Fork Springs for S2R1K

[BK_856er]

At 165 the 0.85 springs should be workable for you I think.  The sag numbers should tell the story.  Maybe altering the compression setting will get you in a happier place?  Or dropping the oil level a bit?  Also don't fixate solely on the front...if the rear is out of whack or out of balance you can sometimes get the sensation of a harsh front end.  A good suspension guru might be able to make things right.  Having said that, I also find that my SBK is far more plush than my monster!

BK

[Ivan]

Nice work

How did you do it

Only time I seem to lose weight is when I'm stressed & these last few years have been mellow

Dr said that I needed to lower my cholesterol.  I've just been watching what I eat and exercising more regularly (read: everyday).

[Ivan]

At 165 the 0.85 springs should be workable for you I think.  The sag numbers should tell the story.  Maybe altering the compression setting will get you in a happier place?  Or dropping the oil level a bit?  Also don't fixate solely on the front...if the rear is out of whack or out of balance you can sometimes get the sensation of a harsh front end.  A good suspension guru might be able to make things right.  Having said that, I also find that my SBK is far more plush than my monster!

I can't even get anywhere near 20mm of sag with the 0.9 springs, I'd like the sag to be about 30mm to match the rear.  On top of that, I'm still losing weight and will probably be dropping another 5 to 10 lbs.   All of the on-line calculators and charts point to 0.8 as the correct rate, but I'm probably going to be forced to try the 0.85 with minimal preload.  So far, no luck finding anything lighter except for progressive rate springs, which I'm not enthused about trying.  

I'm not even to the point of worrying about oil level and compression damping, need to get the correct sag first.

The rear sag is fine at 30mm.  I had to back off some preload to account for the weight loss.  I'm sure I'll need to make more adjustments once I have the front end sorted.  Fortunately, I have a lot of adjustments and leeway at my disposal for the rear shock.

[pintsizejesus]

Try seeing what Ohlins has, I'm going to be putting an Ohlin's shock into my 848's rear shock.  So I will have a Showa unit with an Ohlins shock.  The spring is physically different from the showa one but it still works.

[BK_856er]

I'm not even to the point of worrying about oil level and compression damping, need to get the correct sag first.

Gotcha.  Yep, sag first!

BK

[Ivan]

After insisting that 0.8 springs are too light for my weight, I'm happy to say that Race Tech stepped up.    

They took some dirt-bike springs (FRSP375046, these are 36.8mm dia, 472 mm long, and 0.46 kg/mm rate), and cut them down to increase the rate to 0.8 kg/mm.  They also revalved the fork, less rebound and higher compression damping (compression = CH32, rebound = RH16).  Internal preload is set for 8 mm.

For the first time in a long time, the fork actually compresses when I sit on the bike!   Haven't accurately measured the sag yet (nobody here to help right now), but as best as I can tell from the zip-tie it is right around 30mm.

Went for a short ride around the hood, did some ugly stoppies to see how much travel is being used, and so far so good.  Hope to get out to the twisties tomorrow to really shake things out.

[pennyrobber]

I can't even get anywhere near 20mm of sag with the 0.9 springs, I'd like the sag to be about 30mm to match the rear.  On top of that, I'm still losing weight and will probably be dropping another 5 to 10 lbs.   All of the on-line calculators and charts point to 0.8 as the correct rate, but I'm probably going to be forced to try the 0.85 with minimal preload.  So far, no luck finding anything lighter except for progressive rate springs, which I'm not enthused about trying.  

I'm not even to the point of worrying about oil level and compression damping, need to get the correct sag first.

The rear sag is fine at 30mm.  I had to back off some preload to account for the weight loss.  I'm sure I'll need to make more adjustments once I have the front end sorted.  Fortunately, I have a lot of adjustments and leeway at my disposal for the rear shock.

This is supprising. I am between 150 and 155 most of the time and I can get the sag spot on with the stock for springs. I have raised the rear ride height as much as possible wich helped a bit but I am still adding preload.

[Ivan]

This is supprising. I am between 150 and 155 most of the time and I can get the sag spot on with the stock for springs. I have raised the rear ride height as much as possible wich helped a bit but I am still adding preload.

The stock springs are progressive, at max rate they reach 0.6x kg/mm.  I'm not surprised that you can get the sag correct, given your weight.  The stock springs didn't work well for me, I had to run a lot of preload and the front never felt planted when I was riding hard.  I went from stock to 0.9, which proved to be way too much spring.

[pennyrobber]

The stock springs are progressive, at max rate they reach 0.6x kg/mm.  I'm not surprised that you can get the sag correct, given your weight.  The stock springs didn't work well for me, I had to run a lot of preload and the front never felt planted when I was riding hard.  I went from stock to 0.9, which proved to be way too much spring.

I see. I missed the swap to 0.9 somewhere. Must pay more attention and drink more coffee before posting. 

[red baron]

 

[Ivan]

Went to Palomar yesterday, by way of Deluze Rd (the back way into Fallbrook). 



My suspension is finally working very well.  The fork is now compliant enough to deal with the expansion joints on the freeway, and there is enough spring to prevent bottoming when I land on the far side of the cattle grates on the east side of Palomar.  The only change that I made was to add 3 clicks of compression damping to tighten up the front when braking or going through roller coaster type hills.

 

[red baron]

Drag gin this back up, my forks get dropped off at Racetech for the same treatment tomorrow. 

[Speeddog]

Drag gin this back up, my forks get dropped off at Racetech for the same treatment tomorrow. 

Say what?

[red baron]

Thanks Ivan for posting this.

Thanks also to the folks at Racetech, the tech took time to listen to my concerns, understand what type of riding I do and explained to me what to check on the bike before and after I reinstall the legs.

For the first time ever, even since new, the bike now drops on it's own weight, and then again when I get on it (never did this before). Looks like we're on the right path. Standing next to the bike I can now push on one bar and the forks will compress, never did that before.

What they found inside was some small plastic guides that were binding up with a washer and sending the washer off at an angle and stopping my forks from compressing unless enough force was put on them to overcome the binding. Which would explain why if I tapped the front brake everything would work a little better. There was a bit too much oil in both legs, and something about the rebound had 24 clicks of adjustment (should only be 14) and that the screw needed to be preset.

If this works , it may just get the 1k a bit longer stay in the garage.
 

[jerryz]

My thread on here about my ktech 996 forks is exactly the same issue need softer springs than 9.0 etc seems only racetech can help with 8 or 8.5 springs... with 9 I get no sag at all