Denver commuter e-bike

[Toshi]

July 2018 update: Built up a new bike:

2014 update: e-bike parted out after a few thousand miles under its belt. I've moved thrice since its original build: Seattle --> Long Island --> Seattle --> Denver. I now bike commute on a non-electric 29er, drive my Land Cruiser occasionally, and the wife tools around in her leased LEAF.


>>>>>>>>> old content below

August 24, 2012 update reflecting its v2.0 rebuild with a 9C 2806 hub motor, 48V 10Ah LiMn and a 48V 35A regen-enabled Infineon controller:

Maiden ride has been accomplished in grand fashion: 8.2 miles, 4.6 Ah, 27.8 Wh/mi. Max speed without pedaling, wide open throttle was around 27 mph on flat ground. With me pedaling along I could get it up to 30 mph. Comfortable cruising speed was more in the range of 23-25 mph while pedaling along, throttle part of the way open. Max indicated power from the battery to the controller (so less at the wheel due to motor inefficiency) was about 1600W at 27 mph. Max regen coming down from 25 mph was around 550W, decreasing as speed decreases. Overall I regened 6% of power input on my errand run today.

original post with original, V1.0 specs below:

As detailed here I've ditched the idea of converting my Klein road bike. It'll stay in the stable unmolested, the perfect ride for short trips and for pure speed or exercise. Instead, my commuter will be a separate bike. Which bike, you ask? Well, that's still a bit up in the air. I do know what electric components it'll run, however, since I ordered them today from ebikes.ca:

Crystalyte 407 in a 26" front wheel
48V 12Ah LiFePO4 battery with the proper charger
was: 36V (48V capable) 35A immediate start controller along with a twist throttle
now: 72V 20A pedal-first controller after Hall sensor failures in the Seattle rain
Cycle Analyst DP

8)

Before anyone asks: Why front wheel given the freedom of platforms? Well, I last ran a freewheel on my personal bikes in 1995. They frankly sucked. If C-lyte rear hubs came in 135mm spacing with a proper cassette freehub body then I'd use one without a second thought, but they don't. A second answer: Why 26"? Increased bike choice (including the two models I'm particularly interested at at this juncture), the possibility of running wider city slicks if need be, and fractionally increased hill climbing torque over a 407/700c setup.

Background info from the previous road bike thread: 26 years old, current but weary bike commuter on a triple-crankset full-on road bike, Seattle so hills in the commute, distance from 4-13 miles one way, 200 lbs, shooting for 20 mph average with some pedaling effort on my part.

In the next post I'll go over my thoughts on bike choice.

update april 16, 2009 with a test-ride video!

Electric Bike Test Ride (hosted on vimeo)

 

[kbarrett]

Yea ... you could put that kit on almost anything.

 

[Toshi]

Ok, my thoughts on bike choice: Keep in mind that I have strong preferences for what I do and don't like in the human-powered bicycle world, and that these preferences may or may not have any bearing on what makes for a good e-bike in your opinion.

What do I want out of an e-bike platform?

1) 26" wheels so that my already-ordered electric bits will fit. I could have chosen 700c, but 26" is how it'll be.

2) A normal wheelbase and layout so that the bike can fit on the bike racks present on the front of every Seattle/King County Metro bus. This page details how electric bikes ARE allowed on bus bike racks: http://transit.metrokc.gov/tops/bike/loadbike.html.

3) Straight handlebars, or at least not drop or mustache bars, so that a twist throttle can be easily mounted. Going with this, Rapidfire shifters would be nice vs. Grip Shift, so as to not have both gear and throttle twist grip units competing for bar space and mental attention.

4) Full fenders and a rear rack, or at the very least mounting eyelets for the same.

5) No suspension or disc brakes. First off, I think the suspension and mechanical disc brakes found on "cheap" bikes are utter garbage. Second, I want less to break. Third, I'm running a front hub motor, so there isn't clearance. Fourth, I've been down plenty of 30 mph+ hills on a road bike with 23c tires and caliper brakes, and have lived to tell the tale.

