How much "power" do I really need?

[HappyNaturalist]

First time ebike buyer. I've learned a lot from reading these forums (thank you to EBR posters!) as well as watching/reading reviews, articles, etc. AND...I am still quite confused about power. So, rather than ask for a full explanation of the terms, I'd like to ask for advice.

I am looking to be a primarily e-bike commuter as well as use the bike both for daily errands (all within 5 miles of home) and fun weekend rides with my husband (we might ride 2-10 miles to get to those paths). The terrain nearest home is mostly gently rolling with small hills, but rides further away will include a pretty significant hill on the route back home. (We also hope to travel with the bikes when we retire in a couple of years so I want to feel confident exploring most any paved/hard packed path.) (Also of note, though I do enjoy the feel of riding a bike and am reasonably fit, I am not a "cyclist" - I tried to learn cadence pacing in my 20s and just never took to it; it felt a bit like running and I am a hiker/walker rather than runner.)

I am limiting my choice to small, lighter weight bikes that are available locally. (In addition to wanting to support LBSs, I have discovered that there is a huge difference in how each one feels when I ride it and so I really want to be able to get my hands (really my butt) on it before buying.) The current top contenders are:

• Gazelle Medeo T9 small low-step - Bosch Active Line Plus (50Nm) w/400Watt battery on rear rack; Shimano Alivo 9 speed derailleur - $2600
• Gazelle Ultimate C8 small low-step - Bosch Active Line Plus (50Nm) w/500Watt downtube battery; Gates belt drive + Shimano Nexus 8 - $3500

I liked both of these bikes. I loved the feel of the C8 - that bike fit me surprisingly well - and with some adjusting, the T9 fit me just fine (and will feel a lot better with an upgraded saddle). My concern with both of them is the power they can offer going up hills. I know the motor will get the bike up the hill - it's really my power giving out that worries me, since I am the one powering the motor. This may be due just to my inexperience, but after test riding both of them (and a couple with even lower torque), it seemed to me that I would feel somewhat worn out by the effort required to get up a longer hill even in the lowest gear/highest assist level. (And I don't want worrying about that possibility to make me shy away from heading out the door for an adventure!)

One more bike that I can test ride later this week is:

• Momentum Vida E+ small step-through - Giant SyncDrive Life (60Nm) w/375 or 500 Watt downtube battery (not sure yet which one that bike will have); chain-driven Shimano Nexus 5 - $2850

And this is one that I'd love to test ride but cannot find in stock within even a full day's drive (but might consider waiting for):

• Gazelle Ultimate T10 small low-step - Bosch Performance Line (65Nm) w/500Watt downtube battery; Shimano XT derailleur - $4000

Both of those two offer more torque, which I think will help with getting up hills. But I also know that there are many factors impacting that ability/experience (including the loss of efficiency when an IGH is involved). I can't really tell until I test ride them whether they fit me - although since I have sat on the same Ultimate frame with the same tires (in the C8), it's a pretty good bet I'll like how it feels.

I realize these are all pretty different bikes and that higher components contribute to the differences in price. Of course, I'd like to spend as little as possible to get a bike that fits me well and fulfills my needs but I also realize I may need to spend more to get that. As long as it's reliable, I don't need to be picky - but I do want to be sure I'm buying enough bike. (And yes, we have become pretty fond of the Bosch motors...their reliability is a huge attraction.)

So, if these were the four I had to choose from which would you recommend (and why) for my use? How does your recommendation change if I ask for the best value among the four?

Thanks in advance for so generously sharing your knowledge, experience and expertise!

 

[HappyNaturalist]

This chart offers some interesting data...(that still did not help me make a decision!)

