Denver commuter e-bike

[Toshi]

I test rode a Novara Gotham today at REI Seattle to check out a few things: whether a frame battery pack would fit; how the sizing runs; and how the NuVinci hub/Gates belt drive system feels.

First up, pack fitment. Here's what dimensions are required:

Here's what the L/XL frame's triangle looks like:

I think it'd work.

With regard to sizing, the L/XL didn't have a lot of standover clearance for me (not a surprise) but would certainly work for road riding. Reach actually felt too short, but that's probably an artifact of the narrow markedly pulled back handlebar setup. I certainly wouldn't want to go smaller, and slapping on my wide flat bars would probably make it nice and stretched out.

The NuVinci hub actually worked really well. The amount of slop in its freewheel is akin to that of a normal hub (but not a Chris King or modern XT), which is much better than the loosey goosey Alfine 8 that I had before. (Was it a Nexus 8? Can't recall. Shimano 8 speed internal geared in any case.)

I didn't sense an elastic feel from its innards when climbing, either, which was similarly a complain of mine with the old hub.

There seemed to be a wide gear spread, which is corroborated by this chart:

The absolute legend on the chart is inaccurate as this bike had 700c wheels and a 50t front chainring. Uh, toothring? Beltring? The correction factor should be 622/559 * 50/36 ~= 1.54, which in turn would imply a feel about the same as a double crankset road bike. That impression was pretty spot on--maybe a bit easier on the low end but the high end gears were ridiculously long. This would be perfect for e-bike conversion.

Here's that 50t beltring:

Partially obscured in the above photo is the name CenterTrack, which is evidenced by the ridge up the middle as pictured here:

Although this gave me brief hope that it'd have enough "chainline" tolerance for a mid drive setup to work +/- shimming the adapted beltwheel inwards, this guy has already tried exactly that on this same bike, unbeknownst to me (and he's from Seattle!):

http://endless-sphere.com/forums/viewtopic.php?f=28&t=65093&p=986793

Cliffs Notes are that it didn't work, due to chainline/beltline and eccentric BB issues alike.

The Gotham would still work fine with a front hub motor, probably a geared eZee since I haven't gone down that route before (other hub motors I've used were direct drive) and because they promise more torque. The bike itself is not compelling enough to warrant abandoning the mid drive concept, though, so perhaps it's back to the Surly Ogre idea.

 

[Toshi]

Next thought:

Kona MinUte "midtail". That'd make for good pannier-foot clearance (a bit of an issue on my OG Novara Transfer build), the possibility to cart around my kids with Xtracycle seat accessories for that big rear deck, and a reasonably clean look.

Here are three possible setups to run with it:

It'd be nice if Justin Le has some production-ready Field Oriented Controllers available when I approach build time, about a year from now. No sense in me buying one of the 2 available prototype units and hanging onto it for the better part of the year.

 

[Toshi]

In the interim I've read a ton about Crystalyte HS3540, the BBS02, and the Lightning Rods mid drive. I ruled them out due to freewheel and cable routing issues, non-ISIS crank and integrated controller, and ugliness/overkill, respectively.

Meanwhile, I streamlined the MinUte plan down to a single, sane option:

[elided since it's always changing]

Note 40A non-BAC controller, upsized triangle battery, Cycle Satiator, and pricing reflecting dual torque arms. I think this would be a good evolution of my original build back from when I lived in Seattle:

- practical base bike with fenders and storage
- rear cassette since freewheels really are horrid, ditto for ISIS
- PAS since that's the new thing and Justin Le likes it
- more power to up cruising speed from mid-20s to around 30 mph

The only thing I don't like is the frame bag for the battery, but if I want to pull 40A at 48V then the slicker pack won't cut it, I believe.

 

[Toshi]

So on my old e-bike build as detailed in this very thread I ended up with a 48 tooth chainring driving a 16 tooth cog on a Nexus 7 hub. Top gear on a Nexus 7 is 1.545 per sheldonbrown.com. Sheldonbrown.com also has their awesome gear-inch calculator, which yields 105 gear-inches in the top gear, or 25 mph at a cadence of 80 rpm, in other words.

