Courier ebike project advice
- Thread starter Neowise
- Start date
According to the article I linked,dogman dan said:
https://www.curbed.com/article/nyc-delivery-workers.html
looks like they pool their resources and rent space in a centrally located garage. Photo shows shelving with lots of chargers, charging (labeled) batteries, couch, chairs, coffee table, storage for their large backpacks, bikes, etc. Like a clubhouse with dedicated charging capabilities.
Those are still low enough speeds (max 20-21MPHish) to not really have to worry that much about aero regarding range, though high enough to make a difference, if not as dramatic as at speeds several MPH higher or more (where it begins to affect things much more rapidly as speed increases).Neowise said:
You can check this out in the http://ebikes.ca/tools/simulator.html even using a basic "bicycle" setup that can reach the speeds you're after. It's not perfect but it gives a good idea of what happens under various conditions. Here's what comes up as the default for me, changed only to open system b to compare mountain bike upright to road bike tuck for aero comparison, turning off the 100w human input so it's motor power only, and changing kph to mph since I'm more used to that:
https://ebikes.ca/tools/simulator.html?bopen=true&axis=mph&hp_b=0&hp=0&frame_b=road&add=false&blue=Lbs
THe max speed does increase one MPH on the more aero position, from 24.9MPH to 26.2MPH, and takes significantly less power to maintain that.
Graph Syst A Syst B
Thrust 12.0Lbs 9.0Lbs
Mtr Power 592W 464W
Load 597W 465W
Efficiency 81.4% 81.9%
It's a pretty significant aero change, though, because it takes the rider torso from being a sail/parachute/brickwall to a much narrower plane, so I would expect a significant reduction in power needed to maintain speed.
To see what this change looks like thru the speed ramge:
If I set throttle to auto instead of 100%, then move the speed line to 21.0mph for both:
Graph Syst A Syst B
Thrust 9.0Lbs 6.1Lbs
Mtr Power 375W 254W
Load 376W 255W
Efficiency 80.6% 79.8%
As you go down in speed to 15mph, it goes down to
Graph Syst A Syst B
Thrust 5.4Lbs 3.6Lbs
Mtr Power 160W 105W
Load 162W 109W
Efficiency 77.5% 74.8%
And at 10mph
Graph Syst A Syst B
Thrust 3.4Lbs 2.2Lbs
Mtr Power 67W 44W
Load 68W 45W
Efficiency 72.3% 68.0%
And 5mph:
Graph Syst A Syst B
Thrust 2.1Lbs 1.4Lbs
Mtr Power 21W 14W
Load 22W 14W
Efficiency 61.9% 56.9%
I'm not sure how accurate this is at the lower speeds, (can't remember enough of my old regular bike days to know if it reflects the results I've gotten in real life or not), but setting it to high speeds like 31mph gets the even greater difference in results I'd expect (requires a higher voltage battery and a higher current controller, too):
Graph Syst A Syst B
Thrust 18.0Lbs 12.2Lbs
Mtr Power 1115W 754W
Load 1123W 760W
Efficiency 82.1% 83.1%
and 38.6mph (fastest it would go at 72v 40Aa for both positions)
Graph Syst A Syst B
Thrust 26.5Lbs 18.0Lbs
Mtr Power 2025W 1378W
Load 2029W 1384W
Efficiency 81.8% 83.6%
RPM
Anyway, just an example of a "simple" change you can make to get better aero.
If there are old diamond-frame ten-speed bikes available used, (or old diamond-frame 80s MTBs) they're a decent source of chromoly. Many of the ones that are made of that are actually marked on the frame decals, making it easy to tell. Some of them are "butted" tubing (like butted spokes, different thicknesses at the joint areas vs the middle), many are regular.Neowise said:
That's how I built CrazyBike2 (and Delta Tripper, etc). SB Cruiser is made of all square tubing (also recycled from other things) except the headtube and part of downtube from an existing bike. (and part of a cheap heavy-steel trike "kit" that bolts to a regular bike to make a a trike out of a bike--a quick way to do it I wouldn't do if I rebuilt it). The square tubing isnt' really better than round, but it made it easier to build the specific structures on the trike.
dogman dan
1 PW
More info always better, now we know you have a length limit. Is the elevator 2 meters corner to corner? You might have more length that way.
