Hi-Efficiency Recumbent Commuter Conversion

[jkbrigman]

Guys, thanks for the comments and heads-up. Veloman, I'll see what I can come up with for moving the pack - that box isn't usable as a long-term solution, it's just the cheapest thing I could quickly find and I bungeed it to the top of the rack. It was all just to get the test ride done.

By the way: I drove by that station on my way to work this morning and it now says $3.85 - the price went up 6 cents overnight.

JKB

 

[jkbrigman]

The best price I found this weekend was 4.259 for regular.
And it took quite a bit of it to tow the trailer on a camping trip.

Great on your test ride! Excellent energy consumption rate!
So you pedaled up to get going and then engaged the motor! You'll probably get over that.

I'll confess to you that I started "getting over that" toward the latter part of the ride. I don't think I pedal-started the last 3 stoplights of the ride, it was getting very dark and I was in a giant hurry. I saw "1628 Kw" pop up very briefly toward the end.

I absolutely love the backlit display of the CA. Justin, dude, your CA is a fantastic device. I've never had one before and it's amazing. Yeah, you COULD ride without one, but having one makes all the difference in understanding how to efficiently use the bike.

 

[Kinni420]

Woot gratz on the test ride JKB! now finalize that baby and GO GO GO!

 

[jkbrigman]

Woot gratz on the test ride JKB! now finalize that baby and GO GO GO!

Thanks man!

I have to tell, though: I'm worried about that tiny front wheel. I hit 32mph on that thing, and if I hit a pothole with that 20" front tire, I might end up highway hamburger. I'm thinking about swapping out the front wheel/forks for a 26" front wheel and suspension forks. That, or discarding the idea of a recumbent and switching to an upright bike...

Going to try to get in one more test ride. I still have to prove out the battery, so I'm not done until I do. I have to go the entire distance of my ride route and back. If weather holds, I'll try this weekend, if not, well, later. Then I'll figure out what I'm doing - whether it's modding the recumbent or moving to a different bike.

BTW: I don't have another bike I can easily mod. The others are a road bike and two flat-bar road bikes with Shimano Nexus hubs on the rear. None of them good candidates for a rear motor.

I have a front motor that could be laced into a large rim (currently in a 20" rim) and put on one of the flat-bar bikes. But none of those bikes have suspension, so I'm not sure if that's a good idea or not....

JKB

 

[docnjoj]

Lowering that batterypack to an underseat mount should make a huge difference in handling qualities. I had problems even on a suspended trike with the battery mounted on the rear rack It made the handling much worse but when I put it under the seat it was like a different trike.. Definitely worth the effort.
otherDoc

 

[jkbrigman]

Lowering that batterypack to an underseat mount should make a huge difference in handling qualities. I had problems even on a suspended trike with the battery mounted on the rear rack It made the handling much worse but when I put it under the seat it was like a different trike.. Definitely worth the effort.
otherDoc

Agreed, agreed. RIght now that plastic tote is purely for testing. Do you have any recommendations on how to get the battery down under the seat? (ie: are there any commercial products out there or should I plan to make a box and strap it underneath?

JKB

 

[Kinni420]

only thing I can think of atm is fabrication. Perhaps a metal shop could build you something under there with padding and a nice secure door, welded to the frame or something to keep it from swinging. No where to really hang a pack under there without that problem. Ill have to grind my brain on this one. Watch for sharp corners! your calves with thank you when you come off the pedals for a stop or something.

 

[Kinni420]

My lights suck. They are ordinary AA and AAA powered bicycle lights. They worked, but they don't cut it. I want to make something way more powerful and use a DC-DC converter as the power supply off the main traction pack. This little battery action doesn't cut it.

you want real light?

http://ebikes.ca/lights/ only 200 bux or so Those DC-DC converters are $50+ themselves and you dont need one with the Luminator.

I personally prefer the darkness (great night vision) and only have a 2 bulb led on my head and a flasher in the rear. Its enough for me. Safe enough since my head is on a swivel. I have more idiot issues in the day than at night. That headlight on my head doesnt provide illumination on the pavement but is bright enough for staring people down when they are about to do something stupid.

 

[jkbrigman]

Well, I've done some research and found out some disheartening news: I'm way, way over the weight limit for this bicycle.

I realized this week that this bike is a clone of the Bachetta Giro 20 - in fact, if you look closely at the two, you can see enough similarities to wonder if it's only the minor differences in frame construction that differentiate between the two. (and, by the way, that made this $500 recumbent a stone cold bargain relative to the $1495 Bachetta Giro 20)

The weight limit - rider AND gear - on the Bachetta Giro 20, is 230lbs. Even if you derate this bike a few lbs, let's say 260lbs, I'm probably 300 lbs all-up: rider, motor, batteries, controller and other misc. I don't have any weight limit to carry anything else.

