Hi-Efficiency Recumbent Commuter Conversion

[jkbrigman]

So wait...

I really think this bike would be much better with the batteries on both sides under the seat, attached to a mid rack, nice and low. I do this on my LWB Sun EZ-Sport, and it is a very meaningful improvement. As well as on my Rebike, a cheap CLWB 20/16. It feels way better than on the back rack.

OK, will do. Working on that battery situation. I think you will like what I come up with. About that Sun EZ-sport....

I just read through your bike list:

DevinciVancouver Front9CHybrid with DiskBrakes
Rebike 20"R/16"F Bent C404 Front 48V 20A Crystalyte Pedal First
CCM 26" Cruiser Nexus 7 C406Front 48V 35Amp Crystalyte Start Imm
Sun EZSport CX 26R/20F LWBBent C405 Front 48V 35Amp Crystalyte Start Imm
Giant Revive DX 20" Nexus 7 RearSusp with GearedBrushed Front 48V 800W ecrazy
Actionbent T1 trike with Rear9C BMSBatterySensorless 12MosfetUniversal
Toucan20 dogscooter GearedBrushed Front 48V 800W ecrazy

It reads like a "Who's Who" of electrified recumbent vehicles. Which one do you like the best?

Please Please tell me about that Sun EZSport CX? Does it ride comfortable, stable and efficiently??? What's your typical ebike ride with it and does it perform well? How's your Wh/mi?

 

[chvidgov.bc.ca]

I've got two others to add to the list now....Sun EZ1 Compact LWB recumbent 20/16 with mid-rack, and Bazooka Explorer steel folding bike 20" with Conhis front 1000W.

It's really hard to say which of my bikes is the favourite. It depends on the application. I really like the semi-recumbent Rebike, for general hacking around town with its big tractor seat, and the Giant Revive is a super comfortable urban ride as well, kind of scooterlike with a nice Nine-C on it. For mid-range comfort the small Sun EZ1 is excellent, with the mid-rack. In winter wet conditions here in Victoria, for urban commuting I often ride the big hybrid, with dual disk breaks, and the larger big Apple tires. Very safe in very wet conditions. For long range touring the long-wheelbase Sun Ez-Sport recumbent with the fairing is very good, also a dry ride. But ultimately, the trike rules. No question. It is AWESOME. You can load it up with gear and dual packs and go for the weekend, and it won't fall over. Cruises nicely with moderate pedalling in the high twenties. The folders are for the occasional trip to Arizona, for compact travel. I'm out of ideas, and I've pretty well got all the bikes I'll ever need so just riding these days, not building. The Dog-scooter is awesome, but it turned out to be illegal. I just ride it at night very occasionally. I've got a mix of rear and front hubbies, and generally like the fronts better, for the balance.
On the Suns, the mid-racks are very good for balance and handling, and leave the rear rack for gear. On the trike I've got the batteries down low, right under the seat, and that craft really feels planted. Since I'm so tall I've pretty well gone with apehangers on all the non-recumbent bikes, and extra long 400mm seatposts and stems on the smaller 20" bikes, so there was a lot of searching for those parts in bike recyclers around Victoria.

Too many ebikes - but I enjoy them all. I even enjoy my one non-motorized bike, a Raleigh twenty one-speed, with a full front fork replacement, new bottom bracket. and all alloy wheels, which just leaves the original frame and that's all. I guess I'm bike crazy.

The EZSport is a great bike - a nice strong chromolly frame, easy to electify, and pretty nice and standard parts on it. Again, with the mid-rack and the fairing, it is easy to carry two Ping packs right under the seat, and still have all your cargo capability. I've been averaging around 14 watt hours per mile on that one, which means you're good for around ninety miles on two 48V 15Ahr Pings, with a nice easy pedaling cadence. And the seat is very comfortable I've found - the same seat btw as is on the smaller EZ-1. If I had to choose between the EZ-Sport and the EZ1, I'd definitely go with the EZSport - it is a much better distance tourer, and can be found for not too much money - maybe 700 Cdn, in good condition. I got mine with the fairing for 700 which I thought was an excellent deal. I was surprised how dry the fairing keeps you in rain. The EZ-1 is perhaps a bit twitchy at speed and demands a lot more concentration - the EZSport is like floating on air. All of that steel, along with the seat, and BigApples makes for a totally cushy ride.

 

[Kirk]

You might be forced to go with a less expensive trike, like a Terra Trike to keep in budget but I found my Catrike Expedition to be just about the most efficient and quickest ways to get around. I use it a couple of times a month to commute 70 mile round trip thru Springfield IL and 108 mile round trip thru Peoria, IL. The traffic in both cities is pretty nuts but they see my trike just fine and give me plenty of room. I use Zippy 6s1p 8000mAh 30C packs in a 12s6p configuration, for a 48V 48 Ah battery, with a GM 48V 1000W motor laced into a DT/Swiss F630 DH rim. The cruising sweet spot on old Route 66 is 32.4 mph, 13.8 Wh/mile. I've thought about going to 72V 48 Ah but icecube and I kept running the numbers and 48 Volts is a bit more efficient. If you decide to change bikes, please keep recumbent trikes in mind. They look too low for traffic but people see them just fine.

 

[jkbrigman]

You might be forced to go with a less expensive trike, like a Terra Trike to keep in budget but I found my Catrike Expedition to be just about the most efficient and quickest ways to get around. I use it a couple of times a month to commute 70 mile round trip thru Springfield IL and 108 mile round trip thru Peoria, IL. The traffic in both cities is pretty nuts but they see my trike just fine and give me plenty of room. I use Zippy 6s1p 8000mAh 30C packs in a 12s6p configuration, for a 48V 48 Ah battery, with a GM 48V 1000W motor laced into a DT/Swiss F630 DH rim. The cruising sweet spot on old Route 66 is 32.4 mph, 13.8 Wh/mile. I've thought about going to 72V 48 Ah but icecube and I kept running the numbers and 48 Volts is a bit more efficient. If you decide to change bikes, please keep recumbent trikes in mind. They look too low for traffic but people see them just fine.

