Go Back   Horizons Unlimited - The HUBB > Technical, Bike forums > BMW Tech
R100rs 1979 R100rs 1979
Register FAQ Calendar Today's Posts
BMW Tech BMW Tech Forum - For Questions specific and of interest to BMW riders only.
Photo by Marc Gibaud, Clouds on Tres Cerros and Mount Fitzroy, Argentinian Patagonia

25 years of HU Events


Destination ANYWHERE...
Adventure EVERYWHERE!




Photo by Marc Gibaud,
Clouds on Tres Cerros and
Mount Fitzroy, Argentinian Patagonia



Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 6 Aug 2009
Registered Users
Veteran HUBBer
  
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
Your question is indeed tricky - the fault will be rediculessly obvious when located -

Note BMW "sickness" such as:
- oil leaking into the shaft from the gearbox.
- oil leaking into shaft from the bevelbox => lose nut => bevel about to get really badly damage.

In a way you kind of describe what happened to my 32/10 bevel - the bevel part connecting to the shaft suffered one bad ballbearing causing excessive travel. It was seen only as a bit more metal on the magnet than could be expected. My mechanic said I was over concerned... I drove -many- miles with a really bad bevel... broke some teeth... and what prompted me to check was that backing the bike became weird.
Svenska BMW MC Klubben • Visa trÃ¥d - Tandläkare sökes till slutväxel
If I had not used Omega 690 80W/90 the bevel would have jammed for me... the oil was still in very good shape after 40-45 000km incl the "broken" ballbearing(!) - point, change oil to look at the magnet(!) every 5-8000km or there about = very cheap "insurance".

Check you disc-brake. Check that you did install all parts correctly and bleeded the caliper fully. A warped disc / worn-out (common BMW sickness) could cause the sounds (but that kind of requires you to have touched the brake-pedal...).
__________________
Drive Safely,
Albert
Reply With Quote
  #2  
Old 6 Aug 2009
Registered Users
New on the HUBB
  
Join Date: Aug 2009
Location: Shefield
Posts: 15
more descriptions
i'll look ast the bevel too - but at the back of my mind is the thought that the fault should really be to do with something I've disturbed.

the sensation is similar, (if you have ever had the misfortune to ride such a worn out bike) to a chain that is so stretched that it climbs and jumps the sprocket, i.e a rhythmic twang !

does this help or just make things stranger !!

Regards Julian Delaney
Reply With Quote
  #3  
Old 7 Aug 2009
Registered Users
Veteran HUBBer
  
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
No that info did not make it more complicated - it simplyfied matters.

It is not the clutch.
It is not the gearbox (less you have the shock-absorber on the out-going shaft).
It it not the splines in the shaft.

It may be the shockabsorber in the shaft - it happens, rare but still.
It is highly likely to be a damaged bevelbox, very much like mine.

See, a clutchdrag - you would have noticed revving, hence excluded.
Ballbearings act differently; they will grind/rumble and make such noice that you will stop driving.
Splines just loose tracktion and sounds like a slow machine-gun (12mm at a distance).

What you are left with are:
- spring shockabsorber gone bust; not snapping over but giving way too much play; checked by turning the rearwheel in gear. A few inches of play is normal.
- bevelbox bearings and/or teeth bad, really bad. => acute dismantling before a seazure occurs (that -will- lock you rearwheel and send you skidding which may be an unpleasant experience, like into oncomming traffic...).

Use the stetocope method and listen to you bevel; a gentel whining is all there should be.
Change oil in the finaldrive to study the condition of the used oil, the magnet for any metal.
__________________
Drive Safely,
Albert
Reply With Quote
  #4  
Old 7 Aug 2009
Registered Users
New on the HUBB
  
Join Date: Aug 2009
Location: Shefield
Posts: 15
Motorworks (BMW spares supplier) seemed to think it was the bevel too, I am going to grasp the nettle over the weekend and make all the checks you have suggested. An added complication is I've just fried the diode board by not having the nuts tight enough on the earth points !!!!- ordered a new one from the above, this bike has become a money pit !!.