So, doing some more meditation. It's likely that this bike needs to be returned to it's stock configuration and I need to choose something else to convert. Not an easy task.

 

[Warren]

"I realized this week that this bike is a very good clone of the Bachetta Giro 20 - in fact, if you look closely at the two, you can see enough similarities to wonder if it's only the minor differences in frame construction that differentiate between the two."

Sorry but your bike has some very significant differences. The front wheel is much further back. This makes the wheelbase too short, and puts too much load on that small front wheel. If you get a chance, ride a modern medium wheelbase bike like the Bachetta, RANS, Volae, etc. You will be amazed at the difference.

 

[jkbrigman]

"I realized this week that this bike is a very good clone of the Bachetta Giro 20 - in fact, if you look closely at the two, you can see enough similarities to wonder if it's only the minor differences in frame construction that differentiate between the two."

Sorry but your bike has some very significant differences. The front wheel is much further back. This makes the wheelbase too short, and puts too much load on that small front wheel. If you get a chance, ride a modern medium wheelbase bike like the Bachetta, RANS, Volae, etc. You will be amazed at the difference.

Warren, the numbers do not support your contention. On the Bachetta Giro 20, the wheelbase is 47", per:
http://www.bacchettabikes.com/bikes/touring-commuting-bikes/giro-20
The precisely measured wheelbase, axle-to-axle, on my Bachetta clone is 46.5".

Below is a photo of the Bachetta Giro 20 I pulled off Google:



The image of the bike from the Bachetta website even shows the same brand of brakes, wheels and tires. The only differences I can see are in the seat and seat stays, driveline components and the handlebar assembly and the fact that the boom on my bike is adjustable, while on the Bachetta, it is not. My bike is over 5 years old and I'm comparing it to an image off the Bachetta website of a 2012 Giro 20. (In the image I have in this posting, that bike has disc brakes. The stock Giro 20 has V-brakes that are identical to mine.)

I do not mean to diminish the quality and value of the Bachetta Giro 20, which is off topic of this forum post. This thread is, if nothing, a tribute to the comfort and capability of the design. The most important point I'm making in this thread that my research has (sadly) revealed: a SWB recumbent with a 20" front wheel is too dangerous to mod into an ebike that runs at 30mph. I do not recommend this be done by anyone else in these forums and I plan to remove the components from this bicycle and put them on something else. I am in mourning about this and trying to get used to the idea of giving up this bike for commuting, because this recumbent is a thing of beauty: I biked 31 miles on it in jeans and street clothes in complete and absolute comfort. But I just can't recommend anyone else do this ebike conversion for safety reasons.

 

[jkbrigman]

only thing I can think of atm is fabrication. Perhaps a metal shop could build you something under there with padding and a nice secure door, welded to the frame or something to keep it from swinging. No where to really hang a pack under there without that problem. Ill have to grind my brain on this one. Watch for sharp corners! your calves with thank you when you come off the pedals for a stop or something.

K, you're right on that. The bike has bosses on the rear seat stays for something. I think you can buy pannier mounts that'll fit those bosses, but I would have to remove the rear rack to use them. More in a moment - I have news to report...

 

[jkbrigman]

I've got some exciting news to report: On a street recumbent with high pressure tires, you can go 30 miles, at speeds between 20 and 30mph, on 18S3P LiPo and still have plenty of juice left in the pack. On Friday, 30 March 2012, I did exactly that, completing a 62.5 mile commute with an 18S3P LiPo pack and a bulk charge halfway through.



This is an unstable bike, but the pannier improved stability perceptibly. Note to self: try putting the batteries in a pannier on the other side to see what that feels like.

I made it the first 31 miles in about 1hr, 45 minutes. I had a chain malfunction (it got jammed between the freewheel and the derailleur hanger) so I spent 20 minutes fixing that, but arrived at work only slightly delayed and none the worse for wear. Here's the view of the bike in the bike rack at work, after completing the 31 mile inbound leg of the trip:



On the trip back, I stopped at the convenience store from earlier photos in this thread and snapped another photo showing the sign with the current gas price as-of 30 March 2012. Compared to that earlier photo, the price digits on the LED display have flipped position: gas that was $3.79 only days ago is now $3.97 today. I'm not saying everyone needs to abandon their cars and ride with me, but I am saying that I sure enjoy not buying this gas today.



