Dengfu E10 - The CHEEB V1.0 - Discussion

[Mr-EPIC-3]

By pure chance! I bought this paint a couple months ago

Yea that is a great looking color! I would have order the Rail 5, but here in the USA it only comes in Olive Green, which is just ugly.
I don't understand why some product managers pick some of the colors they do, if they can't pick a great color just go with gunmetal grey.

 

[Rob Rides EMTB]

Yea that is a great looking color! I would have order the Rail 5, but here in the USA it only comes in Olive Green, which is just ugly.
I don't understand why some product managers pick some of the colors they do, if they can't pick a great color just go with gunmetal grey.
View attachment 47059

Maybe they would prefer you buy the more expensive bike based on it being a better colour? The paint on the purple Rail 5 is colour flip paint which will be more expensive , no idea why they have it on a base model to be honest, I think it’s a better finish / colour than the more expensive models.

 

[Mr-EPIC-3]

Maybe they would prefer you buy the more expensive bike based on it being a better colour? The paint on the purple Rail 5 is colour flip paint which will be more expensive , no idea why they have it on a base model to be honest, I think it’s a better finish / colour than the more expensive models.

I think you are right Trek what us USA customer to upgrade to the Rail 7, which is offered in 2 colors.

 

[CRFan1]

Battery secures into what looks like aluminium mounts at both ends. When I get a chance I’ll unscrew them again and take some pics.

Thanks Rob...that is awesome if so and hopefully they changed it for the better. Hopefully They will fit on my X1, hahah.

 

[CRFan1]

I have this problem of cracking with all chines battery (not built for TT), i solve it by use external straps to secure. I doing also for the shimano on the canyon, no cracks, but i losen it one time. How you doing to strap the battery inside the frame? I think it is not the same size but the same kind of fixation in the E10 than X1 (E09 for dengfu)

The battery on the X1 has a lip that resides over the edge of the frame so I use a strap around the lower downtube. Its very secure and I have had zero issues.

 

[KeithR]

Yea that is a great looking color! I would have order the Rail 5, but here in the USA it only comes in Olive Green, which is just ugly.
I don't understand why some product managers pick some of the colors they do, if they can't pick a great color just go with gunmetal grey.
View attachment 47059

Your personal opinion of a colour doesn't make it bad.

Indeed, I love these "stealth" colours - so much so, that all things being equal, I'll be taking ownership of one of these early in the New Year.

The discreet colour scheme is a big part of its charm. Not because it's "military" - I'm neither an excitable child nor a Rambo wannabe - but simply because "earth" colours are a palette which appeals to me.

It's a big old world out there - more than one opinion is supportable.

 

[Gary]

in charcteristic that BB height is 324mm. I hope it is with 27.5 wheel ? that is too short for my use, I need 350mm at least with 165 cranks arms length and 150mm travel. Using shortened arms will be necessary

Frame is listed as 20mm BB drop. So for 27.5x2.5 tyres front and rear that would actually equal a BB height of 335mm
But even if it were 324mm, That really isn't all that low for a 150mm travel bike anyway. it's a similar height my 170mm travel Eeb. (so this bike has 20mm MOAR clearance.

 

[Mr-EPIC-3]

Your personal opinion of a colour doesn't make it bad.

Indeed, I love these "stealth" colours - so much so, that all things being equal, I'll be taking ownership of one of these early in the New Year.

The discreet colour scheme is a big part of its charm. Not because it's "military" - I'm neither an excitable child nor a Rambo wannabe - but simply because "earth" colours are a palette which appeals to me.

It's a big old world out there - more than one opinion is supportable.

You are right, personal opinion. I will take back that olive green is ugly, just not for me. If I am going to spend $5000 on a eMTB, I want a flashy color or gunmetal grey. The Zero DS looks more grey then green too me

 

[Konanige]

Frame is listed as 20mm BB drop. So for 27.5x2.5 tyres front and rear that would actually equal a BB height of 335mm
But even if it were 324mm, That really isn't all that low for a 150mm travel bike anyway. it's a similar height my 170mm travel Eeb. (so this bike has 20mm MOAR clearance.

If only Ebike riders would bother to learn how to time pedal strokes and when and how to position their cranks in technical/rough terrain we could all benefit from manufacturers making Eebs with nice low BB heights and normal crank lengths.

Totally agree there, my acoustic bike is 20mm lower than my SL with 5mm longer cranks and I don't suffer unduly from pedal strikes on either, unless of course I cock it up !!!

