebyepetrol]

 

[Tats]

Hi Scotty, I found with the frame battery I also lost speed as the charge went down - related to the drop in volts and the discharge curve. That's why I went down the LiFePo chemistry route - the discharge curve is much much flatter - something I need as my hills are at either end of my commute, not in the middle. Over 20ks I'll drop less than 1 volt whereas my frame battery would drop between 4 & 6 volts. A much bigger %age drop-off.

 

[Scotty T]

Hi Scotty, I found with the frame battery I also lost speed as the charge went down - related to the drop in volts and the discharge curve. That's why I went down the LiFePo chemistry route - the discharge curve is much much flatter - something I need as my hills are at either end of my commute, not in the middle. Over 20ks I'll drop less than 1 volt whereas my frame battery would drop between 4 & 6 volts. A much bigger %age drop-off.

Thanks for that info mate, I guess it is much less noticeable on the 250w, mainly because it doesn't have a speed display on the handlebars

The drop is fine for me though, I pulled a 24.5 km average speed home last night (25.5 is fast for the home leg) on PAS 9 with about half battery and easily made the 72km total on one charge. It only just hit 1/4 indicators on the display on the final climb that ends my ride so I reckon it had several more km before any cutting out, I have quite mellow climbs over roughly a couple of km at each end. It also just hauled up the climbs even though a couple of kays slower, it still pulls like a truck.

 

[byebyepetrol]

The BBS01 failed after 2300km; details here in the Bafang Fault finding and fixes thread:

http://endless-sphere.com/forums/viewtopic.php?f=28&t=58898&start=525#p1058199

New part fitted AOK
The replacement BB axle/ spur gear / freewheel assembly http://www.emax-ebikes.com.au/ arrived yesterday and fitted without any trouble.
The ride to work this am was liberating after slugging it out over the last 2 weeks on my other standard bikes.

I hope this axle assembly doesn't expire quite so soon. It had a few differences in outside appearance to the old one but without opening it up I couldn't say
if they'd changed anything.

 

[eMax]

Well done, you got that in and fixed very fast!

I have a new frame to build up. Can anyone guess what motor is being bolted in? Hint..not Shimano, not Bosch.

 

[eMax]

I hope this axle assembly doesn't expire quite so soon. It had a few differences in outside appearance to the old one but without opening it up I couldn't say
if they'd changed anything.

No changes in BBS01 driveshaft. The BBS02 has changed though. The main gear is slightly smaller in diameter and the spur has grown slightly. Just make sure you first driveshaft nut is not too tight or there will be unwanted friction and added strain on the motor.

 

[byebyepetrol]

Re: first nut torque
Roger that, thanks Evan.

As for the gaping hole in your frame; I reckon it'll be populated by bits of old washing machine and a small well-trained- thrill-seeking marsupial.

 

[LewTwo]

Thank you for posting the Bafang Mid drive components on your scales.
I have been trying to weigh (pun intended) the pros and cons of a Bafang Mid Drive vs a front hub motor for a lightweight ebike build. Most all kits will have a display, trottle, cables and some misc hardware ... I think those will probably be a wash. I make the Bafang 'bottom end' to come out near 4.5 KG.

 

[LewTwo]

...
Crank Yankers
The cranks loosen up far too quickly. I've tightened them 3x already.
One remedy however will be to dremel or scribe some friction tracks into the spindle or even a mild sanding with 180 grit might do it. It needs something since it's too smooth for a proper fit. ...

Loctite makes an alternative to their famous #249 blue thread locking liquid in the form of a small roll of blue tape. I use it rather than the liquid because I am lazy.
http://www.amazon.com/Loctite-1372603-Blue-Thread-Locker/dp/B004B6T4KG

I wonder if putting a couple of wraps of this around the tapers before the arms are installed would solve the problem ?

 

[byebyepetrol]

Hi LewToo,
re: Loctite tape
That might just work for those who don't have the luxury of a Dremel cutting disc.

As for mid-drive vs hub drive, there's not a lot in it IMHO.

If it was my money and I was asked to build a new bike for light commuting, no hills, no heavy payload (like a trailer)
the rear hub drive would be preferable.

However, if you're after a drive-train to handle heavy loads, hills, high speeds, offer higher efficiency, better handling
then mid-drive gets the nod.

Battery; same for both, I've had two LiFeMnCo bottle batteries and they've been fuss-free. Get the biggest you can afford.
My next battery will be at least 16AHr.