Kurt in CT
Active Member
Hi. I've had the Peak for a month now. Very pleased. Hill-climbing seems to be superb. Also have spoken to Magnum HQ couple of times. Very responsive.
Hill climbing ability
- Thread starter keithd
- Start date
TForan
Well-Known Member
Nice for what you are using it for but 20 mph would be a no go for me. And I'm not sure if the Ultra and the CX have "pretty much the same specs".
keithd
Active Member
Bob, what is your touring bike model and setup? I have thought of a setup like this guy on youtube with a Trek 820
TForan
Well-Known Member
So which one has the same specs as the Bafang Ultra ? I'm new to this but it sure didn't feel like it when I rode a Trek.
keithd
Active Member
I think the Bafang BBS02 750 watts, BBSHD 1000 watts and, the ultra up to 1500 watts those are some pretty powerful mid-drives. I see only 250 and 350 watts on the Bosch. So if the gear set and chainrings are the same the only difference being the watts on the motors would this not make the Newton Meter output higher on the Bafangs. Maybe the gearing on the Bosch system produces more torque at the motor output shaft.
TForan
Well-Known Member
Is it legal restriction determining what the builders use ? I'm pretty sure the Ultra is off-road only in most areas.
Mr. Coffee
Well-Known Member
- Region
- USA
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- A Demented Corner of the North Cascades
In general I'd always give wattage figures for e-bike motors a large amount of skepticism. They are sometimes useful for comparisons within one manufacturer but that is about it.
Some manufacturers wildly exaggerate their power figures.
Some, like Bosch, tend to understate their figures. One reason for this is that some jurisdictions in Europe regulate e-bikes depending on the wattage of the motor, with 250 watts being a common limit. Hence a lot of Bosch bike motors are "rated" to 250 watts.
A better estimate is to look at the controller specs. That will give you a pretty good idea of (at least) the maximum power that the motor can put out. The sustained power output is likely to be much lower, possibly a third or a quarter of the maximum power. So a 36v battery and a 20amp controller can put out (at least briefly) 720 watts.
keithd
Active Member
@Mr. Coffee
You mentioned your Pedego 7 speed lagged on some steep hills this is a geared hub drive correct? If so is it a Bafang? I am wondering how the same 7 speed would be with a mid-drive.
You mentioned your Pedego 7 speed lagged on some steep hills this is a geared hub drive correct? If so is it a Bafang? I am wondering how the same 7 speed would be with a mid-drive.
Mr. Coffee
Well-Known Member
- Region
- USA
- City
- A Demented Corner of the North Cascades
It is a geared hub drive. I think it is a dapu motor. The controller is rated at 20 amps and so with a 48v battery that gives a peak power output of around 960 watts. Pedego's marketing material lists or has listed the power rating of the motor as 350 or 375 watts.
A 7-speed mid-drive would be better, largely because you could have the motor running at higher and more efficient RPMs. An 11-speed or IGH would be better than any 7-speed.
keithd
Active Member
Thank you @Mr. Coffee
Bob, what is your touring bike model and setup? I have thought of a setup like this guy on youtube with a Trek 820
Keith, I ride a 24 year old Bruce Gordon Rock & Road. You could call it the original "29er gravel grinder" built long before those marketing terms were coined. It will take up to 700x45 tires. I usually ride 700x32 Gatorskins around town as pictured. I use drop bars. The ubiquitous flat bars of most ready made e-bikes would never work for me. I require the comfort of brake hoods with my palms shoulder width and parallel to the bike. Tops of bars are 2" above the saddle. The R&R also has 135mm rear axle spacing making it compatible with the BionX retrofits. The bike weighs in at 48 pounds.
I use the G2 control console over the stem for all functions. Cross top brake levers are nearby on the tops for safety and mountain bike leverage, Gevenalle shifters are on the regular brake levers. The kit comes with a throttle but it is designed for grip mount on flat bars so I don't use it. If I need a throttle I just put it in level 4 assist and apply light pressure on the gas pedal. The bike then shoots ahead as if it had a motor!
That trunk bag pictured is the Performance Bike Shop house brand and it is a perfect fit for my new spare battery!
The frame is from an "old school" builder with a quill stem and cantilever brakes but it is identical in function to many of the "gravel grinders" popular today.
