Final Drive Design Weakness? - BMW Luxury Touring Community
 
LinkBack Thread Tools Display Modes
post #1 of 4 Old Oct 15th, 2012, 9:51 pm Thread Starter
Lifetime Supporter
 
deanwoolsey's Avatar
 
Join Date: Aug 2008
Location: Topeka, KS, USA
Posts: 3,105
Final Drive Design Weakness?

Having recently joined the "4 percent" group I was curious if anyone else had noticed this with the FD. In order of appearance we have a tapered roller bearing, pinion gear, ring gear, and a caged roller bearing. Because the pinion gear is between the ring gear and the tapered roller bearing, wouldn't that cause the torque generated by the ring and pinion set to load up on the caged roller bearing? It just seems to me that if the drive-shaft turned the other direction and the pinion gear was between the ring gear and the caged roller bearing, the torque and subsequent lateral load would be applied to the tapered roller bearing. Hmmm........


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
deanwoolsey is offline  
Sponsored Links
Advertisement
 
post #2 of 4 Old Oct 15th, 2012, 10:08 pm
Senior Member
 
dshealey's Avatar
 
Join Date: Apr 2002
Location: Dandridge (Near Knoxville), TN, USA
Posts: 12,165
Re: Final Drive Design Weakness?

The lateral load developed by the ring and pinion is a fairly small percentage of the torque load applied, and the fact that the ball bearing is HUGE in comparison to the tapered roller means that it has probably higher lateral load capacity, and in fact sees most of the lateral loads applied by the wheel in different riding conditions. Any lateral loads applying force to the left by the wheel are ALL taken by the ball bearing.

I don't want to achieve immortality through my work...I want to achieve it through not dying.

David Shealey
Dandridge, TN
EX: '01 Black LT, BAT BYKE (Totaled at 110,000 miles)
IBA SS, BB, BBG, 10/10ths.
No bike now, but maybe in the future.
dshealey is offline  
post #3 of 4 Old Oct 16th, 2012, 1:51 am
Senior Member
 
casualemt's Avatar
 
Join Date: Jun 2009
Location: Oak Harbor, WA, USA
Posts: 676
Re: Final Drive Design Weakness?

Yea!....What Dave said...

RICH CANNON
2000 K1200LT "a great ride"
2002 GL1800 powerful, but boring..(gone)
1979 XS1100 (gone)
1986 VT500 Ascot (gone)
1972 Honda 500-4 (gone)
1961 Lambretta (way gone)
1962 Allstate Compact (gone but not forgotten)
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
casualemt is offline  
 
post #4 of 4 Old Oct 16th, 2012, 10:06 pm
Senior Member
 
K100Dennis's Avatar
 
Join Date: Jul 2008
Location: Railton, Tasmania, Australia
Posts: 876
Re: Final Drive Design Weakness?

Engineering design almost always ends up being a compromise, be it based on cost, space restrictions, performance constraints or even in some cases aesthetics. That being a given, in an ideal world we might have seen a tapered roller bearing each side of the crown gear, we would (most likely) have also seen a much more expensive bike with possibly a larger and more ugly FD gear casing. My point is that the whole drive system would have been engineered fit for purpose whilst meeting the design criteria. It is highly unlikely that a company as large as BMW "just got it wrong". Where they may have fallen down is in training of their assembly techs in the correct preload setting operation.Others may have a different view, that's mine.

Dennis
1987 Yamaha TY250R
1991 Aprilia Climber 280
1988 K100RT (the pack horse)
2005 K1200LTE Light yellow metallic
K100Dennis is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the BMW Luxury Touring Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
What to do with a "used" FD jers99lt K1200LT 23 Dec 9th, 2011 11:31 am
Final drive pivot bearing change method CharlieVT K1200LT 13 Aug 17th, 2011 1:14 pm
HELP NEEDED - Final Drive cccpastorjack K1200LT 20 Aug 2nd, 2009 8:57 am
Final Drive murray K1200LT 22 Sep 28th, 2008 10:02 am
R1100RT Final Drive Oil Leak markbreen Other R-Bike Discussion 3 Jul 12th, 2006 10:11 am

Posting Rules  
You may post new threads
You may 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

 
For the best viewing experience please update your browser to Google Chrome