My longtail schwinn was built shorter than most longtails, because I wanted to be able to use the bus bike rack, or my own carries by the wheels bike rack. To use the bus rack, I turned the front wheel backwards.
So build so it fits the elevator, for sure. But maybe you can still lengthen it a few inches, back it in corner to corner, and flip the front wheel just before you get it all the way in.
My longtail schwinn was built shorter than most longtails, because I wanted to be able to use the bus bike rack, or my own carries by the wheels bike rack. To use the bus rack, I turned the front wheel backwards.
So build so it fits the elevator, for sure. But maybe you can still lengthen it a few inches, back it in corner to corner, and flip the front wheel just before you get it all the way in.
I can't remember, but the longtail Schwinn isn't the one you brought here several years ago, is it?
dogman dan
1 PW
No, that one was much longer. That one was great, till it got a flat and needed a ride home. No way it could carry on my cars bike rack.
khorse
10 W
As a bike delivery guy myself, I want the following:
- ease of getting on and off. I have to do it many times an hour. If there's a big obstruction I have to swing my leg over, or a weird center of gravity, it's going to piss me off
- comfortable, not cramped position. Aerodynamics do not matter, we have a motor and a huge battery pack. We're not setting top speed runs. It's also important because the job is stressful enough without having to endure it in a weird position. If I can sit upright I can see comfortably ahead and around me.
- front and rear suspention, and wide 2.5+ inch tyres. Delivery fleet ebikes don't and it makes working some streets unbearable. This is the number 1 improvement you can make
- the pedalling position needs to be plausible, like a non-ebike. Here in europe throttles are a no-no. We still use them, but we ghost-pedal so we don't get pulled over.
- good brakes with normal handlebar controls. The ebike I have to ride for work is awful, with a weak front brake. It also has a coaster brake, which is extremely unpleasant to use, and makes it difficult to position the pedals for a good start at traffic lights. Two hydraulic handbrakes please.
- something to protect the hands from cold and wind.
- rear wheel drive.
Personally I have to wear a backpack (company rules) so I don't care too much about a cargo carrier. But one that can be bolted to the front of the frame would be nice.
- ease of getting on and off. I have to do it many times an hour. If there's a big obstruction I have to swing my leg over, or a weird center of gravity, it's going to piss me off
- comfortable, not cramped position. Aerodynamics do not matter, we have a motor and a huge battery pack. We're not setting top speed runs. It's also important because the job is stressful enough without having to endure it in a weird position. If I can sit upright I can see comfortably ahead and around me.
- front and rear suspention, and wide 2.5+ inch tyres. Delivery fleet ebikes don't and it makes working some streets unbearable. This is the number 1 improvement you can make
- the pedalling position needs to be plausible, like a non-ebike. Here in europe throttles are a no-no. We still use them, but we ghost-pedal so we don't get pulled over.
- good brakes with normal handlebar controls. The ebike I have to ride for work is awful, with a weak front brake. It also has a coaster brake, which is extremely unpleasant to use, and makes it difficult to position the pedals for a good start at traffic lights. Two hydraulic handbrakes please.
- something to protect the hands from cold and wind.
- rear wheel drive.
Personally I have to wear a backpack (company rules) so I don't care too much about a cargo carrier. But one that can be bolted to the front of the frame would be nice.
I tried to understand your comments and I am sure it helped me gain a better perspective on what I want to build. The Arrow 7 ebike was very interesting to read about and also gave me a good ideea in what working as a courier may be like.
So by now my project has evolved into this:
Moved the rack to the rear for better stability and visibility;
Integrated the rack into the frame;
Both wheels 28" or both 26" with wider tires;
Standard fork, preferably with suspension;
Big battery in the middle with a bit of a longtail (+4-5 inches);
The rear rack can be used as a solid base to make a lockable anti battery theft device;
I'm thinking of using a klunker geometry/handlebar sizing for a more fun/confortable position;
So by now my project has evolved into this:
Moved the rack to the rear for better stability and visibility;
Integrated the rack into the frame;
Both wheels 28" or both 26" with wider tires;
Standard fork, preferably with suspension;
Big battery in the middle with a bit of a longtail (+4-5 inches);
The rear rack can be used as a solid base to make a lockable anti battery theft device;
I'm thinking of using a klunker geometry/handlebar sizing for a more fun/confortable position;
Thanks for your comment!khorse said:
Do you think a suspension saddle post would help improve your comfort? There are some pretty cheap ones that would maybe help?
