Ohlins Front springs, not much of an improval

[StarWing]

Hi all,

Yesterday, I swapped the standard front springs of my FZ6N S2 '07 with a pair of Ohlins front springs:
08711-85 - Öhlins

As these were not new ones, they came without fork oil. My dealer gave me A-grade 10w oil.

I fitted them according to the instructions in the service manual. I've set the air chamber to 134mm as stated in the service manual. I measured this without springs and bushings, with the fork pushed to the lowest point.
To get the level to 134mm, I approximately had to put the same amount of oil in that I've drained out of them.

But I cannot say I got much of an improvement. The front end is much more wobbling than before and the bike dives hard into the front end when braking hard. That is the reason why I swapped them in the first place.

I also noticed that the std springs look alot like progressive ones, with the coils more together on 1 side and that the ohlins have the same coil distance over the whole length of the spring.

So, the question is: did I do something wrong ? Or is this normal behaviour ?

 

[Pauly_V]

Depends. How much do you weigh? 85kg/mm front springs aren't very stout to begin with.

I'm ~220lbs and will be swapping the stockers for 1.0kg/mm RaceTech springs this, er... Spring.

What do you mean by, "wobbling"?

 

[StarWing]

My weight is about 61kg dry on the hook That should be something like 135lbs

Its hard to explain, but I'll give it a shot. I have the feeling that the damping is not what is should be. I have the feeling that the front end is more loose than with the std springs. Although I do not have a lot of expirience with suspension in the first place, it feels like I don't get enough damping (incoming and outgoing).

I hoped that the the replacement of the springs would cause that the front end of the bike would not dive so much than with the std setup. I have the feeling that this is not better, or even worse.
Although the ride overall is much "smoother", the bumps and dimps are more filtered out

 

[Pauly_V]

Wow.. yeah, then the 85kg/mm springs should be plenty stiff for you. Maybe you're just too damn fast for Ohlins.

 

[StarWing]

Maybe you're just too damn fast for Ohlins.

I seriously doubt this . I'm still in winter-mode.

 

[RJ2112]

Hi all,

Yesterday, I swapped the standard front springs of my FZ6N S2 '07 with a pair of Ohlins front springs:
08711-85 - Öhlins

As these were not new ones, they came without fork oil. My dealer gave me A-grade 10w oil.

I fitted them according to the instructions in the service manual. I've set the air chamber to 134mm as stated in the service manual. I measured this without springs and bushings, with the fork pushed to the lowest point.
To get the level to 134mm, I approximately had to put the same amount of oil in that I've drained out of them.

But I cannot say I got much of an improvement. The front end is much more wobbling than before and the bike dives hard into the front end when braking hard. That is the reason why I swapped them in the first place.

I also noticed that the std springs look alot like progressive ones, with the coils more together on 1 side and that the ohlins have the same coil distance over the whole length of the spring.

So, the question is: did I do something wrong ? Or is this normal behaviour ?

I too installed .9 Kg single rate springs in my OEM fork, and did not have the issues you are. In my case the single rate springs cured excessive front end dive issues I had with the OEM springs. Did you remove the fork legs from the triple clamps when you did all the work, and were you very, VERY careful to realign the fork when you put it back together?

If it is not absorbing bumps smoothly, that is usually an indication that the fork legs are not parallel. The twisted legs with relation to each other cause binding, which does not let the fork action be smooth.

Try this:

1) Loosen all bolts that clamp onto the fork legs EXCEPT for the lower triple clamps. Axle, fender, upper triple clamp. Ensure the tubes are level with the upper surface of the upper triple clamp.

2) Sit on the bike, grab all the front brake that you can and bounce the front end 'down' through as much of the stroke as you can. Do this 6-10 times. Really heave on it. This will make the fork legs become parallel to each other.

3) Re-torque all clamping points.

Take it for a spin and see if that sorts it out.

 

[mxgolf]

I have the same springs and am going to install them in the next month or so. Please keep us posted as I am curious if that helps. I have got a feeling those were pretty stiff and the 80 is for lighter riders. I have the 85 and that is for 190# riders and over. With my gear on I hit the 190+ range.
Thanks

 

[StarWing]

If it is not absorbing bumps smoothly, that is usually an indication that the fork legs are not parallel. The twisted legs with relation to each other cause binding, which does not let the fork action be smooth.

Hi,

I don't quite see how you can mis-align the fork legs.
As far as I know, the lower legs turn indepently from the upper part.
When mounting, they will align themselves when mounting the wheel ??

 

[RJ2112]

Hi,

I don't quite see how you can mis-align the fork legs.
As far as I know, the lower legs turn indepently from the upper part.
When mounting, they will align themselves when mounting the wheel ??

The upper and lower triple clamps have enough slack in the clamping surfaces that you can have the legs mounted up with a few degrees of difference in their angle. If you tighten everything up, without compressing the fork legs multiple times first you will 'set' the difference. If you did this on the side stand, the legs are binding.

A few degrees does not sound like much of a problem, but the legs are near a meter long..... the offset adds up at the far end. (The end the axle bolt 'ties' together)

When you put the legs in the triple clamps, do not tighten them all the way down on the upper clamp. Just the lower clamp.

Leave the axle loosely installed, as well as the fender mounts. Pump the fork as I described, then tighten everything up to spec.

 

[StarWing]

So,

I've sent a message to Ohlins and got an answer

As the service manual says 134mm air chamber, Ohlins recommends to use 120mm instead.
This is measured without springs and bushings/spacers.

They also recommend to use oil 01314-01.

I'll adjust my forks this weekend and post the results.

 

[mxgolf]

What's up with the air chamber? I am not familiar with that. Is that how much oil you put in? Thanks for the help.

 

[StarWing]

What's up with the air chamber? I am not familiar with that. Is that how much oil you put in? Thanks for the help.

You measure the air chamber by removing the spring, bushing and washer and compress the fork. Then you measure the "depth" of the oil from the upper part of the fork till the oil itself inside the leg. This is called the air chamber

In the service manual is written that you should use 134mm. Ohlins recommends 120mm, so I'll need to put some extra oil in.

To get to the level of 134mm I had to put approx 500ml of oil in the leg.