6) Aesthetic cleanliness with a decent gear range. Ideally this would mean an internally geared 7- or 8-speed rear hub with a full chainguard and clean lines, but this isn't necessary, I suppose.

7) Decent componentry. Doesn't need Ultegra or Deore XT, but I have no desire to ride something with a BMX BB, 1-pc cranks, stamped-steel caliper brakes, any unified rear triangle (URT) suspension design, friction vs. indexed shifting, "hi-tensile steel" anything, or a quill/non-threadless stem. There's a reason department store bikes are cheap, and there's a reason they don't make good "real" bikes. I don't see why they should make any better e-bikes. Furthermore, given that batteries and the like are already really expensive, why shave off pennies on the bike itself when it is the item with which the rider interacts most directly?

 

[Toshi]

What bikes fit or approximate the above criteria? Well, it's no coincidence that many of these criteria mirror those that non-electric bike commuters tend to look for, and in years of late manufacturers have actually responded with appropriate bikes. Someone at kentuckybicycling.com put together quite a nice list of commuting bikes for the 2008 model year:

http://kentuckybicycling.com/2008-commuting-bikes/

Ones off that list that catch my eye (sorry for the overly compressed jpgs, blame the kentuckybicycling webmaster):

Bianchi Milano, $775 (but would need a rack and possibly less-ugly tires )

Novara (REI) Transfer, $599 (and wouldn't need anything whatsoever! indeed I could sell the dynamo front hub and light setup to recoup some of the cost!)

There are several other, similar models in 700c from Jamis and Specialized, and generally speaking most 26" wheel bikes with a 7- or 8-speed rear hub would do the job about as well with a few part swaps here or there. Searching for Shimano Nexus (title and description) on eBay yields one good hit for a 22" (huge!) frame 2006 Bianchi Milano, for example.

 

[Toshi]

Additional factors to consider:

REI offers 15% one item for new subscribers to their email newsletter, and everyone has multiple virgin-to-REI email addresses, no? 8) Also, shipping to REI stores for store pickup is free, even on big items like bikes. Also worth re-noting is that the Novara comes equipped with everything that one might want (fenders, rack, even lighting), and its front dynamo hub and light setup could be sold for some meager but non-negligible profit.

$599 - 15% is $509 and change. Factor in sales tax and it's still an excellent deal for a "real" bike with all the commuter fixings, in my opinion. It's kind of ugly and has no brand cachet, sure, but the price is tough to beat.

Gah. Just read the fine print: 15% off coupon not valid on bicycles. Oh well, it was worth a try. Even barring this coupon the Novara is a good deal. It might make sense to wait for the seemingly biweekly REI sales, however...

 

[Link]

Ok, my thoughts on bike choice: Keep in mind that I have strong preferences for what I do and don't like in the human-powered bicycle world, and that these preferences may or may not have any bearing on what makes for a good e-bike in your opinion.

LOL, I'll say.

5) No suspension or disc brakes. First off, I think the suspension and mechanical disc brakes found on "cheap" bikes are utter garbage. Second, I want less to break. Third, I'm running a front hub motor, so there isn't clearance. Fourth, I've been down plenty of 30 mph+ hills on a road bike with 23c tires and caliper brakes, and have lived to tell the tale.

Suspension on my S40 is great. I can endo with the front disc. Nothing has yet to break on the bike (save a small piece of plastic when I almost crashed and kicked the derailleur really hard). There's clearance for a BD36, but I dunno if it would fit a C-lyte. 30mph isn't that impressive for some here. Even I can do that with (very undersized) fresh SLAs and some pedalling. And while I technically have "working" brakes. I'm pretty much screwed if I have to stop fast. I really need to get that Golden Motor ready so I can put the front disc back on...

6) Aesthetic cleanliness with a decent gear range. Ideally this would mean an internally geared 7- or 8-speed rear hub with a full chainguard and clean lines, but this isn't necessary, I suppose.

