Building an EV more efficient than walking

[chris_n]

Putting silicone on a bike tyre is a recipe for disaster. I have a friend who did that to blacken his tyres when he wanted to smarten his up when I got a new bike. First run out he had a flat front tyre, the base of the valve had pulled out. Next time out the same thing happened again. The tyre had moved on the rim and pulled the tube with it. It was just as well we weren't coming down one of our fast mountain roads or he wouldn't have got away without a big crash!

[Saladin]

What's that Chris?



I had a run in with a car. It wasn't the silicon.
Here's a great video all about it.



I was travelling behind a car in town after a trip over two local hill ranges to do some grocery shopping. The car in front was turning left at a junction and I observed a car at the junction turning right, I also observed hadn't seen me and were getting ready to pull out in front of me. I was already on the brakes but as soon as the oncoming car moved I realised I had to drastically stop and minimise liability, I threw the bike into a wheels first slide using the frame as an e-brake.

I got away lightly. Only 20 stitches in the jaw, a mild concussion, fractured nose, swollen cheekbone, black eye, fat lip, bruised inner leg, two bruised knuckles and minor road rash on my left elbow. I was wearing a T-shirt, shorts and a climbing lid.

The bike was equally fortunate. The electronic display is cracked with 5% of the non-essential pixels expired in the upper left corner, missing front mudguard stays and one taco-d wheel.



I ascertained I slid the bike under the car wheel which is what stopped me.

On the way into the ambulance I heard the driver victim blaming me for signalling left and also claimed I had hit the A-pillar on a dent that had been coincidentally sanded down to bare metal in a rectangle ready for bodyfiller and paint.

I don't especially care for societal norms. I got the bike back and repaired it, I won't be chasing compensation. As far as I'm concerned regardless of the character and observational skills of the motorist it's my fault for allowing it to happen. I had right of way so the ball is in my court to walk away.
The expired wheel was end of life anyway. 4 of the spokes were detensioned because it was so far from true. I took the opportunity to replace the pair for stronger. My rear is D-shaped being a hardtail and hitting pot-holes loaded and at speed.



The latin translates as "Life without Wisdom"



To address two concerns of yours Chris; You can clean off the Silicon Grease with brake cleaner or any solvent and a rag. You'll find a pot of the potion beside every tyre mounting machine in every auto tyre fitters.

The reason for it is to sit the bead uniformly on the rim thus creating a round wheel. All tyres have a round indexing mark beside the mounting flange if mounted correctly this will be equi-distant from the lip of the rim edge.
On the Schwalbe Road tyres this happens to be a smanchy photo-reflective band.



Another feature is metal valve stems. These are resistance to chaff, shear and penetration. They don't really cost extra compared to rubberised stems and have a locknut for retention.

[Saladin]

Chain Wear

Back to routine maintenence...

450 kms on my daily it's time for a new chain. Replacing a Decathlon rebranded KMC E-11. The own brand KMCs seem to be even better; 0.25% tighter tolerances outtov the box.

It's best to keep an eye on chain "stretch" and replace the chain every 0.75% wear on the outside. I use two chain checkers because one validates thuther.







Yurp...she's done. Some people advise replacement at 0.5% wear for 10 -12 speed chains. Meh...go ahead if you want..
Elongated chains first destroy your cassette then your chain ring...ignore it too long and you'll be buying a new drivetrain. If the rollers aren't engaging uniformly on the teeth of the sprockets they'll deform them and then the chain starts skipping instead of pulling. Steel cassettes are cheaper and more resilient to this.

Sometimes a worn chain won't skip because it's already deformed the cassette to it's conformity but as soon as you replace it the new chain will skip because the sprockets (usually the high gears first) have been compromised by the old chain.



Mid-drives + gravel tracks + wet riding have a high wear rate on chains. Some lubricants are better than others. The Halfrauds stuff I pictured earlier isn't great. It's also made of liquid PFAS (teflon) which is horrendous for the environment...I'm in the market for better, more eco, substitute potions.

