NC30 fork bottoming point

[Spike16]

Hi trying to setup my syspension and need to know the bottoming point of the nc30 forks, trying as hard as i can jumping on the front of th ebike it seems about 30mm off the bottom yoke, is that right?

also to stiffen the front end so it dosnt bottom under braking am I right in thinking i need stiffer springs or oil?

[CMSMJ1]

does it bottom out or not?

You need the right weight springs to prevent bottoming out. However, you need to know how much travel you are using.

get a ziptie on the stanchion and see what travel you use now.

Does your mudguard hit the upper rad?

You'll not be able to jump on the forks to bottom them out..you are only lightweight and they just don't work like that..

[Spike16]

yeh did that and the zip tie is 25mm away from the bottom of the bottom yoke

from trying to measure my static sag and rider sag i think my front end is soft but need to know how much extra travel i have before it bottoms out, is this th epoint were the forks hit the yoke?

think im gona try new stiffer fork oil in the forks to stiffen them up before i get a rick o kit cos im quite light so the standard tiny jap spec springs should be ok (but i understand their probably past their best being 18 years old)

[CMSMJ1]

Oil does not stiffen them up in the way you think - it will slow them down and that is not what you want.

You want a fork to react as fast as possible and not be out of control.

How much preload have you wound on? Have you measureed the length of the springs? Haynes has a min and max length for them before they are supposedly dead. You could insert a larger preload spacer which will increase the effecive rate of the forks and is easier than an oil change too..unless they need it

[Spike16]

not a clue, suspension is very confusing to me tbh, there's 2 lines showing on the preload (bottom of visible bit is on third) and the rebound are 12 clicks in (about two out)

apart from that the forks seem to go up and down and it seems to corners well, but nothing to compair that too as iv never touched the forks or ridden another big bike hard

[CMSMJ1]

Well..if it works OK...I'd leave it alone!

Measure the travel from seal to ziptie - pretty sure these forks have 110mm rated travel. You want to be in the middle third of it when you are in corners under a steady state/sniff of throttle.

A bit of reading and figuring stuff out should help you along the way.

The best setup, IMO, is one that allows the softest spring and the least damping but where everyting is in control.

[RonniB]

Spike, if you put in thicker (more viscous) oil, you will increase your compression and (rebound as well, but you can adjust to compensate) damping, only do that if you are having problems with the fork diving to fast. In order to help with bottoming you can fit stiffer main springs, a secondary bottom out spring or decrease your airgap, the latter is the fastest and easiest to experiment with.

[Spike16]

kl so reducing the air gap and replacing the oil would stiffen the front up a tad and help bring the rebound back to the centre of adjustment (its two clicks off full in)

Also been thinking about fitting those anti bottom springs.

but mostly when do i know it has bottomed out!!!!!? just tell me that and il know if it needs messing with lol

[Cammo]

think im gona try new stiffer fork oil in the forks to stiffen them up before i get a rick o kit cos im quite light so the standard tiny jap spec springs should be ok (but i understand their probably past their best being 18 years old)

Spike just bite the bullet and get Rick's front end kit, it's some of the best money you can spend on these bikes. I weigh the same as you (big bonus!) and the standard front springs aren't good enough for serious track use, whatever condition they're in.

Get some linear springs (the standard ones are rising rate/progressive, I don't like that on the track) and just change the fork oil. Changing fork oil weight is probably unecessary at this stage.


If you want to find the travel of your standard front suspension out, just jam the brakes on at 100mph on a bumpy road and measure the cable tie! You'll feel it bottom out!!

[CMSMJ1]

lol - if you bottomed it out would know about it.

I'll guess you haven't..so stop worrying about it. Being only 2 clicks off 12 for full rebound is not cool though.

When were your forks last serviced and how much oil did you put in?

reducing air gap creates a stiffer air spring right in the last 10% or so of travel. Works..but you are talking mm differences rather than loads.

If you are bottoming out, or feeling like it, then it is your compression damping that will calm it down.

Slighly thicker oil for your next rebuild I'd say.