Tuesday, November 14, 2017

Ebikin' 2


"She may not look like much, but she's got it where it counts, kid." -Solo to Luke about the Millennium Falcon

This is my ebike. 1989(ish) Rockhopper, acquired in the late 1990s. Original (to me) parts: wheels, seat stem, brakes, kickstand, frame, pedals. Pretty much everything else got replaced, either through normal maintenance, my previous program of "making the bike comfortable for a middle aged guy whose hands (and junk) don't like being beaten on" or as part of the BBS02 kit install.

Since you asked, the seat is an ISM touring model (I think. It looks like them, anyway.)  The idea is it only supports your "sitting bones" the bottom of your pelvis, rather than pressing on your tail bone, your crotch, etc etc.  It works for me.

Biggest pains in the rear partswise: the fork and headstock bearings. 1 inch quill front ends on mountain bikes have gone the way of the dodo, for the most part. Getting a fork that fits took me a couple tries. The headstock bearings were a pain mostly because (I think) my headstock is slightly out of round at the bottom. The top race pressed in without a fuss. The bottom? Not so much. In any case, it works and it seems solid now.

Lessons learned: 1. A sledge hammer is almost always the wrong tool on bikes. 2. So is a Sawzall. 3. So is a crowbar. It's a good thing I didn't need to reuse that crank bearing cartridge, or the old cranks themselves. Nuff said.

Sometimes the custom bike tools really are the best way to go. Crank pullers and chain breakers are high on this list. Get good ones. I twisted a Walmart chain breaker into scrap metal in about an hour of use. Also, if you're putting in the BBS02 kit, spring for the Bafang wrench to go with it. Feeling flush? Get the Bafang socket set instead. Lunacycle has both. Repair chain links are worth having, but the special pliers aren't. (These are the KMC type) You can set them with the shaft of a punch (press down between the rollers and wiggle until the link latches on both sides), or just get on the bike and stomp on the pedals a few times, and you can punch the shafts/rivets out of them with a chain breaker just like you can regular chain links. If you have a good chain breaker.

Special chain lube? Mm. Mine's new, and has its factory grease/oil, which is very sticky indeed. I've read that this is excellent lubrication and to leave it that way until it squeaks. After that, I have a gallon of lathe way oil for the job.  Don't ask why. It's a long story. It's the same story as why everything else is/will be lubed with lathe spindle oil, also from a gallon jug. Or one of two tubes (another long story) of white lithium grease. Will this bite me down the road? Maybe. But I'll learn something, at least.

"I am smiling a great smile. The smile of a man who f***ed with his car and  didn't break it." - Andy Weir, The Martian

Why not just buy an ebike? That, mostly.

Sunday, November 12, 2017

E-bikin'

For some years (nearly 20, in fact) I've owned a late 1980s Specialized Rockhopper. For those too young to remember, these were early mountain bikes. Steel frames, no suspension, designed for durability rather than super-light-weight. I've been riding it, because after sitting and writing for hours at a time, my back is very appreciative of balancing a bike.

The problem was endurance. Let's face it, I'm not a small man, and I haven't been a regular biker since the early 1990s, when I was 20some years younger and there was considerably less of me. Also, I live on a pretty significant hill. So I'd get out, get going nicely (down the hill), go once around the block, and by the time I got up the hill again, my lungs basically wanted to climb out of my chest. No problem with legs, just... no wind. One trip around the block, a bit less than a mile, and about 10 minutes, and I was done for the day.

That's no way to build endurance.

So back in July, I ran across GoodTurn cycles. These guys. I took a test ride on a few ebikes, gawked at the price (they sell nice - expensive - bikes) but... I was interested. By August, I'd dragged M, my very patient sweetheart, to come rent a pair of their bikes and go for a ride.

Hint. When you rent their bikes, if you are of size, don't let them stick you with one of the ones with seat post suspension. Those things are worse than useless if the springs can't hold you up.

Still, we had a nice ride, marred only when M fell and scraped her knee. (She's fine. It was, as she says, a booboo.)

