Serious Safety Question - Handlebars!

[chibbert]

Some time ago, whilst cinching my bike down on a trailer, I rolled the handlebars under (rotated them in the clamps) a few inches. Not thinking at the time, I jerked them back upright and then went and got an Allen wrench to tighten them up. Hadn't much thought of it since then. Today, I got a little spare time to take my wife to dinner on my bike and when we were leaving the restaurant, I was maneuvering my bike (on foot) out of a parking spot, I rolled them under again and jerked them back up. My concern is that I am smoothing off the bars where they seat in the clamps and that some day unexpectedly, the handlebars are going to come loose at the most wrong of moments and I am going to wreck.

My question is: Is there anything I can do to make the clamps bite more aggressive to prevent this from happening? Can I stick some 60 grit sandpaper in there or something? Anyone ever had this happen?

Looking forward to your responses.

Thanks,
Chris Hibbert (missing Hungry Mother)

[GJBushman]

Chris,

I did have this happen once. I was leaving a gas station and they slipped down. I stopped and tightened them up and have never had a problem again. This was a few weeks after removing my barbacks. I assumed I just never got them tight enough. No problems since.

[DJ Downunder]

I would not worry too much about it as long as they can't move too easy.

It's sometimes best in a drop or fall to have the bar move rather than bend.

Dirt bike guys set up their bars and levers this way and can save heaps of damage.

They should be torqued to the correct spec..whatever that is...IMO

DJ

[Ves]

... My question is: Is there anything I can do to make the clamps bite more aggressive to prevent this from happening? ...

I have three suggestions.

1. Are you clamps on with an airgap, on both sides, between the upper and lower part of the clamp. In other words you don't want to screw one of the clamp screws in all the way before you tighten the other one. You want to tighten evenly so that an air gap remains.

2. Get a pair of vise grips, with some nice sharp teeth, and use them to bite into the handlebar and create additional serrations (score the surface). Note: If you have aftermarket aluminum bars, they specifically say not to score the surface.

3. A little more on the drastic side... you can pin the bar in place. With the bar in place, and only one clamp holding it, on the side that you removed the clamp, use a 1/8" drill and drill through the center of your bars and into the triple clamp (you have wires in there? be careful). Don't drill all the way through the triple clamp! You can now insert a 1/8" pin through both, and then trim it so it's flush with the handlebar. Or you could drill and tap your clamp for a small set screw. Drill a small divot on the bar to match, and you're set.

Honestly I can't see that you would need to do #3. I've never had a problem with bars rotating once they are clamped right.

Good luck.

[duckdave]

When I removed my Aeroflow w/s for summer I had reason to look up the procedure for tightening up the H-bars. I just went and looked it up again, both on the instructions that came with my Areoflow, and in the BMW Motorad R1150R Repair Manual.

Both sources specify tightening up the FRONT of the clamps FIRST ("no gap", as per Aeroflow instr.), THEN the BACK of the clamps. BMW Motorad specifies 21 Nm; Aeroflow (with upper fairing mounting bracket in place) calls for 10-15 Nm.

Tho I can't see why it should make a difference... that's the way I did it and have had no problems.

[Sunbeemer]

I think the manual recommends torquing down both front clamp bolts and then the rears so that the air gap is all at the rear clamp

The Clymers Manual also recommends this procedure:

Install the handlebars and align the index mark with the split line of the upper holders and tighten the front bolts first and then the rear bolts to 21 Nm (15 ft-lbs).

Hope that'll do 'er!

[Rog(UK) - Yorkshire Dales]

I'm wondering if the top clamps are deeper at the front than at the back. The instructions would then make sense.

If you have symetrical top clamps and torque the front bolt down first, then the clamps will be scewed. ie the bolt holes will not be aligned with the clamping bolts and they will tend to bend the bolts. In the 60s you could tell someone without any mechanical sympathy because that is exactly what they would do.

Maybe, the manufacturers of these clamps know this and (as I said), make the front of the clamp deeper, so that when it is torqued down first, the clamp is correctly aligned.

...it's just a thought.

Ride safely,

Rog

PS I wouldn't drill through the handlebars at the handlebars clamps. If the handlebars can be rotated even when the clamps are correctly tightened, then you have a different problem which needs to be solved.