That jives mentally with my experience with the thing: I would often spin along in gear 6 of 7 at 23-24 mph, and with a high cadence could hit 30 mph with assist.

[35 mph musing elided--not going to run 72V, not going to be going 35 mph]

 

[Toshi]

[road cassette musing elided--I will run one, though]

 

[Toshi]

Hmph. Stepping back from the brink and spending more time in ebikes.ca's motor simulator it looks like I must have plugged in 72V systems to see these 2 kW power levels and 35+ mph ratings. At 48V it looks like 29 mph is more realistic, which means that 25A controllers and batteries might cut it after all:

This is actually good because it gets away from the crazy big chainring world, and it allows for the cheaper, lockable-to-frame battery option from em3ev that can still pump out 25A. A 48 or 50t chainring would work for a ~30 mph cadence, and Black Spire makes DH rings in this size.

 

[Toshi]

As a preface, I'm not going to be buying/building anything until my new house mortgage closes, so spring of 2016 is realistic. That aside, more speculation about what I could build for my to-be-6.5 miles each way, windy, slightly hilly commute:

I've been pretty happy with the idea of the MinUte "mid tail" as a road friendly commuter/utility bike. I could run my 700c x 47 mm tires on it, for instance. For daily commuting on gravel and bumpy dirt, however, I wanted to explore options with larger volume tires. (Full suspension is still out, as it was when I built my first commuter bike, because of ugliness, cost, and that rack/pannier options become severely compromised once it's thrown into the mix. Again, this is a bike to get me, my clothes, and my lunch to work, not a bike for some retiree to putter around on.)

One option would be a factory mid drive fat bike. There are a few now, the nicest probably the Felt:

That photo illustrates nicely that the rack situation is well taken care of with (rigid) fat bikes. Note absence of fenders, however. I guess one could rig up some motorcycle fenders, as they certainly run tires as wide as those on fat bikes, but there seem to be no good fat bike fender options that I could find. That's a deal killer for me, again as I have to show up to work clean and relatively well kempt.

Besides, I don't think 350W nominal from these legal fat bikes, mid drive or not, would actually keep me going at 20 mph with any sort of meaningful headwind or grade thrown into the mix. Maybe that'd suffice for a sleek thing like the Raleigh Misceo iE, but not for a fatbike:

(Note lack of fender clearance on that Raleigh. Also note that fatbikes with 170 or 190 mm rear dropout spacing do not lend themselves easily to hub motor conversion except with 135 mm front forks, and I don't want another front drive bike.)

Anyway, I found another possible bike, the Surly Troll. It's the little brother of the Surly Ogre that I've posted about on the last few pages of this very thread. The difference is that the Troll is 26" vs. the Ogre's 29".

Pluses:

Rack and fender compatibility is a go.

What's more, I could run 65 mm fatbike rims with it! and at least 2.5"-2.7" tires. 3.0" tires such as the Surly Knard effectively don't fit out back, although they fit fine in the front fork. It'd be a "half-fat bike".

That's it next to a Pugsley.

Plug that same 9C/ebikes.ca PAS kit from the MinUte idea on it along with a 25A capable frame battery from em3ev and that could be a comfortable commuter indeed...

 

[The Stig]

A fatbike would be great!
A mid drive would be nice but how making peace with significantly higher maintenance involved? With hubbies you can neglect the chain and all that, pretty much your only regular maintenance becomes break adjustment, with regen even that may become rare. You know all this of course but I'm curious to hear your thoughts about commuting hubbie VS mid.

 

[Toshi]

The Bafang doesn't look to be the best in terms of reliability and the Lightning Rods kit is both ugly (sad to say it but it's true) and probably overkill. I think a hub motor is the way to go, again.

With regard to fat bikes, why can't some manufacturer build these?

People can jury-rig their fenders and they certainly have, as with the photo. Why is this apparently an unmet need in the marketplace?