Active Line Plus (20 mph)	Active Line Plus (20 mph)	Performance Line (20 mph)	Performance Line (20 mph)
System	Bosch eBike System 2	Bosch eBike System 2	Bosch eBike System 2	Bosch eBike System 2
Gear type	Hub gear system	Derailleur system	Hub gear system	Derailleur system
Support level (%)	TURBO: 250 SPORT: 170 TOUR: 100 ECO: 40	TURBO: 270 SPORT: 180 TOUR: 100 ECO: 40	TURBO: 300 SPORT: 200 TOUR: 120 ECO: 55	TURBO: 300 SPORT/ eMTB**: 120-300 TOUR: 120 ECO: 55
Maximum possible drive torque (Nm)	TURBO: 50 SPORT: 45 TOUR: 40 ECO: 35	TURBO: 50 SPORT: 45 TOUR: 40 ECO: 35	TURBO: 65 SPORT: 50 TOUR: 45 ECO: 35	TURBO: 65 eMTB**: 60 TOUR: 45 ECO: 35
Maximum cadence (rpm)	105	105	> 120	> 120
Start-up behavior	harmonious agile	harmonious agile	dynamic	sporty
Max. Support up to	20 mph	20 mph	20 mph	20 mph
Gear shift detection	nein	ja	nein	ja
Weight	approx. 7.1 lbs	approx. 7.1 lbs	approx. 7.1 lbs	approx.

 

[mschwett]

when i hear "pretty significant hill" and "lighter weight bike" i think derailleur with a decent gear spread rather than gear hub. the 9 speed alivo is only 327% range, although the gearing is fairly low, decent for climbing. the ultimate t10 looks to have a 46 tooth ring up front and 11-36 in the back, which IMO (i live in a very hilly place) is absolutely not suited for climbing big hills on a 50+lb bike unless your plan is to let the motor do nearly all the work. the nexus 5 on the vida is only a 263% range, again very difficult to ride up a steep hill unless you're relying pretty exclusively on the motor. in turbo mode, the batteries of these bikes are not going to last very long, so assuming you're riding for pleasure (setting the errands aside!) i'd prioritize a bike that has the proper gearing to let you comfortable share the work as you ride fairly slowly up that hill.

how big is "pretty significant?" you can use rideWithGPS's online route planner or even google maps cycling directions to see an elevation profile...

 

[indianajo]

Depends on the gross weight and how fast you want to go.
I can pedal up a 15% grade of 80-100' with 330 lb gross (160 lb me, 74 lb bike, 14 lb battery & motor, 20 lb tools & water, 60 lb groceries) without power. My 500 W geared hub drive can start and power the bike up that hill @ 6 mph without my help if I have hurt my knee recently. However, with 32:32 sprockets self powered I'm going @ 1 mph. 32:28 I can pull by June of the year I'm going 1 1/2 mph. The more expensive bosch drives will power you up the hill faster in a higher sprocket. Also wear out the battery faster. I get 30 miles & 80 hills (only 3 15%) out of a 840 wh battery: your gross weight is probably lighter without groceries tools & water. So you'll get as far on a smaller battery. I measured the grade with a 6" level and a scale. 7/8" rise on a 6" level run is 14.6% grade. The grades here are rollers, so if I hit a 15% upgrade with 25 mph from the previous downgrade, I'm still going 8 mph at the top of the next one. Bosch drives don't have throttles like I use, so you'll have to pick a sprocket that the motor can sustain going up the next grade to not bog down.
I only use 25 mph where the pavement is superb & there is no water or ice at the bottom. On average, I ride 8-10 mph. I'd have to have a suspension to enjoy going faster than 10 on our typical pavement, and suspensions are not compatible with carrying groceries to my summer camp. Some of the models you quoted might have suspensions, if you enjoy going 20 or 25 on a bicycle. I've fallen at 25: it takes full coverage (long sleeves long pants closed shoes) in work grade polyester clothing (at least) to avoid road burn, poly gloves, and a helmet with a chin guard to protect that.

 

[HappyNaturalist]

when i hear "pretty significant hill" and "lighter weight bike" i think derailleur with a decent gear spread rather than gear hub. the 9 speed alivo is only 327% range, although the gearing is fairly low, decent for climbing. the ultimate t10 looks to have a 46 tooth ring up front and 11-36 in the back, which IMO (i live in a very hilly place) is absolutely not suited for climbing big hills on a 50+lb bike unless your plan is to let the motor do nearly all the work. the nexus 5 on the vida is only a 263% range, again very difficult to ride up a steep hill unless you're relying pretty exclusively on the motor. in turbo mode, the batteries of these bikes are not going to last very long, so assuming you're riding for pleasure (setting the errands aside!) i'd prioritize a bike that has the proper gearing to let you comfortable share the work as you ride fairly slowly up that hill.

how big is "pretty significant?" you can use rideWithGPS's online route planner or even google maps cycling directions to see an elevation profile...

