50 miles with 4600 ft gain

[Energetic James]

I have a beautiful commute through the mountains in the NW, but it is 50 miles with a 4600ft gain. Maybe I'm dreaming, but can I do this on an ebike? I have a fast Trek 520 touring bike that I could convert with a hub motor or I could just buy a new mid drive bike. Using some physics and bikecalculator.com I figured I'd need an average of 500W (plus my 120W contribution) to do the trip in 2 hours (25mph). I figured I'd need to carry a spare battery or even two. I can recharge at work. Looking for 1) acid test - should I just give up now? 2) recommended technology hub or mid drive? 3) recommended power rating 4) I don't care about starting torque. Is torque a factor near top speed or just power? 5) battery capacity and ideas - higher voltage, etc? 6) also maybe someone could check my math?
I am 190lb dressed to ride, bike is about 30lbs, 100psi clinchers, 700c wheels, nice solid touring bike.

 

[mrgold35]

Is it 50 miles one way or 50 miles round-trip?

That distance is more of a weekend fun ride compared to a daily commute for me. I'm not sure if I could bike commute that long 3-5 days a week. 50 miles with a 4600ft climb might take 2 hours at a minimum and maybe 2 1/2 to 3 hours depending on average speed up the inclines. That would be a 4-5 hour bike commute per day on average. You might have to pick between speed or range with your batteries because it might take 3-5 hours to recharge a single battery that is nearly depleted. Might need to have two chargers to speed up the re-charge time by half at work if you have 2-3 batteries.

 

[James Alderson]

That is not a commute.. that is a trip.

 

[Trail Cruiser]

I have a beautiful commute through the mountains in the NW, but it is 50 miles with a 4600ft gain. Maybe I'm dreaming, but can I do this on an ebike? I have a fast Trek 520 touring bike that I could convert with a hub motor or I could just buy a new mid drive bike. Using some physics and bikecalculator.com I figured I'd need an average of 500W (plus my 120W contribution) to do the trip in 2 hours (25mph). I figured I'd need to carry a spare battery or even two. I can recharge at work. Looking for 1) acid test - should I just give up now? 2) recommended technology hub or mid drive? 3) recommended power rating 4) I don't care about starting torque. Is torque a factor near top speed or just power? 5) battery capacity and ideas - higher voltage, etc? 6) also maybe someone could check my math?
I am 190lb dressed to ride, bike is about 30lbs, 100psi clinchers, 700c wheels, nice solid touring bike.

Fifty miles, even for a car is quite a distance and would take me more than an hour , even if there are high speed sections. I recently did a 48 mile round trip on my ebike with minimal elevation changes (I assume since I did not did not check them), at a bike trail (North County Trailways, NY) and my ride time was 2 hours and ten minutes, average speed of 22 mph. My 52V 13Ah (676 Wh) battery powered up for 35 miles before I changed to my spare battery. If you ride fast at more than 20 mph, your battery consumed goes up exponentially for every mph increase in speed. Your battery consumption may vary from 15-20 wh per mile depending on speed, rider's weight, rider's effort, number of stops, and elevation changes.

 

[Energetic James]

Agree. I'm thinking once per week and building to twice. Likely not more than that.

 

[Sonoboy]

Here's a link discussing the elevation climb capabilities and battery draw for a Bosch Performance speed motor (not the CX).

http://www.ebikeportal.com/test-bat...0-meters-of-elevation-gain-with-a-bosch-ebike

If you are using the upper ranges of the Bosch, for example SPORT and TURBO, you most definitely will need two batteries.Here is the Bosch range calculator:

https://www.bosch-ebike.com/en/service/range-assistant/

If you can afford it, get one of the Bosch powered bikes that are dual battery configured. I just got the Riese & Muller Delite with dual battery, and am still enjoying not having any range anxiety. Mine is the 20 MPH version with the CX drive. From what I've read, a speed version (28 MPH) will lose about 20% of range due to air resistance. So, there's that to think about.

 

[JRA]

For the amount of money you would have to spend to make a bicycle that meets your requirements in a safe and sound manner you would be better off getting a Zero e moto for about the same price and get there in under an hour to boot.

Averaging 25mph with that much elevation gain, even though you lose it in a round trip scenario, from a bicycle based platform is not realistic. If you dropped your expectations to 20 mph avg. spd. it would be more feasible however. You could probably do the uphill way on 52v 17.5 ah battery at that or close to that speed. I have done 42 miles with 2500' gain with an 11 ah battery a few times averaging close to 20, and I pedal all the time in appropriate gear ratios with aggressive input.

I also live in the PNW btw.

 

[ROJA]

I think this is a super interesting question. I know of a guy who built up a bike himself and can do a hilly 100-mile ride (at speeds much slower than 25 mph, though), so anything is possible. Supposedly the high-end Stromer can also go 100 miles on a charge.

My view is that with a good ebike, you could probably do your 50 miles at an average speed of close to 20 mph using two batteries. Keep in mind that an extra battery can be around $1000. That assumes you can currently do this ride on your Trek at an average speed around 14-15 mph. @Energetic James - is that about right?

Here are some data points in case it's helpful:

BACKGROUND: I'm a fairly fit recreational cyclist in my 40s. I will routinely ride the local hills (Bay Area) and average ~100 ft/mile. I'm riding a $4500 Specialized Turbo X (nice hub-drive bike with a 250W nominal motor and a 562WH battery). You could certainly beat these specs, but I like the warranty and dealer service that comes with buying a major brand from a shop.

HIGH SPEED: Flat 18-mile commute (sometimes windy; mix of dirt and pavement; very few lights): I can average about 21-22 mph (feels like I'm mostly cruising at 24-26 mph) and it will use 65-80% of my battery. Expect a range of 20-25 miles per battery.

LOWER SPEED: Hilly ride: 32 miles; 3800 ft of climbing averaging 19.4 mph used my entire battery (and I used regen on the downhills). Assuming you are at least as fit as I am, this would mean you could definitely do your commute on two batteries.

Bottom line is that I don't think 25 mph is doable without a monster motor and a huge battery capacity. But 19 mph? Definitely. And we're still talking about at least an hour quicker than riding your Trek.

Let us know what you're thinking. This would be a significant investment for you, but I think you'd love being able to do it!

 

[indianajo]

Look at these 25 ah 48 v batteries from a US supplier: https://www.amazon.com/48V-25AH-LIF...1504791594&sr=1-1&keywords=lifepo4+48+v+25+ah
and
https://www.amazon.com/48V-25AH-LITHIUM-BATTERY-PACK/dp/B01N6GP21T
I calculate 1200 watt hours. No battery change.
See also a 48 v 30 ah battery https://www.amazon.com/Lithium-Batt...rd_wg=aRmLC&psc=1&refRID=98YEZRGJXD0JWEX3HB86
for 1440 watthours
They are rectangular. I'm putting my 15 ah one in an aluminum frame with screws, glued, so it takes a screwdriver & coupla wrenches to steal it. Since price is $435. up to $630 for the 30 ah one. These come with an internal battery monitor PCB, and an external charger. Mine will be 12 lb, mounted over the front wheel since I carry supplies & tools in the back.