Road or Mountain Bike Conversion for Commuter

[adamc]

I am considering making a commuting bike by converting one of two bikes I already have. I have been reading a lot but wonder if it is time to get some personal experience input. My ride is about 22.5 miles and I have done it in 75 minutes on a Cannondale CAAD9 but it leaves me gassed when I get to work. I would like something that will allow me to do the commute faster and with less effort on my part although I am happy with pedal assist.

I am considering the 500 W or 750 W Bafang conversion kit and am looking to put it on my CAAD9 or a Specialized StumpJumper 29 that I have. The commute is all on streets.

Do you have suggestions for 500W vs 700W? Road conversion or MTB conversion? What is a good way to incorporate the electronic brake sensor into the road bikes integrated shifters if I went with the CAAD9? Battery size if I can recharge at work?

I know these are a lot of questions but any advice would be helpful.

Thanks.

Adam

 

[bowlofsalad]

I am considering making a commuting bike by converting one of two bikes I already have. I have been reading a lot but wonder if it is time to get some personal experience input. My ride is about 22.5 miles and I have done it in 75 minutes on a Cannondale CAAD9 but it leaves me gassed when I get to work. I would like something that will allow me to do the commute faster and with less effort on my part although I am happy with pedal assist.

I am considering the 500 W or 750 W Bafang conversion kit and am looking to put it on my CAAD9 or a Specialized StumpJumper 29 that I have. The commute is all on streets.

Do you have suggestions for 500W vs 700W? Road conversion or MTB conversion? What is a good way to incorporate the electronic brake sensor into the road bikes integrated shifters if I went with the CAAD9? Battery size if I can recharge at work?

I know these are a lot of questions but any advice would be helpful.

Thanks.

Adam

"Road conversion or MTB conversion?" Some might disagree, but in my opinion it is hands down the mountain bike. If I am looking at this correct, your mountain bike has front and rear suspension, combine that with wide tires and some level of flat protection and you'll have a pretty decent ride. I might suggest considering schwalbe big apple plus or schwalbe marathon plus tires. The wider the tire you can use, the better.

If you have your choice of either a bare hub or one pre-built, get the bare hub. If you don't know how to build wheels, you can either learn or find someone who will do it for you. Not breaking a spoke and being able to choose a wide strong rim is something that seems invaluable to me.

It's hard to give much other advice without being speculative, but http://www.ebies.ca/tools/simulator.html this might give you an idea on what sort of battery sizing might be ideal for you.

Personally, if I had no mountains to climb and was willing to pedal plenty, I would go with the 500w and probably use less than that (you can set power limits with something like a cycleanalyst, which is a tool I highly recommend).

 

[DanGT86]

I also vote for the mountain bike for durability, comfort, and ease of build. Roadbikes are great when you are the power source. They seem to lack comfort and durability in exchange for efficient rider position while pedaling. Under electric power you are going to increase your average speed so all of the potholes and bumps in the road will be even harder on the roadbike and your body than if it stayed human powered.

If you do end up converting the road bike the brakes can be converted using magnetic switches that install on the outside of the levers or you can put a small micro switch on the brakes at the wheel end instead of at the hand levers. The goal is to have a switch that detects movement of the brakes anywhere in the system. One of my bikes I just glued a switch to the lever itself so I can choose any combo of e-brake regular brake or both.

As for battery, most of my hub conversions get about 20wh/mile when I am riding at 20-25mph with little to no pedaling. I cruise at 20-25mph the whole time but with stops and intersections the avg speed usually comes out to 17ish mph and 20 wh/mile. So 20wh/mile X 22.5 miles=450 watt hours. I would look for at least 500-600 watt hours to be safe. This is a little harder to predict without testing your own personal situation. Slowing down a few miles per hour and pedaling can make a huge change in energy consumption. I would suspect a crank drive would be more efficient than my hubs especially with pedal assist instead of being lazy with a twist throttle.

When it comes to battery shopping round up to be on the safe side. Having too much battery means you wont have to overcharge and overdischarge it in regular use. Using the middle of the battery prolongs cycle life and requires less attention from the user because batteries stay balanced better in the middle of their range.