[Sellingson69]

I have been ridding this bike for about 2 years now and never had this horrible experience, not with the OEM rear shock nor with the K-Tech Razor. High speeds all kinds of acceleration not a problem, but that Sunday I almost get killed.
This bike makes 140 ~ 160 mph very comfortable and safe and probably may do 190 mph because all restrictions were removed with the Dano's Flash.

Very strange. I know if it were me I would keep it slower until I found the problem.

 

[Supercharger]

I know I am late to this post but I can tell you exactly why it happened and how to make sure it does not happen again. You weigh 140lbs. The OEM fork preload is WAAAAY to stiff for your weight. For your weight I would have 4 lines showing. Trust me, it will make your bike feel super stable at speed. I am 165lbs and had the same experience. You are also not using much of the fork stroke, your just riding around at the top of the stroke with so much preload which is why the bike feels nervous at speed. If you want to see how much of the stroke you are using you can put a zip-tie around the lower fork leg. Don't pull it too tight, you want it move but not loose enough that it can work its way down from gravity or vibration. Push the zip-tie up against the upper leg and go for a ride. When you return that zip-tie will show you exactly how much suspension stroke you are using.

 

[john2019]

I know I am late to this post but I can tell you exactly why it happened and how to make sure it does not happen again. You weigh 140lbs. The OEM fork preload is WAAAAY to stiff for your weight. For your weight I would have 4 lines showing. Trust me, it will make your bike feel super stable at speed. I am 165lbs and had the same experience. You are also not using much of the fork stroke, your just riding around at the top of the stroke with so much preload which is why the bike feels nervous at speed. If you want to see how much of the stroke you are using you can put a zip-tie around the lower fork leg. Don't pull it too tight, you want it move but not loose enough that it can work its way down from gravity or vibration. Push the zip-tie up against the upper leg and go for a ride. When you return that zip-tie will show you exactly how much suspension stroke you are using.

Thanks Supercharger,
Sorry I have not seen your post. I'll try your suggestion. I have started to riding again but not over 70 mph and just under 5K rpm. I'm very afraid to go even 120 mph again

 

[kjhaynes78]

Funny that this post should be resurrected now! My 2022 does this under really hard acceleration - front end gets light and gives a little wobble. Not all the time. Seems to be influenced more by road conditions rather than my body position, as I deliberately put weight forward under hard acceleration.

@john2019 - will be curious to see if this works for you.

@Supercharger - I weigh in at around 190lbs and figured the stock suspension setup would already be in that range. Thoughts?

 

[john2019]

What I'm doing now when going over 65 mph is I laying down in my belly over the tank.
I guess this horrible behavior is normal under hard acceleration due to a very light weight rider like me.

 

[Supercharger]

Funny that this post should be resurrected now! My 2022 does this under really hard acceleration - front end gets light and gives a little wobble. Not all the time. Seems to be influenced more by road conditions rather than my body position, as I deliberately put weight forward under hard acceleration.

@john2019 - will be curious to see if this works for you.

@Supercharger - I weigh in at around 190lbs and figured the stock suspension setup would already be in that range. Thoughts?

It depends on the shock too. If you have reduced the preload on the shock it will magnify the stiff front. I highly recommend to zip tie test, It is very helpful to see if the forks are too stiff. Put one around the lower fork leg and push it up against the upper leg. Go for a ride and ride like you normally do, If you come home and that zip tie is still pretty far up the lower fork leg you have too much preload and/or too much damping. During my normal riding and braking my zip tie is about 1 1/2in from the bottom. That gives you room for very hard/panic braking without bottoming, I have 3 1/2 lines visible on my fork preload adjusters. Am at 8 clicks out on compression and I think 7 on rebound. Works well for me. When the preload was set to stock 2 1/2 lines I got some bar wag over 100mph. Now I don't. My bike handles great and is very stable and planted at speed. If you go too soft on the front you will feel it. The steering will be a bit sluggish and heavy.

 

[john2019]

I turned the nut all the way to "S" position showing about 5 lines. I took a ride and now seems smoother in front but I don't know how it would handle about 140 plus mph.

 

[Supercharger]

Baby steps....

What ramp position you running on the shock?

 

[john2019]

Baby steps....

