syaped

Hey guys I don't know jack about bike wheel axle setups, would it be feasible to replace the the axle with a long bolt of the same diameter and have all that extra bolt length sticking out one side and then attached to some wood (this is for a soapbox derby car type thing . Would the ball bearing setup still work?

HillRider

Threading on decent quality bicycle wheel hub axles is typically 9 mm x1.0 mm for front wheels and 10 mm x1.0mm for rear wheels. You would need fully threaded bolts to allow threading on the cones and locknuts to both sides of the hub and I suggest the highest strength bolts you can find. Even then I'm not sure how well this would work in supporting weight only from one side.

Kaze6

You can TRY. Go with high-grade bolts, which will be less likely to bend, and make sure the threading is the same so the bearing cones will work.

syaped

Hm right, hopefully I can find the same threading. Yeah I'm worried about the bolts being strong enough, I figured it's a cheap way to slap some wheels on a frame and see if it works though

CliffordK

I find bike axles are a pain. As HillRider suggests, metric sizes may be pretty typical threading. Standard sizes are 3/8 x 26tpi, I think which is a bicycle only size.

You can get mighty long bolt-on axles.
https://www.niagaracycle.com/cart.ph...=58574f264c83d (175mm). Probably longer ones too. You can install the axles off-center if you wish. But, as HillRider suggested, it may not be strong enough for a lot of use. Maybe one-time use?

How much do you wish to invest in the project?

A "Through Axle" could naturally be bolted on, and a 3/4" through axe would be plenty strong enough to support your rig.

Specialized also makes the "Lefty" which is similar to what you're looking for.

Depending on your weight and use, many kid trailers also have the wheels attached by one side. Mostly limited to about 100 pounds for 2 wheels, or about 200 pounds for 4 wheels. They generally have part of the frame and a Quick Release system. Does the frame have to be pine?

syaped

Hey Cliff,

I'm willing to invest time but not so much money haha, it's more of a see what I can put together with some broken bikes and a lot of scrap wood type thing. I'll see what kind of long axles you can get down here (New Zealand) but I'm not hopeful. The oldest kid that would be riding it is a scrawny 10yr old so hopefully it will be sturdy enough.

FBinNY 

Forgetting all issues relating to thread, since that be worked around, there's still a very serious issue of strength.

The axles used on bike wheels are designed to be supported at both ends with the wheel in the middle. They are woefully inadequate when supported at only one end, and will flex, bend and/or break under any load above a bare minimum.

They do make hubs designed to be supported on one side only, as used in wheelchairs and sulkies. Like pedals, which share similar design considerations, the mounting axle is beefed up considerably.

Jeff Wills

Bike hub axles are too small to be supported on just one side. You need something like a wheelchair or trike hub with a 12mm to 16mm diameter.

Even if it's a skinny kid, you don't want the wheels coming off (literally).

FBinNY 

Jeff,

You need to learn to type a bit faster. Two minutes off the mark doesn't cut it in today's fast paced world.

fb

coominya

Yes, redundant double post almost. mods to delete

HillRider

Naaah, just another example of "great minds.....".

ramzilla

Be safe & just remember your basic steel rules. When steel yields (bends) it's over. Gone. After yield point is reached it's just a matter of time before breaking point. (snap)(sometimes instantaneous). So, if you try this experiment & the axles immediately bend....... fuhgetaboudit. They're done. Be good. Have fun.

zze86

Grade 8 bolts are used in automotive applications where strength and toughness is desired. For a box car application I would think using rear wheels would be stronger (?)

nfmisso

Good bike axles (example Wheels Manufacturing) are SAE Grade 8 equivalent.

Consider mounting the wheels like a wheel barrow instead, supporting the axle on both sides. As many have note above, single sided axle support requires much beefier axles. Given you have a supply of broken bikes, use frame parts (front or rear forks) to support the axles on both sides, then a wood frame to tie the two cut up bike frames together.

coominya

Perhaps take a look at the wheelchair wheel designs they use in the para Olympics.

CliffordK

I was thinking of the typical cone & cup wheels.

But, some of the wheels you'll run across are sealed bearing. Even on cheap stuff. Those would be the easiest to replace the axle with a bolt of your choice. Simply pull the original axle and slip in the appropriate sized bolt in. Be careful not to tighten them down under lateral torque.

In some cases, people have successfully knocked out the original bearing cups, and installed aftermarket sealed cartridge bearings.

For my personal cargo trailers, I prefer wrap around two-sided support. It makes the wheel attachment much stronger with less flex.

While a little flex may not be the worst thing, proper alignment is critical for efficiency, and anything that would negatively impact alignment will also impact efficiency.

fietsbob

Well Soap Box derby car ' type thing ' is Not usable in the real Akron Ohio Soap Box Derby... Al competitors get the same Official wheels .

What frame construction do you intend to Build ? just drilling a Hole in a piece of wood is pretty Inadequate.

Jeff Wills

My mom's version of that was "two minds with hardly any thought at all".

She also claimed that the the family battlecry was "Charge It!". It's a wonder that I turned out functional. I ain't normal, no how, no way.

Dan Burkhart 

Many BMX wheels, even some of the cheaper ones, have 14mm axles with enough extra length to thread on stunt pegs. You may be able to shift the axle sideways enough to give you enough axle to side mount it.
Rear axles are longer than front, so you could swap rear axles into front hubs to give you more to work with.
There are side mount hubs with 12mm axles, so 14mm should be lots strong enough.

CliffordK

Reminds me of the "Breaking Away" movie. The protagonist was given a stock bike for one event... and spent a significant' amount of time "tuning" it

Reynolds 

FWIW, I used wheelchair hubs with 12mm axles on my homebuilt trailer and they worked OK with 50kg loads.

kevindsingleton 

Specialized has a mountain bike with only one fork leg. I don't know what they did for the axle, but it's definitely not supported on both sides. Also, many kid's bikes use axles that are long, and strong, enough to add those extenders on the outside for doing tricks.

https://www.google.com/search?q=spec...FZqXaxUnc4M%3A

dabac

Not saying its entirely impossible, but it'd be a rare feat.
I've done a couple of those, and always ended up tossing the hub into the lathe to ream the bearing seat out a bit.
Cup & cone tends to be the odd size 29.6 mm. Closest cartridge bearing I've found it 30.0 mm.

dabac

It's quite chunky, particularly at the base. At least twice the diameter of a regular axle.

kevindsingleton 

Might work for OP's needs, then? Disc brakes, too!