Thanks again Julian
Reply With Quote
  #5  
Old 7 Aug 2009
Registered Users
Veteran HUBBer
  
Join Date: Oct 2002
Location: Stockholm - Sweden
Posts: 317
So sorry to hear you shorted your diodboard. The needed parts costs a few bucks, but soldering the new diods are said to be a trycky business.

I forgot one simple test you should do.
- Grap the gaitor at the u-joint. Get a firm grip on the u-joint, then turn the rearwheel. The ONLY motion you should feel is the play in the splines between the rearwheel and the final drive. IF you have more play than that (which feels less than the click of a ball-pen) something may be not so good... there should be absolutetly no detectable play between the bevel (crown sprocket?) and the u-joint - not even the slightes that you can feel with your hands. The play is measurable but with oil in the bevel and shaft you should not be able to feel it.
__________________
Drive Safely,
Albert
Reply With Quote
  #6  
Old 8 Aug 2009
Registered Users
New on the HUBB
  
Join Date: Aug 2009
Location: Shefield
Posts: 15
I've stripped the rear of the bike, cleaned the back wheel caliper etc, and given it a good looking over, the swing arm feels nice and everything seems as it should be.
I've decide whilst I can't do any dynamic testing until I get the electrics back together that I may as well restore the sub frame and get it back in good order,
I will try your later suggestion and let you know the results, just turning the wheel seems very smooth and the oil in the bevel looks like new - I don't want to drain it until I can listen to it running .

Thanks again
Reply With Quote
  #7  
Old 8 Aug 2009
Registered Users
New on the HUBB
  
Join Date: Aug 2009
Location: Shefield
Posts: 15
I've pulled the gaitor back and rocked the wheel back and forth, I can move the wheel about 3mm only (measured on the tyre thread) before the universal joint moves, which feels to me like the slack on the splines between the wheel and the bevel. The diode board should come Monday , i'll try the rest of the test then. I've got my eye on a gearbox on Ebay just in case !

Julian
Reply With Quote
Reply

« Previous Thread | Next Thread »

Currently Active Users Viewing This Thread: 1 (0 Registered Users and/or Members and 1 guests)
 

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Alternator output on '82 R100RS John Roberts BMW Tech 29 6 May 2006 14:42
BMW 1979 R100T Off Road? Universalcat Which Bike? 3 11 May 2005 09:45
R100RS reliability John Roberts BMW Tech 2 1 Apr 2004 01:52
Noisy Helmets on R100RS John Roberts BMW Tech 3 19 Mar 2004 23:52

 
 

Announcements

Thinking about traveling? Not sure about the whole thing? Watch the HU Achievable Dream Video Trailers and then get ALL the information you need to get inspired and learn how to travel anywhere in the world!

Have YOU ever wondered who has ridden around the world? We did too - and now here's the list of Circumnavigators!
Check it out now, and add your information if we didn't find you.

Next HU Eventscalendar

25 years of HU Events
Be sure to join us for this huge milestone!

ALL Dates subject to change.

2025 Confirmed Events:

Virginia: April 24-27
Queensland is back! May 2-5
Germany Summer: May 29-June 1
Ecuador June 13-15
Bulgaria Mini: June 27-29
CanWest: July 10-13
Switzerland: Aug 14-17
Romania: Aug 22-24
Austria: Sept. 11-14
California: September 18-21
France: September 19-21
New York: October 9-12 NEW!
Germany Autumn: Oct 30-Nov 2

Add yourself to the Updates List for each event!

Questions about an event? Ask here

See all event details

 
World's most listened to Adventure Motorbike Show!
Check the RAW segments; Grant, your HU host is on every month!
Episodes below to listen to while you, err, pretend to do something or other...

