ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-17-2013, 01:24 AM   #1
Andy_unaventurous OP
Lost but not fearful
 
Andy_unaventurous's Avatar
 
Joined: Jan 2008
Location: Melbourne, in the bastard son of Roy
Oddometer: 73
Totally worn out rear hub

Greetings knowers of more than me!
My R80G/S has a totally worn out rear hub, brakes dragging or being ridden on I suspect. Anyway , gotta do something about it for rego. The great guys at BM Ringwood talk of machining out the hub and pressing in a sleeve internal diameter ( when surfaced down) same as a stocky. They are pretty straight guys , but I'm just checking what else is out there? Must have happened to other 31 year old bikes I guess

Anyone hear about this or have any knowledge of any other way, or indeed (ha ha ha ) have a second hand 3 bolt hub for sale?

Andy
__________________
For a hundred, a girl would lend you her Bartok records, have dinner, and then let you watch while she had an anxiety attack.
Andy_unaventurous is offline   Reply With Quote
Old 01-17-2013, 01:34 AM   #2
8jest
Adventurer
 
Joined: Nov 2012
Location: Portland, Or
Oddometer: 18
Man. How many miles you have on it?

There is some bidding going on here on eBay:

http://bit.ly/10B4Ir9
8jest is offline   Reply With Quote
Old 01-17-2013, 01:54 AM   #3
TEXASYETI
Call me "thread killer!"
 
TEXASYETI's Avatar
 
Joined: Dec 2002
Location: Fort Worth, Texas
Oddometer: 1,886
Went through this myself recently. Ended up getting a wheel from Germany and it was not cheap. Someone did a modification where they put a 4-lug monolever reardrive on a G/S. They took a GS paralever rear wheel (4 lug and spoked) and machined some metal off on the inside and popped it on.

Problem is, paralever rear wheels seem to be just as rare as g/s monolever wheels. I hope that BMW is hearing the increasingly numberous and loud cries for these rear hubs and does something about it.
__________________
BobFV1 to Putts: "Congrats on the bike. Also, congrats on having a dog with a perfectly heart-shaped asshole."

1981 R80G/S
1991 R100 GSPD

FIRST TIME RIFF RAFF - Go Jonah!
TEXASYETI is offline   Reply With Quote
Old 01-17-2013, 01:57 AM   #4
Rob Farmer
Beastly Adventurer
 
Rob Farmer's Avatar
 
Joined: Aug 2002
Location: Loughborough, Leicestershire. England
Oddometer: 5,122
I didn't think you could sleeve out the GS wheel. the steel drum is cast in below the level of the aluminium around it. Be nice if you could but I don't see how they could fit a new one without chopping out a lot of aluminium.
Rob Farmer is offline   Reply With Quote
Old 01-17-2013, 02:44 AM   #5
Andy_unaventurous OP
Lost but not fearful
 
Andy_unaventurous's Avatar
 
Joined: Jan 2008
Location: Melbourne, in the bastard son of Roy
Oddometer: 73
Hi Mate, Impossible to say how many miles, there are some areas where its really tight and you think , wow, low miles, but then I took off the rear wheel and the drum is so worn you have to adjust the brakes up before you can remove the wheel, such is the lip on the drum itself? That there auction is for a diff/final drive, that seems ok on mine
maybe we'll be able to 3d print one soon :-)
Andy

Quote:
Originally Posted by 8jest View Post
Man. How many miles you have on it?

There is some bidding going on here on eBay:

http://bit.ly/10B4Ir9
__________________
For a hundred, a girl would lend you her Bartok records, have dinner, and then let you watch while she had an anxiety attack.
Andy_unaventurous is offline   Reply With Quote
Old 01-17-2013, 02:46 AM   #6
Andy_unaventurous OP
Lost but not fearful
 
Andy_unaventurous's Avatar
 
Joined: Jan 2008
Location: Melbourne, in the bastard son of Roy
Oddometer: 73
Hi Rob, please clarify mate, are you saying the 'level' of the brake hub is below the outer cast alloy of the hub? If so is it normal to have to adjust the shoes in to be able to remove the wheel?
thanks for your thoughts

