Schwinn 2011 model Coffee conversion

[happycow]

Hello,

I have been doing a fair amount of research on Ebikes. I even went as far as renting one to see if I liked the way they handled on my last trip to San Francisco from a place called PLUGZ. I loved it!! now I am interested in converting if I can my commuter bike so my questions are the following.

I have a 2011 Schwinn Coffee which is sort of a retro newish model of their popular collegiate models from the past. It is a 3 speed with an internal hub now here is where I have too ask all models I have seen come with 7 gears if not more is this necessary? Now I am somewhat mechanically inclined but not a garage head either I want too buy maybe a 500W or 750W rear tire conversion kit. So I want this to be as easy as possible. Is this possible with this type of bike? Or do I need to get a bike that comes with multiple gears, deraileur, and 3 speed crankshaft?

Also keep in mind that I don't want to be evil knivel on this thing but if I can get 25 mph and a min of say 25-30 miles I am golden.
I was also curious is there a way I can perhaps add a sort of banana seat on to it so that I can have the option of giving my GF a ride on it. I figure since it isn't a hot rod bike it would be safe. Please if any of the experts can advice...

 

[melodious]

Also keep in mind that I don't want to be evil knivel on this thing but if I can get 25 mph and a min of say 25-30 miles I am golden.
I was also curious is there a way I can perhaps add a sort of banana seat on to it so that I can have the option of giving my GF a ride on it. I figure since it isn't a hot rod bike it would be safe. Please if any of the experts can advice...

That last paragraph is just begging for an electric cargo bike. 1st on the list is http://ebikes.ca/store/store_edgerunner.php and you won't get any disagreements for this choice from members here. The THUN torque sensor seems to be the way to go for pedal assist (its optional).

2nd on the list is http://www.juicedriders.com/. More affordable on the wallet too.

If your the Do It Yourself type and like to learn as you go, there are kits available that can do the trick as well given the proper frame. I think we are nearing a crossroads where DIY is not as practical (nor as pretty) as these "store" bikes.

You need to provide more info about where you live so others can chime in on who or what's available near you.

 

[dogman dan]

Given that the bike has a three speed rear hub, you might start considering using a front hub motor on it. Front hubs are probelmatic on bikes with shocks, but I assume yours has a steel fork. It should be fairly easy to put a front hub on it. You will want to use C washers from Grin Cyclery with a front hub, and a torque arm.

Your requirements are pretty easy to fill with a typical direct drive hubmotor, and a 48v 15 ah battery, or a 36v 20 ah battery. 48v will be a bit faster, but if you ride about 20 mph, either battery will take you 25 miles easily. 30 miles will require slower riding, 15-18 mph. A bigger battery is too cumbersome to carry, unless it's a cargo bike. So stick to big, but not too big.

I'd say if riding the GF is a priority, find an old tandem bike, or get the longtail in the pic above. Get something built for the extra weight. It will be sketchy if you put her on a rear rack on your bike, you aren't sub 100 pound kids anymore.

 

[melodious]

Oh wow, I'm sorry. I didn't realize you have the bike already. My bad...

As far as the usefulness of the 3speed hub, unless your in big hill territory where you need the lower gear ratio, the combination of pedal assist (even throttle positioning) with your own pedal input would get you through most paths robustly. The higher speed gear ratios on the other hand may be an issue if your shooting to go above 20mph. Even my 8 speed IGH shimano with stock crank setup on my commuter rounds about the low 20s mph. Maybe more if I were to up the front gear. My LBS sells the Nuvinci drive system and they have a poster of the various amount of gear ratios the current generation of IGH offer. Nuvinci's own was 360% (hence the "360 Nuvinci" name), the most I saw was 500+% (515%?) from Rohloff's speed hub, while shimano's 8 & 9 IGHs fell inbetween those two.

found it: http://www.nuvinci.com/Docs/GearInchChart_N360.pdf

 

[geeeyejo1]

The Coffee is a cool retro looking Schwinn - with it's steel frame and fork should be suitable for a conversion. I would go the front geared or gearless hub route - you might have to choose between a higher speed winding to reach your speed goal or a lower speed/higher torque winding if you wish to have your girl friend hitch a ride (alot depends upon both of your weights too). Should be no reason you can't pick up a large sissy bar and banana seat on Ebay to fit to this bike(I did to build an adult sir Schwinn "Stingray" as one of my earlier regular bike projects). The triangle opening on your frame could easily accommodate a Falcon EV frame bag to carry your battery.

 

[spinningmagnets]

This one?

 

[amberwolf]

I expect that you could probably spread the dropouts enough on that frame to use a front hubmotor with a singlespeed freewheel added to it, like I did here:
http://www.endless-sphere.com/forums/viewtopic.php?f=30&t=37837

You could also use some of the rear motors the same way, with a bit of careful filing-back (or machining) of the axle "shelf" on the freewheel side.




FWIW, that bike can do 20MPH for at least 30 miles, and probably 40 if I didn't have to stop for traffic controls, with 16s (66V hot) 20Ah (~16-17 usable with my chosen HVC/LVC) RC-LiPo-like pack, and an 80A controller, on a 20" wheel. I can still reach 25MPH if I need to, probably 30 but not quickly or for long, but it's not meant to, as 20MPH is max legal here anyway--the extra speed is just for gettin' the heck outta the way of ohter vehicles in traffic if I have to. On a 26" wheel, same motor, it'll go faster but it has a bit less range in traffic cuz it takes more power for a longer time to get started from the frequent stops.


But you could do it with a 40A 12FET controller, maybe even a 20A or 30A, mabye even a 6FET if you don't mind pokey acceleration or if you intend to pedal significantly for startups from a stop to get faster accelration.

Battery, as long as you have at least a "48V" (58-60V hot) 20Ah pack it'd almost certainly have 20 mile range at 25MPH, especially if you're going to pedal.

Might want a bigger chainring up front if you wanna pedal along with the motor at that speed, though.