Someone please tell me they're kidding...

[Marrock]

$350 for a trailer fork, wheel, front fork, and pannier rack?

http://www.biketrailershop.com/catalog/620-extrawheel-voyager-trailer-wsetup-options-p-342.html

I could cobble one of these together from my junk bin.

[puppydog]

I'd give it 2/10, as long as it had panniers. I suppose I could recycle the rest into a unicycle.

PuppyDog:mad:

[canalligators]

I did make something like this once, except it attached to a rack. I used a socket universal joint and it was too sloppy for the job, so I abandoned the effort.

I think the idea has promise, but I think I'd also build one.

I wonder if it can be safely operated at higher speeds than a BOB? That's really the only thing I don't like about BOBs, in hilly country it's a drag keeping it below 25 (30 on the tandem).

[Marrock]

It's been my experience that the faster you go the more stable it becomes, probably due to the gyroscope effect... or maybe not and I hallucinated the whole thing again.

Really need to air out the lab once in a while.

[puppydog]

Perhaps for high speed/heavy load work the BoB might need an "over-ride brake" to stop it pushing the bike too fast downhill.


PuppyDog

PS Baron, perhaps the hallucination is caused by the ozone from all the electrical equipment.
:D
PD

[canalligators]

Gyroscopic effects are negligible for bicycle wheels, MV is too low to have a significant effect. But it's a common myth.

The problem with high speeds is quick maneuvering. The combined bike and trailer will suddenly oversteer, which goofs up your lean, which makes you lose steering control, which goofs up your lean... I forgot once and took the rig up to 35 and it was fine, as long as I kept it in a straight line.

[Marrock]

You should probably get your rig checked out then since I've never had any oversteer issues.

But I suppose blaming the equipment is easier...

[puppydog]

Gyroscopic effects are negligible for bicycle wheels, MV is too low to have a significant effect. But it's a common myth.


I'm going W-a-a-a-y back to high school here, but I recall doing the "bicycle wheel in a rotating office chair experiment" and that gyro effect was certainly not negligible.

http://www.youtube.com/watch?v=dVwKE9yDqVo&feature=related

And if my maths is not too rusty, the amount of "gyroscopic force" (precession??) is calculated using not only the radius of the wheel, but also the velocity, so I would suspect that if your bike is towing a trailer, then the angular momentum (if I've got my terminology correct) is going to be roughly similar, since both wheels are travelling at the same speed.

But I stand to be corrected.

I suppose your post begs the question, is the oversteer greater on the tandem than on a solo, and does the number of riders on the tandem, and their seating position, ie who is captain and who is stoker, change matters? I've only ridden a tandem a couple of times, and it was absolutely weird, and there would be so many factors involved it would be very difficult to pinpoint a single cause.

What diameter wheel(s) are on the bikes?

I use my BoB behind a recumbent trike, which (obviously) causes me no problems, even going down a hill at 60+ km/h, but I also use it behind a fold up 3 speed with wheels the same size as the BoB's. I use this to do my shopping, and whilst I don't get up much of a head of speed, I've found that the distribution of the load can have an extremely marginal effect on the stability of the fold-up, but absolutely nowhere near as much as carrying exactly the same load in a box on the back of my road-tyred mountain bike, over the back wheel.

I've had my BoB for several years now, and I'm still pleasantly surprised how little it intrudes on my riding. (I initially chose my screen name, PuppyDog, because that's how I found the BoB. Like a little puppy dog. It followed me closely everywhere but caused no problems.)

http://www.bobgear.com/bobtalk/showthread.php?t=37

I think you've got quite a big handful of confounding factors to pick from. Have fun.


PuppyDog

[canalligators]

I think if gyroscopic precession were really a factor, it would be harder to turn one way or the other - or hard to turn at all. Also, when I spin a bicycle wheel and hold it by one side of the axil, it moves slowly around, developing about as much torque as very gently pushing a disk in a circle.

The behavior comes, I think, from the bike changing its direction of travel and the mass of the trailer trying to keep going straight, acting on the towing bike via an articulated hitch (not connected near the center of mass of the towing bike). That is, it has a long lever arm about the CM of the bike. Reference: an overloaded Bugger trailer handles well at speed, because it's hitched to the towing bike near its center of mass (at the seatpost). Also, two wheeled trailers, with their mass close to the trailer's axil, don't affect towing bike steering much at higher speeds because there's a very low moment at the hitch.

I'm sure it's a dynamic situation related to the articulation, and I haven't thought it all out. (Or dug out my college physics texts to apply some math.) But my rig (a short wheelbase recumbent) feels strange at higher speeds so I don't go there. Maybe if I practiced, I'd be more comfortable with it.

[puppydog]

But my rig (a short wheelbase recumbent) feels strange at higher speeds so I don't go there. Maybe if I practiced, I'd be more comfortable with it.