 

[Mteam]

Here are the individual costs of the parts by the way. In terms of warranty I personally think Dengfu would honour manufacturing defects etc. But a grey area with carbon frames if it cracks. I doubt I’d get the kind of goodwill a big brand would offer.

Absolute worst case is that I’d pay the replacement cost. Best case is free or discounted parts.

Look at the price of the battery. Just $350 for a 17.5Ah.

E10 21" in UD matt finish: $680
A headset for E10: $14
Rear thru axle for E10: $10
M500 Bafang motor 48V 250W: $650
Battery 48V 17.5Ah: $350

It going to be tough to sell on second hand though compared to a known brand, i guess thats fine if its a keep it until its dead bike, but If you're just keeping it for a couple of years until the tech has moved on then get another, then I think a 'big brand' would work out cheaper overall.

Interesting thing to do though - will be watching with interest.

 

[paul-g]

It’s 48v system and a 17.5Ah battery.

So 48 x 17.5Ah battery = 840Wh total.

If it were a 36v system it’d provide 630Wh (36 x 17.5 = 630Wh) ?

are you going to test the battery to see if the quoted figures are correct ?

 

[Rob Rides EMTB]

are you going to test the battery to see if the quoted figures are correct ?

Any idea how I can do this? Happy to do so if there’s a safe and accurate way of doing it.

 

[paul-g]

Any idea how I can do this? Happy to do so if there’s a safe and accurate way of doing it.

apologies Rob, unfortunately i as you it seems are not an electronics engineer.
might you have some friend or colleague that might help you on this matter.
(might be a reader near you)
the reason i asked was some batteries coming from the orient saying 5000ma
really turn out to be 2400ma or even less in disguise.(not good business)(you tube)
i think a lot of other readers are very interested in your build and possibly
some have emailed the company with a view to maybe purchasing.
unfortunately you seem to be the Guinea Pig with this one, but just consider how good it would look for you personally and the company that you purchased from that everything is as good as they say.

 

[patdam]

Frame is listed as 20mm BB drop. So for 27.5x2.5 tyres front and rear that would actually equal a BB height of 335mm
But even if it were 324mm, That really isn't all that low for a 150mm travel bike anyway. it's a similar height my 170mm travel Eeb. (so this bike has 20mm MOAR clearance.

If only Ebike riders would bother to learn how to time pedal strokes and when and how to position their cranks in technical/rough terrain we could all benefit from manufacturers making Eebs with nice low BB heights and normal crank lengths.

I read that sometimes on forums about problems with E bike BB height "You have too poor technic", May be. Off course i suppose this is not a problem for macaskill, but i do not think that the basic rider have this level, you ? do you know that if you stop to turn your pedal with an ebike, to change position of pedals for exemple, it is alike if you break ?

Unfortunaly where i ride, i never see this "technical rider" to show me her hability. In regard of my experiency (and my technical level), 320mm are enough to use on DFC tracks or cleanned bike park, but impossible to climb in rock garden. That's my opinion.

 

[Zimmerframe]

Any idea how I can do this? Happy to do so if there’s a safe and accurate way of doing it.

I doubt it will be super easy for you with things "lying about" .. the long and short (simplified) is that you'd need something to connect to the battery with an exact known current draw and then you'd time how long it would run that item/test piece - which would give you the Wh's when you worked it out. Not sure how the BMS works on that, or if it's an external controller ? But you wouldn't want to over draw it either. For instance the early dewalt 36v Li tool batteries would cut out when you used a tool and the battery was low to stop the battery getting damaged. If you used the 36v work light though, the current draw was so low it didn't cut out and then your battery was toast.

You could probably get a rough idea by charging it and using one of the in line power monitors to see how much power went into it from flat - assuming it was flat ! But you'd have to guess/approximate for efficiency losses and heat.

 

[Motofinne]

This will be very, very interesting to follow. I'm myself looking to build a carbon Chinese Gravel bike at some point. There are lots of options out there, some are absolutely horrible. But there are lots of manufacturers that are legit (Western bike brands buy their frames are rebadge them and sell them for a huge profit), it's pretty easy to research and find the good ones.

 

[Gary]

I read that sometimes on forums about problems with E bike BB height "You have too poor technic", May be. Off course i suppose this is not a problem for macaskill, but i do not think that the basic rider have this level, you ? do you know that if you stop to turn your pedal with an ebike, to change position of pedals for exemple, it is alike if you break ?

