As I explore designing bikes with mismatched wheels, I have discovered certain issues that impede performance and reliability.
On the Orange Dream bike, the short chain line makes for unreliable shifting of the front derailleur.
The “Custom” (see previous projects), has a propensity to wheelie when a lot of force is applied to the pedal from a standing start, due to the short wheelbase where the rider’s weight is almost directly above the rear axle.
With most of my designs that sport a 20-inch rear wheel, high quality wheels, hubs, and freewheel are limited as I don’t build my own wheel sets. Instead, I rely on what can be found on existing 20-inch wheeled bikes. Usually kid’s bikes, cheap folding bikes and low-end BMX bikes I find at thrift stores and yard sales.
I know what you’re thinking; I need to learn to build wheels with components that are compatible and specific to my designs. But that just opens up the Pandora’s box of pricey elements for my designs. Spending money I don’t earn goes against my design philosophy.
Maybe someday, bikes like mine will be produced by companies with marketing departments that feel the consumer wants and shall have high-end componentry that puts them in a price point into the thousand$. That is so not me. So, instead of chasing the “small wheel in the rear” concept, I thought I would try something different but still the same.
How about a larger wheel up front with a more “normal” sized wheel on the rear?
I have found that affordable, quality rear wheels with sealed bearings and free hubs are plentiful starting in the 26-inch range. Couple that with a 29er front and voilà, my concept, scaled up.
I found a 29-inch front wheel with a 3.0-inch wide knobby at a local swap meet for 18 bucks. Widest tire I have so far but not a “fat” tire and not a fat rim. In fact, the hub is not sealed and of a normal width, so it must have been from a low-end 29er mtb.
I started to gather components to create a bike that would perform as well as any in my collection.
First hurdle was the fork. I could not find a 29er fork through my usual channels, so I had to make one. I selected a segmented crown that had the widest clearance between the vertical tubes, which I raided from a department store steel suspension fork.
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| Segmented crown freed from the suspension tubes |
I was ok with the relatively short, threaded steer tube. Next I had to come up with the extension arms and dropouts. I had two, near identical post-war seat posts that fit nicely inside the crown’s vertical tubes. Dropouts were cut from scrap stock.
Once the fork was fabricated, I was well on my way to “connecting the dots”. What followed was a geometry that seemed to fall into place as I easily solved each issue that arose.
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| Fabricated fork and truss rods |
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| Short Nishiki MTB frame |
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| Down tube extension from top tube scrap |
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| New head tube from large diameter EMT |
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| Zeroing in on head tube angle |
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| Raiding brake posts for the fork |
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| New sloping top tube for a comfortable stand-over height |
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| Test assembly to check angles and clearances |
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| A paper template was made to cut gussets from an old saw blade |
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| Gussets strengthen the head tube and covers the spliced down tube welds |
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| Ready for prep and paint |
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| Rattle-can Rustoleum Satin Nickle |
Maxxis Hookworm 29x2.5 in the front and 26x2.5 in the rear really make this bike look like it means business. The ride is smooth, stable, and efficient. The only real issue that I have not yet solved is the plus sized rear tire intruding into the chain line at the lowest gear combination.
The remedy is simple enough. I need to use a longer (wider) bottom bracket spindle, and find a high quality free-hub wheel. Then, I’ll rearrange the cogs and spacers of a 9-speed cassette, possibly editing out a gear or two closest to the spokes, making it a 7-speed with 9-speed spacing. I’m using friction thumbies, so indexing will not be an issue.
The ease in which this project came together, surprised me.
I now have a 29er...or half of one anyway.