Next up to bat:
Shimano E8000 most expensive chain I've ever bought.



Freshly soaked overnight in degreaser to remove the factory grease that dirt loves to stick to. It's not a lubricant it's an anti-oxide. Before installation strip the grease off and lubricate it.

WTF...



100% worn outtov the box!!!!
Do not buy chains on that "jungle rainforest" site. This is the last in a long series of fakes I'm after getting. The QC is so bad it's more likely you'll get a counterfeit than anything else.

Bin!

New KMC E-11...tested 0.25% wear outtov the box.

[Saladin]

Wifey and kiddo returned home after holidays.

I moved the cargo bike into the living room and I'm just about getting away with it because it's clean and a family vehicle and all other things considered.

Haven't made much progress. Just roughing in the final placement of things but we'll get into the specifics when I mount them for final installation as I do. The motor has departed Asia.



Front and rear dyno-hub lights came with the bike.

The handlebar forward facing and tail lights are user and/or light sensing off the system battery with thumb controls and a discrete photosensor in the display.

Front & rear indicators are button actuated. Brake light is going to be sensed off a reed switch on the front brake and the yellar manual motor-cutout switch {electronic clutch}.



The horn speaker is integrated into the main battery powered forward facing lamp.


Rear Lights et al



The suspension seat rocks..actually and figuratively, souper comfy and responsive..the suspension seatpost is in the ether coming from Holland, I'm using a rigid as a temp.

Stereo batteries. I'll add more later for extended range but 2kWh is the base model.

[Saladin]

Why not just buy a prebuilt?

If I did that I'd get a
650Wh super expensive proprietary battery without an expansion facility,
A non-programmable, non-serviceable restricted motor with 70Nm of torque,
An aluminium cassette with not much in the way of increased gear range.



for ~€8050 ex. works

Instead I bought a used muscle bike base vehicle for €2k
Added €450 of battery and already had a sister partner from the fleet because they're universally compatible
+€700 of motor kit,
+€100 of drivetrain and the rest could be argued are add-ons anyway.
- A 2x10 Shimano Deore Groupset leftover going on Fleabay complete with cranks and bottom bracket.

Giving me a comparable
Fully programmable motor and modular accessory kit that's serviceable with readily available and inexpensive parts. 160Nm of torque.
A rugged drivetrain.
anna 2kWh expandable fuel tank.

Time? Labour? ...time's a concept {it's a reference standard for rate of spin from the perspective of Terra Firma...that is all! If you confuse it with experience, entropy, education, efficiency, productivity, causality, cell reproduction, wisdom or the ability to heal you'll severly curtail your growth potential}.
Labour's a birthright.

[Saladin]

I noticed the battery holder I had fitted to the downtube on my full-suspension eMTB was shaking itself to smidereens. I bought some spares to replace it and also to speed up battery transplants when I want to take a different bike.
I went with a 4 slot holder battery style, thinking it'd be stronger than a regular 2 slot because it has 4 mounting points to the frame but these are very light ABS plastic with two teeny screws on a slim reinforcing plate.

I elected to ruggedise them with car in a can (U-pol P40, glass fibre) by filling in the cavities on the rearside of the mounting plates.



Some spares are for MPPT inputs to casemount gensets, they're not all for bikes. It's handy having lightweight batteries for my batteries.
It's not just an ebike it's a self-propelled deployable auxiliary fuel tank too.

I gave them the flappy disc treatment and recut the holes with a dremel.



While the paint as drying I got the terminals out to put connectors on the fresh recruits.



They were shipped with 30A Anderson connectors and 60A XT60s.

I prefer the XT60s, I have my own stealth black ones I'll be fitting. I much rather crimp connectors but these aren't that...soldering takes soo much longer..