No, you definitely won't find that on a cheap bike. But you won't be using it much, either. :wink:

7) Decent componentry. Doesn't need Ultegra or Deore XT, but I have no desire to ride something with a BMX BB, 1-pc cranks, stamped-steel caliper brakes, any unified rear triangle (URT) suspension design, friction vs. indexed shifting, "hi-tensile steel" anything, or a quill/non-threadless stem. There's a reason department store bikes are cheap, and there's a reason they don't make good "real" bikes. I don't see why they should make any better e-bikes. Furthermore, given that batteries and the like are already really expensive, why shave off pennies on the bike itself when it is the item with which the rider interacts most directly?

Caliper brakes are definitely old hat. They're okay for the rear, but a front disc is a must. I don't think they even make friction shifters anymore. Steel is good for an ebike. You want a strong frame, not a light one. There aren't any electrified carbon fiber road/racing bikes (that I know of) for a reason.

Ironically, quite a few here use very cheap Schwinn frames (myself included) as bases for ebikes. They're excellent for this purpose. Cheap, fairly light (for a cheap mountain bike), and full suspension (which happens to be a URT ). The only thing I would do if I could would be to make the drops steel instead of aluminum. You wouldn't need torque arms with steel drops that thick.

 

[CGameProgrammer]

If you're loading the bike onto a bus, the battery pack needs to be easily removable. There are many ways to accomplish this; I recommend using velcro tape to hold it onto the rack, so you can easily undo it to remove the batteries.

 

[Toshi]

Link, thanks for the reply even though you disagree.

My complaints with "cheap" bikes generally are:

- excessive weight, in the frame, wheels, components alike
- excessively upright riding position and geometry that can't be fixed through component swaps (e.g., too short of a top tube with a too-tall head tube)
- poor drivetrain components and shift quality (remember, I'm a snob even if I've managed to escape the magazine-fueled buying cycle: I run old XTR bits on my similarly old, rigid mountain bike, and 9 speed Ultegra with STI shifters on my road bike)
- poor suspension quality, both in terms of excessive weight but also in terms of short travel, ridiculously high leverage ratios, and short travel shocks with little damping to speak of

If these things don't bother you, then more power to ya. 8)

I do wonder why you think front disc brakes are a must? That'd mean running a rear hub motor, which would require a 7 speed freewheel... my hackles are rising just thinking about that. My story about the 30 mph that I regularly see coasting on the road bike on my commute is to show that on-road speeds in that range are highly manageable with no suspension, 23c tires, and caliper brakes. I'm not convinced that non-hydraulic discs offer any advantage over V brakes in the dry, and in the wet tire traction is already compromised...

CGameProgrammer, thanks for the tip about making the battery pack removable. I ordered one of those Swagman rack trunks off of amazon.com, and hope that Velcro + some internal bracing in that trunk will do the trick. The ebikes.ca LiFePO4 battery pack's reported dimensions are within an inch or three of the internal dimensions of the trunk so I have hope that it will work well.

 

[lazarus2405]

Nothing wrong with the Target "Schwinn" (Pacific) S25/40/60 for electrifying for commuting. If you're on roads and not going too fast, you won't have any problems at all. I've had mine up to 47mph, and the bike was fine. Only problem I had was because I was throwing too much power through the thing without torque arms.

Of course it's heavy (40lbs stock), but the donor bike weight is pretty unimportant after electrifying. The drivetrain is cheap too, but you don't end up using that much. Of course the shocks suck, but you aren't doing trails on it; they're for the potholes, for your butt's comfort, and not for doing jumps and taking drops. In general, the cost to fix those isn't worth it for an electric that stays on the road and under 35mph, especially compared to the improved batteries that that money could buy.

I just bought an actual bike yesterday, a decent used xc/dh diamondback. The difference is amazing (unelectrified). It'll be a much better ride at those speed, and I'll get to enjoy trails at the state park I discovered right under my nose!