Unfortunaly where i ride, i never see this "technical rider" to show me her hability. In regard of my experiency (and my technical level), 320mm are enough to use on DFC tracks or cleanned bike park, but impossible to climb in rock garden. That's my opinion.

Yeah. Your opinion is wrong. Looking ahead, planning your line and timing your pedal strokes and paying attention to your crank position are all very basic mtb skills.
An Ebike actually makes it easier not more difficult. But too many folk who ride them are lazy and just want to keep pedalling as if they have a throttle.

 

[patdam]

Yeah. Your opinion is wrong. Looking ahead, planning your line and timing your pedal strokes and paying attention to your crank position are all very basic mtb skills.
An Ebike actually makes it easier not more difficult. But too many folk who ride them are lazy and just want to keep pedalling as if they have a throttle.

definitvely we do not doing the same practice, when i climb in rock garden i do not count or plan anything, i just fight to do not lose speed. One clarifications, if i need throttle it is only for walk assist when i am beside the bike, not on. But you can do as you want, not a problem for me.

 

[Gary]

when i climb in rock garden i do not count or plan anything

Yeah.
Exactly the laziness in Ebiking I was talking about.
You simply could not ride this way on a normal bike and expect to get very far.

 

[apac]

Any idea how I can do this? Happy to do so if there’s a safe and accurate way of doing it.

Just put a multimeter on the pos and neg pins and it will show you the voltage.

just buy a cheap one for a fiver.

Ah measurement will be more complex. You'll need more expensive equipment.

I doubt the capacity is untruthful.

sounds like a 13s and 7p pack if the cells are 2.5ah. 91 cells

 

[JetSetDemo]

Great Idea all this Rob, wife wants me to do the garage out next year, wondering if I could get away with this as part of the doing up of the garage.
Curious if you have thought about a name for this baby yet? maybe run a competition on the channel.

 

[thewildblue]

Yeah.
Exactly the laziness in Ebiking I was talking about.
You simply could not ride this way on a normal bike and expect to get very far.

But isn't this why we have ebikes, to climb the climbs that aren't normally possible. Yes there are lines, but you also need to carry momentum and stopping pedalling even for a second can mean you come to a halt due to the slow speed. I flipped the chip to high, shorter crank arms and a stiffer rear cut down my strikes massively. If I dont have the skill, I use my brain and look for other alternatives to get me through....

 

[Gary]

Oh.. .so you wanted a bike to remove ALL of the challenge of the "difficult" climbs you couldn't achieve?
Fair enough but to me that's completely regressive for fitness, skill progression and any sort of actual achievement fulfillment.
So. No. That's not why I personally bought an Emtb. But we're not all the same.
It might be news to you but most climbs on mtb trails have previously been climbed cleanly by fit skillful riders with normal BB heights and normal crank lengths.

 

[Gary]

Anyway. Back on topic.
The BB isn't too low on rob's project. not by a long way

 

[patdam]

Anyway. Back on topic.
The BB isn't too low on rob's project. not by a long way

Lucky boy, full of certainty and know.

It is true, this is not on rob's project. May be better to cancel all these off topic, I will open an new one if necessary when i can try my bike, but i need to wait several month before to acced at my playing ground. Let the snow melt.

 

[thewildblue]

Oh.. .so you wanted a bike to remove ALL of the challenge of the "difficult" climbs you couldn't achieve?
Fair enough but to me that's completely regressive for fitness, skill progression and any sort of actual achievement fulfillment.
So. No. That's not why I personally bought an Emtb. But we're not all the same.
It might be news to you but most climbs on mtb trails have previously been climbed cleanly by fit skillful riders with normal BB heights and normal crank lengths.

Hardly, I stopped biking in 1999 and moved onto motorbikes and cars. Ebikes gave me the enjoyment of riding again. Yes I'm not superfit, but over the last 2 years its improved massively. For example I would never have considered riding up Snowdon as its too much of a ballache, but now I can ride up 95% of it with my bike. I go out with other "oldies" and we look for silly climbs to do. For me its an achievement, similar to popping up a 100mph wheelie on a motorbike, getting my knee down or drifting in a car. Yes most climbs have been done before, but I'm not an Olympic athlete, just a mere mortal aged 43 with a beer belly and a desk job, so these climbs are out of the question on a normal bike. We haven't all lived and breathed bikes since being a teenager.

 

[Zimmerframe]

It is true, this is not on rob's project. May be better to cancel all these off topic, I will open an new one if necessary when i can try my bike, but i need to wait several month before to acced at my playing ground. Let the snow melt.

