Fork Oil

[instigator]

Does anyone know what fork oil 'rating' I should put in my forks of my 600 hornet if I want to stiffen it upa little?

I find the front moves too much and needs stiffening. I'm replacing fork seals at the moment, not willing to buy better springs as of yet as I don't want to spend that much money really.

Ideas?

[BFG]

[Kickstart]

Hi

You can use thicker oil, but as mentioned above this affects the damping. The forks will still dive just as far but will just take longer to dive (and also longer to return).

A couple of 10p piece worth of preload on the springs might help.

Also try fiddling with the fork oil level. More oil means less air above the oil, and the air needs to be there to compress when the forks compress. Reduce the air gap and you stiffen the forks. Very cheap and easy to do (although potentially putting more stress on the fork seals). Probably worth reducing the air gap by 10mm and see how that goes. Easy to add a small measured amount of oil to each fork afterwards to reduce the air gap further.

All the best

Keith
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[jay12329]

You have 3 options to improve the front end of the hornet.

1, Replace oil with thicker, or use one of the little tricks mentioned above. Will improve slightly but genrally at the cost of other performance.

2, Replace springs with ohlins or WP. Changeing oil at the same time. This will reduce dive but can also cause issues with other areas of the suspention performance.

3, Full re spring and revalve from BSD. This is the most expencive and best option for both track and road rideing. The forks are set up to your body weight.

I have fitted ohlins springs to my hornet 6' this has reduced the dive under brakeing but there is very little dampning causing the front to skip under braking as the springs force the front end up sudenly. I will be changing my oil for heaver 15w oil shortly to try and reduce this.
The only sure way to sort the hornet suspention is to replace the rear shock and get the front end re-valved. This will cost £500 for an ohlins shock and around £200 for the re valve. BSD are the only company i would trust with my forks as they do all the work for the Hornet cup bikes so have devolped there own method of revalving the basic hornet units.

HTH
J

[instigator]

Right.



Didn't realise it was that much of a deep-rooted problem. I mean, the bike handles amazingly, just less so at say 80-90+mph. Just dives a lot is the problem. I'll try the thicker and more oil to see what happens with it. Cheers for the assistance folks.

[BFG]

Sorry to labour the point, but most people play with the oil because it is cheap and easy. But, the short path leads to the dark side!
See our advice on damping.......

[Kickstart]

[Robby]

Getting back to the root problem, you currently have blown seals. That means the air isn't getting compressed much and a large amount of the oil has probably pissed out of the blown seals.

Its going to handle shit on bumps in this situtation.