Riding long and lean

JennyB

1 kW
Joined
Jan 25, 2008
Messages
449
Location
Northern Ireland
Since I started logging my rides at the start of the year I've ridden over 3,600km on two bikes, both sometimes assisted, sometimes bare:

Trek FX7.1 (basic hybrid)
Bare 596 km. Ave 18.6 km/h
Assisted 497 km. Ave 21.9 km/h

Boardman Hybrid Comp (entry level performance flat bar road bike)
Bare 2383 km. Ave 19.8 km/h
Assisted 197 km. Ave 23.8 km/h

The difference in speed may not seem very much, but that's the way I ride, and it's clear that even the basic hybrid with a 350 watt gearhub got me round faster than the most expensive unassisted bike would have done. Even when average speed is similar, the ebike is a lot easier, because your work load is more even - a bit more on th e level, a lot less on the hills. :) The average speed for the unassisted average for the Boardman would have been over 20 km/h but for the 400k Audax that I attempted two weeks ago. A lot went wrong that day, and I finally rode 354 km mostly on my own all day and all through the night, and walked up a lot of hills. :(

Energy used declined as my fitness increased through the year, from 11.4 wh/mi for a fast hilly run in January down to about 7 wh/mi. Then I experimented with raising the amp limit, to get faster up the hills where 15 amps wasn't quite enough. That was fun while it lasted, and didn't seem to affect the consumption much because I was using the power harder but less often. I'd just about decided that it wasn't a great strategy for distance and reliability when the clutch broke.

Now I have a BBS01 in the Boardman and it seems to be doing everything I need. If I leave it in the top assistance level it's just as fast as the unrestricted hub with about the same consumption and a lot less - drama. It's great just to keep your hands on the bars and ride; I haven't needed the throttle at all so far. As with cruise control on the hub, the motor takes about 17 watts to keep spinning when you pedal faster, but unlike cruise control, that power drops as soon as you stop pedalling; I don't feel the need for ebrakes. It may be slightly harder to pedal power-off, but it coasts better, and generally is a lot more like riding the bare bike.

Yesterday I did a relaxed 78 km shopping trip, and averaged 22.9 km/h at 3.5 wh/km. Next week, I shall be attempting to add another 1200 km in four days.

Wish me luck!
 
I think your style of riding is just made for the bb motors.
 
Wow, man. If i use throttle lightly maintaining around 27 km/h, i can keep it on 6wh/km. Usually i average around 8-9wh/km on suburban rides.
Empty bike without battery is 30,5kg. Huge cruiser handlebar and 100% upright position, strong drag and less pedal force.
 
Hi JennyB I love your last travel log. My friend has a bb motor and gets great distant with a small battery. But he does have higher chain wear and needed a new derailuer. Let use know how these hold up on your journey. What battery and size are you using ? Good luck.
 
The battery is from Schwibsi of this forum, 20ah of Sanyo V3 - half the size and weight and twice the capacity of the first lithium battery I had. I'm charging with a couple of 6 amp Cellman chargers in parallel. Together they fit neatly in the bottom of my Carradice saddlebag. In total, this setup adds about 9 kg to the weight of the unassisted bike.

This morning I went for a 55 km ride that included some monster hills. Shortly after I started the first light on the 'fuel gauge went out. The CA showed I'd used seven-and-a-bit ah and the voltage was at 36. It seems each subsequent light out indicates half a volt drop. I finished on 35 volts and over 12 ah used. Put it on the chargers for an hour, and the voltage stood at 41.7.

That's over 80 mph recharging! 8)
 
Back
Top