Final results of the ride:



Speeds:



Final Efficiency Numbers:

View attachment 3

I have already been asked: "Could I make the trip on this bike every day?" Well, I have to admit, the answer is NO. The average speed I made this trip in, about 20mph, is too slow. It takes too long to cover the distance. The bike is not as stable as I'd like (fixable) and the front wheel is too far back (not fixable) making me worried I'll hit something, cantilever over the bike and do a face plant at 30mph.

What next? I don't know. I absolutely hate to give up the recumbent - the comfort is impressive. I made this commute in street clothes with no chafing or discomfort whatsoever. That's the incredible benefit of a recumbent. But for an ebike to work on this route, I need just a little more average speed (closer to 30mph) and probably a suspended bike to manage that kind of speed safely.

But I am happy to finish this thread with the following conclusions:

1) An 18S3P LiPo provides enough power to travel 30 miles in moderately hilly terrain at an average speed of 20 miles per hour.
2) The experience of commuting to work on an ebike is amazing. Although the trip took roughly 2 hours each way, the recumbent was amazingly comfortable, even while pedaling in jeans!
3) Gasoline is seeing rapid rises in price, which make the economics of an ebike even more favorable. I "saved" over $10 on this experimental trip against the cost of the bike and parts.
4) The knowledge and support of the members of Endless Sphere forums were crucial in making this possible! I doubt I could have succeeded so much the first time out without the help of all you great forum buddies! Special thanks go out to Kin, veloman, cell_man, methods, dogman, neptronix, Kinni420, Alan B, DrkAngel, all who have responded in this thread and all who have patiently answered my endless questions!

No matter how you see it, this ebike has been a success, meeting the design criteria of the mission in every way.

 

[jkbrigman]

Four LiPo 6S bricks, in series, fit nicely in the "battery tote" shown in prior postings. Thought I'd try an experiment and see the "theoretical maximum speed" the wheel can turn on 24S, and also to see if the CA and 25A 6 FET IRFB controller can handle the juice. Here's the image of the CA while I'm letting the rear wheel spin off the ground on the kickstand:



Keep in mind that my LiPo hasn't been charged from the last use, the giant commute posted above. I wanted the voltage sag to protect the controller and CA. Results look promising! I know what my next test is gonna be!

Update Sunday Night: Took a short ride on 24S LiPo with the 9C 2810 and it was incredible. Big, big boost in performance and responsiveness! Nice push of the high-end speed from 31.7 to 35.6MPH. It was a rush, even if it was dangerous. Wonderful thing is that the Methods 6FET Infineon 25A controller can handle the voltage - at least the 91V the 24S of semi-discharged LiPo was producing at the time - I was afraid to go any closer to 100V, as that's well beyond the advertised rating of the controller.

Strange, strange observation, however: I was seeing usable regen and LOWER speeds with the higher voltage battery! The CA indicated -2% regen at only 14mph. I have no explanation for this.....

JKB

 

[Kinni420]

Hey James...sorry I havent gotten back to your question. The only time Ive seen heat was climbing that single-track last weekend. Id call it "warm" about 50C or so on all parts.

I fell yesterday and screwed myself pretty bad. probably a couple cracked ribs. pushing it for film doh. Ill survive...bikes fine...pretty low speed fall, just landed wrong. loving to see that kind of range!

aren't you running methods 40A controller? or do you have it set down to 25A?

supposed to rain here tomorrow...not looking forward to the commute in pain and wetness. Ill try to take some video lol.

p.s. not gonna post me crashing on vid lol.

 

[veloman]

This is what you need for 30mph commuting.
Oh, and thanks for the thanks! Glad I could help!

 

[Recumbent Bicycle Source]

There are a lot of generalizations here about recumbent bicycles based on a single bicycle experience (The one you own). There are a whole lot of flavors of recumbent bicycles. So the generalizations are not valid. I ride a SWB and have no difficulty looking behind me any more than when I'm on my mountain bike. Heel strike is only a problem on some models. Changing the front fork and steering (bars) can have dramatic effects on handling. So just like an upright or road bike or trike or ??? it's all about finding the bicycle that fits you and your riding style.

The advantage of crank forward semi recumbent is not efficiency it's rider position. The crank forward allows the rider to place both feet flat on the ground while still in the saddle. I find them more difficult to climb vs a diamond frame mountain bike, but very pleasant on the flats as long as there is not a lot of wind. I've ridden Day 6, Townie/Pure and they would make nice electric conversions, but are not as comfortable as a nicely fit recumbent. Back support makes riding much more enjoyable and relieves the pressure on the wrist.