Andy

Quote:
Originally Posted by Rob Farmer View Post
I didn't think you could sleeve out the GS wheel. the steel drum is cast in below the level of the aluminium around it. Be nice if you could but I don't see how they could fit a new one without chopping out a lot of aluminium.
__________________
For a hundred, a girl would lend you her Bartok records, have dinner, and then let you watch while she had an anxiety attack.
Andy_unaventurous is offline   Reply With Quote
Old 01-17-2013, 04:19 AM   #7
bikerfish
flyfishandride
 
Joined: Aug 2010
Location: western pa
Oddometer: 1,428
I always have to adjust the brakes to remove the rear wheel on my airheads, G/S included. before jumping to conclusions, take measurements to see if it is truly worn out, I'm sure someone here has the specs.
bikerfish is offline   Reply With Quote
Old 01-17-2013, 04:28 AM   #8
Rob Farmer
Beastly Adventurer
 
Rob Farmer's Avatar
 
Joined: Aug 2002
Location: Loughborough, Leicestershire. England
Oddometer: 5,122
Andy,

I didn't word that too well.

When the wheels are new there isn't a lip. What I was trying to say is the steel liner is cast into the wheel. I cannot see how you could remove it or fit a replacement in there as the outer diameter of the replacement liner would need to be smaller than the worn original drum to fit it through the gap in the aluminium casting...hope that makes sense...I have a g/s wheel in my spares I'll dig it out and take a picture if needed.
Rob Farmer is offline   Reply With Quote
Old 01-17-2013, 05:09 AM   #9
mendoje
Gnarly Adventurer
 
Joined: Jun 2009
Location: Los Angeles
Oddometer: 235
Quote:
Originally Posted by Andy_unaventurous View Post
...I took off the rear wheel and the drum is so worn you have to adjust the brakes up before you can remove the wheel,
Rather than mileage, what is the measured diameter of the drum? I cant recall the number from memory, but the max acceptable diameter is cast on the hub somewhere. As others have said, it's normal to readjust the brakes when R&R'ing the wheel.
__________________
2004 BMW R1100S / 2003 Ducati M800Sie / 1986 R80 G/S / 1993 Suzuki RMX250 / 1981 BMW R100RS (Sold ) / 1977 Kawasaki KE100 (1st Bike )
mendoje is online now   Reply With Quote
Old 01-17-2013, 06:16 AM   #10
One Less Harley
OH.THAT'S GONNA HURT
 
One Less Harley's Avatar
 
Joined: Nov 2006
Location: Bowling Green, Ky
Oddometer: 4,611
I'd be interested in what you find out. I purchased an extra rear wheel from Germany, used and at a pretty good price and was glad to get it. At the time he had one other wheel for sale. I checked and he no longer has it.
__________________
2004 BMW R1150RS
1984 BMW R80G/S
(wrenching index)
2003 Suzuki DRZ 400S (TAT Prep)
One More DRZ does the TAT (Ride Report)

One Less Harley is offline   Reply With Quote
Old 01-17-2013, 06:34 AM   #11
AntonLargiader
Beastly Adventurer
 
AntonLargiader's Avatar
 
Joined: Aug 2003
Location: Charlottesville, VA
Oddometer: 4,132
The rear hub from my R100R is similarly shot, probably from maladjustment. It is worn with a curve dug into the center of the drum face. I'd love to find a solution for that, also. We have a local machine shop that does some very trick stuff, so maybe I'll ask them one day.

At least for that bike I can still buy a new hub, but it's not cheap.
__________________
Anton Largiader largiader.com BMWRA.org
AntonLargiader is offline   Reply With Quote
Old 01-17-2013, 07:06 AM   #12
_cy_
Beastly Adventurer
 
Joined: Sep 2011
Location: Tulsa, Oklahoma
Oddometer: 5,426
Quote:
Originally Posted by AntonLargiader View Post
The rear hub from my R100R is similarly shot, probably from maladjustment. It is worn with a curve dug into the center of the drum face. I'd love to find a solution for that, also. We have a local machine shop that does some very trick stuff, so maybe I'll ask them one day.

