E bike plus frame

[gido]

Looking for X large ebike carbon frame that fits bafang mid drive motors. I found only this http://m.dengfubikes.com/index.php?s=/192.html

[Sitar_Ned]

I'm interested in this as well, if anyone has any info. Really interested in ebikes and am hoping to see a growing number of choices in chiner ebike frames. If you build one, please post a build thread.. I'd love to get an ebike section of the forum going.

Gido, is the bafang motor one that you own or plan to buy? Would you say it's the best bang for your buck? I literally just started looking into ebikes a couple of days ago so don't know much about the motors.

Thanks, and welcome to the forum btw.

[gido]

Thanks Sitar_ned,
I will post a tread if I find a suitable frame for my build. Bafang is the undisputed king for DIY ebike community(BBS series) and best bang for your buck. Their new generation motors with integrated tourqe sensor are on par with big players Bosch, Shimano, Brose, Yamaha...and have many advantages in price, throttle option, DIY battery, open software, more power, easy availability. We just need modern geometry quality frames with short chain stay, boost rear spacing, intube battery space...then we can build excellent DIY ebikes

[Sitar_Ned]

Thanks Sitar_ned,
I will post a tread if I find a suitable frame for my build. Bafang is the undisputed king for DIY ebike community(BBS series) and best bang for your buck. Their new generation motors with integrated tourqe sensor are on par with big players Bosch, Shimano, Brose, Yamaha...and have many advantages in price, throttle option, DIY battery, open software, more power, easy availability. We just need modern geometry quality frames with short chain stay, boost rear spacing, intube battery space...then we can build excellent DIY ebikes

Ah, okay.. So the motor tech is there and affordable we're just waiting for some frame options. Well, hopefully the demand is enough to make that happen.

Thanks for the info.

[Sitar_Ned]

Oh. Just checked and the bafang is a touch over $700.. a bit higher than I expected it to be. I was guessing $400ish

[Peter60]

Is there any experience with the E bike carbon frame from Ican (or Imust):
http://www.icanbikes.com/html/MTB/E_bike_series/355.html

What do you think about this proposal?

[Sitar_Ned]

After a bit of research, it seems ebikes are mostly limited to 20mph due to US laws. While I think that's acceptable, I would prefer it be 30mph at least. I would think you could build up a pretty stout ebike with fat rims that would remain stable at pretty high speeds. Hell, road cyclists get over 40mph on those skinny ass wheels. Luckily, it seems there are ways to bypass the manufacturer's speed limitations on some models. I'm sure within a couple of years the options will open up even more, and as battery technology / electric motor tech progresses.. I think ebikes are shaping up to be pretty interesting indeed.

[mezastel]

I have extensive experience with ebikes, so let me add a few subjective thoughts:

• You don't need a carbon frame on an ebike. In fact, I would advise against it due to the higher stresses on an ebike's rear wheel. Steel - heavy steel - is just fine. I mean one of my ebikes is 27kg and I don't care - why should I, it's an electric bike. And no, getting it up the stairs isn't a problem.
• Comparing factory bikes with Bosch/Yamaha systems and Bafang is like comparing BMW and a Lada. Factory systems feel solid and safe, Bafang is a random chinese factory experiment where key features such as pedal assist are an afterthought.
• Bafang does not have a torque sensor. This is a critical feature in an ebike and not having it means your Bafang-equipped bike is essentially a moped that has no idea how much torque you need at a given time. Makes the bike harder to drive and a lot less safe!

If you do decide to go for a Bafang, I would recommend a fatbike rather than a plus bike because, honestly, it doesn't matter and the fat tyres will give you even more comfort. Remember -- weight doesn't matter at all.

Another recommendation -- don't install a derailleur. I used to have derailleur-equipped ebikes, then I got one with Rohloff 500/14 and OMG I will never have a derailleur on an ebike ever again. There's just no point! Also, remember ebikes can wrap a dirty chain around the motor when you have enough slack, well, with a hub gear your chain doesn't move anywhere -- it's stretched to maximum, so you're never at risk of chewing it up. I had so much trouble with this!

Let me know if you have any more ebike questions

[Sitar_Ned]

Thanks for the input, mezastel... good info.

I'm a little confused though as to why you would disregard total weight when building an ebike though. I understand your point about needing addition strength, and I haven't looked into it but I had assumed carbon would be plenty strong enough. Evidenced by the current carbon fiber ebikes on the market, right?

