Front wheels and brakes

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The front wheels are the most important parts of the trike. These will determine the type of brakes, steering geometry, and trike dimensions.

 To mount the front wheels single sided, the axles on a adult trike should be at least 12mm thick. Standard front hubs have 9 or 10mm axles. It means we have to get hold of special wheels and hubs. Trailer hubs often have 12mm or 12.6mm axles when these are used single sided. Not all have spacers inside to keep the sealed bearings from getting pressed when you really tighten the axle bolt. Some do.
BMX wheels can be purchased with 14mm axles. Both these types basically means the trike will have rim brakes. Not as powerful as discs or high end drums, but very affordable and hassle free.


Plain hubs will mean the brakes have to be rim brakes. They won't have the stopping power of disc brakes. But they're cheap and hassle free. With good rims they will bring your trike to a halt. Calipers are the obvious choice. V-brakes are possible but I have not tried them yet.

 
 


Drum brake hubs are an option. Sturmey Archer sells single sided hubs, the X-SD. But these are pricey are often hard to get. RonB from the USA managed to order them here.

Some Sachs models can be modified to host 12mm bearings and axles. Like the VT 6000 was used on Greenspeed trikes. I don't know exactly what Greenspeed did to modify them.

I used a set of vintage Sachs Orbit VT drums. First I made a new back plate on them. Later with the centerpoint steering knuckles I could stick the two bolt that prevent the hub back plate from rotation directly into the knuckle itself. These hubs proved not to be ideal. They are too thin to use a spacer inside. You need to be careful tightening the bolt.

In fact cheaper Sachs hubs would have been better for there can have a bearing spacer inside.

Disc brakes are possible if you have the right hubs. And though I have not tried yet, V-brakes shouldn't be too difficult and cheap as well.

Both front wheels have a separate operated brake. A rear brake does not have the same stopping power unless a super fat grippy tire is used. It's only useful if the front brakes are linked and operated with a dual lever. But a parking brake on the rear wheel operated by a friction shifter is a good idea.    


The most common size used on tadpole trikes is 20x1.75 inch. The ETRTO size (European Tyre and Rim Technical Organization) is 406. Keep in mind 20 inch rims also come in 432,438,440 and 451 ETRTO. We prefer 406 for in this size there are more high performance tires available. BMX wheels are also 406 and some BMX tires are a good choice.
The trike can be build with 16, 17, 18 or bigger front wheels. I've made a trike with the smallest 16" size, ETRTO 305. Yes these are tiny.
Smaller wheels need more steering angle (axis inclination) or you'll end up with severe brake-steer. More on this later.

Building your own wheels is not very difficult. The first sets won't be perfect. But it's a pleasure to be able to use hubs and rims from different sources. It's also a fun job. Give it a try.

Update Sept 27 2013

I bought a 18mm drill bit to drill out the Sachs VT Orbit hubs. These large drills cost money. Mine was 40 Euro. If you don't plan to do future builds and have a set of hubs that need to be drilled out I suggest you have it done for you.

OK. With the 18mm hole I can now easily fit spacer tubes inside. I should be a huge difference on how much I can tighten the axle bolts. The length of the spacer tube is trail and error. Just file off some and try again for the best fit. The bearings should just touch it.