At least for that bike I can still buy a new hub, but it's not cheap.
not cheap is an understatement on top of extremely hard to find!

it's worth noting that original BMW brake shoe material can get extremely hard. either from age and/or very hard to begin with. while it's normal for brake drums to wear a little. most of the wear needs to come from brake shoe materials.

assuming your drum is still within tolerances... to save what left of your G/S drum. take your drum and old shoes to a local brake/clutch repair shop. find one that will custom fit shoe to drum. if there's wear on drum, thickness for shoes needs to be slightly thicker. reason is max braking occurs at beginning of brake rod travel. when brake cam is in optimal position.

new shoe material will be much softer than OEM. much rather brake shoe wear vs drum. had no clue just how hard shoe material had become. until I tore into my G/S drum to track down why my rear brakes were so underpowered. getting brake shoes relined with slightly thicker/softer brake shoe lining fixed problems of excessive drum wear and lack of braking power.

_cy_ screwed with this post 01-17-2013 at 07:18 AM
_cy_ is online now   Reply With Quote
Old 01-17-2013, 07:59 AM   #13
jackd
Beastly Adventurer
 
Joined: Dec 2006
Location: North Cowichan
Oddometer: 2,952
Quote:
Originally Posted by _cy_ View Post
not cheap is an understatement on top of extremely hard to find!

it's worth noting that original BMW brake shoe material can get extremely hard. either from age and/or very hard to begin with. while it's normal for brake drums to wear a little. most of the wear needs to come from brake shoe materials.

assuming your drum is still within tolerances... to save what left of your G/S drum. take your drum and old shoes to a local brake/clutch repair shop. find one that will custom fit shoe to drum. if there's wear on drum, thickness for shoes needs to be slightly thicker. reason is max braking occurs at beginning of brake rod travel. when brake cam is in optimal position.

new shoe material will be much softer than OEM. much rather brake shoe wear vs drum. had no clue just how hard shoe material had become. until I tore into my G/S drum to track down why my rear brakes were so underpowered. getting brake shoes relined with slightly thicker/softer brake shoe lining fixed problems of excessive drum wear and lack of braking power.

That is a very good suggestion - I'll be following that route when the time comes for my rear wheel to be dealt with.
jackd is offline   Reply With Quote
Old 01-17-2013, 10:57 AM   #14
Airhead Wrangler
Adios Mexico
 
Airhead Wrangler's Avatar
 
Joined: Mar 2008
Location: Back in Seattle, FINALLY
Oddometer: 6,342
For building up spent brake drums I've been curious about trying a thermal spraying process aka "flamespray" or "plasma coating". I've seen various mention of people using this to build up spent wear surfaces before.

http://en.wikipedia.org/wiki/Thermal_spraying


These guys even mention using it on clutch plates and brake drums. Some of the coatings can be finish ground after application as well. Looks very promising to me:

http://www.plasma-group.co.uk/therma...-coatings.html

Hmmmmmm. My only concern would be that the heat might separate the cast-in drum from the outer aluminum casting due to the difference in coefficient of thermal expansion of the two materials. The flame spray process is much lower temp than welding though, so maybe it wouldn't be a problem. Who wants to be the guinea pig?
__________________
R80ST Gets The HPN Treatment
Seattle to TDF on an airhead

Current rides: HPN #834, '93 R100GSPD "red rocket", '73 R75/5 Toaster mongrel, '80 Ducati Pantah 500SL, '92 DR350, '67 Honda SS50, '80 Honda Chaly.
Airhead Wrangler is online now   Reply With Quote
Old 01-17-2013, 11:20 AM   #15
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,275
Brake drums are a problem for us. Too bad every airhead ever sold didn't have the brake shoe lining replaced with a lining that actually wears versus the drum! Those linings don't get old and hard. They come brand new like that. The drum wear isn't necessarily from high miles or maladjusted brakes. It's from the linings. A curve dug into the center of the drum? I call that a glaciated drum. The same basic U shape as a glaciated valley. It's from those rock hard stock brake shoes. I see it ALL the time on all the beemers I have been around.
supershaft is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 09:10 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014