Personally, if I was buying an ebike (and I may within a couple of years) I would absolutely care about the weight and would make efforts while doing the build to keep it fairly lightweight. I mean, wouldn't the weight directly affect the effectiveness/efficiency of the battery? Also, I was under the impression that you can pedal an ebike when not using the battery power.. the weight would certainly matter, it seems.

[mezastel]

The weight of the ebike has marginal effect on the efficiency of the battery. Most of the energy goes into acceleration, not into actual maintaining of speed. What an ebike give you is an ability to very quickly accelerate from stationary position. I have ebikes of different weights, from 16 to 27kg and I see no difference in battery consumption. Ultimately, the weight of the bike is marginal compared to my weight (77kg) so a +/- 10kg change in the weight of the bike only translates to just around 10% total weight saving. It's just not worth it.

Some of the things you can have as a result of "f~k weight economy":

• Install a heavy planetary gear hub such as Rohloff or NuVinci
• Install a rack and put a load on it. I use the rack to take my son to school (30kg)
• Use heavy 1.5mm bicycle tubes; this is puncture protection at the cost of extra weight

Honestly, I wouldn't worry about weight unless of course you go for carbon. Carbon doesn't take the stresses so well, not to mention that any direct impact has a chance to just break it. With carbon, perhaps you do need to calculate weight. And I do know that carbon ebikes exist, but they mainly exist because they are commuter folding bikes that you need to be able to pick up. Most ebikes are too heavy to pick up, which is why manufacturers add Walk Assist functionality so you can get them easily up the stairs.

About pedaling the ebike when not on battery power. On Yamaha: yes, doable. On Bosch: no way; the front sprocket is too small to make pedalling comfortable. And if you go for a gear hub, well, that makes things even worse: pedaling a Rohloff without assist is possible, and if you run out of power you can do it for short periods of time, but it's not very efficient and you won't go fast. You should be OK pedaling on a Bafang, but I haven't tried it myself so I cannot say for sure; Yamaha bikes have large front sprockets so it's not such a big deal there.

[karstenhorn]

Hello all

I'm about to start a build of a electric MTB based on an old Specialized Enduro SL FSR full suspension bile. If there is interest, I can do a build thread here even though it is not a carbon Chiner frame - All the principles would be exactly the same.

The project will be based on a Bafang 750W BBS02B kit and before flaming starts I will just highlight the fact that the product is not as bad as mentioned earlier in this thread - There are 1000s of build threads out there backed up by videos that if done smartly with the right setup/programming, it is possible to build a quite capable bike for less than 600$ if on a budget. That is compared to the cost of a EMTB from a well known brand where one easily can spend $3500+ for a EMTB with less power and weaker battery. right now a basic kit can be found for 400-500$.

Pic of my donor bike:

[carbonazza]

Hello Karsten,

Count me in the interested
I have all the parts, but still haven't mounted a 1000w Bafang on my wife's city/MTB bike.

What cassette, ring, chain, derailleur did you plan to put on it ?
I took a Luna BBSHD 130bcd Spider Chainring Adapter, as it looks the default chainring is not very good.

PS: what a fork !!

[karstenhorn]

Hello Karsten,

Count me in the interested
I have all the parts, but still haven't mounted a 1000w Bafang on my wife's city/MTB bike.

What cassette, ring, chain, derailleur did you plan to put on it ?
I took a Luna BBSHD 130bcd Spider Chainring Adapter, as it looks the default chainring is not very good.

PS: what a fork !!

As I will us the bike mainly for commuting between home and work(55 km round trip) together with a little gravel roads, I will properly end up with a 40-42 tooth chain ring in the front. The MTB had a 10 speed 2X SRAM X0 prior to the conversion and I will stick with the rear dérailleur together with the 11-36 cassette. The stock chainring seems like complete crap and I intend to use it only as a paper weight I have bought a 110 BCD spider and will use a RACE Face chainring together with a chain guide. What I'm not sure of yet is the chain line so I will wait until I have everything installed weather I need spacers or not. I have also bought the gear sensor so it will cut out the engine when I shift the gears in order not to destroy the cassette/chain - I guess I will try to see if my SRAM chain survive the torque but else I will try to find a strong 10 speed echain.

That front fork is as a matter of fact fantastic when you use the bike for downhill, it is a good 160mm travel and I think the frame will break before the fork

Karsten