What ramp position you running on the shock?

The rear shock is adjusted to the softest position. The rings are set almost to the top of the shock (I don't want the spring to be compressed at all to make sure is soft)
The reservoir is set to 15 clicks starting from the 0 position.

 

[Supercharger]

The rear shock is adjusted to the softest position. The rings are set almost to the top of the shock (I don't want the spring to be compressed at all to make sure is soft)
The reservoir is set to 15 clicks starting from the 0 position.

Thats what I thought. That is too soft. I am on the 4th ramp position and I'm about 165-170 in riding gear. 15 clicks out on the rebound adjuster is the limit and gives you very little rebound damping. You are practically just riding around on the springs if you have compression and rebound 15 clicks out. That will cause massive handling issues!

 

[john2019]

I'll screw down those nuts on the shock to compress the spring and reduce or increase some clicks on the reservoir to see if I get some real change.
For the money that this rear shock cost it should come fixed for my weight. Why so many adjustments?

I don't do track racing just simple street riding, not a big deal.

 

[Supercharger]

John I would recommend adjusting fork preload the 4 lines visible. Adjust compression and rebound on the forks to 8 clicks out as a good starting point, I would set the rear shock at the second or third position and rebound at one turn from fully closed. That will at least restore your confidence in your ride. I agree on the springs. The MFG must try to accomodate very light to very heavy riders with the same spring rate which is impossible. Those who are at the weight extremes will never get the handling they want wthout a spring change IMHO.

 

[john2019]

John I would recommend adjusting fork preload the 4 lines visible. Adjust compression and rebound on the forks to 8 clicks out as a good starting point, I would set the rear shock at the second or third position and rebound at one turn from fully closed. That will at least restore your confidence in your ride. I agree on the springs. The MFG must try to accomodate very light to very heavy riders with the same spring rate which is impossible. Those who are at the weight extremes will never get the handling they want wthout a spring change IMHO.

Thanks Supercharger,
I'll do these adjustments, see if I get a better ride.

 

[kjhaynes78]

It depends on the shock too. If you have reduced the preload on the shock it will magnify the stiff front. I highly recommend to zip tie test, It is very helpful to see if the forks are too stiff. Put one around the lower fork leg and push it up against the upper leg. Go for a ride and ride like you normally do, If you come home and that zip tie is still pretty far up the lower fork leg you have too much preload and/or too much damping. During my normal riding and braking my zip tie is about 1 1/2in from the bottom. That gives you room for very hard/panic braking without bottoming, I have 3 1/2 lines visible on my fork preload adjusters. Am at 8 clicks out on compression and I think 7 on rebound. Works well for me. When the preload was set to stock 2 1/2 lines I got some bar wag over 100mph. Now I don't. My bike handles great and is very stable and planted at speed. If you go too soft on the front you will feel it. The steering will be a bit sluggish and heavy.

View attachment 48740

Thanks for the help - will definitely try this out!

 

[john2019]

I screwed it to the top position then reversed 8 clicks, then I gave one click counter clock, I went for a test drive, then I gave another click counter clock then when for a final test. No much difference.

When I press down on the forks still darn hard. The forks should go down and come back up, just like the other 2 bikes do. I push down on the Honda CB500 and the Kawasaki Z650 and the forks go down and come back up fine. This bike is like a train, my weight does not do anything to this suspension.

 

[Rim72]

John2019 I strongly recommend that you measure your suspension sag when you sit on the bike. You need to use the travel provided. And it should look like the picture Supercharger put in above. If you don't measure it we won't be able to advise further because it is all guess work. However, you are right in the fact that the suspension should move like your other bikes. And you are doing the right thing by pushing on it see how it moves.
Suspension basics: the spring supports the bike (although I am struggling to describe this). You need that set to this in the correct ballpark to allow it to do its job. Dampening controls the speed of movement.
Springs generally have a rising rate which means the get stiffer as they compress. My fear with what you are describing above (and I hope I am not miss reading it) is that you have the spring in the portion where it gives the most resistance. If this is true then no amount of dampening adjustment is going to replicate the movement in your other bikes.
Having said that dampening adjust doesn't change much one click at a time and is therefore hard to feel; especially if you are tense when riding.
Hope this explains things better.