How big is your battery pack? And what range does it give you? If you can give me more info on your real life range vs how much do you have to ride everyday to have a good paycheck?
Bigger tires are less efficient, they have more rolling resistance, but will certainly leave space in the frame for 2.5 tires, I can always put skinnier tires if I want more range.
Why does your company make you wear the backpack? What is the thinking behind that? Its not really good for your lower back...
What are you thinking about to protect the hands? something like MX style hand guards? or moto heated grips?
khorse
10 W
Neowise said:
A sprung seatpost isn't very helpful for a couple reasons. They aren't very durable or very stiff, meaning they either seize up after a while or they get sloppy and make the saddle rock side to side. Then there's that when they compress, they shorten the distance between ass and pedal. They don't protect the bike from shocks or rattles at all, instead they expect the bike to transmit it, so they don't help for durability.
They also don't help for controllability. An important part of suspention is keeping the wheel firmly on the ground. A hardtail with a suspention post ends up getting airtime on a hard hit. No good.
The battery packs we run on our (allegedly) 250W bikes are 750Wh, I've had one last 60 kilometers. On my personal build, 1.4kWh, about the same range, but that's a 2000W bike. The biggest difference is that the 250W bike was running flat out all the time at 25kmh, but the 2000W bike I rarely hit it's limits.
For hand protection the guards would definately help, and heated grips too. In fact a bigass motorcycle windscreen would be great. Remember we can be riding these things below freezing, in snow, all kinds of terrible conditions. Hands are the biggest concern because any glove dexterous to use ebike controls isn't near insulated or waterproof enough.
The backpacks are a kind of standardization. Some riders use the company bikes, some use their own, some rent through a scheme. The company doesn't want to give us cargo boxes because then they'd have to deal with people who don't know how/can't fit them to their own bikes.
I tell you that guy who said make it longtail is completely right, by the way. Bikes are rear heavy, adding motors and batteries even in the middle doesn't help as much as you'd want, because it gets too high up. The front wheel never seems to have enough weight on it to grip on slick surfaces.
There's also that sitting over the back wheel like a normal bike makes dropping down kerbs with the back wheel much worse than the front. But things like cobblestones are equally awful on both wheels. That's really why I want a couple inches of suspention travel and a long wheelbase.
khorse
10 W
Neowise said:
This is at the least much more of a looker than I have to ride! For a hardtail, not bad at all!
two points:
It doesn't look like there's any space to fit a ring lock. These are bolted to the inside of the seat stays and lock the rear wheel, making it impossible for a thief to wheel the bike away. you just turn the key, push the lever down and take the key out. Very quick for this line of work
At this wheelbase you've put the center of the cargo box behind the rear axle. For weight distribution reasons this is really a no-go.
The more weight you put to the rear of a bicycle, the less stable it gets. I've done this and got a very severe death wobble even at walking speed. It was enough to crack the welds in the aluminium carrier.
Suspension seatpost only takes the edge off, not a real substitute for well-engineered suspension. "Cheap ones" even less effective.Neowise said:
Dogman dan told something interesting. If you get the wheelbase right, with the seat in a good location, the bumps encountered on a stretched wheelbase result in more of a rocking motion at the saddle rather than the sharp vertical impacts felt when the saddle is located more directly over the rear wheel. This has been my experience, riding a (extended rear) utility bike.
Not so true anymore. Technology and thinking have evolved in this area.Neowise said:
https://www.renehersecycles.com/12-myths-in-cycling-1-wider-tires-are-slower/
There are wide tires with more supple casings that have low overall rolling resistance. My current favorite is Schwalbe Big Ben 26x2.35.
Motorcycle cops around here have those insulated housings over the hand grips/clutch/brake levers. Not sure if they are heated.Neowise said:
Heated MC gloves are a thing:
https://www.revzilla.com/heated-motorcycle-gloves
Also there are several cordless tool lines with heated gloves in case you already have investment in cordless tool batteries.
