benefit of aftermkt springs?

[26667]

So we "discovered" the cause of the clanking noise in my front forks. The PO had installed stiffer than oem fork springs(Luft?) and four of the six rings on the pistons inside were missing. (two out of three on one fork, zero on the other)...Nice.

Everything seems fine now, but my Q is what's the real advantage gained from stiffer fork springs?

If there's less "dive" in the front end does that put more weight/traction at the rear? If there's a less pronounced rebound, does that keep the front tire more firmly on the pavement? Therefore, better handling? Or just better handling when you push it a bit?

[ebeeby]

Dive was awful on my R75/5 until I threw away the oem springs and put in a set of Progressives,

[26667]

I never really noticed it on a couple of previous airheads, an R100 and a 65, but the R100 had a Pichler, which I'm sure is lighter than the factory RS fairing. This current bike never seemed to me to handle much differently than the other, but of course the springs weren't properly installed. Maybe that made them a bit softer. we'll see.

I've been reading David Hough's book and I'm kinda getting a clue as to what happens to the suspension and clearance under braking and accel.

[rinty]

Gene:

The stock springs in an airhead give a real hobby horse ride from acceleration and deceleration forces. According to Joe Minton, the BMW springs were so bad that some of them were actually sacked when they got to the dealer.

I once rented a stock RT in San Francisco, and went for a ride in the twisties south of there. That was a real eye opener, as it bucked all the way to Santa Cruz and back (via Alice's!). It required a very gentle throttle action to keep the bike composed. On my own RS, which had Luftmeister anti bottoming springs and Progressive Suspension progressive springs, there was hardly any dive at all, and no pogo-ing (I had heavy duty Koni's on the rear).

It makes the bike a lot easier to ride when you have quality aftermarket stuff installed by someone who knows how to set it up.

My bike, which was set up by Dave Anderson, was incredible. You could run rough corners at high speeds and it would never get thrown off line, or get out of shape. But it also had the other mods: the swing arm brace and CC products upper triple tree.

Rinty

[26667]

Yes, mine has the billet upper triple clamp and Telfix lower fork brace. I changed the oem shoks for Ikons last year. The biggest difference I've noticed is whether there's a load on the back.

I haven't yet ridden the bike since the fork springs were re-installed. The guru tells me it was a booger to get them down to tighten top nut/cap. A two-man job and one of the men needs to be BIG. That hadn't been the case when we changed the fork oil last year, but I believe that EZ re-install was the result of the missing oil control rings.

When you say "set up properly", does that indicate that I have some other options yet to consider with these forks? I suppose a lighter oil would have some bearing if they seem "harsh" to me for my everyday riding. But as near as I can tell, they only go back together one way.

[20774]

I'm not sure the oil scraper rings had any effect on getting the springs installed. Sounds like the new fork springs have less sag in them then the originals. They must have stuck up past the top of the upper tree an inch or more. When they stick out that far, you have to compress the spring while turning the fork cap at the same time. It can be a bear to get the cap started.

If the springs are that "stout", that will make them less likely to dive, due to the increased spring tension. The rebound is controlled by the fluid weight and the holes that are at the bottom of the forks. Light weight oil flows easier than heavy weight oil. People have been known to braze closed some of the holes to modify the damping.

[26667]

these springs were installed by the PO many years ago. We just discovered recently that they were aftermarket. There was "suddenly-out-of-nowhere" a clanking noise in the forks. I'd ridden this bike 4 or 5000 miles w/o any noise. But as my guru discovered after much trial and error, the oil rings were incorrect (two and none). God only knows why. .....unless that might be a way to tune the ride.

Installing the correct number of rings seems to have quieted the noise. We'll see about the ride and handling if it ever gets above 30 here.

[sumran]

I replaced my stock springs when I got my bike. I knew there were problems when I bought it. The PO even knocked some money purchase price because he knew the forks needed to be rebuilt.

The handling and diving were a real problem with the old springs. At the mechanic's suggestion, I used the heavy duty BMW springs. The handling and braking are good now, but the ride is stiff. If I had it to do over again I would have used progressive springs. I plan to put a Hannigan fairing on the bike at some point. Perhaps I will be glad to have the heavy springs to handle the additional weight and downforce from the fairing. I will add a fork brace and billet triple top one of these days.

I have Koni's on the back and I am very happy with them.

[rinty]

Does that indicate that I have some other options to...consider....26667

I was just referring to the sag, and I assume your tech addressed that.

Incidentally, my tech does away with the fork brace when he installs the good springs and triple tree. Then you don't have to worry about perfect fork alignment.

Mine was braceless and it worked fine.

Once the RS is properly suspended, the only limiting factor in cornering is the low bar leverage. But you you're used to that. Also, the suspension will soften up with use, and the bike will become more comfortable.

Have fun this summer.

Rinty