Adventurous Bikers – We've got all your Hygiene & Protection needs SORTED! Powdered Hair & Body Wash, Moisturising Cream Insect Repellent, and Moisturising Cream Sunscreen SPF50. ESSENTIAL | CONVENIENT | FUNCTIONAL.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

2020 Edition of Chris Scott's Adventure Motorcycling Handbook.

"Ultimate global guide for red-blooded bikers planning overseas exploration. Covers choice & preparation of best bike, shipping overseas, baggage design, riding techniques, travel health, visas, documentation, safety and useful addresses." Recommended. (Grant)



Ripcord Rescue Travel Insurance.

Led by special operations veterans, Stanford Medicine affiliated physicians, paramedics and other travel experts, Ripcord is perfect for adventure seekers, climbers, skiers, sports enthusiasts, hunters, international travelers, humanitarian efforts, expeditions and more.

Ripcord Rescue Travel Insurance™ combines into a single integrated program the best evacuation and rescue with the premier travel insurance coverages designed for adventurers and travel is covered on motorcycles of all sizes.
(ONLY US RESIDENTS and currently has a limit of 60 days.)

Ripcord Evacuation Insurance is available for ALL nationalities.


 

What others say about HU...

"This site is the BIBLE for international bike travelers." Greg, Australia

"Thank you! The web site, The travels, The insight, The inspiration, Everything, just thanks." Colin, UK

"My friend and I are planning a trip from Singapore to England... We found (the HU) site invaluable as an aid to planning and have based a lot of our purchases (bikes, riding gear, etc.) on what we have learned from this site." Phil, Australia

"I for one always had an adventurous spirit, but you and Susan lit the fire for my trip and I'll be forever grateful for what you two do to inspire others to just do it." Brent, USA

"Your website is a mecca of valuable information and the (video) series is informative, entertaining, and inspiring!" Jennifer, Canada

"Your worldwide organisation and events are the Go To places to for all serious touring and aspiring touring bikers." Trevor, South Africa

"This is the answer to all my questions." Haydn, Australia

"Keep going the excellent work you are doing for Horizons Unlimited - I love it!" Thomas, Germany

Lots more comments here!



Five books by Graham Field!

Every book a diary
Every chapter a day
Every day a journey
Refreshingly honest and compelling tales: the hights and lows of a life on the road. Solo, unsupported, budget journeys of discovery.
Authentic, engaging and evocative travel memoirs, overland, around the world and through life.
All 8 books available from the author or as eBooks and audio books



Back Road Map Books and Backroad GPS Maps for all of Canada - a must have!

Your ad could be here, on EVERY page of the HUBB, or the whole website, or as many as you like!

New to Horizons Unlimited?

New to motorcycle travelling? New to the HU site? Confused? Too many options? It's really very simple - just 4 easy steps!

Horizons Unlimited was founded in 1997 by Grant and Susan Johnson following their journey around the world on a BMW R80G/S.

Susan and Grant Johnson Read more about Grant & Susan's story

Membership - help keep us going!

Horizons Unlimited is not a big multi-national company, just two people who love motorcycle travel and have grown what started as a hobby in 1997 into a full time job (usually 8-10 hours per day and 7 days a week) and a labour of love. To keep it going and a roof over our heads, we run events all over the world with the help of volunteers; we sell inspirational and informative DVDs; we have a few selected advertisers; and we make a small amount from memberships.

You don't have to be a Member to come to an HU meeting, access the website, or ask questions on the HUBB. What you get for your membership contribution is our sincere gratitude, good karma and knowing that you're helping to keep the motorcycle travel dream alive. Contributing Members and Gold Members do get additional features on the HUBB. Here's a list of all the Member benefits on the HUBB.



All times are GMT +1. The time now is 21:21.

Contact Us - Horizons Unlimited Motorcycle Travellers Website - Archive - Privacy Statement - Top