None of these connectors are waterproof...What? No these kits don't come with fuses! On a bike?! Are you serious?..why would you need a fuse on a bike!?¡



Silicone sealant for good measure.

Then I impregnate heat shrink with more sealant and apply heat to squeeze it into the nethers.




Ready for reassembly



I know they're not pretty. Don't care. Function over form me. They're about 4 times stronger now. I could have given them a second round of car in a can..you won't notice when it's covered in mud hanging off a downtube!

[Saladin]

Motor Programming

There's a few ways you can program a Bafang motor. If you have a very specific display head unit you can use that, or an App(lication for a phone) on another variant display that's equally rare.
I don't use applications for phones or clouds or carry a smartphone most of the time and bluetooth gives me a pain in the noggin' so I don't buy dofers that use it as a perma-feature or require me to carry a phone.

For all other setups there's this interface:



You install drivers and after it will appear as a serial or com port.
You might as well get it, it's only about €30 and the stock flash is really bad. It'll save you the cost in prematurely worn drivetrain parts.
Outtov the box bafangs are waay too tenacious starting from a dead stop and the low level pedal assists are too high powered too. They could throw off a novice or unprepared rider, and the slowest pedal assist is too fast for manouevering amidst pedestrians.

After refitting a reinforced battery tray to my full-sus I wanted to reflash her because she was a mite skitish on take off.



You turn on the bike battery, disconnect the display on the bike from the bike's motor and plug the interface into the bike motor and then a computator. Be careful the throttle is live when you do this...it can make for a bad day if you hit it and the bike jumps across your workshop taking your laptop with it.



You get 3 menus



I lower the current limit in the Summer because the BBS02s get red hot if you run them at the limit for many kms on a warm day.
The BBSHDs are able for max current at 100% duty. They've much better heat sinking.



Next tab: parameters of note: You can set a max speed limit here that cannot be superceeded by the display.

Start current: motor inrush. 1% is perfect. It's set to 30% from factory.

Slow start mode: ramp up time. The lower this is the longer your drivetrain will last.

Crank trigger pulse is pedal assist delay according to cadence rotation.

Stop delay also known as over-run: how long the motor keeps going after you stop pedalling. I set this low because I don't run motor cutouts on my brake levers.

Current decay the lower you set this the earlier the motor backs off at higher cadence. It's a kindov software based torque sensing.

Stop Decay Over-run ramp down rate.

Keep Current is the minimum the motor will output after current decay is triggered.



Mode Current is smooth. Speed is aggressive and hard on the drivetrain.

Speed Limit Throttle speed limit can be different to pedal assist. Some people like to use it as an "afterburner / turbo" feature by setting this higher than the pedal assist max.

Start Current Throttle input motor inrush.


No shop bought e-bikes allow you to edit the motor settings and very few other conversion kits do either.

[Fintray]

A lot of good information there Saladin for anyone building an e-bike, I didn't realise there was so much tinkering that could be done with them.

[AGT]

A lot of good information there Saladin for anyone building an e-bike, I didn't realise there was so much tinkering that could be done with them.

Likewise very interesting thread didn’t appreciate the technology in electric bikes.

[Saladin]

tehehe..thanks gents..there is and there isn't.
I have a penchant for building best-in-class hardware. Plenty of fit-and-forget 20min videos on Utoob on the same subject.
I tend to include the maintenance and soak test results most gloss over. I generally don't recommend anything I haven't tried and tested.
I husta get stick to the back teeth asking sparkys if the fitment they were recommending for campers/boats etc. was something they use themselves every day and had installed in their dwelling. I'll swing from the rafters if someone mentions butane fridges....

I usually do a bike conversion in a day or two. Often I spend longer rebuilding the frame because I always buy used. The full-suss got stripped to the bearings over the Winter. Trueing a wheel can take 3 hours. Rebuilding wheel hubs is great craic too.

Customs are holding my motor to ransom...it's in the country. I'll be giving them what-for after tonight's update.