I wholeheartedly agree that department store bikes are cheap for a reason, but sometimes that isn't a problem. At this point, I'm going to keep my motor on my S25 until the frame really dies. You can trash it in the course of electric riding and not sweat the small lost investment.

Link considers front discs to be a must because he runs a rear motor. The very valid point is that you need decent brakes, considering that you're adding a good 40+lbs and will be regularly going a bit faster. Sounds like you won't settle for bad brakes anyway, but keep it in mind. You can always use your motor to brake, too, if you need to.

We prefer running rear hubs because forks break relatively easily with a motor. In a high-power setup, you have to put the motor in the back, period. You won't need to worry about this. The freewheel doesn't bother people because it doesn't get used too often, partially because of laziness, partially because of gearing (can't keep up with the darn motor on a 42t ring and 14t gear). Because of mounting difficulties, it's simpler to forgo a rear disc and just use one on the front. Because of the rear motor's and battery's weight, there's less of a tendency to do frontstands.

An unrelated thought: you could reuse the light, powered off your main battery. Lights are good. Of course, if you never ride after dark...

 

[kbarrett]

With a c'lyte hub, pedaling without powering it becomes a major pain. Which means you won't be doing a lot of non-powered biking unless it is an emergency. I'm getting a used Heinzmann geared hub to replace mine for that reason ... no drag when using the 'bent as a bicycle.

Your main reason for having the pedals is to assist the bike on hills. You will ( probably ) want a high torque small gear for this ... the tall gears are unusable when the motor is pushing you at 18+ mph.

I have found that I seldom, if ever use the tall gears on my 'bent, or my gasser.

I singulated the gasser with a 17 tooth single gear freewheel, instead of replacing the cheesy plastic derailer when it started failing, and have not missed the tall gears at all on it.

Consider a top end three speed or beach cruiser ... with powered bikes, durability, simplicity, and ability to absorb 20 MPH pothole strikes becomes more important than what one would normally look for in a straight road bike.

Just my $0.02 ... you will do as you please, of course.

 

[ort5]

I currently own a Kona Smoke which I bought last year. It's a great commuter bike and fits much of your criteria. It's very sturdy, and the price is very reasonable at around $350. Not sure if they sell them anymore though, but perhaps you could find one used?
I haven't electrified it yet, but I hope to this year.
http://www.konaworld.com/shopping_cart/FrontEnd/Products/product_detail.aspx?productid=85&parentid=182

 

[Toshi]

I wholeheartedly agree that department store bikes are cheap for a reason, but sometimes that isn't a problem. At this point, I'm going to keep my motor on my S25 until the frame really dies. You can trash it in the course of electric riding and not sweat the small lost investment.

Good point.

The freewheel doesn't bother people because it doesn't get used too often, partially because of laziness, partially because of gearing (can't keep up with the darn motor on a 42t ring and 14t gear).

This is part of my fear of using a bargain-basement bike: if it's so unwieldy as a bike that I wouldn't pedal, why am I doing this with a bike platform at all except for the registration/parking benefit?

I want to pedal. Part of my reason for bike commuting up to this point has certainly been for the exercise, and I don't want a bike that is only usable while riding the electric throttle.

An unrelated thought: you could reuse the light, powered off your main battery. Lights are good. Of course, if you never ride after dark...

An interesting thought, this. I've currently sworn off of expensive, heavy "real" lighting setups, however, in favor of cheap LED flashers. Having one less battery pack (or wiring, if wired centrally) to unhook and stash away each time I lock the bike up is nice, and I manage as it is by streetlights.

My aim is to make this bike, well, a bike, and not a mini electric motorcycle with a crankset.

 

[Toshi]

With a c'lyte hub, pedaling without powering it becomes a major pain. Which means you won't be doing a lot of non-powered biking unless it is an emergency. I'm getting a used Heinzmann geared hub to replace mine for that reason ... no drag when using the 'bent as a bicycle.

Your main reason for having the pedals is to assist the bike on hills. You will ( probably ) want a high torque small gear for this ... the tall gears are unusable when the motor is pushing you at 18+ mph.

