2-Wheeled Joy: Parts-Bin Bike Build (Part 2)

Part 2: The Build

It started here:

It all started here - I need to get better at taking "before" pics.

(This part is for youse guys who want the gritty details.)

The cranks, chain, and derailleur were gone by the time I bought the frame, so I came home with a bare frame.

A few days after the frame came home, I was given this Magna bike. A local bike shop had told the owner it was not worth repairing. The owner contacted me and asked if I'd like to haul it away before she threw it in the dumpster. How could I refuse a deal like that?

It needed tires, brake work, a rear axle, and a serious tune-up. But the wheels were straight, the tubes were thorn resistant, and nothing was rusty. Big score!

I've been wanting to build a single-speed mountain bike, a strandie, and a BMX cruiser. After looking at the Huffy frame and the free Magna, I started seeing the parts to build all three bikes in one.

Huffy + Magna = match made in heaven (or maybe in my junky garage.)

After a few hours of work, it turned into this:

No, chain, no rear freewheel, no rear brakes, but it looked cool.

A few days later I was able to gather up all the parts I needed except a single-speed chain. That came in the mail in two more days. Three hours later I had a completed bike.

On the maiden voyage I found three changes I needed to make it more comfortable:

• a longer cockpit
• taller bars
• a lower gear ratio

The handlebar tub yielded a pair of Honda motocross bars. The stem crate offered an old mountain bike quill stem. The seat tub held a laid-back seat post I didn't know I had.

Next I went to the oogle and found that the ideal gear ratio for a 26" single-speed cruiser bike is 55. I had no idea what that meant. I was expecting a ratio. For all I knew the number came from a huge supercomputer created by mice.

So I went back to the oogle and found the the magic formula:

I was running 71.5 gear-inches [(44T/16T)x26"]. My legs and lungs did not like it! So I started plugging in numbers based on my 26" wheels and the16-tooth freewheel.  I figured out that I needed a 34T chainring to get 55.25 gear-inches [(34/16)×26"]. Take that, Math!

(For reference, the Retrospec Sully runs 74.74 gear-inches, the Gravity Area 51 runs 52.0 gear-inches, and the State Klunker runs 52.5 gear-inches.)

In the gear tub I found a 3-gear chainring with a 34T chainring sitting right in the middle.

After a little drilling and grinding, I had a single 34 tooth chainring. It just needed a little paint.

I installed the chainring, shortened the chain, and headed north on a test ride. I determined that 55.25 GIR was the perfect gear ratio. I  smugly rode a few blocks further. Then I turned around and headed south. My smugness quickly slipped away as I rode headlong into a light breeze and remembered that home was slightly uphill.

What a difference one tooth makes!

Back home, I dived into the gear tub again and found a 17-tooth freewheel. [(34/17)x26"=52 gear-inches] It's amazing how much nicer the bike is at cruising the streets. Next, I plan to take it out to the mountain bike trails and see how the the old guy and the old bike handle the new ratio.

And the Wrap-Up

Since all that was written, the old Huff has turned into my daily rider for street and mountain bike trails. And I love this thing. I thought about adding some BMX tires for riding at a BMX park, but decided it's just right as is.

Hanging out at the house

Mountain biking in Rockwall

Lesson learned: single-speed bikes are great for simple-minded riders.

Mountain biking in Lubbock

Yes, I recommend it - a parts-bin bike is a great learning experience and (eventually) a great riding experience. I hope you find such joy on your 2-wheel projects!

Be well, friends!