Pedaling at high speed

[The Madmadscientist]

Unless you're building a mid drive. you'll never use that 50 tooth cog in the rear. I'd be surprised if you use anything more than about 26 to 30 teeth in the rear. Any bigger than that and you won't be able to pedal fast enough to keep the motor from bogging down and frying itself...unless you can pedal like a hamster. With 60 front and 26 rear and 80 cadence, you'll be going 15mph, which is a good speed to avoid meltdown when climbing a hill. With 50 in the rear, you'll be going 7.5mph, so too slow, so you'll never use it.

I use 46:16 for climbing hills, 46:18 if it's super steep. That would equate to 21T and 23T rear when using 60T front.

I'm thinking about my fat but on a heavy bike starting from a dead stop at a light...
I'n new to proper gear ratios for ebikes...well honestly having ridden bikes for years I've never really thought about gear ratios until now.

 

[Chalo]

With 60 front and 26 rear and 80 cadence, you'll be going 15mph, which is a good speed to avoid meltdown when climbing a hill. With 50 in the rear, you'll be going 7.5mph, so too slow, so you'll never use it.

He'll use it to limp home with a dead battery or an electrical problem.

 

[The Madmadscientist]

With 60 front and 26 rear and 80 cadence, you'll be going 15mph, which is a good speed to avoid meltdown when climbing a hill. With 50 in the rear, you'll be going 7.5mph, so too slow, so you'll never use it.

He'll use it to limp home with a dead battery or an electrical problem.

I know I'm new here and haven't gotten accustomed to the "regulars' different personalities but.... sir, would you be the designated troll?

 

[Chalo]

With 60 front and 26 rear and 80 cadence, you'll be going 15mph, which is a good speed to avoid meltdown when climbing a hill. With 50 in the rear, you'll be going 7.5mph, so too slow, so you'll never use it.

He'll use it to limp home with a dead battery or an electrical problem.

I know I'm new here and haven't gotten accustomed to the "regulars' different personalities but.... sir, would you be the designated troll?

That's not trolling. You need gearing for when something goes wrong, unless you're comfortable calling for rescue any time your motor won't go. So make sure your gears include ones that are low enough to get you back to base with the motor shut off.

 

[E-HP]

You need gearing for when something goes wrong, unless you're comfortable calling for rescue any time your motor won't go. So make sure your gears include ones that are low enough to get you back to base with the motor shut off.

Theoretically. In reality, you only need to be able to pedal about 3 blocks maximum. By that time, even the most stubborn person figures out it's easier to push it.

 

[Ianhill]

Id regularly push my range by riding downwards to sea with no assistance and then come back with just a little got 330wh to do 34miles like that and could of beat it with better terrian, valleys are quite hilly.

Id also do the opposite and ride upwards till the bike had tapped out and then freewheel back down id only get about 12miles doing that though theres a slow climb from sea level then a harsh mountian with an ice cream van ontop that felt rude not to visit, all this befire the crona hit and the bikes been sold and back on ebay again old days now I've moved on as well as the world.

Is it just me or is diy ebikeing slowing as manufacturer middrives take over, the innovation in hub motors has slowed down theres nothing good available without a silly price tag making the bikes either high power for the crazy engineer with money to burn.

 

[The Madmadscientist]

With 60 front and 26 rear and 80 cadence, you'll be going 15mph, which is a good speed to avoid meltdown when climbing a hill. With 50 in the rear, you'll be going 7.5mph, so too slow, so you'll never use it.

He'll use it to limp home with a dead battery or an electrical problem.

I know I'm new here and haven't gotten accustomed to the "regulars' different personalities but.... sir, would you be the designated troll?

That's not trolling. You need gearing for when something goes wrong, unless you're comfortable calling for rescue any time your motor won't go. So make sure your gears include ones that are low enough to get you back to base with the motor shut off.

This is why I'm interested in the 2 speed high speed model with the 2.5 overdrive.
It seems like I could have sane gearing for around town and then high speed gearing with the overdrive.

 

[E-HP]

This is why I'm interested in the 2 speed high speed model with the 2.5 overdrive.
It seems like I could have sane gearing for around town and then high speed gearing with the overdrive.

Future upgrade. You are making a lot of uninformed decisions when you don't need to. There are very few builds that are a one and done. Build the bike, ride it for a while, make informed decisions about your next upgrades.
Nobody providing advice is informed, since nobody can provide informed advice with just vague ideas or descriptions. There are stickies at the top of the page that tell you what to provide in order to obtain advice, but the evidence indicates you haven't read them.
If you take the route of building the bike over time, you will likely make very different and better decisions about where to direct your next dollar spent.

