I recently ordered an inline child trailer (Weehoo model) which all told adds approximately 130 lbs to the back of my bike, and I myself weigh around 140 lbs.

The bike I own is a Cannondale F400 (2005). I'd post a picture, but I don't have URL privileges yet. I'm pretty sure it's made of some kind of aluminum, but I'm not 100% sure.

I live in a moderately hilly part of the Midwest USA, and so I want to add some oomph to my ride so that I can tackle the inclines better. The typical ride length I expect to do would be 3 to 5 miles.

My question is, which kind of e-bike conversion kit do you recommend? I was personally attracted to the Clean Republic Horizon 350W model front hub kit, due to its ease of installation and reportedly good support. But I'm having second thoughts because 350W might not be powerful enough (?) for the trailer in tow and also concerns about the probably aluminum fork.

Would my situation effectively limit me to a mid-drive solution, or to buying a new bike altogether in every case? I value reliability and ease of installation/maintenance the most, and of course safety.

I appreciate any wisdom and suggestions!

IMO, a mid-drive would be your best choice, but you chose correctly by not installing a low-power front motor. It's possible, but more problematic to consider a "big" front or rear hub motor. The front would require a steel fork and front or rear need torque arm(s).

You can use a magnet to find out if your front forks are steel, but I still wouldn't do front motor. A little more work and any risk is avoided is how I look at it.

I have several rear wheel motor kits and one mid drive kit. I use the mid motor (BBS02) to occasionally tow a light cloth trailer with a 35 pound grand kid. My problem is not feeling any weight behind me, so I need a mirror to make sure the trailer is still there. While my trailer/load is under 100 pounds, I'm heavier, so I suppose my cargo approaches 300 pounds too. At the same time, I tow at bike speeds, so it's not about having power. I could do it with a 500w hub motor.

However, if I were to build a bike for my son to tow my grand daughter, it would be a mid drive. A little more money, a little more work and it makes for a better bike.

I'd go with a Luna mid drive. I put one on my hybrid and it is pretty robust. Certainly enough to pull a trailer, which I may add this summer as well.

I'm with a rear hub, as the motor is pulling the trailer directly, then. There's no additional stress on the bike no matter how heavy the trailer, and it doesn't matter what gear you're in, the hub motor is always in the right gear to pull the trailer (such as a wheel dropping in a hole, or a sudden step/object to climb).

My Phillips Cleveland trailer, which i've modified with alloy leaf-spring suspension, now hitches directly to the 14mm rear axle (it clamped onto the chain-stay before, which got in the way of my foot/power-cable/disc..).