Standard bike wheel only fastened at one side possible?

Hello!

I'm building a tadpole trike at my Uni's workshop now and I have two identical standard 26" bike wheels.

On a regular bike the wheels are fastened at both the left and right side by the fork, but on my trike i want it to only be fastened at one side, like this velocar:

http://farm6.staticflickr.com/5446/6966556982_a3d551d85f_z.jpg

Is this possible without any modifications?

Most peeps turn to wheelchair parts, but if your bearing are the cup&cone type then the axle is only threaded rod. It could be just 10mm rod though, which is not particularly strong. I have no idea what chairs use, but it does look like a normal hub size from here.

Go to Atomic Zombie, they have plans that show the detail you need.

Or, look for some of the Cannondale "monofork" bike parts.
http://www.vintagecannondale.com/cannondale/headshok/Lefty/lefty_hub.jpg

Watt said:

I'm building a tadpole trike at my Uni's workshop now and I have two identical standard 26" bike wheels.

On a regular bike the wheels are fastened at both the left and right side by the fork, but on my trike i want it to only be fastened at one side, like this velocar:

http://farm6.staticflickr.com/5446/6966556982_a3d551d85f_z.jpg

Is this possible without any modifications?

Click to expand...

Short answer? No. You'll bend the axles.

If you use freestyle bike hubs with 14mm axles, that would probably do okay. And if you use 14mm axle freestyle hubs with sealed bearings, you can extract the axles and mount the wheels on 15mm stubs that you can weld right onto the trike frame.

Likewise, you can use mountain bike front hubs designed for 15mm or 20mm through-axles. Those would allow you the use of disc brakes.

Hillhater said:

Or, look for some of the Cannondale "monofork" bike parts.
http://www.vintagecannondale.com/cannondale/headshok/Lefty/lefty_hub.jpg

Click to expand...

That's a 'lefty'

I have heard the term monofork used for motorcycles, but in the uk we called that a lefty, as they are calling it in your link.

friendly1uk said:

...., but in the uk we called that a lefty, as they are calling it in your link.

Click to expand...

maybe, but Watt wont be able to call it that on both sides of his trike ! :lol:
.... If it looks like a duck, walks like a duck, and quacks like a duck,..then its a "Monofork" ! :wink:

There's a whole point that isn't being made. That Cannondale has a hefty hub, spindle and whatever you want to call that arm. To use the conventional 26" wheel's hub, you're going to use such an axle. Which MIGHT survive. But what about that arm the axle/spindle it's mounted to? That is probably the weak link in what you're trying to do. I'm not so sure your example is such small equipment.

Standard 10mm axles are not thick enough to use for trike purposes because of the high side loads. Custom mono-stay hubs are very expensive. Many people use the BMX hubs with the large 14mm axle bearings, and then make their own spindles.

-Warren.

I have been considering a DIY reverse trike too. There are some nice ones out there with a sculpted chassis made from layers of plywood.
I ran across this site that provides parts for building a qudracycle with PVC pipe. The americanspeedster.com steering components look like they could be adopted to a rev trike project and they require only bicycle hubs and axles. The disadvantage is that this steering hardware accepts only 16 inch wheels, limiting tire choices. You could possibly adapt some of the below pictured hardware to a couple of 26in forks so that you can use the big wheels. Definitely not as cool as using a couple of C'dale Lefties,

Here is another way to use bicycle wheels to steer a reverse trike.
http://www.atomiczombie.com/TriCruiser%20Winter%20Ready%20Tadpole%20Trike.aspx

Holy cow that is an appalling piece of engineering construction !

Yep. Just because you can does not necessarily mean you should.

Awww, come on, let them get it out of their system.

I didn't see any links to packrat workshop, which has built some trikes using full U-forks off of bikes for his tadpoles, so that he can use regular two-ended axles supported like they were designed to be. Might save you some money/time that way.

If you really wanna do single-ended axles, I'd definitely go wiht something heftier than regular 10mm bike axles/etc--they almost certainly will not handle what you will put them thru.

I have some 16" or 20" wheels off a baby stroller ("jogger stroller") that use a single-ended 10mm axle, but it's not intended to be used with an adult weight on there--just babies and such, and not any faster than someone might casually jog at. I was going to use them on my own tadpole project until I figured out what would happen to them if I did (and most likely at the worst moment, turning in traffic at a busy intersection).

Here are some links to the pack rat workshop. First is a photo page. Second link has plans. Scroll all the way to the bottom on the plan page for some scale drawings.
http://www.packratworkshop.com/trikmain.htm
http://www.packratworkshop.com/trike8.htm

Packrat build is the way I did mine.
It's a good build because it's strong (assuming you can weld fairly decently) and the front fork brakes are already there lining up perfectly with the wheels. Also donor bikes are usually pretty cheap.

