Fork or single-sided wheel support on a tadpole???

[mrbechtel1]

I went to a local bike shop this past weekend to order some wheels for a tadpole I'm building. I really trust the bike builder there, and was disheartened when he cautioned me to rethink my choice of support for my front wheels.

The plan had been to use a heavy-duty BMX hub with a 14-15mm axle to support the front wheels, attached only on one side of the wheel. My builder said that it would work, but even with the extra axle thickness, it would likely bend and eventually fail fairly early on in my cruising. (I'm a slightly hefty guy...)

My options so far to fix this issue are:

1. To use a regular fork for each wheel. Just a normal fork and headtube to allow for even support on the wheel.
2. (Not sure this is possible, or too complicated) Use a regular fork for each wheel, but place the headtube (pivot point) on one side of the fork. I'm pretty sure this idea may get into steering issues I don't want to deal with on my first trike build.

Are these good options, or should I consider something else entirely?

And by the way, thank you for all the help so far. It has been invaluable!!!

 

[Popshot]

I'm 19 stone or 270lbs and 14mm BMX axled wheels will be fine. Many bike shops will never have seen a recumbent let alone made or ridden one and whilst their general bike knowledge may be ok their specialist knowledge may be lacking. Plenty of people have used 14mm axles without issue. I've even got 12mm axles on some trikes and they are fine too. The only option bigger than 14mm is 20mm. 15mm hubs do exist but 15mm bolts are rare. At 20mm you'll be building your own wheels though and 20mm bolts are very heavy.

 

[stormbird]

If you see ANY commercial trike with Sturmey Archer hub brakes they have a 12mm axle and do not have problems , mine run purely on 8.8 grade bolts and are fine.
I have also used BMX wheels with 14mm axles with no problems.

Not sure why you chose a tadpole ? delta trikes are much easier to build and don't have steering issues ?
Paul

 

[DannyC]

14mm or better axle and single sided will be fine.
My tadpole runs on 12mm single side axles.

 

[maddox]

My commercial trike runs on 15mm schafts.
Just a rod cut on lenght, and on each end a 20mm deep m8 hole.

You even can find 15mm/20mm silversteel or even case hardened shafts* in industrial enviroments.

*lineair motion shafts...

 

[DannyC]

10.9 and 12.9 hardness bolts are available in 12mm & 14mm.

 

[mrbechtel1]

If you see ANY commercial trike with Sturmey Archer hub brakes they have a 12mm axle and do not have problems , mine run purely on 8.8 grade bolts and are fine.
I have also used BMX wheels with 14mm axles with no problems.

Not sure why you chose a tadpole ? delta trikes are much easier to build and don't have steering issues ?
Paul

I chose a tadpole mainly because of the stability, but also like the aesthetic.

 

[stormbird]

I chose a tadpole mainly because of the stability,

A tadpole is no more stable than a delta IF they both have the same w/b , track and seat height.
For either trike the rider needs to sit as close as possible to the centre of the paired wheels , and all trikes can be unstable if ridden hard.

but also like the aesthetic.

A perfectly valid reason , you will have to build it and ride it so must start out happy with your choice,
Paul

 

[Popshot]

A tadpole is no more stable than a delta IF they both have the same w/b , track and seat height.

That applies if not moving or in a straight line. In a corner the cornering forces dictate otherwise. Also most deltas do not have the same w/b and often take advantage of the narrower track that can be adopted with no turning of the paired wheels. Getting between the paired wheels on a typical delta means very little weight over the front which is a long way away from the rear. A typical tadpole = good weight over the front and enough weight over the rear. There's no outside front wheel on a delta.