forks, seals and squreely handling

[agf]

Over the last week or so I have noticed that on cornereing my bike doesn't track exactly how I figure it should. I checked tire pressures and it was all ok, only about 5000kms on the Z8's so plenty of life there still.

Tha handling is like hitting a tar snake or riding along a white lane marking that has been done with heaps of paint or like ridingacross tram tracks, only not as bad, just enough to make me keep thinking I'm not riding right???!!!

Yesterday I stopped to do a spot of shopping and in Melbourne we can park on the footpath(sidewalk), so as i left I just slowly went of the curb and the front end felt like it was about to bottom out. It is certainly pretty easy to get a bounce going. I also feel like its dropped as I can nearly flat foot it and I know when I bought it I was on the balls of my feet. I guess as it has sagged a bit I have got used to it.

Anyway, this morning I booked in for seals and fresh fork oil. The bike has done 30,000kms roughly. I take it in on Monday morning

any further advice, or experience you might be able to offer? I did talk to the mech about running 10w oil as opposed to the 5-7w that apparently comes as stock. That's one of the tips I read about a while back

I'm not looking to do a big mod, as I generaly use the FZ as a commuter and have been pretty happy with the set up as it has been.
I'll keep you posted as to what they find.

 

[TownsendsFJR1300]

I used 7 wt and I think you'll be fine with up to 10 wt.

If their the stock springs in the front end their soft to start with and sag with time. You either look at after market springs, or new adjusters to replace the fork caps. They adjust the preload and will help lift the front end up

After I changed my fork oil and reading up on sag, I ended up modifying the stock fork caps with shrader valves. I used a metal lather but it can be easily done with a drill press. Here's a link to the thread;

http://www.600riders.com/forum/fz6-mods/54803-air-assist-fork-caps.html

Its been over 4 months since installed, 14 PSI is plenty. Absolutly no leaks, air or oil. Unlimited adjustability. Picked up just over about 1.25" static sag, nose dive is 1/3 of stock. It also take a bit of the load off the stock springs so they should last a bit longer. One of the best mods IMO, love, a very different bike..

 

[agf]

Thanks scott i remember reading about that mod
Be interesting to hear what the mech reports on general condition of the forks and their guts


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[TownsendsFJR1300]

The spring lenth new is 354mm, worn limit is 347mm's (just is case he doesn't have the spec's)

 

[FinalImpact]

I think the bigger issue is the multi rate springs up front go limp after a while esp if installed incorrectly which plenty seem to be. Its simply no match for the rear with its linear rating.

I highly recommended anyone reading this to MEASURE YOUR BIKES SAG and RECORD the VALUES! Now you have reference for the future. One person, a ziptie and tape measure and you can record the SAG values for Bike and Bike + Rider.

To your point; unless you grew or drug your soles off, the bike has lowered itself which indicates the springs rates are decreasing and are making the handling more unpredictable. I'd recommend some linear rate springs or the air cap.

The fact that the OEM spring starts life 0.75 kg/mm and goes up to 1.20kg/mm, well its simply consuming too much travel holding itself up, let alone a riders weight.

I was watching MXGolf's bike afer 0.95kg/mm install and 7.5wt and the travel on / vs / off the throttle is pretty amazing how much the front moves up and down from throttle input let alone corner loading. Regardless, SPRINGS and OIL is Good starting Point!

FWIW: Not all oils are the same. Use Yamalube of 7.5 to 10wt, as some brands may indicate 7.5wt but be less than OEM 5wt. Using OEM oil (Yamalube) takes this "unknown" out of the equation.

 

[agf]

well I have the Wasp back and the yam guys checked the forks and said the sag and reboundfall well within what they expect for a 30,000km bike age.
Thy checked the steering head bearings and reckoned all was as they might expect, but they did say that there was evidence of scalloping and significant sidewall cracks in the front tire likely from under inflation-my bad! and I do remeber thee was a few times when new that I had been a bit tardy with my tire pressure maintence. Damage done early by the look of it!

Reccomendation -a new front tire. they came came to this conclusion after test rides. They said they could feel exactly what I was talking about and If i want it stiffer they will happily drain clean and re-fill with 10wt oil. But for now I have a Mich PR4.on the front.
Interestingly I had been looking at the specs for thes tires. I like the braking and wet riding capabilities and while I thought there was plenty of life in the Z8's- front's been on for about 2 years, replaced the rear 12months back due to a screw!- didnt really consider swapping to new rubber in the short term.


So100kms to scrub them in and already on the 20km ride home, I find the turn in really different( I know new tires always come across way better), but this feels really light and extremely "sound" when riding along tarsnakes, or tram tyracks, or slightly uneven pavement in the direction of travel.

So later in the year I'll do the rear and have tires that complement each other properly

 

[FinalImpact]

If you can remove the front wheel / calipers, a fluid change is pretty easy DIY action item. Remove fender and loosen pinch bolts and the Wasp hands you its forks! You could even shim the front with washers and get some ride height back w/out a spring change.

Are the forks leaking oil? If no, do a fluid swap. Everything to gain and nothing to loose. Besides, oil will help the rebound rate and reduce the tire scallop effect!

 

[agf]

No leaks Randy thanks for the tips - my biggest problem is time to spend on spanner work- always time poor!


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