Thank you for your comment and advice! Gives me a more understanding - and something more specific to think about.

There's four main routes; the shortest and safest is unfortunately the steepest, about 200' elevation change over 3/4 mi. Other routes take a little over a mile to cover approximately the same elevation change and add an additional 2-4 miles distance overall (not an issue on an ebike).

 

[HappyNaturalist]

Ride a non motored dual suspension bike and time your ride. From there you decide of more power is needed to your requirement.

Thanks for the tip - I may try that on the longer routes. (This is likely a mental more than physical thing, but I would definitely end up walking up the steepest hill - heck, I won't even ride DOWN it, it's a completely straight shot down the hill and I'm just not comfortable with that kind of speed on a bike - been in an accident going too fast down a paved road and seen too many others have bad accidents doing the same. Like I said, not exactly a "cyclist" but still enjoy riding a bike! )

 

[mschwett]

Thank you for your comment and advice! Gives me a more understanding - and something more specific to think about.

There's four main routes; the shortest and safest is unfortunately the steepest, about 200' elevation change over 3/4 mi. Other routes take a little over a mile to cover approximately the same elevation change and add an additional 2-4 miles distance overall (not an issue on an ebike).

200’ in 3500’ won’t be a problem for any of those bikes, although i’d still go for the one with faiely short gearing to allow as much of the power to come from you as you’d like. if i’m understanding the specs on the belt/IGH setup of the C8 correctly the low gear is fairly close to the alivo 9 speed setup and nearly 1:1. (55 tooth chainring, 26 tooth rear cog, and .527 lowest gear ratio, equivalent to 55:49). rear wheel goes around 55 times every 49 times you pedal - 1.12:1. the T9 has 38 teeth in front and 36 in back; for every 36 times you pedal the wheel goes around 38 times - 1.05:1. that and being almost 10lb lighter will make it easier to pedal uphill, but the battery is 20% smaller, and belt drives are very nice, and the battery is down low integrated into the downtube, and you liked the bike better. C8 seems like a great choice.

 

[HappyNaturalist]

200’ in 3500’ won’t be a problem for any of those bikes, although i’d still go for the one with faiely short gearing to allow as much of the power to come from you as you’d like. if i’m understanding the specs on the belt/IGH setup of the C8 correctly the low gear is fairly close to the alivo 9 speed setup and nearly 1:1. (55 tooth chainring, 26 tooth rear cog, and .527 lowest gear ratio, equivalent to 55:49). rear wheel goes around 55 times every 49 times you pedal - 1.12:1. the T9 has 38 teeth in front and 36 in back; for every 36 times you pedal the wheel goes around 38 times - 1.05:1. that and being almost 10lb lighter will make it easier to pedal uphill, but the battery is 20% smaller, and belt drives are very nice, and the battery is down low integrated into the downtube, and you liked the bike better. C8 seems like a great choice.

Your description of gearing ratios for hill climbing is super helpful - thank you!

 

[HappyNaturalist]

Update - a bike shop about 4 hours away got in a Gazelle Ultimate C380 in a small step through frame size! It has a Bosch Performance Line motor (65Nm) and a Gates belt drive + Enviolo hub. I can't test ride it until Saturday but I am feeling pretty confident that's going to be my bike!! (so much so, I put a deposit down on it so they can't sell it to someone else before I get there. Every nearby Gazelle dealer has told me it will be months before they expect to have any of these bikes in stock.)

Also - while out searching for bikes for me, hubby found a fantastic deal on a Bulls Urban EVO 10 Step-Thru that fits him, so we'll be ebiking partners! So excited! (When we were first married one of our dreams was to be able to head out our door and go bike-trekking/camping...family demands kind of interrupted that plan - we may opt for B&Bs over camping now, but it's cool to be reviving that dream!)