 

[Chalo]

This is why I'm interested in the 2 speed high speed model with the 2.5 overdrive.
It seems like I could have sane gearing for around town and then high speed gearing with the overdrive.

That's a huge range, slightly wider apart than the top and bottom gears of a Shimano Nexus 7 hub, or the extremes of a 14-34 Megarange 7 speed freewheel. But if you put the high gear at a useful ratio for pedaling along with the motor, you'd definitely have a nice low limp-home gear.

 

[LewTwo]

Is it just me or is diy ebikeing slowing as manufacturer middrives take over, the innovation in hub motors has slowed down theres nothing good available without a silly price tag making the bikes either high power for the crazy engineer with money to burn.

I do not believe that it is just manufactured ready made E-bikes. As Chalo is quick to point out, mid-drive motors wear out drive trains. However they allow a greater choice of rims, gearing (single speed, IGH and derailleur) as well as getting the additional weight closer to the CG.

Thirty years ago about the only choices we had were hub motors or that god-awful bolt on the side thingy. Today there is a wider variety (although in most cases the cases are only available in ugly, hot black). There have also been some innovations in hub motors such as the Grin all axle drive and the Bafang 31x series. We also have the option of belt drive as well as chains (not likely see a return of maintenance free shaft drives unfortunately).

My current pet peeve is the tendency toward proprietary systems like Bosh that only work with their controller, their battery, their pre-programmed limitations, etc.

 

[nicobie]

You might also look into 'pedal forward' style bikes like the Electra Townie. They make a decent bike that is a step above what you find at Walmart etc.

Take a look at what I built 10 years ago. It had no problem with 40 mph, but after awhile I figured out that 20 mph was way safer. (Chalo is correct and not a troll either )

Links are below this post.

 

[E-HP]

Thirty years ago about the only choices we had were hub motors or that god-awful bolt on the side thingy.

LOL, I saw one for the first time day before yesterday. A guy even older than me , riding at maybe 12mph. He looked like he was enjoying himself, just putting along. Met the two main criteria for fun; two wheeled, and powered. It was fairly quiet too.

 

[BalorNG]

"God-awful bolt on the side thingy" is actually the lightest, most effective solution.
Ok, not the 'god-awful' one, right, but the 'side thingy'

As in - left-sided middrive using chain/belt reduction, which can easily be setup both with freewheel (ok, that would need a reducer though) and fixed gear. Latter is better because you can simply replace the brake disk with sproket and use regen instead of rear brake as 'drag brake'. Works great.

You just want a decent motor for this, not a brushed godawful one with (likely) inefficient gearbox... a brushless e-board ~60$ 120kv motor (weight just one kg) plus 100$ Vesc ensures your motor will provide you with assistance up to 35 mph you desire on 36v battery plus pedalling with almost 90% efficiency, keep human and motor drivetrains separate, total weight at least 2x less than a motor wheel of similar power and contributes only a small fraction of unsprung weight compared to a hub motor (depending on where you put it)... and some work in CAD and 3d printing/laser cutting which is cheap now.

Otoh, maybe not on YOUR bike - as in upright bike with fat bike tires, but most certainly on mine if I care enough
You do need a fairly large one-step reduction (9x) for that to work, but it is quite doable.

I have such a setup with a less powerful motor and don't have an urgent need for speed, but I can get up to 30 mph top speed with some pedalling, however that is quite wasteful on the battery so I limit my cruising speed to 25mph and get about ~12 wh/mile.

Problem with 'crank mid drives' is schizophrenic arrangement where you first add 3 steps of reduction to match motor RPM to human pedalling RPM, and than a consierable *multiplication* so you can get high speed!
It does make sense on 'real' MTBs, where you need stump-pulling torque to climb very steep mountains at slow speed, but high efficiency w/o overheating your motor.

 

[BalorNG]

You need gearing for when something goes wrong, unless you're comfortable calling for rescue any time your motor won't go. So make sure your gears include ones that are low enough to get you back to base with the motor shut off.

Theoretically. In reality, you only need to be able to pedal about 3 blocks maximum. By that time, even the most stubborn person figures out it's easier to push it.

Dunno, unless you have really steep hills around, going slow sure beats walking - unless you have one of those beasts where pedals are truly 'just for show' and nobody gave a damn about biomechanics. A besides, weight, unless steep uphill, is overrated. I weight more than most people + their ebike naked (and that's not all muscle, unfortunately) and that does not prevent me from riding under my own power considerably more than a few blocks.