 

[The Stig]

You mean ready bikes with fenders? there are some fender kit sellers out there. This guy seemed honest and responsive when I bought from him. Haven't used the fenders yet. For some reason his websites down but I could pm you his email if your interested.

http://forums.mtbr.com/fat-bikes/big-o-fenders-anyone-use-them-889081.html

(Website Down 05/04/2015)
http://stores.bigomfg.com/

 

[Toshi]

Now that I dig a bit deeper it does seem that some people have the fat bike fender issue figured out:

That's a Planet Bikes Cascadia modified by cutting it down the middle and splicing in 3" of [pickyourmaterialhere].

MK Fenders makes wood fenders up to 135 mm width! http://mkfenders.com/options.html

Here's a Big O commercial fender, which I see The Stig has posted since I started composing this post:

I'd link to their site but they're down.

 

[The Stig]

There is also this front and rear set: https://www.ridepdw.com/goods/fenders/daves-mud-shovel-rear

 

[Toshi]

Those are no substitute for full fenders. PDW and SKS were the first places I looked. Perhaps by this time next year there will be more offerings.

 

[Toshi]

An update:

- moved a few miles north within the same greater neighborhood
- commute is now 6.1-6.5 miles each way (depending on where on campus I'm headed to) if on bike, 8-11 miles in car depending on route
- been pedal biking religiously the last few weeks since I want to get into shape
- picked up mountain biking again, which is non-motorized by definition/trail access and involves much more pain than my commute

On the mountain I'm often climbing 1600 vertical feet. I thus figure rightly that I can handle 150 vertical feet on my bike commute without electricity. I take anywhere from 21-35 minutes depending on motivation, freshness of legs, wind, and direction.

My commuter bike therefore will remain unelectrified, at least as long as I'm above my target weight and below my target fitness. (I'm using a 29er with 47 mm Schwalbe Marathon Plus semi-slicks, a front rack, and one or two front panniers for commuting.)


Update: Ditched the front rack for a nice Tubus Vega Evo rear rack. Same panniers. (Note that I used to run a Tubus Cargo on my e-bike. Good racks from that outfit.)

 

[Toshi]

Another update:

- might be moving back to Seattle, but not before the end of calendar 2017 if this happens at all
- if I move back I'll build or buy another e-bike as my commute probably would be West Seattle -> West Seattle Water Taxi -> e-bike through downtown to Swedish or thereabouts
- wife's RAV4 EV continues to do great, as does my dino juice-swilling Land Cruiser that would be the tow rig to get said EV to Seattle

 

[Toshi]

A possible Seattle e-bike for commuting, putting the DIY option aside since I want internal cable routing and non-ugliness this time around assuming the mid-drives are sufficiently powerful these days:

Trek Super Commuter+ 8S. Coming in Spring 2017. $5k but oh so pretty.

XM700+ clearly a cheaper but less pretty option. I should test ride one of these and see how the performance feels coming from my ex-motorcycle and ex-48V 35A hub motor build background.

 

[Toshi]

I am rather bored at work today so finished sketching out a DIY build, ugliness and all.

It'd start with a Surly Ogre, for compatibility with my nice 29er wheels (or at least the one that wouldn't be replaced):

I'd go with the frameset because I don't like their stock parts and wouldn't use many of them. I'd reuse the rear wheel, rear drivetrain, bars, grips, stem, brakes, tires, rack, and lights from my 29er (latter via a custom 8.4V DC-DC converter?).

Complete specifics are very boring, so here would be the highlights:

- 1 x 10 setup since 44 x 11-42t would give me a very useful 8-29 mph range
- 14s frame-mounted lithium pack (51.8V nominal, hopefully less ugly overall than the linked setup), 13 Ah, rated for 40A as would be the now sine-wave controller (so quieter than my old setups)
- torque sensing bottom bracket with control logic through a newer generation of the same CycleAnalyst I used to run
- this would be a full torque-sensing pedelec, in other words
- 2 kW from the battery, and about 1000-1600W max to the pavement at climbing and cruising speeds, respectively, limited in reality on all but the steepest hills by my own output and the multiplier chosen
- even with getting a new frameset, King this, Thomson that, it'd be about as expensive as a mid-drive IZIP with only cadence sensing

Here's how it'd perform on the steep hill up from the water taxi to the level where my MIL's house is:

A mid-drive would have the advantage of running its 350W through the gears, but between me and it I could put down perhaps 600W to the ground. Me + the above hub motor running even in its inefficient, slow range would be about 1250W.