 

[Stefan Mikes]

we may opt for B&Bs over camping now

So no issues to find a charging outlet for e-bikes

 

[HappyNaturalist]

So no issues to find a charging outlet for e-bikes

LOL - right! Definitely an ebike newbie!

 

[AleksR]

First time ebike buyer. I've learned a lot from reading these forums (thank you to EBR posters!) as well as watching/reading reviews, articles, etc. AND...I am still quite confused about power. So, rather than ask for a full explanation of the terms, I'd like to ask for advice.

I am looking to be a primarily e-bike commuter as well as use the bike both for daily errands (all within 5 miles of home) and fun weekend rides with my husband (we might ride 2-10 miles to get to those paths). The terrain nearest home is mostly gently rolling with small hills, but rides further away will include a pretty significant hill on the route back home. (We also hope to travel with the bikes when we retire in a couple of years so I want to feel confident exploring most any paved/hard packed path.) (Also of note, though I do enjoy the feel of riding a bike and am reasonably fit, I am not a "cyclist" - I tried to learn cadence pacing in my 20s and just never took to it; it felt a bit like running and I am a hiker/walker rather than runner.)

I am limiting my choice to small, lighter weight bikes that are available locally. (In addition to wanting to support LBSs, I have discovered that there is a huge difference in how each one feels when I ride it and so I really want to be able to get my hands (really my butt) on it before buying.) The current top contenders are:

• Gazelle Medeo T9 small low-step - Bosch Active Line Plus (50Nm) w/400Watt battery on rear rack; Shimano Alivo 9 speed derailleur - $2600
• Gazelle Ultimate C8 small low-step - Bosch Active Line Plus (50Nm) w/500Watt downtube battery; Gates belt drive + Shimano Nexus 8 - $3500

I liked both of these bikes. I loved the feel of the C8 - that bike fit me surprisingly well - and with some adjusting, the T9 fit me just fine (and will feel a lot better with an upgraded saddle). My concern with both of them is the power they can offer going up hills. I know the motor will get the bike up the hill - it's really my power giving out that worries me, since I am the one powering the motor. This may be due just to my inexperience, but after test riding both of them (and a couple with even lower torque), it seemed to me that I would feel somewhat worn out by the effort required to get up a longer hill even in the lowest gear/highest assist level. (And I don't want worrying about that possibility to make me shy away from heading out the door for an adventure!)

One more bike that I can test ride later this week is:

• Momentum Vida E+ small step-through - Giant SyncDrive Life (60Nm) w/375 or 500 Watt downtube battery (not sure yet which one that bike will have); chain-driven Shimano Nexus 5 - $2850

And this is one that I'd love to test ride but cannot find in stock within even a full day's drive (but might consider waiting for):

• Gazelle Ultimate T10 small low-step - Bosch Performance Line (65Nm) w/500Watt downtube battery; Shimano XT derailleur - $4000

Both of those two offer more torque, which I think will help with getting up hills. But I also know that there are many factors impacting that ability/experience (including the loss of efficiency when an IGH is involved). I can't really tell until I test ride them whether they fit me - although since I have sat on the same Ultimate frame with the same tires (in the C8), it's a pretty good bet I'll like how it feels.

I realize these are all pretty different bikes and that higher components contribute to the differences in price. Of course, I'd like to spend as little as possible to get a bike that fits me well and fulfills my needs but I also realize I may need to spend more to get that. As long as it's reliable, I don't need to be picky - but I do want to be sure I'm buying enough bike. (And yes, we have become pretty fond of the Bosch motors...their reliability is a huge attraction.)

So, if these were the four I had to choose from which would you recommend (and why) for my use? How does your recommendation change if I ask for the best value among the four?

Thanks in advance for so generously sharing your knowledge, experience and expertise!

Gazelle bikes are great, my wife is riding T10 and absolutely no problems scaling steep San Francisco hills. The power will not be an issue.

