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News about Chain Reaction Bicycles

E-Bikes and range/mileage… why speed matters!

We had a customer who recently upgraded from a 20mph Class 1 e-bike to a 28mph Class 3. He was really happy about being able to easily do 24 mph on his commute now, instead of the 18 mph he’d been doing on his prior bike. But he was not happy with the “mileage” he was getting. He was expecting a “new & improved” model to have more range, and he was getting less (note that both bikes had the same 400 watt/hour battery size). Well, there’s really good reason for that.

Head to this page-

Using the defaults, which will be a bit off because they’re assuming the more-aero positioning on a road bike (which means a typical e-bike will actually fare worse), this is what you find-

At 18mph, it requires about 144 watts of power on level ground.
At 24mph, it requires about 300! More than double the amount of power.

Let’s say the cyclist is producing 75 watts him/herself at 18mph, and 100 watts at 24mph.

At 18mph, the bike’s motor/battery contribution is just 69 watts.
At 24mph, even with greater output from the cyclist, the motor/battery have to provide 200 watts. Nearly 3 times as much.

Even comparing a 400 watt/hour battery on the slower bike to a 500 watt/hour battery on the faster bike, the range, at 18mph vs 24mph, will still favor the slower bike.

What happens on a climb? If you’re riding with friends, no difference between the Class 1 & Class 3 bikes because A: You’re going the same speed either way, and B: At slower speeds (let’s say your friend are fit and managing 10mph on a 6% grade) air resistance is almost an insignificant factor. But this means there’s also less advantage to the more-powerful e-bike (providing you and the bike can put together the roughly 300 watts to climb that grade at that speed).

Another way of looking at this is that it’s no more difficult for an e-bike to do 10mph up a 6% grade than to go 24mph on level ground. So whatever amount of time you have on level ground at 24mph will be about the same time you’d have on climbs. Locally Kings Mtn would be an easy example, since it’s about 6% and takes about 30 minutes. You would go 12 miles in 30 minutes at 24mph, while on Kings, you’d cover 4.3 miles up, but your total range might be considered 8.6 miles because you’re coasting back down. Interesting stuff, this. I’d never thought about it until getting the email from the guy asking about the range issue on his new, more-powerful bike.

Where have I been???!!!

Last Thursday, wow, quite a few days ago, nice ride with Todd & Kevin (kid, not the pilot). Nothing fast, except when the road didn’t tilt up too much so I could hang on the wheels in front of me. Didn’t even come close to breaking 30 on the ride up Kings through the park, but somehow that didn’t seem like such a terrible thing. Sadly, this would be my last real ride for a while, because Sunday I would be flying to Wisconsin for a series of biz meetings & seminars at Trek.

Friday morning it was time for my now-monthly blood test, but not before first trying, and somehow succeeding, to order an iPhone X during the first ordering window. It took a few tries, bombing out several minutes after each attempt, before I game up at 12:40am and went to bed (ordering started at exactly 12:00am, and the initial window that came up shortly thereafter said I had just a 3 minute wait before it would be my turn, but when it was my turn, it did the hourglass thing for 10 minutes before I gave up and tried again… did the same sort of thing). But I did, before taking my shower, set it up to try again. And what do you know, I couldn’t get to sleep so I check my phone and, at 1:01am, it let me order one. In theory it will arrive sometime between November 3rd and 11th. What a dork.

Friday morning, without as much sleep as I would have liked, it was off to the vampires for the latest blood test, as well as coffee at Sheri’s Java Shack. Almost makes it worthwhile! Becky and Kevin always accompany me for good luck; in the early weeks, they came with me to make sure I wouldn’t chicken out. Thankfully my fear of having blood drawn no longer causes my veins to collapse! And this time the good luck seems to have worked because I had my best blood test since my diagnosis last May! Platelets have come down to 505k (they’d been as high as 1.2 million; normal is 400k), RDW showed smaller difference between largest and smallest blood cells (a good thing) and overall things just plain looked good.

Sunday it was off to Wisconsin. Uneventful flights (although the inflight entertainment system went out for about half an hour, making me wonder if I’d get to finish watching Wonder Woman or not) and one of the worst excuses for a $13 hamburger EVER in the Chicago airport. The place was called Santa Monica something-or-other and I think the hamburger probably had been made in Santa Monica… the day before.

Today? A lengthy series of 7 different business speakers and guess what? They were amazing! Trek paced things just right, with enough time in-between that it never dragged like I feared it might. Keynote address by John Burke, President of Trek, followed by various people telling us how we could be more relevant to our customers and more efficient for a better bottom line. After having to close our Los Altos store due to bottom line issues, this was good stuff to hear!

More meetings tomorrow, which means… yes, I’m still in Wisconsin, missing yet another day of riding. Looking forward to being home late Wednesday. –Mike–