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BOB trailer and disk brakes

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RideMonkey

Guest
Has anyone pulled a BOB trailer on a bike with a rear disk? Does the torque a fully loaded BOB applies on the rear triangle cause the caliper to rub the rotor?
 

JohnMc

Chimp
Aug 9, 2002
30
0
St. Louis, MO
The BOB hitch doesn't put any weight or torque on the frame - it hooks onto a special rear quick release. Thus all the weight goes right onto the rear axle. And it can pivot freely up and down and side to side, so there are no torque forces either. Its possible a flimsy rear axle/hub could flex a little more, but compared to the normal stresses a hub is built to handle 1/2 of a 70 lb loaded BOB trailer (the other half goes on the BOB wheel) shouldn't be a problem. Same issue applies to the extra forces on the drivetrain required to pull the trailer - small in comparison to hauling around your own butt.

PS - I don't have a BOB but my wife uses one on her commute.
 
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RideMonkey

Guest
Originally posted by JohnMc
The BOB hitch doesn't put any weight or torque on the frame - it hooks onto a special rear quick release. Thus all the weight goes right onto the rear axle. And it can pivot freely up and down and side to side, so there are no torque forces either. Its possible a flimsy rear axle/hub could flex a little more, but compared to the normal stresses a hub is built to handle 1/2 of a 70 lb loaded BOB trailer (the other half goes on the BOB wheel) shouldn't be a problem. Same issue applies to the extra forces on the drivetrain required to pull the trailer - small in comparison to hauling around your own butt.

PS - I don't have a BOB but my wife uses one on her commute.
Eh I don't think I agree with that. I pulled a BOB with a lightweight steel frame and it caused a great deal of frame flex.
 

JohnMc

Chimp
Aug 9, 2002
30
0
St. Louis, MO
In what way? The only force that it could put on the frame is a sideways 'lean' if the trailer is loaded off balance, and you have to lean the other way on the bike to conteract. And possibly under braking where the push from the rear goes mainly to the front wheel. But under normal use the weight and pull of the trailer doesn't go through the frame - just the rear wheel.
 
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RideMonkey

Guest
Originally posted by JohnMc
In what way? The only force that it could put on the frame is a sideways 'lean' if the trailer is loaded off balance, and you have to lean the other way on the bike to conteract. And possibly under braking where the push from the rear goes mainly to the front wheel. But under normal use the weight and pull of the trailer doesn't go through the frame - just the rear wheel.
Unless you are perfectly upright at all time you will have this lean. In off road conditions you will get all kinds of sideways deflections that will cause the trailer to twist the frame.
 

JohnMc

Chimp
Aug 9, 2002
30
0
St. Louis, MO
(shrug)
In which case the flex would have to be in the very short bit of frame between the rear dropout and the caliper mount which is usually an inch or so of pretty stout metal. I'd suspect flex in the hub more than the frame.
 
R

RideMonkey

Guest
Originally posted by JohnMc
(shrug)
In which case the flex would have to be in the very short bit of frame between the rear dropout and the caliper mount which is usually an inch or so of pretty stout metal. I'd suspect flex in the hub more than the frame.
I was thinking that but wondered if anyone has tried it.
 

2melow

Chimp
Apr 19, 2002
12
0
Fort Collins, Colorado
Yo - am running a Yakima Big Tow (yea, copycat of the BOB trailer I know... but it was cheap). My bike setup - I am riding a Independent Fabrication steel 29er frame w/ Avid mechanical disk brakes and i've had no rubbing at all...and i've loaded it over 80 pounds with camping gear before.

now I am not sure about the BOB quick release attachment, but my Yakima uses a huge and heavy q/r that is stiff. If you saw one or picked it up, you'd see what I mean.