Ilmberger Hugger Failure

Roger Justus · 09-27-2002, 01:19 PM

This week I was riding for about three kilometres on a smooth packed road (no bumps, no loose grave) at 40 kph. Suddenly without warning my bike made a strange noise, and the rear end started to slide and I managed to get the bike stopped upright. The hugger was jammed up against the tire and against the paralever arm acting like a brake against the tire and wheel. The hugger was wedged tight in there after having broken its metal support at a point less than an inch below where it enters the carbon fiber part of the hugger. I will e-mail pics to Tominator and perhaps he can post them. In short, what happened was the metal arm failed. At that poiont the hugger dropped down onto the tire which, rotating forward pulled it downwards and tight against the tire acting as an independent brake over which I had no control. The hugger was split from the forces and gouged the paint on the paralever housing. I am out a hugger which until this happened I liked perfectly fine and was happy to recommend. At the time I was riding with a friend on another R1100S with the same hugger which he has had on for three years and about 39,000 kms and no problems. I can only conclude there must have been something about my hugger that wasn't up to scratch such that it failed under those conditions. My hugger has not vibrated against anything on the bike, nor been ridden on rough roads. Actual "road time" of the hugger has been about nine months. In short, I don't get it. This is not the quality I was expecting from this hugger. I have e-mailed and faxed Mitch Herman to report this along with pictures of the break. He has forwarded the material to Ilmberger in Germany. That was on Thursday. As I have not yet heard back I am posting this to give you all a "heads up". As there are a lot of these huggers out there and there might be a safety issue consider checking the metal arms on your huggers for cracks or anything unusual. Mine was purchased in July of 2000. I will let you know what happens.

lennie · 09-27-2002, 01:32 PM

Roger,

Thanks for the warning. As with all things there are bound to be failures.

It is good you managed to keep the bike under control and not toss it down the road.

I will check mine out today before I ride again.

tominator · 09-27-2002, 01:51 PM

Just wanted to post these pictures for Roger. Please review the following pictures and check yours if you own a Ilmberger!

Cheers
Tomas

jclark · jclark's Garage

Were any of the shiny spots there before the break?
I've got 2 years, 10k miles on mine w/no problems.
I take it off for track days, so I keep tabs on it that way...

Did it clear the brake caliper when mounted ( that is, could you wiggle the caliper around while everything was tight –*you should be able to )

It appears ( from the pics ) to be a resonance failure...

No answer, but I would talk to whom I bought it from, and inquire about return policy.

jeff

jclark · jclark's Garage

Glad you are safe.
Will keep an eye out for this.

jeff

Joe · Joe's Garage

Roger thanks for the heads up .Glad your ok must have been like throwing a chain when they get jammed. I have over 20k mi. on mine I'll give it a good look in the am.

cliff randall · 09-27-2002, 05:59 PM

Thanks I'm on it!
Cheers,
Cliff

DavidSoine · 09-28-2002, 06:40 AM

Welcome to the world of durability and aftermarket parts!

Ask the manufacturers if they did an FMEA...

best,

Dave

Chris Canning · 09-28-2002, 08:53 AM

Oddly enough mines just broken as well,but across the circumference,as your sat on the bike from left to right,it went back in the post to Germany a week ago i'll be interested to see what happens,as i still think it's the best hugger by some distance i'd be happy to fit another.

Chris

Roger Justus · 09-28-2002, 10:57 AM

Thought you guys needed to know, and thanks for the kind thoughts. Could have been much different outcome at greater speeds and a less isolated road.
J Clark: didn't notice any shiny spots on the metal arm before breaking. Just looked like uniform finish. Bolts were torqued to spec. Also was caliper wiggle and no unusual break drag.
Chris C: weird about yours breaking too. Under what conditions did yours give way?
Anybody know if these huggers need to be TUV approved for Germany? Are they? Any standard they have to meet in USA and Canada?
Initial impressions from you guys seem to be that it is a resonance or vibration stress fracture in the metal. Look carefully at the rough edges and colouration of the break in the first picture. Any engineers/metal specialists out there?

lennie · 09-28-2002, 01:52 PM

Roger,

I guess a little linishing to polish out the rough edge would help prevent this kind of failure.

tominator · 09-28-2002, 07:09 PM

Added the pics to this thread for Roger.

Cheers
Tominator

Oilhead259 · 09:21 PM

By viewing the pictures only, the third picture in particular, I would warn anyone with the same hugger to make sure there is always proper clearance between the support and the brake caliper. There is considrable vibration in that area and although the Ilmberger is designed to handle it, it looks like the stress fracture occurred at that spot where the strut touched the caliper. Does anyone remember twanging a ruler on a desk top during old school days and changing the pitch by sliding the ruler in towards the desk? The vibration was concentrated at the point where the vibrating part of the ruler touched the desk. Without ZYGLO or X-Ray it does appear as though there is slight vectoring of force eminating from that point of contact on the strut.. I know that this a lot of supposition on my part but maybe it will help someone else and prevent them from going down as a result of another failure. One might also try chamfering or negative radiusing the edges of the support arm

Oilhead259 · 09-28-2002, 09:26 PM

check this out

Micky Motor · 09-29-2002, 04:17 AM

Yeah, you can definitely see a mark on the calliper where it has been rubbing on the hugger. Am I to understand the bracket in question is the only thing that holds the hugger on?

(I don't have one, real men clean their pipes and shock when they are dirty, and like it!!) What about the marks on the carbon part of the unit above the bracket? Were they caused when it got jammed or has it been rubbing somewhere else? It all seems a bit dodgey to me. I would'nt be able to concentrate on my riding wondering if the thing was going to come off and send me down the road! Now that I've got you all paranoid, I'll sign off.

M Motor

Roger Justus · 09-29-2002, 06:07 AM

OIlhead259 and Micky: Just went out and held the hugger in place and yes, it did touch just a hair on the caliper where you see a light coloured mark on the caliper in the picture. Never noticed it touching. Just put the bolts in the holes provided and torqued it up properly. Any other marks on the hugger are from when it got jammed. I'm no expert but I think you're onto something Oilhead. Everybody should consider going to look and see if their metal piece of the hugger touches the caliper body. The metal piece is much thinner there than at the back where the bolts go through. Logically, the piece is beefier at the bolts. However, since it tapers where it approaches the carbon fibre and, if it touches the caliper, there could possibly be a problem like I have had. Having a hugger that doesn't touch the caliper in this way would seem to be a good idea. Not an engineer but Oilhead's chamfer idea on the inside if it touches just slightly should be considered. Still waiting to hear back from Julius Ilmberger.

R-monster · 09-29-2002, 08:37 AM

Roger,

The failure you are describing would not happen with the hugger from France as the support for the French hugger is way more substantial than the "hamburger" hugger. Another reason why I did not buy one.

Busabim

markjenn · 09-29-2002, 08:51 AM

I just checked mine and the hugger arm clears the brake caliper - not by a whole lot, but it clears it. The theory that lack of clearance here might have caused a nick and a stress riser is a good one, I think.

This will be something I'll be checking VERY closely during rear tire changes. I do a lot of 90+ MPH cruising on less than smooth-roads and a rear wheel lock would be something that I'm not sure I'd survive without a bad fall.

- Mark

Merrimac · 09-29-2002, 08:51 AM

Just looked at my hugger. It appears the design of my unit, purchased in 2002, is different from the pictures of the broken unit.

First I have about 1/8 of an inch clearance between the hugger and the brake caliper. Second, the carbin fiber is not squared off where it ends. My huger has the carbin fiber tapered, getting thinner as it ends.

This design differences may have an impact on the problem as well.

Jeff "S" Moore

bigwhup · 09-30-2002, 08:42 AM

Jeff just got a harumph out of me. I have the same as his.

Its frustrating to hear these stories come out days after I installed it. I don't think I would be as calm as you guys if it happened to me. I'll follow this post to see what comes out of Ilemberger corporate.

Thanks again for the info.