I'm sure you will be fine. It is a phenomena many people go through with the transition to EMTB, we pedal where we wouldn't have pedalled before, so we have to learn a new skill. It's taken me a long time to learn, and I still run short cranks - but then I also catch the top of the cranks when I'm trying for the fastest line. There is grazing and there is impacting ..

Je pense que vous serez très bien. C'est un phénomène que nous traversons avec la transition vers EMTB. Pédaler là où nous ne pédalerions pas normalement. Nous apprenons une nouvelle compétence. Il m'a fallu beaucoup de temps pour apprendre, et j'utilise toujours des manivelles courtes - mais j'attrape aussi le haut des manivelles lorsque j'essaie de trouver la ligne la plus rapide. Il y a des frottements et des impacts.

 

[GrandPaBrogan]

People please, stop justifying your unwillingness to learn proper techniques of riding technical or uphill sections, so that we can get back to the context of this thread. All this bickering is getting OLD... and boring...

Here, learn something you should've learned long ago, and just shut up.

 

[GrandPaBrogan]

Sorry, I was 'hangry.'
Just had lunch... I'm good now!


Ok, so where were we?
Oh yeah, Chinese bike build... carry on then...

 

[apac]

Here is a simple way to test the battery capacity with out any expensive tools or testing stations. As we all know a lithium battery cell is considered fully charged at 4.2V and fully depleted at 3.0V. In most cases the BMS will prevent the cells from over charge and stop the cycle at 4 volts, with 12 cells in series = 48V. The BMS will also most likely stop the cell from discharging past 3.2V or right around 38V on your pack.

So now that we know we can have a safe differential voltage of 10 How are we to find the true capacity of the battery? well that can be simple. what you need is a lamp, a 48v DC bulb, and an volt/amp meter. you could probably buy it all on amazon for 30 bux...

step 1, measure the battery voltage at full charge to verify 48 volts
step 2, connect the lamp leads to the battery + and - using some insulated stakon female flat connectors (make sure you use the insulated connectors to protect the battery from a possible cross connection)
step 3, Turn on the lamp and measure the amperage draw, since we already know the true voltage we can multiply the amperage for the real wattage consumption. A 9W bulb may in fact draw 10W due to power factor or other electrical losses.
step 4, Now you can do this step a couple ways but I would rather not actually measure how long it takes to consume 10 volts on a 9W bulb because that may take days. Instead, fully charge the pack again, verify 48volts, hook up the lamp, turn it on, start the timer, wait for the volt meter to show a drop by 1 volt and record the time.

Lets hypothetically say it took 240 minutes (4 hours) to discharge 1volt at 209 milliamps or 10W. We can take that time period of 240 minutes multiplied by 10(the amount of consumable volts between full charge 48v and empty at 38v) and we get 2400 minutes or run time / that by 60 minutes to get 40 hours. Now you take the available run time of 40 hours and multiply it by the wattage consumed (10watts) = 400Watts.

So now we know the battery can run 400 watts for 1 hour at 48V giving it an approximate 400Whr rating. I did this test on a few cheapo lithium batteries and found them also to be over rated on the label. Your real world experience CAN be different once the cells get out of balance. My girlfriends specialized levo would not charge all the way and would also discharge very fast when it was low. This was because the BMS of the pack is cheap as hell and the charger does not balance the cells the way it should. As soon as any of the battery banks reached 4.2 volts it stopped charging. I found 2 banks with cells that were only at 3.6v while the others were at 4.2 so it never got a 100 percent charge. Also when the cells began to drain those two banks that had a low voltage condition would drop out and it was the equivalent of losing 20 percent all at once.

I could pick a lot of holes in this post, but don't have time or patience right now. But there are some things wrong with the examples...

48v is 13s (54.6v)
lithium cells (18650 format) have a cut off of 2.8 to 2.5v depending on the specific cell.
Sadly manufacturers do allow batteries to fully charge to 4.2v... and discharge to 2.8v thus reducing life span.
Capacity of a cell is determined by rate of discharge. The higher the discharge rate the lower the capacity.
A bms will cut out a charger from constant current charging and go into constant voltage charging when a cell hits 4.2v. Balancing gets done right at the tail end of charging when current draw is very low, and then continues after the charger has switched off.
Weak cells in a pack usually cause imbalance in strings of cells due to internal resistance. A bms can only do so much, and it should balance down cells by bleeding them.
As voltage starts at 54v and ends at approx 36.4v there is no 48v constant voltage but only a linear drop.

My experiences building battery packs and monitoring bms behaviour.