Chalo
100 TW
99t4 said:
Jobst Brandt did instrumented tests to demonstrate that wider tires have lower rolling resistance, all the way back in the 1980s.
The problem with taking that to heart is it assumes equal construction between the narrower tire and the wider one. This is very rarely the case in practice except when the sizes are very similar. Jan Heine's tires (branded Rene Herse now, Compass before that) are the exception in that even the fattest ones are constructed like thin, narrow sport tires. However, in my observation they get a puncture when exposed to minor hazards like you thinking about going for a ride.
Fat tires can be fast-- I've used a lot of Schwalbe Big Apples over the years-- but if they're thicker walled or better armored than a narrower tire, they probably won't be quite as fast.
I tend to use the widest tires that will fit in my bikes' frames, but not for reasons of rolling resistance.
khorse
10 W
Agreed. "thinner = faster" has been known to be wrong for years. We're stuck with it because the bike industry fragmented the drop handlebar bike into 1000 catagories. The allegedly fastest bikes, of course, being ones where enough frame clearence to fit a 25mm tyre is seen as the ragged edge of acceptability, and fender eyelets aren't allowed in case the added weight makes you lose the tour de france. It's really stupid, even before you consider the realistic prospects of the middle aged heffers actually buying these things...
Not to say that they were originally stupid 40 years ago, when they first went to mega skinny tyres. They work very well at reducing rolling resistance in a velodrome, where the track is perfectly smooth. It all falls apart in the real world, when the skinny tyres can't absorb any shock and so you can't get your effort down to the ground properly.
It gets worse when you're dealing with an ebike carrying it's own weight in batteries and motor, not to mention actual payload. I'm not going to go very fast at all when every time I do the bike bounces me all over the place.
Not to say that they were originally stupid 40 years ago, when they first went to mega skinny tyres. They work very well at reducing rolling resistance in a velodrome, where the track is perfectly smooth. It all falls apart in the real world, when the skinny tyres can't absorb any shock and so you can't get your effort down to the ground properly.
It gets worse when you're dealing with an ebike carrying it's own weight in batteries and motor, not to mention actual payload. I'm not going to go very fast at all when every time I do the bike bounces me all over the place.
MadRhino
100 GW
+1Chalo said:
Rolling resistance is a minor factor. Safety is a priority, and reliability is not far behind. The moment a bike has a motor, we shouldn’t care anymore about rolling resistance consuming a few watts, especially when this rolling resistance is a consequence of better grip and reliable construction.
khorse said:
I'm not sure I'm using the right words to express this stuff but:
It's not just the tire size, it's how stiff they are. Stiffer means less flex of carcass, which means less energy lost in squishing the tire. If the carcass too soft, but you use higher pressure, they may use the same energy as a skinnier tire (or close enough), and still give a better ride (or have better grip).
Suspension-wise, the more air volume you have (at the same pressure as a lesser volume) the more bump absorption you get. (so a larger diameter tire that holds more air, like 29"x2.1" vs 26"x2.1", would give a better ride...but so will a wider tire like 26"x2.5"vs 26"x2.1"...the greater the volume difference, the better the ride.
The squishier the tire feels (the more it has to flex while rolling), the more energy it loses to this process, and the less efficient it is.
Also, the heavier the tire is, especially in sidewalls, it usually means it is going to take more energy to flex those, like moped or motorcycle vs bicycle tires. (sometimes that tradeoff is worth it, but not if you ever have to pedal the thing around! :lol: I use moped tires on the back of the trike for loading and puncture resistance and wear, and they give a better ride since i have no suspension, but they take notably more power to move...the front tire is a bicycle tire though)
Chalo has written a bunch of good posts about tires, wheels, etc., from long experience with many types of bicycle usages (including very large pedicabs and other cargo/people mover applications), if you want more details about that stuff.