I have found that I seldom, if ever use the tall gears on my 'bent, or my gasser.

I singulated the gasser with a 17 tooth single gear freewheel, instead of replacing the cheesy plastic derailer when it started failing, and have not missed the tall gears at all on it.

Consider a top end three speed or beach cruiser ... with powered bikes, durability, simplicity, and ability to absorb 20 MPH pothole strikes becomes more important than what one would normally look for in a straight road bike.

Just my $0.02 ... you will do as you please, of course.

Thanks for the input. I have test-ridden 3 speed bikes as I had a similar thought, but I don't think a 3-speed is a good solution: the three gears have a reasonably wide gear range and I found the gaps between the gear ratios to be huge. Again, this might not matter that much ultimately if I'm not pedaling, but the mental leap from the close gear ratio spread of a 9-speed road cassette to a 3-speed internally gear hub was too much to handle.

 

[Toshi]

I currently own a Kona Smoke which I bought last year. It's a great commuter bike and fits much of your criteria. It's very sturdy, and the price is very reasonable at around $350. Not sure if they sell them anymore though, but perhaps you could find one used?
I haven't electrified it yet, but I hope to this year.

Thanks for the input, and for the bike suggestion. This year the Kona Smoke is only offered in 29" (~700c) form, which takes it out of the running in my particular race.



As quite a few posters in this thread have made the point that pedaling may not be the integral part of the riding experience that I envision I'll take a look at the cheap-bike market, say from Costco, and see how their offerings stack up.

I'm not against saving money, by any means. Instead, I'm against ugliness: URT FS MTBs with seatpost racks, mile-high stems, wide gel seats, kickstands...

8)

 

[kbarrett]

You will get exercise ... but only on hills. And a lot of that pedaling will have to be on the short gears, especially at 48V, unless you have a cadence like a crack-addled monkey.

If you went to 36V, you would get more exercise. I tried 48V with SLAs, and decided it was too motorcycle-like for me.

 

[Toshi]

You will get exercise ... but only on hills. And a lot of that pedaling will have to be on the short gears, especially at 48V, unless you have a cadence like a crack-addled monkey.

If you went to 36V, you would get more exercise. I tried 48V with SLAs, and decided it was too motorcycle-like for me.

Hmm, interesting point. I figure that if I'm going to fight the drag of a brushless hub motor and carry the weight of the entire setup then I might as well extract all the power I can out of it. Dialing down the current to 20A or less would always be an option, too.



With properly tall gears (thus a 8-speed internal hub or a standard derailleur setup) what would prevent pedaling along at high speeds? Is getting the gearing that tall the issue itself, or is it just the feeling of futility in face of the electric assist?

 

[lazarus2405]

Well, the drag of a brushless hub motor is not too bad. Not even an x5. If you need to pedal a 400, the drag is annoying. If you want to pedal it, you'll be happy. Except on hills. I once very loudly complained that the x5 was ridiculously hard to pedal. Turned out that my rim was out of true and my brakes were dragging really badly.

Remember that if you want to pedal, you can give the motor just a little throttle to overcome its drag. Or you can do most of the work with the motor taking the edge off, with extra power in reserve should it be needed. I sincerely believe that that is how the 400 is supposed to be used 85% of the time. If I understand you, that's exactly what you want to do. In that case, you really do want a real bike.

If you're pedaling, you can add about 150w continuous. Depending on your goals, this is not inconsiderable.When we talk about the futility of pedaling, we mean when you're running a kilowatt or more, the penalty of pedaling (exertion, getting sweaty) outweigh the benefits. Many people use ebikes for commuting so that when they arrive, they're fresh (and don't need a shower).

When we say "...but you won't be pedaling much", it's because almost all of us expected to pedal but found that we didn't, and that we didn't mind. It's a very different experience. If you haven't ridden an ebike before, be prepared for a different experience.

