Wheel bearing help
 

I'm about to start a build of 1st recumbent. I bought a set of 20" wheels that have 20 MM hub bores. In looking for bearings for these, I'm confused as to weather these should use bearings. The ones I can find so far use a 9MM axel. Is this strong enough for a front wheel on a recumbent being only supported on one side? What would you recommend? Guide me please.
Thanks
Aaron

I have zero experience building a trike but know from having replaced wheel bearings that the major trike manufacturers use sealed roller bearings. On my Greenspeed trike there are two bearings on each side, an inner bearing and an outer bearing both press fitted into the hub. The opening in the center of the bearing for the GS GTO is 11.5 mm and outer is 28 mm (6001RS). It's not hard to find a bearing that will fit your hub https://www.vxb.com/SMR699-ZZ-Bore-D.../smr699-zz.htm It.s the same company I bought my bearings from years ago.

Whether or not a 9mm axle is strong enough for a trike is another question. I don't know. There are lots of things that go into making a steering system that will be stable. The major manufacturers mostly have gotten it right. You need to connect both wheels together and be able to set the toe-in on the front wheels. If it is wrong, the trike will handle poorly and you will wear through tires at a rapid clip. It only took 300 miles when my GS GTO was not set correctly after changing out the bearings.

There is a major recumbent bike site that has a section on homebuilding. Try googling on "recumbent bike message boards" and you should be able to find it. Someone there may be more qualified to answer your questions.

Thanks.
I found it and the answer is 12MM min.
Aaron

Long ago and far away I built recumbent trikes using moped hubs on the front wheels. They had 12mm diameter threaded axles. They broke after a some hard riding, after which we converted them to straight bolts and cartridge bearings. They held up after that.

Nowadays you can get mountain-bike hubs that can accept a 20mm diameter axle and disk brakes. These are more than adequate for a recumbent trike.

Me in 1982-ish:

https://cimg1.ibsrv.net/gimg/bikefor...e6ffda9880.jpg

I would go ahead with the wheel bearing. It could last that long or it could go out tomorrow and leave you stranded. You do not need to do an alignment after the wheel bearing, wait to have that checked when you get your new tires.