 

[4speed]

Here's the problem (I think), around here cars cruise at 35mph on 25mph roads. To keep up with traffic the ebike will need to be able to cruise at 35mph.

Is it possible for a geartrain to be set up to where I am honestly pedaling at that point?

You are asking for a lot there...
Gearing is one thing, and possibly the least problematic imho. The pedal work you put in will be a fairly small portion of the required power anyway.
As already pointed out, motor power may be around 1500 W on flat ground with no wind. Double that when selecting motor to have some headroom for slopes and headwind.
Then there is the battery issue; a BIG battery is 1500 Wh (and $1000 if you want brand cells).
Then you need tires. There is the ECE-R75 rating for 50 km/h which is 31 mph. They will not blow up just as you exceed 31 but if you want to do it continously and also around their max load rating (typically 200 lbs)... you will want something reliable.

And like Chalo said, the cars will pass you anyway. :wink:

 

[E-HP]

Here's the problem (I think), around here cars cruise at 35mph on 25mph roads. To keep up with traffic the ebike will need to be able to cruise at 35mph.

Is it possible for a geartrain to be set up to where I am honestly pedaling at that point?

You are asking for a lot there...
Gearing is one thing, and possibly the least problematic imho. The pedal work you put in will be a fairly small portion of the required power anyway.

Well if 33.7mph isn't fast enough, he could pedal like hell to get up to 35mph, if that's the magic number. At that speed, you have a lot more to pay attention to than the cars, so the risk that you think you're avoiding may actually be going up since your attention is more spread out.

https://ebikes.ca/tools/simulator.html?motor=M2705_SA&batt=B5220_GA&cont=C35&hp=0&axis=mph&frame=mountain&autothrot=false&throt=100&grade=0&wheel=26i&mass=110&cont_b=C35&motor_b=M2705_SA&batt_b=B5220_GA&mass_b=110&hp_b=200&bopen=true

 

[RunForTheHills]

Is it just me or is diy ebikeing slowing as manufacturer middrives take over, the innovation in hub motors has slowed down theres nothing good available without a silly price tag making the bikes either high power for the crazy engineer with money to burn.

I don't think that there are fewer DIY'ers, but there are a LOT more non-DIY'ers buying ebikes.

 

[The Madmadscientist]

This is why I'm interested in the 2 speed high speed model with the 2.5 overdrive.
It seems like I could have sane gearing for around town and then high speed gearing with the overdrive.

Future upgrade. You are making a lot of uninformed decisions when you don't need to. There are very few builds that are a one and done. Build the bike, ride it for a while, make informed decisions about your next upgrades.
Nobody providing advice is informed, since nobody can provide informed advice with just vague ideas or descriptions. There are stickies at the top of the page that tell you what to provide in order to obtain advice, but the evidence indicates you haven't read them.
If you take the route of building the bike over time, you will likely make very different and better decisions about where to direct your next dollar spent.

Hello, I'm not trying to make any hard and fast decisions here. Just a locus of reasonable possibilites for the different major bike componenents or maybe systems is a better word.
I have read the sticky that you mention but I must need to read it again as I didn't think I was doing anything wrong.

 

[The Madmadscientist]

This is why I'm interested in the 2 speed high speed model with the 2.5 overdrive.
It seems like I could have sane gearing for around town and then high speed gearing with the overdrive.

That's a huge range, slightly wider apart than the top and bottom gears of a Shimano Nexus 7 hub, or the extremes of a 14-34 Megarange 7 speed freewheel. But if you put the high gear at a useful ratio for pedaling along with the motor, you'd definitely have a nice low limp-home gear.

I've been playing with a gear calc and believe I can make the 1.65 overdrive model.
Theres a guy on ebay selling several complete kits for under $400. He's checking if he can get the 100mm BB version...hope its true that that size won't require the 45 deg bevel tool...am not relishing the search for a local one that I can rent for a day.

 

[The Madmadscientist]

You might also look into 'pedal forward' style bikes like the Electra Townie. They make a decent bike that is a step above what you find at Walmart etc.

Take a look at what I built 10 years ago. It had no problem with 40 mph, but after awhile I figured out that 20 mph was way safer. (Chalo is correct and not a troll either )

Links are below this post.

That's an interesting bike. Ahead of its time a would say.
I'm a sucker for carbon-fiber. I think your side panels look awesome.