Getting the gearing that tall, for many, is the issue. With a department store bike, you simply will not be able to get that gearing stock, and in most cases the frames will not be upgradable. Depending on the frame, you can replace the crankset, remove the front derailleur, and use a crazy big chainring (62t does sound fun...) but then you'll have another set of complications (like hills). I don't know whether you can use freehubs on them, but they sure won't come with em.

Be careful of the mindset you take into Costco. Don't expect to find a bike that will stand on its own merit, but instead look for a bike that would make a suitable platform to electrify. You're looking for a good donor bike, not a good biking bike.

 

[Link]

Link considers front discs to be a must because he runs a rear motor.

No I don't. I run a front BD36 (at least until I get the Golden Motor up and running). I haven't put the calipers on the front yet, so I have no front brakes at all .

Well, the drag of a brushless hub motor is not too bad. Not even an x5.

Lucky X5 people. I've been playing with the Golden Motor (took off the side plate to have a looksee at the stator coils). It drags pretty badly. Far worse than the BD36.

When we say "...but you won't be pedaling much", it's because almost all of us expected to pedal but found that we didn't, and that we didn't mind. It's a very different experience. If you haven't ridden an ebike before, be prepared for a different experience.

Getting the gearing that tall, for many, is the issue. With a department store bike, you simply will not be able to get that gearing stock, and in most cases the frames will not be upgradable. Depending on the frame, you can replace the crankset, remove the front derailleur, and use a crazy big chainring (62t does sound fun...) but then you'll have another set of complications (like hills). I don't know whether you can use freehubs on them, but they sure won't come with em.

Indeed. Unless you have a huge front chainring, you won't be able to pedal at all when you get up to full speed. My bike's sprockets are designed for about 25mph top speed (about as fast as I can go on that bike anyway), and I can't add anything to the motor when I'm full out, and I don't even go that fast (little under 30mph tops). I only pedal at low speeds to help the motor out. I rarely even reach the amp limit by doing this.

Thinking aloud: My front derailleur is broken (still) and I've just shoved a nut into a hinge that opens when I'm in high gear. Come to think of it, I might as well just take the whole damn thing off. I never even need the lower gears anyway (love the flatland :wink.

 

[lazarus2405]

No I don't. I run a front BD36 (at least until I get the Golden Motor up and running). I haven't put the calipers on the front yet, so I have no front brakes at all .

I stand corrected. So all you have right now is a pair of rear calipers and the motor's drag to slow you down? Or did you add a rear disc? Any plug braking? I swear we went over this, but I can't remember. *wanders off to find Link's build thread*

Lucky X5 people.

Eh... Your bike still goes faster than mine. Still waiting for all those pesky non-electrical bike bike parts to get my S25 usable again.

Which Golden Motor? Don't they have a handful of motors, geared and dd, brushed and brushless?

Here in Oklahoma, there are constant rolling hills. I tend to change front gears every quarter mile. I figure in Washington it'd be a tad worse with the, um, mountain ranges.

But yes, gearing can be difficult if you want to pedal above 20mph. I don't know if a single, tall front chainring and a good 9spd cassette will do it; we can agree that you're able to much better answer that question. The problem, again, is hills. The added human power is most useful for hills, when the motor can bog down at low RPMs. If you gear to keep up with it on the flat, you won't be able to help on hills, but if you gear for hills, the pedals will become footrests on the flat.

That's another reason those department store mountain bikes aren't bad for a pedal-assisted electric: they're geared pretty low.

They make cranksets with planetary gearboxes, for just this problem. Press a button and the gearbox will engage, giving you a 2.5x or whatever higher gear ratio. Toggle it again and it's back to normal. Put a big chainring on that and you could keep up with a 16" wheel at 40mph. Of course, they're ungodly expensive, at ~$800. Overkill in most cases, but in rare instances they would make a lot of sense. I'm not seriously suggesting that, but throwing is out there as a "huh, neat".

 

[Link]

So all you have right now is a pair of rear calipers and the motor's drag to slow you down? Or did you add a rear disc?

Pretty much. I'm fuXXored if I have to stop fast.