Aahh, SWB. I also have a SWB recumbent bike and I've never tried towing the BoB behind it, but I'd probably, like yourself need to practise that sort of stuff, mainly because of the "flicking" from side to side as I pedal. I had a LWB 'bent before I bought the BoB (and the SWB) and I don't think that would have been much of a problem. My current SWB is absolute speed machine (solo), but by its nature at low speed it's very unstable.

http://i82.photobucket.com/albums/j245/saxeharp/recumb2.jpg

I'd be interested to hear about the experience of other SWB riders who've towed a BoB. I've certainly seen photos of it, but I guess with the wide variety of machinery available it would depend on the individual design.

PuppyDog

[canalligators]

I did a five day tour in the Adirondaks and I got more experience at higher speeds towing Bobsicle. I found that I was OK up to about 30 (miles/hr), but had to keep in mind that I shouldn't be doing any quick maneuvering. If I had a short dip and wanted to get the momentum up for the other side, and good pavement and lane space available, I might go up to 33 or 35 for a short burst.

[brent]

I did a five day tour in the Adirondaks and I got more experience at higher speeds towing Bobsicle. I found that I was OK up to about 30 (miles/hr), but had to keep in mind that I shouldn't be doing any quick maneuvering. If I had a short dip and wanted to get the momentum up for the other side, and good pavement and lane space available, I might go up to 33 or 35 for a short burst.
Canalligators, have any photos of your tour in the Adirondaks? As all of us know the maximum speed limit for pulling a trailer is 25 mph. With that said, I have also had my ride above the recommended maximum speed limit of 25 mph and trully believe the way the trailer is loaded makes the most significant impact on riding/pulling characteristics. I'm assuming all of BOBsters in the trailer forum would agree. And remember, the maximum recommended speed for pulling your trailer is 25 mph :).

[Marrock]

Canalligators, have any photos of your tour in the Adirondaks? As all of us know the maximum speed limit for pulling a trailer is 25 mph. With that said, I have also had my ride above the recommended maximum speed limit of 25 mph and trully believe the way the trailer is loaded makes the most significant impact on riding/pulling characteristics. I'm assuming all of BOBsters in the trailer forum would agree. And remember, the maximum recommended speed for pulling your trailer is 25 mph :).

So I should stop holding onto the backs of UPS trucks on the highway?

By the way, I found out that the Racor bike rack (http://www.amazon.com/Racor-PLB-2R-Two-Bike-Gravity-Freestanding/dp/B000077CPK/ref=sr_1_1?ie=UTF8&s=home-garden&qid=1258559859&sr=8-1) is ideal for storing a BoB with a minimum of finagling.

http://i34.photobucket.com/albums/d133/MarrockV/bikes/Mvc-260f.jpg

And one more thing, Brent, is there any way I can get some more of the plastic clips that hold the flag to the mast, mine appear to have gone walkabout on me.

[canalligators]

Canalligators, have any photos of your tour in the Adirondaks? As all of us know the maximum speed limit for pulling a trailer is 25 mph. With that said, I have also had my ride above the recommended maximum speed limit of 25 mph and trully believe the way the trailer is loaded makes the most significant impact on riding/pulling characteristics. I'm assuming all of BOBsters in the trailer forum would agree. And remember, the maximum recommended speed for pulling your trailer is 25 mph :).

My journal is at http://www.crazyguyonabike.com/doc/?o=RrzKj&doc_id=5773&v=6Z. I don't have any good pictures of the rig, though. Sorry, I checked my archives and I don't have any better pictures.

I do understand that I'm on my own when I exceed the speed limit. I understand and accept the risks.

[brent]

My journal is at http://www.crazyguyonabike.com/doc/?o=RrzKj&doc_id=5773&v=6Z. I don't have any good pictures of the rig, though. Sorry, I checked my archives and I don't have any better pictures.

I do understand that I'm on my own when I exceed the speed limit. I understand and accept the risks.
Thanks for the link to the pics. The road conditions looked great and the weather looked even better. If I could ride a bike all day long, not see a car and all I would count is farm animals or the number of farms, life would be complete. I did see a back view of the trailer and ride, very nice. I think it is funny how they come up with names of roads, split rock road. What gave them that idea of calling it that :)

[Marrock]

Thanks for the link to the pics. The road conditions looked great and the weather looked even better. If I could ride a bike all day long, not see a car and all I would count is farm animals or the number of farms, life would be complete. I did see a back view of the trailer and ride, very nice. I think it is funny how they come up with names of roads, split rock road. What gave them that idea of calling it that :)

Usually they're named for some defining feature, probably at some point there was a large glacier deposited boulder along that road that had been cracked in half over time, hence the name... or something like that, YMMV.

[puppydog]

Usually they're named for some defining feature ...

Yeah, get a lot of that in Australia.

's amazing how many "Crackanothertube Creeks" there are.

Not to mention "Sameagainluv Crossings".

:D

PuppyDog

[brent]

Usually they're named for some defining feature, probably at some point there was a large glacier deposited boulder along that road that had been cracked in half over time, hence the name... or something like that, YMMV.
I'm not sure if you saw the pictures, but it looks like some just split the rock right down the middle with a sledge hammer. They should call it split boulder, because the thing is huge.