Maybe this would be worth the troubleshooting and cable management. Maybe.

 

[Toshi]

An even better idea:

Note The Crown 4080 hub motor... and a Surly Ice Cream Trucker fork with 135 mm spacing to fit it with just a little stretching. No overheating issues with that setup, and I'd potentially be the only guy around with a Crown on the front.

 

[Toshi]

A possible Seattle e-bike for commuting, putting the DIY option aside since I want internal cable routing and non-ugliness this time around assuming the mid-drives are sufficiently powerful these days:

Trek Super Commuter+ 8S. Coming in Spring 2017. $5k but oh so pretty.

XM700+ clearly a cheaper but less pretty option. I should test ride one of these and see how the performance feels coming from my ex-motorcycle and ex-48V 35A hub motor build background.

So I never moved back to Seattle. Still in Denver. I did get around to testing a factory mid drive e-bike with proper torque sensing PAS, though... albeit a Commencal e-mtb.

I quite liked how those feel and think I'll get such a bike sooner or later.

In the meantime I built this rig as my Denver commuter:

I'm thinking of electrifying it with a lightweight setup:

The eagle eyed will note that the torque arm isn't necessary.

 

[Toshi]

1) Ordered myself a Pivot Shuttle e-mtb. That should be quite nice. (Demoed it, a Commencal Meta Power a la the last post, and a Specialized Turbo Kenevo, and liked the Shuttle the best.)

2) Went ahead with the lightweight electrification plan for my belt drive Soma Wolverine:

MG310, 36V 14Ah frame pack, Gates belt drive, XT hydraulic brakes, CA v3.1. I ended up with a Sempu torque sensing BB ultimately and broke it after 20 miles. Whoops. Awaiting ebikes.ca's response now.

 

[FETguy]

You broke a new Sempu? How? What broke?

 

[Toshi]

You broke a new Sempu? How? What broke?

Not sure what exactly failed. Hopped down off of a curb, pedal assist went all wonky and irregular for the next few hundred meters, then afterward it registered no pedal force at all (as assessed on the little moving legs bar graph at the left of the main CA display). Upon checking its configuration it now shows 0V +/- noise at rest, whereas it was 1.49V when working.

To add insult to injury my new CA appears to have failed on the ride home. Was accelerating from a stop while pedaling, dialed in full thumb throttle (since the Sempu wasn't telling the CA to do squat at this point), then the CA screen went dead and the throttle did nothing. I pedaled the 45 lb bike home unassisted (thankful for the geared hub at least!) and charged the battery full before busting out the multimeter. I show 3.33V across pins 1 and 2 on the CA-DP connector, which I believe to be sane.

 

[FETguy]

Thanks. I was curious in part whether the Sempu BB had broken mechanically (broken spindle = crashed bike, usually).

I'm also interested in the Sempu electronics. Awhile back I posted some measurements and asked if anyone knows how they work. No response to that, although I bet someone in this bunch has torn one apart. If your Sempu has indeed failed, and if Grin does not want it back for warranty, I'd pay for shipping to get it and do a casual teardown.

The CA3 is usually powered from the CA-DP connector, which should have full battery voltage between pins 1 - 2; if it is only ~3V, maybe the problem is upstream of the CA3. . . maybe the motor controller? You have probably got this figured out by now.

 

[Toshi]

Interesting. I didn't know if it was already regulated or full. I'll check again tonight, but I'm pretty sure I saw 3V. (I guess that makes sense since it has the battery voltage accessory out bit.)

 

[Toshi]

I had the connector flipped mentally. 3.33V across 5 and 6. Full battery voltage across 1 and 2. The CA still won’t turn on.