Well, sorta. I can drift the bike pretty well. 8)

I haven't put the disc on the rear because while there's a place to mount the actual brakes, the rear hub won't take a disc. They only put those on the S60, I think. I haven't put the calipers on the front because I haven't got a replacement brake cable for it.

I'd need torque arms for plug braking. Plus, I wouldn't be doing plug braking. I'd be testing out Fechter's regen thing. :wink:

Which Golden Motor? Don't they have a handful of motors, geared and dd, brushed and brushless?

They only really sell one of them. It's a brushless and gearless 500W rated one. It's pretty heavy (like 25lbs or something), even though it's mostly hollow. The bearings are good, but the magnets in it are pretty strong, so they drag quite a bit. A few 4110s should sort that out.

But yes, gearing can be difficult if you want to pedal above 20mph. I don't know if a single, tall front chainring and a good 9spd cassette will do it; we can agree that you're able to much better answer that question. The problem, again, is hills. The added human power is most useful for hills, when the motor can bog down at low RPMs. If you gear to keep up with it on the flat, you won't be able to help on hills, but if you gear for hills, the pedals will become footrests on the flat.

The highest gear on the S series bike is good for about 20mph or so comfortably. You could get to 25mph if you pedal like a madman and are strong enough to get up to that speed in the first place. Any faster and you'll need a higher ratio.

Yeah, pedalling at low speed helps motor heat a LOT. I was messing around one night (fairly cold) and only used of 500mAh of battery, but didn't pedal at all. The motor was too hot to touch for any extended length of time after that. Today I rode to work and used up 1.7Ah of battery. However, I pedalled at the start, and only got up to 26A peak draw (limit is 31A). The motor was maybe 102F when I got there; barely warm at all.

[

I can see why it's so expensive. It's practically useless. Most people can only reach maybe 25mph tops. Pro bikers maybe 30mph. It would only be good for going fast in a small rim, but rims smaller than 26" are really only used on downhill and BMX bikes, neither of which would find much use for it.

But it is kinda neat.

 

[lawsonuw]

RE: gears

On 26 inch tires with a 52T up front any a 14T in back I can pedal ~70rpm at 20mph. (faster than I'd like but not bad) If I could get a wide range rear cluster with a small 11T sprocket, I think I could pedal along at 25mph. (stock 48T to 14T is hard to pedal above ~17mph) So road gears up front, and a wide range rear cluster should be plenty.

Marty

 

[kbarrett]

Volts = RPM, Amps=torque.

If you want to be able to add more pedal power on level ground, you need to lower voltage.

Lowering amps will force you to assist, but only when you hit hills.

Clyte 40x do not have variable speeds ... on or off is all you get.

 

[Toshi]

No variable speeds even with a controller?! As in twisting the throttle 10% or 100% will give the same amount of assist?

 

[lawsonuw]

Clyte 40x do not have variable speeds ... on or off is all you get.

wha! huh? I kind of thought that's what the controller is for... (i.e. providing options between on and off)

Toshi: I'm 99.99999999% certain that the controller throttle works on the Clyte 40x series too.

On my BD-36 assist only starts kicking in after a minimum amount of throttle has been applied. (higher speeds = higher min throttle) After that, throttle movement pretty quickly ramps up the amps to the max the motor/controller will take.

I think you'll be able to pedal along just fine with the right gears. I.e. a rear cluster that goes down to an 11T sprocket, and a set of ring up front that go up to at least 52T.

Marty

 

[D-Man]

Hi, I run 42 volts of sla's with a 408. The speed on the flats is right at 20-21 mph. When I had 36 volts, I couldn't pass anyone. Now I can push it up to 22-24 mph with pedalling and they don't even know. I get a decent reduction in amps too by doing this. Its a great workout and feels like riding an exercise bike. You can control the amount of assist with the throttle and pedal as hard as you want.
If you like to pedal, it would be best to either cap the voltage like I have done or have an amp limiter of some kind. Thats why I run 42 volts. Also, throttle works full range 0-20mph.