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Odd spring in bottom of 77 Type 1 fork

Posted: Sat Aug 18, 2012 6:35 pm
by Krauser4valve
I took the bottom threaded cap off my right fork after draining the oil, something didn't seem right. I found this, anyone seen a spring added to the BOTTOM of a fork? The gunk in the bottom cap has a lot of silicone sealant in it, someone had added it to the threads. The spring is smaller in diameter than a normal BMW fork spring and is ~ 5 inches long. Image

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sat Aug 18, 2012 6:55 pm
by Krauser4valve
Hmm, I took a look at Snowbum's site and I see a spring here that looks like the one I have. http://bmwmotorcycletech.info/ForkTool.jpg That looks like a later bike than mine though as it has electronic ignition :?

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sat Aug 18, 2012 9:11 pm
by Kurt in S.A.
Possibly aftermarket anti-bottoming springs? They were highly touted at some point.

Kurt in S.A.

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sat Aug 18, 2012 9:31 pm
by Krauser4valve
Thanks, I had no idea. I googled "anti-bottoming springs bmw" and found a reference to Luftmeister selling them.

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sun Aug 19, 2012 9:03 am
by lrz
I had/have those in my '77.

After the rebuild, including new bottom "bumpers", I was informed that it should be either the springs or the bumpers, not both.

Mine handles well with both...

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sun Aug 19, 2012 11:46 am
by Krauser4valve
I think I'm going to ditch the springs and order new bumpers and washers. With the Progressive Suspension springs on top it is just way too stiff to ride around here with our lousy roads. BMW HD springs might be the next step.

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sun Aug 19, 2012 11:59 am
by Duane Ausherman
I remember those and they are just more snake oil.

It doesn't matter where you put the spring, top or bottom, the result is the same. You just have a longer spring.

So much was made of the added spring that it became outside of physics. People want magic and are willing to pay for it.

Yes, there is a valid question of ride height and spring compression. However, most of the attempts to fix the forks ignored the most important thing, the alignment. If the forks have stiction, then the rest is a waste of time and energy.

So many riders keep to the idea that what worked on forks on other bikes will work on the much stiffer BMW fork. Wrong. If they have stiction, the bike won't handle as well as it possibly can. It may even have a wobble. If you aren't deathly afraid of a wobble, then you haven't been in one.

Ask anyone who has been in a tank slapper at 80 mph if they want to do that again.

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Sun Aug 19, 2012 5:08 pm
by mattcfish
The biggest advantage I can see to the springs is that they don't desolve

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Tue Sep 25, 2012 5:26 pm
by Krauser4valve
After re-assembling the fork with the stock bumpers and washers replaced, I inserted the axle to check on the alignment. It doesn't line up without applying a decent amount of force to the left lower vertically. I could be nuts, but I'd swear that the left fork side looks to be longer from the bottom of the RS fairing. If I measure each fork tube distance between the top and lower clamp, the left fork tube is .020" shorter. Time to make a adjustment?

Re: Odd spring in bottom of 77 Type 1 fork

Posted: Wed Sep 26, 2012 6:57 am
by lrz
When I refreshed the forks myself, I didn't have that problem.

When a MaxBMW tech replaced fork tubes after a deer collision, I experienced that exactly. Also, the front end did not track right at all.

Though I finally had them make it right I don't know 100% what the issue was, but was told that the wiper rings had been destroyed during the initial repair.(?)