Kirk, thanks a ton for the data....your speed - Wh/mile number is incredible. I know that area (wife's family is from Mattoon, IL) and it's beautifully flat, but how much pedaling and how hard are you pedaling to get that number?

I've admired the simplicity of the low-end Terra Trikes and I've often looked at the low-end "Rover". It's an amazing value (sub-$1k) for what it is. Even the low-end one speed has front disc brakes! http://www.terratrike.com/rover.php I like the 8 speed enclosed hub/transmission (Shimano, but they don't say whether it's the Nexus or the Alfine), but it hampers being able to use a hub motor - I wish they put an 8 speed derailleur on their low-end trike instead of the enclosed hub. Roger wilco on the GM at 48V: You make me wonder if a mid-drive or could improve on those efficiency numbers.

You can add an external cassette to the Shimano Nexus hub using this:
http://www.ebay.com/itm/FH-1056-Shimano-8-9-Speed-Road-Bike-Free-Hub-Body-Rear-Hubs-New-/220988911670#vi-content

You talk about it being a commute: do you carry anything to/from on the trike? Laptop, clothes, briefcase?

 

[jkbrigman]

You might be forced to go with a less expensive trike, like a Terra Trike to keep in budget but I found my Catrike Expedition to be just about the most efficient and quickest ways to get around. I use it a couple of times a month to commute 70 mile round trip thru Springfield IL and 108 mile round trip thru Peoria, IL. The traffic in both cities is pretty nuts but they see my trike just fine and give me plenty of room. I use Zippy 6s1p 8000mAh 30C packs in a 12s6p configuration, for a 48V 48 Ah battery, with a GM 48V 1000W motor laced into a DT/Swiss F630 DH rim. The cruising sweet spot on old Route 66 is 32.4 mph, 13.8 Wh/mile. I've thought about going to 72V 48 Ah but icecube and I kept running the numbers and 48 Volts is a bit more efficient. If you decide to change bikes, please keep recumbent trikes in mind. They look too low for traffic but people see them just fine.

Kirk, I thought your comments were so good I cross-posted them to my "what is an efficient e-bike?" discussion. Your efficiency at 32.4mph is extremely impressive...

http://endless-sphere.com/forums/viewtopic.php?f=2&t=39174&p=576076#p576076

 

[swbluto]

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

Yeah, for sure, I wouldn't be using a 20inch bike to regularly travel on pothole-infested roads at 30 mph, even with suspension. I mostly use my recumbent for 15 mph riding, occasionally 20 mph on the more empty 25 mph roads (I religiously avoid the busy 30+ mph roads), and it has a rear suspension and 16" front wheel. Going slow enough given the road conditions and I don't have to worry about potholes as they're pretty easy to miss and it's pretty easy to brake quickly should I need to and the falls don't hurt nearly as bad if they happen. It seems most of my safety problems aren't related to potholes, rather, mainly bugs getting into my clothes.

If I was trying to design a recumbent bike for higher speed use, I'd probably go with a cruz-bike conversion on a dual-suspension 26" mountain bike. Most of the ordinary recumbents lack the suspension that I find necessary for higher speeds on the pothole infested roads around my city.

 

[1KW]

how would you build one of these now days...with the current tech out there?

 

[veloman]

I wish one of the dept store brands would build a suspended recumbent. Keep the frame the trash the rest.

I too agree that you need full suspension for an e-recumbent traveling over 20mph. I was popping spokes on my rear wheel (front wheel drive) Lightning hardtail recumbent. You can't unweight the bike when lying down.

I think you need to homebuild one if you don't want to spend big bucks on a manufactured one.

The cruz bike conversions - I wonder if the wheelbase is too short and will cause twitchy handling. Handling changes a lot when you are parallel to the ground, very sensitive.

 

[jkbrigman]

Hi veloman! Hi 1kw!

I still have plans to build a LWB recumbent ebike. I want to go with a lightweight, direct-drive rear hubmotor (like the little 9c that GrinTech sells now). I'm thinking somewhere around 500-1000 watts. I have no plans to convert a SWB in the future and I'll likely strip the frame of this SWB of it's parts and use them on the LWB bike.

The SWB had "torque steer" when you are pedaling hard. Not to mention it was twichy as hell, just like veloman said about short wheelbase bikes. I never fell over on a bike as much as that one - I fell over about a half-dozen times with it. I never fall over on my diamond frame bikes.

I hear you loud and clear about suspension, and that's the one thing that gives me pause. The frame I have that I want to use is not a suspension frame - there are some LWB 'bents out there with a beautiful rear shock and front fork shocks that look pretty nice. But I was going to simply try first with some slightly larger tires before i worry about suspension.

I've thought about a BBS-style chain drive on a recumbent. The nice thing about that is your wheels would remain stock, removable for flat repair. And it's a very lightweight drive system. But I think I'd keep it low power to prevent damage to the chain drive components.

 

[jkbrigman]

By the way, I found this link only a few months ago:
http://www.recumbentblog.com/2010/05/04/the-greenriders-fascinating-trip/

and their blog:
http://www.thegreenriders.blogspot.com/

also:
http://www.almanacnews.com/news/2010/04/21/two-aim-to-cross-country-on-electric-bikes

All links very old, no updates. I'd love to hear how they fared on their trip and if they still ride these bikes. Fine job outfitting their recumbent bikes with electric drive.