Although BionX is in receivership the motor is their latest offering and (would be) still on warranty. That battery is brand new. I bought it from NYCeWheels just two weeks ago on sale before they ran out. The parts on the bike are all fairly new... Paul Cantis, Brooks C17, Gevenalle shifters, Salsa Cowbells and SKS Velo 47 fenders. There is one antique on the bike...The front Phil Wood hub is at least 25 years old! Now laced to a new Velocity rim.
Although BionX is in receivership the motor is their latest offering and (would be) still on warranty. That battery is brand new. I bought it from NYCeWheels just two weeks ago on sale before they ran out. The parts on the bike are all fairly new... Paul Cantis, Brooks C17, Gevenalle shifters, Salsa Cowbells and SKS Velo 47 fenders. There is one antique on the bike...The front Phil Wood hub is at least 25 years old! Now laced to a new Velocity rim.
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mrgold35
Well-Known Member
One thing to add to hill climbing is head winds. I didn't ride my ebike to work yesterday because I would be heading home in a 20-25 mph headwind with gusts up to 30-35 mph for 6.5 miles all uphill for a 500ft elevation change. I'm 6'3" and 270lbs riding upright can really catch a lot of wind to cut my average speed into the single digits sometimes at PAS level 4 (5 levels of assist). Having 80 Nm of TQ on my Radrover really comes in handy since those kinds of headwinds can come from any direction with work commuting or fun rides anywhere. I end up using about 2/3 to 3/4 of my battery power on those extremely windy days riding home trying to keep my mph in double-digits.
Another reason for more TQ if you get extremely windy days.
Another reason for more TQ if you get extremely windy days.
keithd
Active Member
@mrgold35
I can only imagine that tire drag would have a major effect as well. Back when I was in my late thirties early forties I got back into bicycles started with an old steel 10 speed. My son wanted to ride the MS150 ride in Maine so after 20 years of not riding I oiled up this old ten speed and proceeded to ride 150 miles over two days. I made it due to sheer willpower. The following year I rode the MS150 on a Raleigh M80 with police road tires and found that to be too slow. The next several years I used a custom carbon fiber 16 lb. Ultegra road bike and that made a world of difference. I just cannot see commuting with fat tires, the drag must be incredible. Several companies list that their fat tire and street tired bikes getting the same range from the battery I cannot believe how this can be possible.
I can only imagine that tire drag would have a major effect as well. Back when I was in my late thirties early forties I got back into bicycles started with an old steel 10 speed. My son wanted to ride the MS150 ride in Maine so after 20 years of not riding I oiled up this old ten speed and proceeded to ride 150 miles over two days. I made it due to sheer willpower. The following year I rode the MS150 on a Raleigh M80 with police road tires and found that to be too slow. The next several years I used a custom carbon fiber 16 lb. Ultegra road bike and that made a world of difference. I just cannot see commuting with fat tires, the drag must be incredible. Several companies list that their fat tire and street tired bikes getting the same range from the battery I cannot believe how this can be possible.
mrgold35
Well-Known Member
The full 4" of the fat tires only get used on trail riding when it gets sandy or when I hit gravel. I air my tires up to 20-23 PSI and only the center tread is actually making contact on the paved road. About 2" or less down the center get worn when I work commute. My old rear Kenda Juggernauts were almost completely worn down the center line after 800 miles and nearly brand new tread on the edges from work commuting (switched to Vee8 120 tpi 26X4").
The big advantage I've found with my 4" fat tires compared to my old 700X40C commuter bike is a smoother ride over broken pavement at any speed. Also, much easier to transition between different terrains at a faster speed because of the fat tires. I can pretty much ride the same speed on a dirt road as I can on paved because of the fat tires smoothing out the ride. Way less zig-zagging with 4" fat tires to avoid bumps in the road. It is like having a Ford F-150 Raptor when I upgraded to an fat tire ebike.
elyhim
Active Member
Again, the output between active line and CX are the same even though it is different motors. I ride a CX with the Trek Powerfly 8.
250 watt is a cut off in some places for being labelled a bicycle. The bafang motors you're listing are not classified as "bicycles" they would be mopeds. In most states that have a class system under 750 watts is bicycle, over is motorbike or moped. You would not be allowed on greenways and certainly not natural surface.
Check out People For Bikes / Ebikes and resources to find state general statutes regarding ebikes/bicycles.
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