Fast forward to this past Friday, November 10th. Combine existing Rockhopper with a Banfang BBS02 750 watt kit as sold by Lunacycle (these guys) and a //lot// of replacement parts, and I have a working ebike.  I took it for its first test ride today, around the same route I'd been riding before without power. Twice. Plus, I explored my neighborhood a little, too. More hills. 3.8 miles seems like a pleasant workout. Legs and lungs are in full agreement that it's plenty for one day.

Observations:
First, at no time did I feel that Colorado's 20mph absolute boost speed limit was inappropriate. (You can go faster, but you have to do it on your own power, not the motor's.) So setting the BBS02's limiter to 20 doesn't bother me. Result: my bike is a legitimate class 2 ebike. 750 watts, pedelec control + a throttle.

Second, anyone who tells you that you don't get a workout riding an ebike hasn't ridden one. A full horsepower (750 watts) isn't //that// much. It's not a motorcycle. It's a bicycle with some help.

Third, anyone who tells you that you don't need gears on an ebike lives where you don't need gears anyway. Or they weigh 150 pounds. Or they have a multi-kilowatt ebike, which is just plain illegal here. Or they're idiots. Let me assure you, I used all 7 of my remaining gears on my ride. (The BBS02 replaces your bottom bracket, cranks, and chain rings, and only provides one chain ring.)

Fourth,  I recommend a throttle. I recommend a throttle, because there are times when you need to get the bike moving, be it up a hill or across an intersection when you have limited time before the cars come to squash you, and being able to just twist for power is a godsend. Especially if you forgot to shift down when you came to a stop.

Fifth, having built my own ebike, I have to say this. If all you want is an ebike, and you don't already have a bike you're fond of, you're probably better off buying a pre-built one. In the intervening months, the prices of ebikes have dropped dramatically, to the point where, for the cost of a good steel bike to start from, plus the kit, you can buy one.
I'm also not at all sure I'd build one around an 80s bike again either. The 1989 Rockhopper has been an unending pain in the ass to find parts for. Bikes have evolved hugely in the intervening years, both in terms of improvements and manufacturing convenience. 1 inch quill headsets, 130 (or so) mm hub widths, 26 inch rims, 7 speed cassettes, and so on cost me a lot of time and difficulty in replacements that I wouldn't have had with a newer bike. And to be honest, I'm still lucky. My Rockhopper was put together out by my old trainer in Colorado Springs (Hi Jeff!) who was (probably still is) a mountain bike racer. So I have far, far better rims than the stock ones, and they hold up under my weight and the added weight and stress of the motor and battery.  Everything was put together well, greased, done with the right tools, and so on.  (Note the past tense verb. As a bike mechanic, I'm still a hack.)

Now. In fairness to myself and the bike, I also have to say I didn't //just// want an ebike. I wanted a project I could tinker with mechanically. It was this or a dead VW engine, and the bike takes less garage space. I wanted to mess around with electric vehicles. It was this or a Tesla... haha no. It was this or do without.  Also, many ebikes have weight limits, and the moment I sat on one of them, I'd have voided the warranty.   So building my own was (probably) the rational choice. And I have to say I'm pretty proud of the result. It looks ghetto, and it is, but it does the job quite well so far.

Suppliers: I'm somewhat ambivalent about Lunacycle. On the one hand, they're selling the Bafang kits for the same price you can mail order them from China, and they've (presumably) paid the import duties and they (presumably) support the warranty. They also carry spare parts. Awesome. On the down side, when my charger was backordered, they didn't bother telling me, nor have there been //any// instructions or documentation, including about the warranty. Also, while my order was in progress, they started a promotion for a free upgrade to a color display. They didn't upgrade me and didn't tell me. I got what I ordered, so I don't feel like I was ripped off or anything, but it would have been nice if they'd thrown one in.  I'm sure that in person they're a great, knowledgeable ebike shop, but their mail order business is probably swamped, and as a result it comes across as sketchier than it probably is. Still. Way more comfortable than ordering from China for a $750 kit. If I wind up building another ebike, I'll probably pony up to them again. At least I know them.

