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Re:Do I need more fork preload or different fork oil?
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TOPIC: Re:Do I need more fork preload or different fork oil?
#1027848
jd750ace (User)
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Re:Do I need more fork preload or different fork oil? 1 Month ago  
I’m here, just not as frequently. Lots of work going on. Anyway, how much preload are you running now, and you said you did springs. If you didn’t do emulators 15w is really going to slow up your rebound a good bit. That’s 3 times the original viscosity, but you are not on 3 times as much spring. Preload at 20mm, and 10W at stock height should have you tracking well. If riding aggressively, I must highly recommend doing the emulators.
 
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#1027849
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Re:Do I need more fork preload or different fork oil? 1 Month ago  
Hey JD, good to see you're still around. I'm running two washers with the RaceTech springs, which I believe is stock preload. And realistically, since it's a blend of 10 and 15w, it's probably more like a 12w, but yah I was thinking too thick. I definitely want to run emulators but probably won't be able to get around to that until the summer. In the mean time would a couple more washers help?
 
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#1027850
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Re:Do I need more fork preload or different fork oil? 1 Month ago  
You should have spacers, springs, and washers in the tube. When everything is stacked up in a tube your cap should be compressing your stack up 20mm. If you are not, lack of preload is your issue.
 
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#1027868
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Re:Do I need more fork preload or different fork oil? 1 Month ago  
That's basically what I've got... Think I'll try adding a couple washers and see if that helps. I suppose it can't hurt...
 
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#1027870
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Re:Do I need more fork preload or different fork oil? 1 Month ago  
Doc_V wrote:
MidwestMike wrote:
...I don't remember anyone else here reporting ride changes as their tires heated up.

You won't really notice tires heating up unless you have semi sticky tires and you ride aggressively on twisty roads. So the stock Bridgestones and Dunlops on freeways won't do it. But it does make a difference when they warm up; it's why race teams use tire-warmers. They're essentially industrial electric blankets that keep the tires warm and therefore sticky.



BTW - I came across these two great illustrations. The first one demonstrates steering head shake; which is what you'd experience with loose head bearings. It's often referred to as a "tank slapper" and is more likely to occur at high speeds in a straight line; usually under hard throttle. It's why you see a lot of sport bikes with steering dampers.



And this is what I'm referring to as "wallow"; which is a little more difficult to diagnose. It's more of a full-bike oscillation that occurs during high speed sweepers.

This "wallow" is exactly what I got with my attempt at "Darkside". No amount of air pressure change made any differance .I threw the dang car tire away and went to C2's. I run 40 lbs front and 44 lbs rear and this Baby rips. 13,000 miles and rear has maybe 2,000 left , front not even half worn. Getting ready to do Racetech Springs and Emulators in next few weeks.
 
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#1027880
jd750ace (User)
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Re:Do I need more fork preload or different fork oil? 4 Weeks, 1 Day ago  
Doc_V wrote:
That's basically what I've got... Think I'll try adding a couple washers and see if that helps. I suppose it can't hurt...

Up to 25mm preload is available. If you have the correct springs, with 15-25mm of preload, you should not have a wobble. I’m thinking more damping.
 
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#1027881
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Re:Do I need more fork preload or different fork oil? 4 Weeks, 1 Day ago  
jd750ace wrote:
Doc_V wrote:
That's basically what I've got... Think I'll try adding a couple washers and see if that helps. I suppose it can't hurt...

Up to 25mm preload is available. If you have the correct springs, with 15-25mm of preload, you should not have a wobble. I’m thinking more damping.


Aside from the whole disassembly, my main reason for holding off on the emulators in the first place was having to drill out the stock dampers. Not really looking forward to that one... I don't have a drill press and it just sounds like a major PITA with high potential for F'ing up.

Horsehammerr wrote:
I run 40 lbs front and 44 lbs rear and this Baby rips. 13,000 miles and rear has maybe 2,000 left , front not even half worn. Getting ready to do Racetech Springs and Emulators in next few weeks.

I guess the *easiest* thing would be to up my tire pressure and see what happens. Been running 39/40, guess I'll try 40/41 then 41/42. As I mentioned above, I'm just concerned about squaring the tires, which only makes it worse.
 
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Last Edit: 2018/01/25 10:33 By Doc_V.
 


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#1027883
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Re:Do I need more fork preload or different fork oil? 4 Weeks, 1 Day ago  
Doc_V wrote:
jd750ace wrote:
Doc_V wrote:
That's basically what I've got... Think I'll try adding a couple washers and see if that helps. I suppose it can't hurt...

Up to 25mm preload is available. If you have the correct springs, with 15-25mm of preload, you should not have a wobble. I’m thinking more damping.


Aside from the whole disassembly, my main reason for holding off on the emulators in the first place was having to drill out the stock dampers. Not really looking forward to that one... I don't have a drill press and it just sounds like a major PITA with high potential for F'ing up.

Horsehammerr wrote:
I run 40 lbs front and 44 lbs rear and this Baby rips. 13,000 miles and rear has maybe 2,000 left , front not even half worn. Getting ready to do Racetech Springs and Emulators in next few weeks.

I guess the *easiest* thing would be to up my tire pressure and see what happens. Been running 39/40, guess I'll try 40/41 then 41/42. As I mentioned above, I'm just concerned about squaring the tires, which only makes it worse.


You didn't mention what brand and model of tires you were running. I had the same exact problem with a Shinko mounted on the rear. They have weak sidewalls and air pressire won't help. Mounted a Metzler 888 and the problem went away.
 
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#1027884
Deerkiller (User)
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Re:Do I need more fork preload or different fork oil? 4 Weeks, 1 Day ago  
Doc, I did the emulators and had the same apprehension about drilling the stock stuff and all that. Probably because I couldn’t visualize what was actually in there.

Once I did it, I couldn’t believe how easy and straight forward it was. I can’t remember if I got the instructions from JD or from Race Tech but they’re available and it’s a piece of cake. JD answered a few questions along the way for sure. Trust me. Just do it
 
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#1027885
jd750ace (User)
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Re:Do I need more fork preload or different fork oil? 4 Weeks, 1 Day ago  
38/40 is plenty of solo pressure, at least for CIIs.
 
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