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Author Topic: Frame to tire alignment?  (Read 1034 times)

Offline crguy

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Frame to tire alignment?
« on: November 01, 2010, 05:49:21 PM »
Hi folks, noticed that the centerline of my rear tire is not aligned to the center of main frame backbone tube, the swing arm is centered to main frame but to center the tire I will need to adjust arm to the right 3/16's. Like to go with centering the tire to frame but not sure if BMW intended for this offset. Thank you, Guy  

Offline montmil

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Re: Frame to tire alignment?
« Reply #1 on: November 01, 2010, 06:12:45 PM »
This topic has popped up within the last few months. General consensus is to center the swing arm gaps, ie: arm to frame, and ride happy.

Several different motorcycles, including the BMW, have a slight wheel centerline-to-wheel centerline offset. The 3/16-inch offset you mention would be excessive, IMHO.

Monte

Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Offline Bob_Roller

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Re: Frame to tire alignment?
« Reply #2 on: November 01, 2010, 06:55:54 PM »
How much of a gap do you have between the rear wheel and the final drive housing ?

How is the extraction hole in the rear axle orientated to the pinch area of the swing arm ?

I just went through this 'exercise' on my '82 LS .

There are different length spacers for the rear wheel, that contact the inner wheel bearing .

A longer one is available from BMW, to give additional clearance between the rear tire and swing-arm, if you have a wider than standard rear tire mounted on the rear wheel .

4 mm is the maximum offset that BMW recommends .
'81 R65
'82 R65 LS
'84 R65 LS
'87 Moto Guzzi V65 Lario
'02 R1150R
Riding all year long since 1993 .
I'll give up my R65, when they pry my cold dead hands from the handlebars !!!!!

Offline crguy

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Re: Frame to tire alignment?
« Reply #3 on: November 01, 2010, 07:20:57 PM »
Rob, the gap is 1/16 between wheel and FD and the axle pushes in nice, axle nut tightens then pinch bolt, I would think that maintaining center-line to frame would overrule swing-arm centered to frame, thanks for the 4mm offset spec. though. My tire wear avg. over the 27 years of ownership is 15k rear and 12K front, don't tell anyone but when coasting downhill hands free the bike always tended to verve to the right, wonder if this is due to offset. Thanks for the replies.

Offline crguy

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Re: Frame to tire alignment?
« Reply #4 on: November 01, 2010, 07:23:45 PM »
Correction: 15k front / 12k rear

Offline Bob_Roller

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Re: Frame to tire alignment?
« Reply #5 on: November 01, 2010, 08:16:19 PM »
There have been members posting here, that with equal gaps between the swing arm and frame, they get a slight 'ticking' sound from the universal joint when the rear wheel is rotated, most likely the universal joint is just barely contacting the swing arm housing .

Adjustments are made to the pivot bolts to  silence the ticking, and the gap on each side of the swing arm ends up not being the same on each side .

From your description, I don't think I would be concerned about the offset, as long as the bike handles well for you .

The habit of the bike wanting to go  right, may be a result of the 'crown' that a lot of roadways have built into them for drainage purposes .
« Last Edit: November 01, 2010, 08:18:15 PM by Bob_Roller »
'81 R65
'82 R65 LS
'84 R65 LS
'87 Moto Guzzi V65 Lario
'02 R1150R
Riding all year long since 1993 .
I'll give up my R65, when they pry my cold dead hands from the handlebars !!!!!

Offline crguy

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  • Posts: 67
Re: Frame to tire alignment?
« Reply #6 on: November 01, 2010, 08:51:25 PM »
Thanks Rob....