 

[HappyNaturalist]

Brought home my beautiful new C380 yesterday! I was so in love with it that even in 40-degree weather I didn't want to come back in from the test ride to drive it home, lol. I'll post a picture soon. Feels great to really love a bike again!

 

[Stefan Mikes]

Congratulations!

 

[HappyNaturalist]

Oh my - soooo much fun to ride this!!!

 

[Robspace1]

Basic guide to amount of power needed: https://www.ebikeschool.com/much-power-electric-bicycle-need/

 

[6zfshdb]

Basic guide to amount of power needed: https://www.ebikeschool.com/much-power-electric-bicycle-need/

I realize this is a year old thread, and there is some good information in the article you linked above, but I have a problem with the A x V = W theory mentioned. Yes, it's basic math but just because a controller is rated at 15A, doesn't necessarily mean the motor can use that much current to propel the bike. The internal resistance of the motor is a big factor in determining how much power is actually generated.

 

[kevinmccune]

Update - a bike shop about 4 hours away got in a Gazelle Ultimate C380 in a small step through frame size! It has a Bosch Performance Line motor (65Nm) and a Gates belt drive + Enviolo hub. I can't test ride it until Saturday but I am feeling pretty confident that's going to be my bike!! (so much so, I put a deposit down on it so they can't sell it to someone else before I get there. Every nearby Gazelle dealer has told me it will be months before they expect to have any of these bikes in stock.)

Also - while out searching for bikes for me, hubby found a fantastic deal on a Bulls Urban EVO 10 Step-Thru that fits him, so we'll be ebiking partners! So excited! (When we were first married one of our dreams was to be able to head out our door and go bike-trekking/camping...family demands kind of interrupted that plan - we may opt for B&Bs over camping now, but it's cool to be reviving that dream!)

I love camping as long as I can go home and go to bed. My last fiasco with a 35 Degree sleeping bag in 25 degree weather put paid to that( maybe would have worked out if I wasnt wearing so little for the weather( the critters wouldn't even get in with me)'For the cost of one of your better bikes you and Hubby could buy two Lectrics with change left over and really check out the ebike experience, how much power you need is dependent on how much you want to contribute, the slower you climb the less power you need, when you are going so slow you can barely maintain balance its time to push, nothing at all wrong with that

 

[Robspace1]

I love camping as long as I can go home and go to bed. My last fiasco with a 35 Degree sleeping bag in 25 degree weather put paid to that( maybe would have worked out if I wasnt wearing so little for the weather( the critters wouldn't even get in with me)'For the cost of one of your better bikes you and Hubby could buy two Lectrics with change left over and really check out the ebike experience, how much power you need is dependent on how much you want to contribute, the slower you climb the less power you need, when you are going so slow you can barely maintain balance its time to push, nothing at all wrong with that

Why would anyone pay so much for a motorized vehicle that they need to push? I upgraded from a slow old VW bug years ago because it was so slow climbing mountains and overheated the engine. Same applies with my ebike. Taking a long steep hill will overheat the battery and motor if it's underpowered. Most ebikes have 7 gears, not 21. Puts a massive strain on the system to overwork it attempting too much hill with too little power. Getting the right amount of power to overcome major inclines will keep the motor and battery happy. It all comes down to the weight of the bike, rider, and terraine. Most people buy ebikes for fun and the joy of riding anywhere with ease. Not to get hot and sweaty and push the thing up a hill. That's why I left my analog bike and dumped my old VW. It's all about beating gravity where I live. Anyone getting their first ebike should take them for a test drive in the area they live before buying. Find the steepest street or bike trails around and see how easy it is to make it up the hill, sitting down using assist, no throttle. If it won't climb it then you need more power, just like it say's in the power guide article link above. More hills, more power. Less hills, less power. Simple.

 

[kevinmccune]

What? Were are you coming from on that? If I see somebody spinning like the devil and doing 2 mph I think just push the danged thing,I have never had to push my ebikes up an hill around here and some of them will give you a 40 mph boost when you top over.If you want to zoom get a Surron or some of the other "epeds", not everybody can afford the elegant middrive bikes, some of you Guys throw 4-5000$ dollars like it is pocket change.