***Correction. The documentation section on Lunacycle's website is here: https://lunacycle.com/documentation***

 I'm also a little ambivalent toward my local bike shop. Some of the guys there have been great, and no lie, I've cadged a lot of knowledge hanging out there and talking to them. On the other hand, there have been times when I felt like I was being suckered a little. They assured me, for example, you can't hook a Sram 7 speed shifter to a Shimano derailleur, so I had to change the derailleur. I did, and it was only 25 bucks,  but I've seen articles online suggesting it might not have been necessary. Their tools are a little pricey, compared to what I can get them for online. I'm not impressed at all with the truing job they did on my wheels. The front is ok, but it wasn't bad to begin with. The rear... well I took it in with a popped spoke and so badly out of true it was rubbing hard on the brakes. They fixed it, and it's way more true than it was, but there's a significant hop in it, and it still wobbles a little. It's usable. For now. If they couldn't get it all the way true, it'd have been nice if they'd told me. In fairness to them, I looked at the work order, and it does not say anything about //truing// the rear wheel, only replacing the spoke, so maybe that was a service I needed to pay extra for. I don't know. I think in the scheme of things they'd really rather sell me a new bike than help some middle aged fat guy (me) learn to fix his own ride, and sometimes it shows. It depends on who you get.  Still, most of the stuff they've sold me has worked, even though they don't have much that fits my bike. (They tell me 7 speed rear ends are pretty much extinct. The Internet says otherwise. I realize they do have to be choosy with what they carry parts for though. In the real world space is limited.)
I wonder if maybe I'm just cross-threaded a little with the biking community, that it's a more rough-and-tumble kind of business than I'm used to dealing with.

Next steps:
Build my own truing stand. I have an extra fork (Steering tube was too long. Threaded, quill front end. Long, unpleasant story). They tell me that because my wheels are under a lot of stress, they'll need spoke tightening and truing a lot more regularly than they would otherwise. At 25 bucks a whack even if I don't break any spokes, that'll get expensive fast. Other than the stand, the tools are cheap. This is something I need to learn to do for myself. Also, if these wheels really do have that much trouble doing the job, I can hand-lace my own mix of components to make stronger ones.
Think about brake improvements.  The Ebike world would have you believe that rim brakes are simply inadequate for an ebike, let alone one with the payload mass my bike deals with. That hasn't been my experience.  All I can figure is these guys are going a //lot// faster, and since kinetic energy = 1/2 mass * velocity^2, the kinetic energy of their higher speed (that the brakes have to handle) quickly goes higher than mine, even with my higher mass. But if I do need better brakes, I've been looking at Sturmey-Archer drum brakes. Disk brakes... on a bike... I dunno. If you get the rotors dusty or oily your brakes malfunction. Badly.  (This is probably what made M fall on her rented bike. The disk brakes were grabby.) Drum brakes are all internal. Even if you ride in the wet (which I have no intention of, but you never know) the brakes will work as advertised. What the tires do is a different kettle of fish.
Lights. I can't even find my tail light, and my headlight is about the size of my thumb. I have a 48 volt battery with 13 amp-hours of current available. I didn't use a measurable amount in my 3.8 mile ride. I can afford to run some bigger, brighter lights.
If the system is fused anywhere, nobody's said anything about it. There are probably polyfuses in the controller, but if I tap the battery directly for lights, that does me no good. The ebike community seems not to be big on fuses anyway. I'm big on not having electrical fires between my legs. I have a 3d printer and I know where to order the connectors (Mouser) and automotive blade style fuses rated for 48 volts. There will be a fuse box.
Riding buddies I know guys at the gym who have ebikes. I know guys at the gym who may want one soon. And of course, there's my bestest buddy for all things, M.  I want to ride with others. I want this to be social.

Anyway.

That's where I am
-JRS

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