Ultimately for comfort a tadpole trike with a headrest can't be beat, but it's scary enough in traffic on a SWB. People haven't seen a lot of them and tend to steer towards you out of curiosity.

Try riding some different bikes and find the one you like... it looks like you've got yours as dialed in as it's going to get. Might I suggest however a head/neck rest to improve the commuting experience. And a Bullhorn to shout at the idiots that are so glued to their cell phones they drive you off the side of the road without even realizing it.

Unfortunately there are not a lot of recumbent dealers in the USA and even fewer manufacturers. To compare a Taiwanese knock off to what is manufactured in Europe is to compare store brand cola to coke. It's just not the same stuff.

 

[jkbrigman]

This is what you need for 30mph commuting.
Oh, and thanks for the thanks! Glad I could help!

veloman - that is one of the sexiest machines I think I've ever seen. Add suspension to it and you'll cause me to drool all over my keyboard.
As for using that as an ebike, you are dead-right about that. And I do truly appreciate your input on this project - cool headed, experienced, just the kind of information I was looking for.

I don't want anyone to think I've "given up on a recumbent ebike", or that I think recumbents are bad for ebiking, or that I would compare my little korean klone to the almighty Bachetta as if they are the same bike. They might be the same general shape, but what I was using the Bachetta comparison for was to estimate if I was over the weight capacity of my own bike, that's all.

In my fantasy world, I'd be able to come up with a suspended version of exactly the bike you've posted. It would be able to hit 40mph, cruise at 30mph, and I'd be able to make the 30 mile commute in 1 hr flat, same time it takes with the car. I'd forget all about gasoline and just enjoy the ride....

Wow....

 

[veloman]

Keep an eye on this for sale section:
http://www.bentrideronline.com/messageboard/forumdisplay.php?f=5

Optima makes a couple suspended recumbents, the Cougar looks like a decent wheelbase. Not cheap though.


There are some rear suspension recumbents, but can't think of any on there at the moment that have a longer wheelbase. I think rear suspension on a recumbent would be a no brainer, especially for electric.

 

[jkbrigman]

Keep an eye on this for sale section:
http://www.bentrideronline.com/messageboard/forumdisplay.php?f=5

There are some rear suspension recumbents, but can't think of any on there at the moment that have a longer wheelbase. I think rear suspension on a recumbent would be a no brainer, especially for electric.

Thank you, will do! I've not bought a "replacement bike" for the recumbent, although I do have my sights on an upright. I think I could be accused of stalling....

I've found these websites and fallen in love:
http://sites.google.com/site/recycledrecumbents/home
This guy takes "junk bikes" and turns them into awesome recumbents.
I'm reading carefully to learn. He's not showing anything suspended, but I think that's just a detail....

And the Good Doctor has the ultimate recumbent medicine:
http://www.elmtreedental.com/AR%20Recumbent%2005.html
He's kicking butt and taking names...this would be my ultimate choice for electrification!

JKB

 

[Alan B]

There is a recumbent dealer not far from me here in Alameda that has a good reputation for helping folks with recumbent selection. He charges for his time but applies it as a discount towards a purchase. Unfortunately high end recumbents are pretty expensive, but with help from an expert and some test rides perhaps the correct model can be chosen. Perhaps a dealer like this one can be located near you. Of course finding one that is electric friendly is important, choosing the right bike must take into account the modifications it will need for epower.

Exploring an upright with dual suspension is a reasonable thing to try. The recumbent reigns supreme for all day riding and long range efficiency, but for a 30 mile commute a fully suspended upright should be adequately comfortable. Years of motorcycle experience in traffic is directly applicable to an upright and staying safe is the top challenge for commuting.

Having one of each is really nice. I enjoy both my ebikes, recumbent and hard-tail so far. Soon the double suspended Cromotored 'Borg will also live.

Best of luck in your search,

 

[www.recumbents.com]

A 20" front wheel is fine. I'd suggest just adding a front suspension fork. You can get them at the Hostel Shoppe. It will make a world of difference in how the bike feels "at speed", and safety in general. Also, change to the fattest tires you can get on the bike. And yes I do have lots of experience going fast on a wide range of recumbent bicycles. Something else I noticed about your bike is that it seems to be forward biased. Can you move the seat back and shorten the boom?

-Other Warren.

 

[chvidgov.bc.ca]

I really think this bike would be much better with the batteries on both sides under the seat, attached to a mid rack. I do this on my LWB Sun EZ-Sport, and it is a very meaningful improvement.

 

[chvidgov.bc.ca]

.

 

[jkbrigman]

I think you repeated yourself...