Trail Reaper: CB175-Powered Honda Mini Trail

Trail Reaper CT70

CB175-powered CT70 built by a team of Wisconsin high-schoolers!

The Honda CT70 — aka Trail 70 — hit the US market in 1969, a dual-purpose minibike with a 72cc four-stroke engine and three-speed semiautomatic transmission. The bike was a huge success for Honda, outperforming the lower-quality pull-start minibikes from Sears, Rupp, and Ward, while finding its way onto farms and ranches throughout middle America:

“Growing up in the 70’s every little boy who grew-up on, went to, or had a friend on a farm knew someone who had a Trail 70. In fact, ask a Biker age 45 to 65 what the first motorcycle he ever rode was, and, he will probably say, ‘Trail 70.'” —Trail70.com

The $395 Trail 70 could be registered for street use, and in stock trim, was capable of 45 mph…depending on rider size! The mighty mini would remain in production for the US market until 1982, with a short reintroduction stint in the early 1990s. Today, the CT70 remains one of the most beloved motorbikes of all time, though many owners have found the stock 4-5 hp wanting.  The orthodox solution is to mount a Chinese-made Lifan or Predator engine, which make marginally more power, but there are those builders with more creative solutions…

Trail Reaper CT70

Enter our new friends at Oak Creek Racing Knights, made up of students and adult mentors from Oak Creek High School just outside Milwaukee, Wisconsin. The Knights Racing team is a part of the larger Milwaukee-based program BUILD Moto:

“Founded by ​The Iron Horse Hotel ​​in 2011, BUILD is a non-profit educational organization dedicated to pairing teams of high school students with bike-building mentors in a collective effort to learn valuable life and interpersonal skills while working on motorcycles.”

During the six-month BUILD season, the program provides each team a Royal Enfield chassis, engine, and set of core components for them to build and customize with the end goal of racing the bike in one or more AMA motorcycle races. Sounds pretty incredible, right? It is, but the season lasts only from January to June. Says Knights Racing mentor Chad Hanebrink, aka Mr. H., who grew up riding a Honda 70 himself:

“We here at Knights Racing usually take things a bit further though, as the BUILD season is roughly only six months. What about the other six?”

Trail Reaper CT70

That’s where builds like the “Trail Reaper” you see here comes in. Chad says it was one of those “what have we got lying around to work with” projects, which included a ’71 CT70 frame and ’71 CB175 engine — a match made in heaven:

“The Trail Reaper is a 1971 Honda CT70 ‘Minitrail 70’ frame with a 1971 Honda CB175 motor shoehorned into it, more than tripling the original motor’s horsepower. Not bad for two seniors, two juniors, and two sophomores right?”

Not bad indeed! The CB175 engine is a SOHC parallel-twin rated at 20 horsepower, capable of propelling the original bike to 86 mph. This twin-cylinder 20-hp Mini Trail now sports a set of clip-on handlebars, a front disc brake conversion, and a custom seat with a hole left for fuel tank access, which doubles as a 12 oz. Mountain Dew holder! The bike’s nickname came from the team’s other mentor, Steve Agg, who’s been playing with motorcycles for more than four decades:

“The Honda CT70 was always known as the Minitrail, but with this new motor, it isn’t so ‘mini’ anymore.”

Trail Reaper CT70

Amen. When asked what part of the build makes him proudest, mentor Chad Hanebrink points not to any one technical point of the project, but the people behind it:

“Yeah, the team. These kids knocked it out of the park. They showed up every night ready to work and dedicated themselves to getting the bike done on time.”

Now, the Oak Creek Racing Knights have taken on their most ambitious project yet, a turbocharged Honda CB350 with which the team hopes to set a new land speed record:

“We want our kids to go into the record books with a bike that they built, but we need your help. Going fast, as simple as that may seem, is not cheap. We need help getting to 121 MPH!”

Oak Creek Knights Racing
Oak Creek Knights Racing
If you’re interested in motorcycles and our nation’s youth, it would be hard to think of a better cause to support. Please consider donating to the Knights Racing Land Speed Record Attempt — we did!

Below, we get more details on the Trail Reaper!

CB175-Powered Honda CT70: Builder Interview

Trail Reaper CT70

• Please tell us a bit about yourself and your history with motorcycles.

My name is Chad Hanebrink, but my students call me Mr. H. I have been tinkering with motorcycles since I was 10, so a little over 20 years now. It started off on a little Honda 70 just like the one we are discussing today. My co-mentor on this project is Steve Agg.

My name is Steve Agg. I have been playing with motorcycles for close to 40 years, like most kids I started with dirt bikes and I have owned most of the brands at some point. The current fleet is a 2009 Harley Road Glide, 1979 Harley Super Glide, 1973 CB750. I enjoy sharing my passion with the students.