I don't think the packrat build looks as nice however. Utahtrikes sells actual trike wheels for $120 if don't mind spending the the extra cash. I forget the diameter, but the ID bearing size matches perfectly with bolts you can buy from the hardware store.

Also I paid for atomiczombie plans and he recommends getting an extra thick bmx hub and welding to it. This build makes me nervous, and I feel farily certain a particularly aggressive ride will push those hubs to failure.

Also one last tip: snowboards make awesome tadpole seats. They are cheap (for a used one), light-weight, but also strong and you can screw bolts into the binding holes and weld the bolts to the frame.

having been confined to a wheelchair for over 20 years I can tell you any axle with a thread holding them to the frame will likely break..the strongest hub axle combo Ive used are holow titanium quick release axles, yet to even bend one, yet have broken many thicker threaded axles along withwheelchair frames ..the hubs and axles though aren't cheap my current wheels are 800 dollars a pair...

KiM

If you are going to have a rigid ( no suspension) front end ..there is much to be learned from GoKart stub axle/wheel mounting methods. Its been well proven for decades under crazy race abuse.
They can be had with a 15mm parallel stub axle, so just need bearings to suit.
Might want to consider a complete kart front chassis member ??

On a tadpole that I built from scratch, I used 20"bmx wheels 48 spoke with 14mm axles, threaded the axle in one direction as far as it would go to give maximum amount of threads to one side, made disk brake adapters out of aluminum, shcs 10-32 to hold it to the hub. I tried 26" 36 spoke wheels on another trike I built, but they would not take any side loading (hole in road turning corner) spokes popped.

Thanks for the overwhelming response! Great forum!

So, if I have understood correctly, the best thing to do is:

- Use 20" Wheels with 14mm axle if I want one side and cheap
- 26" could work, probably need a fork (both sides)
- Lefty/Monofork, sweetest solution but expensive


I think two regular bike forks will look to brutal in my trike-design (tested it on SketchUp), but perhaps this solution will work (added a SketchUp-picture as an attachment). Here the idea is to bend a 3-4 mm steel plate over as a one-sided fork. Do you think this solution will be hopelessly weak?

Probably going to end up with 14mm 20" wheels, but I have to 26" here for free, so maybe just try with them first..


Again, thanks for all the great response

Watt

Watt said:

the idea is to bend a 3-4 mm steel plate over as a one-sided fork. Do you think this solution will be hopelessly weak?..

Click to expand...

YES ! ..you will be wasting your effort and materials !
Even the "PVC" pipe device with that design used much thicker material ( 6+mm?) and on 16" wheels...(all of which make it stronger) .. but its still a poor engineering design.

Ok, probably just try with the 20" wheels then.

http://www.ebay.com/itm/BICYCLE-24-HOLLOW-HUB-WHEEL-144-SPOKES-CHROME-CRUISER-LOWRIDER-CHOPPER-TRIKE-/150695433322?pt=US_Wheels_Wheelsets&hash=item231625d46a


Would these work for free-spinning front wheels or are they meant to be fastened on a rear axle?

Said in another way: If i put a steel tube through that hollow hub and welded that tube to my steering mechanism, would it work?

Other than side-loading, it doens't matter much about the hub itself for what you want to do--it's all about the axle and the retention mechanism to keep the hub on the axle (i.e., not something that comes unscrewed in the same direction the wheel turns, if there is any chance at all the wheel could cause it to unscrew from friction/etc.).

The larger the hub's axle hole, the better, because you can use larger axles, which can support more weight.


One thing to remember is that you are not just supporting the actual weight of the vehicle. You must also support the weight *under vertical accelerations* as well, which means when you hit bumps or potholes, etc., the g-forces created effectively multiply those forces times the weight of the vehicle to create the forces on the axle. And in forward movement, then if you hit bumps that are large enough to cause any slowdown of hte vehicle, some of the forward momentum is also being converted itno forces against the axle, too, depnding on hte angle at which it hits.

When yo uhave a normal double ended axle, that load is spread across it without bending loads of the kind experienced by single ended axles, which get all the load at the point between the hub on the side where it's mounted, and the mounting point itself.



Side-loading...you'd have to look up how wheels are made and why, which is an oft-argued-about topic, with not a whole lot of scientific analysis posted on the web about exactly why certain things are done (just that some work, some don't, and some are disagreed about).

Side loading will also put loads on the axle, as well as the wheel itself--the larger the wheel diameter the higher the loads on the axle (just like the longer the prybar used, the greater the prying force on something is).