I'm in PHoenix Arizona and it doesn't get super cold here, at worst we may have a few degrees below freezing a few nights a year in jan/feb, sometimes dec. But riding around at 20mph my old hands get hurty joints riding in even 50-60F temps, and gloves get in my way, so I use these:
https://www.amazon.com/dp/B07F415V8D/?coliid=I3EZ24BXRYIRD7&colid=1YBJWJ5ZSPNWY&psc=1&ref_=lv_ov_lig_dp_it
and they take care of air deflection well enough most of the time, and i keep thin gloves for the times they don't. Iv'e banged them into things and haven't broken one yet. I did peel off the ugly not-really-reflective strips and replaced them with these marker/turnsignal strips:
https://www.ebay.com/itm/393178503261
though I used silicone to glue them down cuz their adhesive sucks. I used these on the rear top bar of the cargo rack:
https://www.ebay.com/itm/393110680933
(if they're too long you can cut them down from the unwired end and they stiill work, you just have to seal the newly opened end for water resistance). they have their own sequential flashers built in, too. )
It's not cold enough here for heated grips, so no experience with those. Just keeping the wind off worked for me.
I tried one of these from an old Yamaha (kinda like the CHIPS police bikes from the old TV series) out in a quick ziptied experiment for aero difference on the trike, just a straightline run down the street at 20mph, and aside from keeping the wind off of me a fair bit, it also made a difference (as much as 25%!) to the aero of the trike, by forcing the air up and over the top of the canopy instead of under it and onto me, but i had to angle it close to 45 degrees to make the most difference. I didnt' try it on a real road trip because it was going to take a lot more work to actually install, and stuff has always come up preventing me from doing all that work so I don't yet know how well it works overall. There was no wind in the test I did, so crosswinds/etc didn't come into the test, and might seriously change the results.
On the trike the mass and size didn't make any difference to handling, but on a bicycle it would certainly make it harder to deal with when not riding; how much harder depends on the piece's size and shape and how it's installed, and what you're doing with it.
You can make a cheapie windscreen with thin and flexible clear plastic sheeting; it'll scratch and bend easier but it'll be lighter and probably cheaper to replace and definitely easier to work around in confined spaces. (like an elevator), just because it does bend easy. They're not good for high speeds, but if you curve it right (partial cylinder, vertical axis), it'll be stiff enough for 20-25mph.
I made some sketches for a bike with 26" wheels and 100mm front suspension. Rear suspension would complicate the project a bit more than I can handle right now...
This way I can use parts from other bikes I don't use anymore (I have old 26" wheels, hydraulic disc brakes and a rockshox argyle)
As I see on many bikes here the safety factor is also important so I had the idea of using square tubing for the horizontal frame lines and masking them with reflective tape for high visibility at night.
For best reflective visibility, make sure you use *real* retroreflective tape, like the stuff by 3M (not the bajillion counterfeits), which reflects from many angles and does so very very well; it's what is commonly used on street signage and markings.
If you like, rather tahn depending on the cars having their headlights on and pointed at you (so the reflective tape works), you could *also* use actual lighting strips. (with the reflective stuff also there for when you don't have any power, etc).
See my SB Cruiser trike for a few options for those (I think I also posted a couple better versions with built in blinkers in a post above somewhere).
I used to use just reflective tape (I still do in places) but it wasn't sufficient for the numerous places and times where a car's lights or those in surroundings (if any) weren't sufficient for them to see me, and if I had just proceeded instead of assuming they didn't see me, bad things could have ensued. And other cyclists that aren't really paying much attention and/or have no light source of their own (very common here)--the lights they see a lot farther away and constantly, rather than just the moments when enough light hits at the right angle.
If you like, rather tahn depending on the cars having their headlights on and pointed at you (so the reflective tape works), you could *also* use actual lighting strips.
(with the reflective stuff also there for when you don't have any power, etc). See my SB Cruiser trike for a few options for those (I think I also posted a couple better versions with built in blinkers in a post above somewhere).
I used to use just reflective tape (I still do in places) but it wasn't sufficient for the numerous places and times where a car's lights or those in surroundings (if any) weren't sufficient for them to see me, and if I had just proceeded instead of assuming they didn't see me, bad things could have ensued.
And other cyclists that aren't really paying much attention and/or have no light source of their own (very common here)--the lights they see a lot farther away and constantly, rather than just the moments when enough light hits at the right angle.And with this frame shape I have room for two 17.4wh 48v batteries. I think this should give me enough range and does not take more time to charge. For now I only have one battery and probably will try working only with it, but its nice to know I have room for another one in the frame.