21RBS bumper fix

[ROLIN JOSEPH]

The bumper on our 21RBS, like many other 'new and improved' bumpers, are very flimsy and cannot hold much weight.
In my opinion, when transporting bicycles, the problem is not so much a matter of weight, as it is of torsion.
The torsion that a bicycle carrier generates on the bumper causes it to rip away from its welding to the frame. (see welding attachments).
My solution to prevent this ripping was to bind the bumper to the sub-frame with a threaded rod and anchors. (see attachment 0,1,2.)
I have done the mod, and it seems very strong, but I have not been out on the road yet.

[So Cal CPA]

is this for the rear slide bumper system or standard? Also are you comfy that the bumper itself will hold the weight?

[Randy_K]

The weld did not break. The base metal < bumper tube > tore at the weld. The weld was the point where the weaker base metal met the stronger weld and ripped the base metal.

Your mod may just change the place of the next failure if loaded the same.

BTW the higher up the bike rack the more leverage or torque it has on the bumper. Think of how any lever or crowbar works.

Randy
CWB Weld Supervisor.

[SAD]

Seems like a nice turd polishing!!! LOL

I would have just put a real hitch on it and been done with it...

Sorry!!!

[BSHGTO]

Originally Posted by Randy_K

The weld did not break. The base metal < bumper tube > tore at the weld. The weld was the point where the weaker base metal met the stronger weld and ripped the base metal.

Your mod may just change the place of the next failure if loaded the same.

BTW the higher up the bike rack the more leverage or torque it has on the bumper. Think of how any lever or crowbar works.

Randy
CWB Weld Supervisor.

Randy is 100% correct. why anybody uses those clamp on bumper hitches is beyond me. Curt hitches has the only bolt or weld on hitch for this purpose for TT or 5th wheels. The last time I went camping the guy next to me pulled in and the gas grill he was carrying on a cargo tray with a clamp on bumper hitch was half way off. It was the same thing the weld did not fail it was the base metal tearing loose. Those 1/16 wall metal tubes are not rated to carry any weight other than sewer hose.

[ROLIN JOSEPH]

SAD,
Failed to mention that when I did this re-enforcement, my bumper was still new and undamaged. The welding pictures you see are not mine. They are just to show what will happen if you don't do something about it.
I agree that replacing the bumper with a beefier one is a better way to go if money is not an issue.

[Western Traveler]

Agreed the meterial used is too thin but I think the crowbar effect/torque is caused mostly by the spare tire back there. If one removes the spare from the back and uses the bike stand to just keep the bikes upright and secures them ahead of the shelf on the longitudinal rails below it should help a great deal. The other issue with the sliding bumper are the angle iron hangers supporting the rails when extended.
There is at least one thread on here with various fixes posted to strengthen the shelf.

[ROLIN JOSEPH]

Randy K,
I know the weld did not break. Read it again.

[ROLIN JOSEPH]

So Cal CPA,
Not a slide bumper.

[Randy_K]

Saving money is one thing, causing a multi car pile up or killing some one is another. Your choice.

Be careful out there.

[ROLIN JOSEPH]

Randy K,
I agree that the next area to fail is, as you indicated.
In an attempt to overcome that possible scenario, I have removed the spare wheel and BBQ stand, (Keystone setup), in exchange for the weight of two bicycles.
What do you think? You are the welding expert. Thanks.

[Randy_K]

Originally Posted by ROLIN JOSEPH

Randy K,
I agree that the next area to fail is, as you indicated.
In an attempt to overcome that possible scenario, I have removed the spare wheel and BBQ stand, (Keystone setup), in exchange for the weight of two bicycles.
What do you think? You are the welding expert. Thanks.

Im sure it will help. It is a shame that we have to pay so much for something that is made so cheap.