Looking to electrify a new 2015 Jamis Coda Elite

[regmem]

Hi,

I am first timer at ES forums. I recently started biking to work. My commute is mostly a bike trail ( tarmac ) but with some road biking too.

My approximate route is as below

My total one way cycling is 15 miles. Bike and bus commute has started becoming painful and annoying. And now since I recently upgraded from a K2 Astral 1.0 to 2015 Jamis Coda Elite in a fantastic deal,
I was looking to some how avoid taking bus altogether and just biking both ways to work so details here

Total Commute - 30 miles
Trail Type - As shown above in picture, mix of very gentle slopes uphill and downhill
Bike type - Hybrid bike, Steel Frame; 2015 Jamis Coda Elite
Looks - I like the Samsung dolphin battery installed on down rod look, but I am open to better alternative.
Riding Style - I like to have a little workout, so I am looking assisted riding, instead of full motorized.

What kind of kit is suitable for my commute and bike type ?

Welcome all inputs/suggestions/thoughts.

Thanks

 

[Russell]

Since your new bike has a carbon fork that rules out a front motor so a rear motor it'll have to be. If you want to retain the 9 speed drivetrain you'll either have shim out a freewheel equipped motor or buy a cassette rear motor. There aren't many full kits available with cassette motors so you'll probably want to piece something together.

To retain the most "bike-like" quality I would suggest a small geared motor. I haven't tried this model yet but it looks like it would suit you;

http://www.aliexpress.com/item/36V-48V-250W-High-Speed-Brushless-Gear-Hub-Cassette-Motor-E-bike-Cassette-Motor-Rear-Wheel/1888675185.html

A downtube battery is nice to have but it does mean you need to find somewhere else to mount a water bottle cage. It can be a simple annoyance or a big problem depending on your need to drink.

The convenient and stealthy way to carry a battery is in one of Topeak's MTX rear bags that slide off.

(Take a look at my Gravity and Jeep bike builds in my signature for some ideas.)

-R

 

[fesanand]

I agree with Russell about the motor and battery, but I would mount the motor in the front if you don't want to mess with gears and so. Despite your front fork is carbon you have disc mount and eyelet for mudguards, it gives you the chance to mount double torquearms:
a beefy one in the disc brake mount as Kepler did in his carbon frame: http://endless-sphere.com/forums/viewtopic.php?f=6&t=47139&start=125
and a regular one in the other side.

 

[regmem]

Would a mid drive unit work with this bike, something like a Bafang 8fun 350w with 36v 11ah battery

 

[Russell]

Would a mid drive unit work with this bike, something like a Bafang 8fun 350w with 36v 11ah battery

I was going to use one myself on my last build however the very wide Q-factor (1 person measured 188mm) and right side crank offset (16mm) make it unattractive to me. Also the chainline of around 50mm may not allow you to use your lowest gear of your 9 speed rear cassette. This last issue can be helped by using an aftermarket replacement chainwheel or adapter that moves the front chainwheel in a few millimeters. If you can live with these issues then yes it would be a good solution for you.

-R

 

[regmem]

Would a mid drive unit work with this bike, something like a Bafang 8fun 350w with 36v 11ah battery

I was going to use one myself on my last build however the very wide Q-factor and right side crank offset make it unattractive to me. Also the chainline of around 50mm may not allow you to use your lowest gear of your 9 speed rear cassette. This last issue can be helped by using an aftermarket replacement chainwheel or adapter that moves the front chainwheel in a few millimeters. If you can live with these issues then yes it would be a good solution for you.

-R

I am not sure I understand it correctly the part about gear, chainline and aftermarket chainwheel. I am still new to bicycle maintenance.

And to clarify, if I install Bafang 8Fun 350, and if I install the 44T chainwheel, would I not be able to use my current rear deraileur ?

Some pics / diagrams would help tremendously.

Thanks

[Update] I am reading up http://sheldonbrown.com/chainline.html

 

[Russell]

The chainwheel on the Bafang mid-drive is spaced out about 50mm from the centerline of the bike. The ideal chainline for a 1x9 setup to use all of the rear cogs would be for the front chainring to line up dead center to the rear cassette. Depending on whether the rear wheel is spaced 130 or 135mm this ideal alignment would be about 42-45mm. Since the Bafang front ring is out further the chain has to skew more to reach the biggest cog. Depending on your bike this could result in the chain failing to stay on that largest cog or it just may run noisy due to the severe chain angle. There are aftermarket rings and adapters which move the chainline closer to ideal.

The other reason to go to an aftermarket ring or adapter is that they allow smaller than stock front chainwheels. A smaller ring can be desirable for 700C/29" bikes, mountain bikes which will actually be used off-road and those cyclists who prefer a high cadence.



-R

 

[Russell]

And to clarify, if I install Bafang 8Fun 350, and if I install the 44T chainwheel, would I not be able to use my current rear deraileur ?
]

Yes it will work though as I stated above you may have trouble with the largest rear cog with the standard Bafang ring. And if you're a perfectionist you'll want to remove a few links from the chain since you won't be using the "big" 48T ring on the Coda anymore.

-R