Trail Reaper CT70

• Can you tell us about the Oak Creek Racing Knights, the history and purpose of the team?

The Oak Creek Racing Knights (or Knights Racing) is a subset of a larger Milwaukee-based program called BUILD Moto (www.buildmoto.com) that is a non-profit educational organization dedicated to pairing teams of high school students with bike-building mentors in a collective effort to learn valuable life and interpersonal skills while working on motorcycles.

During a BUILD season, from January to June, each participating team of high schoolers will be given a Royal Enfield motorcycle by BUILD to be worked on, along with mentors, in the team’s designated space with the end goal of racing the bike in one or more AMA motorcycle races. The BUILD program provides the chassis, working motor, and core components of the bike for the team to complete building with a few items of customization including the look and design of the bike.

We here at Knights Racing usually take things a bit further though, as the BUILD season is roughly only six months. What about the other six? That’s where specialty projects like the Trail Reaper or our current project (a turbocharged Honda CB350 land speed record bike) come in to play.

Oak Creek Racing Knights

• What’s the make, model, and year of the bike?

The Trail Reaper is a 1971 Honda CT70 “Minitrail 70” frame with a 1971 Honda CB175 motor shoehorned into it, more than tripling the original motor’s horsepower. Not bad for two seniors, two juniors, and two sophomores right?

• What was the design concept and what influenced the build?

There have been a few projects similar to ours done in the past, but ours was mostly a “What do we have laying around that we can work with?” type of project.

• What custom work was done to the bike?

Well, firstly the addition of a CB175 motor is usually what people notice first. This required some extensive frame modification and custom bracketry in order for the frame to accept the engine. The front end is also a pretty cool feature. Thanks to Ron over at Trail Buddy Inc (www.mytrailbuddystore.com), we were able to convert our front end over to a disc brake setup and put some clip-on bars on. The goal was to try to get as much weight over the front end because we had no idea how wheelie-happy this thing would be. The seat is also a custom piece we made in house. We used a CNC router to cut out the base then had a local guy upholster it for us. We left a little hole in the seat for easy gas tank access, and it just so happens to hold a 12oz can of Mountain Dew perfectly, so it doubles as a cup holder.

Trail Reaper CT70

• What’s the story behind the bike’s nickname?

Steve Agg actually came up with the name. The Honda CT70 was always known as the Minitrail, but with this new motor, it isn’t so “mini” anymore.

• Can you tell us what it’s like to ride the finished bike?

Well, I can’t say it’s the most comfortable thing in the world, being 6’3” and all, my knees usually end up being wider than the handlebar ends when I get on it. It rides fairly smooth though and it surprisingly doesn’t want to pull the front end up, but that also might be the tall gearing we threw on there. Honestly, I don’t think anyone has been brave enough to put it into third yet. That much power on such a short wheelbase is a little bit intimidating.

Trail Reaper CT70

• Was there anything done during this build that you are particularly proud of?

Yeah, the team. These kids knocked it out of the park. They showed up every night ready to work and dedicated themselves to getting the bike done on time.

• Please list any sponsors, mentors, or people you’d like to thank.

Trail Buddy Inc, Lil’ Bikes Restoration, Ride Alive Motorcycle Academy, Gallamore Homes Real Estate, Sophia Branen for all of her wonderful pictures and insight, and WisCoat for the beautiful powdercoat.

Follow the Builder

You can find us on Instagram and Facebook or, if you’d like to support us in our land speed record attempt, head over to our Classmunity fundraising site at www.classmunity.com/ocfsd.

If you’re interested in motorcycles and our nation’s youth, it would be hard to think of a better cause to support. Please consider donating to the Knights Racing Land Speed Record Attempt — we did!

More BUILD Teams

 

3 Comments

  1. Fantastic job fella’s , great work not only with what you’ve done to the bike but getting youngsters to have a passion about our collective interest , keep it up .

  2. Good on you guys, obviously having great fun. Motorcycling is safe and well with gentlemen (and ladies) like you promoting it to a younger generation.
    I look forward to your next project.

  3. Super nice project that has a pretty subdued appearance for what it is. This should win some awards at shows.

    Definitely need someone smaller than Mr. 6’3″ to really wring the thing out.

    The 20hp is a factory spec, and the 86mph is likely also a gearing-based top speed. I’m a stickler for the figures for smaller bikes, as they don’t widely vary, and the numbers are highly indicative of what the thing really rides like. 86mph is just not what you would see from such a bike in the real world. The original speedos are optimistic, and rider weight, size, and aero make big differences. 80mph is more the reality with charitable wind conditions. And that’s for the original CB175. This CT70 doesn’t have favorable running gear to get to those speeds even if it has the engine. Thinking this thing would be wheelie prone is silly, those small displacement twins put out very little torque.

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