When i brake on my bike (nc23) the front end dives down and its becoming too noticable for me now i am getting used to the bike. Whats the best way of firming it up? I have heard references to simply changing the oil (however you do that) but before i start thinking what to do with it, has anyone got suggestions? (apart from lose weight!)

The back was also a bit saggy so i have just tightened up the spring a bit on the rear with a c spanner, that sorted that easily.

put a little bit more air in the top of the forks, that should firm them up a bit (no more than 5psi I think the haynes manual said) you could also put thicker/new oil in, that will definately make a difference

Or do it right and get the right springs for your weight...

CMSMJ1 wrote:Or do it right and get the right springs for your weight...

Yeh this.

You can put air assist in if your forks have air valves on the top, but this can stress the seals. You get a similar effect by adding more fork oil, as there is less air to compress so you get a stronger spring.

Putting thicker oil in just increases the damping. It is an old-school trick and I wouldn't recommend it as all you end up with is undersprung AND overdamped forks, which is horrible to ride on.

I had a 600 Divvy that had biro springs in the front, changed them for Hagon progressives and it really absolutely transformed the front of the bike beyond recognition. So I agree with the boss man, get some decent springs in and refresh the oil to the spring maker's spec while you are in there. Eg, for the Divvy spec is 10w, "old wisdom" says to fit 20w and it sorts it out (does it fook) but Hagon recommend 7.5w with their springs and guess what they're dead right.

Where can i get the springs from?

longmoreuk wrote:Where can i get the springs from?

This will sort you right out... for just £62 + P&P
http://www.wemoto.com/bikes/Honda/CBR_4 ... on_-_Pair/

Otherwise you can investigate various suspension specialist to get single-rate springs for your weight, but these have a few disadvantages: not great if you ever take a pillion; not great if you ever sell your bike to someone much bigger / smaller than you; not great on the road as they aren't as clever at soaking up big bumps like potholes; typically more expensive than the set linked.

For the normal, average road rider, a set of Hagon progressive springs with fresh damping oil at Hagon's recommended spec (10w) is more than good enough.

With damping rod forks (which is what you have), it's always going to be a compromise between high and low speed compression. If the forks are set up for decent high speed compression (dealing with sharp bumps and holes in the road), then low speed compression (this is where the braking fits in) is going to be mushy. It's just a flawed design.

Race Tech make a cartridge emulator for the NC29, not sure if they do one for the NC23. These make a huge difference over the stock set up - I have them on my NC29. They give you adjustable high speed adjustment, without compromising low speed compression. Worth looking into whether they fit the NC23.

A mate of mine has an NC23 that moves pretty quickly - he's done a 1.47 at Phillip Island on it. I'll ask him what he has done for his, and post back.

+1 on getting the right springs for your weight.

Pleiades wrote:With damping rod forks (which is what you have), it's always going to be a compromise between high and low speed compression. If the forks are set up for decent high speed compression (dealing with sharp bumps and holes in the road), then low speed compression (this is where the braking fits in) is going to be mushy. It's just a flawed design.

Race Tech make a cartridge emulator for the NC29, not sure if they do one for the NC23. These make a huge difference over the stock set up - I have them on my NC29. They give you adjustable high speed adjustment, without compromising low speed compression. Worth looking into whether they fit the NC23.

A mate of mine has an NC23 that moves pretty quickly - he's done a 1.47 at Phillip Island on it. I'll ask him what he has done for his, and post back.

+1 on getting the right springs for your weight.

Nice post

Aren't NC29 forks already cartridge forks? I always thoguht an emulator was effectively a secondary valve fitted to close off the bath and to provide damping on the compression stroke?

I may well be wrong, but you only fit these to damping rod forks.

For cartridge forks, race Tech do a "gold valve" kit

CMSMJ1 wrote:Nice post

Why thank you

CMSMJ1 wrote:Aren't NC29 forks already cartridge forks? I always thoguht an emulator was effectively a secondary valve fitted to close off the bath and to provide damping on the compression stroke?

NC29 forks are damping rod forks. When fitted, the emulator takes over all the compression duties. As part of fitting the emulator, the compression orifices in the damping rod are enlarged so they essentially no longer affect flow. High speed compression is adjustable, low speed is not, but because high and low compression orifices are separate, the dedicated low speed channel is no longer compromised by what you do to high speed.

I feel much more comfortable at speed on my well set up NC29 than I do on my stock K8 GSX-R 600. It's not an apples with apples comparison, but gives you an idea of what you can achieve with the emulators.

Pleiades wrote:

CMSMJ1 wrote:Nice post

Why thank you

CMSMJ1 wrote:Aren't NC29 forks already cartridge forks? I always thoguht an emulator was effectively a secondary valve fitted to close off the bath and to provide damping on the compression stroke?

NC29 forks are damping rod forks. When fitted, the emulator takes over all the compression duties. As part of fitting the emulator, the compression orifices in the damping rod are enlarged so they essentially no longer affect flow. High speed compression is adjustable, low speed is not, but because high and low compression orifices are separate, the dedicated low speed channel is no longer compromised by what you do to high speed.

I feel much more comfortable at speed on my well set up NC29 than I do on my stock K8 GSX-R 600. It's not an apples with apples comparison, but gives you an idea of what you can achieve with the emulators.

Cool - I never knew that the 29s were all damper rod forks. It makes total sense that seperating the high/low functions of compression would make it miles better. Do you have any thoughts on how the rebound is afected? Do you run a different weight oil with this set-up?