 

[The Madmadscientist]

You need gearing for when something goes wrong, unless you're comfortable calling for rescue any time your motor won't go. So make sure your gears include ones that are low enough to get you back to base with the motor shut off.

Theoretically. In reality, you only need to be able to pedal about 3 blocks maximum. By that time, even the most stubborn person figures out it's easier to push it.

Dunno, unless you have really steep hills around, going slow sure beats walking - unless you have one of those beasts where pedals are truly 'just for show' and nobody gave a damn about biomechanics. A besides, weight, unless steep uphill, is overrated. I weight more than most people + their ebike naked (and that's not all muscle, unfortunately) and that does not prevent me from riding under my own power considerably more than a few blocks.

In Oakland we have the hills which would be considered mountains in some parts of this country.
We also have the Marin Headlands which I would love to be able to do again.
We now have a bike path that starts in Oakland and goes most of the way to SF (so stupid, don't get me started).
So, yes big hills and my desire to get out and enjoy them.

 

[The Madmadscientist]

Hello All,
I seem to kind of 'stepped in it' with my personal idea for my perfect ebike.
Tracer gave me all the dimensions and I actually taped it out on the floor and then laid down like I was riding it. It seems doable except the seat. With the semi-recumbent riding position I might need a seat with a small back that I can push against.
With luck, I'll be ordering the frame and forks from Tracer next week...waiting for a very big check (from a Nigerian prince) to clear and settle several outstanding debts...
The exact handlebar placement... I'm planning on using 'cruiser' handle bars that have a bit of a sweep back. I'm also planning of getting and adjustable handlebar mount that will push the bar closer to me and also raise them up. I'm hoping this will put my back in the right position for long saddle times.

 

[E-HP]

In Oakland we have the hills which would be considered mountains in some parts of this country.
We also have the Marin Headlands which I would love to be able to do again.
We now have a bike path that starts in Oakland and goes most of the way to SF (so stupid, don't get me started).
So, yes big hills and my desire to get out and enjoy them.

No they aren't, but they are steeper than most mountain roads in places, but not as long. I've ridden most of those hills on the east bay, across the Richmond San Rafael Bridge to ride around Marin, and to Treasure Island a month or two ago. Any of those places can be ridden with a 1000W-1500W direct drive motor with some cooling (Statorade), because they are hills, not mountains. And you can pedal, up to whatever cadence you are comfortable with (I climb up the hills at somewhere between 15mph-25mph, but can only pedal up to around 22 mph comfortably).

I like riding along the ridgeline, along the Arlington, Grizzly Peak, and Skyline, but regardless, I have to climb a minimum of 750ft to get up there, and a 1000W-1500W hub can do it with moderate pedaling and no overheating with every route I've taken. And since most of the hills are windy, you don't have a sustained 20%+ climb, but something less with a few steep parts on the way up.

 

[The Madmadscientist]

In Oakland we have the hills which would be considered mountains in some parts of this country.
We also have the Marin Headlands which I would love to be able to do again.
We now have a bike path that starts in Oakland and goes most of the way to SF (so stupid, don't get me started).
So, yes big hills and my desire to get out and enjoy them.

No they aren't, but they are steeper than most mountain roads in places, but not as long. I've ridden most of those hills on the east bay, across the Richmond San Rafael Bridge to ride around Marin, and to Treasure Island a month or two ago. Any of those places can be ridden with a 1000W-1500W direct drive motor with some cooling (Statorade), because they are hills, not mountains. And you can pedal, up to whatever cadence you are comfortable with (I climb up the hills at somewhere between 15mph-25mph, but can only pedal up to around 22 mph comfortably).

I like riding along the ridgeline, along the Arlington, Grizzly Peak, and Skyline, but regardless, I have to climb a minimum of 750ft to get up there, and a 1000W-1500W hub can do it with moderate pedaling and no overheating with every route I've taken. And since most of the hills are windy, you don't have a sustained 20%+ climb, but something less with a few steep parts on the way up.

Well, I guess one mans mountain is another mans hill.
I'm old, fat and unfortunately have a real lung disease (but I can still manage to wear a mask).
I'm planning on the 3KW hub motor for the extra torque compared to a 1k motor and I want a decent reserve of power.

 

[LewTwo]

Well, I guess one mans mountain is another mans hill.

I grew up in Birmingham, Alabama ... the foothills of the Appalachian Mountains. Today I live in Texas. Anything with a 2 meter rise in elevation is a hill. The only Mountains are Freeway overpasses :lol: