K11 Owners Group

chopper_harris · Posted: Sun Feb 17, 2008 5:34 pm Post subject: Aluminium Worm ...

Folks

In 32 years of pratting around with bikes, I've never seen this before Surprised

Whilst bleeding up the rear brake on the LT, I needed to adjust the screw for the brake light switch. Of course, it was seized so I stripped off the RHS carrier, which hold footrest, pedal and rear m/cyl.

I was astounded to find that the lower half of the lever boss had been 'eaten away' - it looks as though rats have been gnawing at it. It has started to peel apart on the upper face, and has also badly decomposed under the serrated foot plate part of the rear brake lever :

I've seen old Mazak castings snap in half, but this is beyond me Razz

From a mechanical perspective, it is fascinating, but from a safety view - jeez.

Have the panel seen anything like this before ?

What is BMWs view on claims for faulty components ? Granted the bike is 13 years old, but a forged Alu part should not fail like this.

I will be taking it to my local BMW main agent, but they are a fair trip away.
Is there a web site with recall data for our bikes ?

Answers on a post card, please.
_________________
C1 200 (2001)
R100 RS (1990)
NSU Quickly N (1964)
Honda 400/4 F1 (1977)
MotoGuzzi 1000C (1978)
Suzuki TL 1000 R (1999)
Kawasaki KLV1000 (2005)
K12R Sport (2007) - Wifeys

Ted · Posted: Sun Feb 17, 2008 6:24 pm Post subject:

Looks like the zinc anodes I replace every year on the Boston Whaler - maybe the same type of corrosion is at work?
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Ted

KOG#1

Off the grid · Posted: Sun Feb 17, 2008 6:56 pm Post subject:

1. Looks like advanced oxidation for sure, but you normally see that in salty environments like Ted mentioned.

2. Your avatar might be the coolest one on this board, but all that means is that someone will take offense to it and it will be changed.
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Bane of your existence since July 2006
2007 Triumph Tiger ABS. "Sabertooth"
2009 Husqvarna TE610. "The dirty Italian mistress"

chopper_harris · Posted: Sun Feb 17, 2008 9:30 pm Post subject:

M'mmm - North West England is officially the wettest part of the UK, and the local councils love to lay down thick coats of 'grit salt' whenever the temperatures threatens to fall below 4'C.

I guess the brake lever design is the root of the problem. It is completely obscured, tucked away in it's own microclimate. Even a regular hose-down would not reach the corroded part of the boss, which is shielded by the top lip of the mounting plate.

I posted this on the UK MBins site, and three more UK riders have reported similar failure of the alloy rear brake lever.

So, I'm glad I found it now, and not in another few winters time when it fell to pieces whilst I was on the road Mad

I'll go shout at my local BMW parts manager, and see what he can do for me.

Rgds

Chopper
_________________
C1 200 (2001)
R100 RS (1990)
NSU Quickly N (1964)
Honda 400/4 F1 (1977)
MotoGuzzi 1000C (1978)
Suzuki TL 1000 R (1999)
Kawasaki KLV1000 (2005)
K12R Sport (2007) - Wifeys

abreeze · Posted: Sun Feb 17, 2008 9:31 pm Post subject:

corrosion....probably from brake fluid.

and that avitar is awesome............who is that? looks familiar.....

max · Posted: Mon Feb 18, 2008 6:58 pm Post subject:

Could be freezing damage too - the alu parts are all chill-cast (eg cast specially to get a solid skin but the inside is like a foam/honeycomb) ... If you've had water getting into the internal "cells" and freezing (windchill down there!) then it ciould fracture/flake off the surface.

My 2c

Max

PS - first experince with all this was trying to get a broken K-RT gearlever MIG welded - wasn't possible, not enough "solid" stuff inside!