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Author Topic: Fork Springs  (Read 315 times)

Offline Adrian

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Fork Springs
« on: June 15, 2023, 11:34:55 PM »
Hi there Brains Trust - having g just finished a nice run through the Adelaide Hills - I feel it's time to change the Old 1984 fork springs.
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So advice please - standard springs or progressive.
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Looking forward to opinions 👌🏍️😉
1984 R65 (860)

Offline Bob_Roller

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Re: Fork Springs
« Reply #1 on: June 16, 2023, 02:38:00 PM »
I replaced the OEM fork springs at about 78,000 miles, 110,000 km in 2007 .
I used Progressive brand progressive springs brought the front up a bit, forks stopped bottoming out handling may have improved but I usually only ride the bike to work  ,no twisting roads anywhere near me just city riding .
One thing I did notice, is leaving home, I have to go down a curb out of my driveway and I get a slight squeak not noticeable when riding .
« Last Edit: June 16, 2023, 02:39:37 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 nhmaf

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Re: Fork Springs
« Reply #2 on: June 16, 2023, 08:40:39 PM »
I also put progressive brand fork springs in my 82 R65LS when I rebuilt the forks back in 2012.  There was a PVC spacer to fit on the top of the springs and it did take some pushing to get it in place - provided some more preload, but I think one could also trim the spacer down a bit if one didn't want quite so much.  I am a heavier (200 pounds) rider and I like to ride the R65 briskly along country roads - the handling is better than it was with the very old OEM springs (obviously) but it doesn't turn the bike into a modern sport bike either.
I am pretty happy with them and yes - it is very hard to bottom them out.  Very light riders might consider them a bit harsher riding, though.
Airhead #12178 ? BMWMOA #123173 ?BMWRA #33525 ?GSBMWR #563 ?1982 BMW R65LS ?1978 BMW R100/7 1998 Kawasaki Concours

Offline dogshome

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Re: Fork Springs
« Reply #3 on: June 18, 2023, 02:08:04 PM »
I'd agree with NHMAF. Some sort of imorivement and nor bottoming. The original springs I took out were in spec. I'm also fairly huge and have an RT fairing. There were no spacers.

I get 2" of sag from off load to me on it. Which is on the high side. I should fit the spacers.

Double hoop fork brace made a massive handling improvement. Frame braces also noticeable despite what others say. Springs or brace? definitely the brace.
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Offline Barry

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Re: Fork Springs
« Reply #4 on: June 19, 2023, 07:33:06 AM »
My original springs are still well within BMW's dimensional limits and being a relative light weight I'm happy with them. Laden sag is about right at just under 1/3 of full travel and that's the best check to apply when considering stiffer springs or pre-load. 

If dive is a concern there is always the option of increasing the air spring by adding more oil.  The difference is quite marked between the recommended min and max limits of 20 to 50mm above the top of the damper piston. I'd be wary of going much above 50mm figure and only add oil in small increments perhaps 5mm at a a time.

At the end of the day, if you can't all but bottom the forks under the most extreme provocation then they are not meeting the design intent. Suspension travel is there to be used.
« Last Edit: June 19, 2023, 07:36:40 AM by Barry »
Barry Cheshire, England 79 R45