[email protected] wrote:
> Peter Cole wrote:
>
>>Lorenzo L. Love wrote:
>>
>>>On Wed, 18 Jan 2006 11:24:52 -0800, <[email protected]> wrote:
>>>
>>>
>>>>[email protected] wrote:
>>>>
>>>>
>>>>>A while ago I built my third trailer, made without welding. And this
>>>>>time I did a full photo documentation as I went along:
>>>>>
>>>>>http://drumbent.com/trailer_big.html
>>>>>
>>>>>Cheers,
>>>>>Mark
>>>>
>>>>
>>>>Nice.
>>>>
>>>>I am contemplating building a single wheel trailer (similar to a BOB)
>>>>for carrying children. I don't like the wide unwieldy feel of a 2-wheel
>>>>trailer with such valuable cargo.
>>>>
>>>>Anyone have any suggestions or tips?
>>>>
>>>>Joseph
>>>>
>>>
>>>Don't. One wheel trailers are excellent for light cargo but any
>>>movement in the trailer will be transmitted to the bike. I used to use
>>>a BOB Coz and now use a BOB Yak and then I take my cat to the vet in a
>>>carrier in the trailer her movement can be felt significantly. A child
>>>doing what a child does could knock your bike around to a dangerous
>>>extent. Two wheel trailers are more unwieldy, but more stable for live
>>>cargo.
>>>
>>
>>I don't know about that. I pulled a child for 5 years with a
>>trailer-bike, and have used a BOB Coz for several years also. Most of my
>>riding with them was/is on single-track off-road. 2-wheel trailers want
>>to tip, 1-wheelers don't, since they lean in the turns. The downside is
>>you'll feel the cargo shift since the trailer is free to flop, but I
>>never found it dangerous from a control POV.
>
>
> Most of my riding with the kids will also be on single-track. I was
> figuring on a secure 5-point belt and NASCAR-type webbing to keep the
> arms inside. The seating would be low with the kid's rump about 10" off
> the ground. Given that the kid will be only able to move the head and
> arms and within the width constraints of the narrow cage, and being so
> low, I don't see how they could affect the balance that much.
>
> Crashing would be a bad thing, but with a single wheel trailer we can
> ride where our only hazards are trees, vs being stuck on roads (lightly
> travelled dirts ones) with a wide trailer where we risk getting mowed
> down.
>
> Joseph
>
Practically speaking, if you're going on single-track, one-wheeled
trailers are the only way to go. That said, given the bumpy ride, the
"window" for a trailer might only be between ages 2-4 (earliest for
off-road trailer to earliest for trailer-bike), so I don't know whether
it's worth the effort.
I pulled my daughter from age 4 - 9, a weight change from perhaps 40-90
lb (reaching the limit of the trailer-bike spec.). The trailer-bike had
a u-joint seatpost mount as opposed to the BOB's rear axle attachment.
The t-b (Adams) always had a significant amount of play in the joint,
allowing it to "flop". As my daughter got older and heavier, the flop
had more effect on balance, but she got much better at balancing
herself, so flops became rare. Part of the equation is the ratio of
parent to child weight, I'm sure. I'm a big person (6'10", 235), I'm
sure a smaller person would have more difficulty with control.
The low CG of the BOB is nice, but I have caught it on rocks/logs a
couple of times, once tossing myself over the bars when I came to an
abrupt stop. The structural members of my BOB are significantly bent
from frequent collisions. Likewise, the trailer-bike's pedals and
chainrings got smashed a few times.
I never crashed with my daughter (100's of rides). You have to be
careful not to weave too close to trees and the combination rig has a
tendency to jackknife, especially on soft surfaces with too much front
brake. On the plus side, the tongue weight completely prevents endos on
the steepest trail descents. I've never had wobble with either trailer,
at any speed.
I would think of a DIY as being a sketchy proposition though,
particularly with hitch design/fabrication. Some of my friends expressed
concern over the kind of riding I did with my child, and I admit to the
occasional second thoughts. I had a few data points such as the Adams
design being used on tandem trailer-bikes with heavier loads. Even being
an engineer, I'm not sure I'd have the confidence in my own design/build
skills to trust my kid's safety to them (or I'd so over-engineer it'd be
a pig).
I could see buying a BOB and using it as a platform to mount a child
seat. It probably wouldn't be any less safe than a lot of the
contraptions people carry children with, but on singletrack, with such a
small rear wheel, the ride would would be dangerously harsh for a
toddler. I'd just wait for trailer-bike age. Although I did less of it
than the woods, we took the trailer bike on city streets many times,
even negotiating busy downtown (Boston) loops. The agility of the
trailer-bike works very well in those conditions.
