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RE:Suspension advice on a CBR400, NC29

Posted: Mon Jul 21, 2008 5:18 pm
by marty400
Hiya All,


RE:Suspension advice on a CBR400, NC29

Hope you can advise, or at least point me towards a good Web site!

The Problem:
(The bike rides fab apart from this problem. She drops into corners fab, and is ace through the Welsh twisties.)

When I go over a road with ripples in it, the bike really starts to "ripple" as well, as opposed to the suspension absorbing the undulating ripples, and delivering a level ride.

The only way I have worked out to ride it out, is to stand up slightly on the footpegs, arms going really relaxed, and just letting the hadle bars buck underneath my hands - it works!



The Suspension adjustment I have available:
Ok, the CBR400 is a 1992 model, and it looks like it only has Rebound adjustment on the front forks as standard.

The 2 Screw heads are screwed in flush to the Top of the Forks.

What adjustments can I do???



Hope you can advise!

Cheers
Martin


NB:
Looks like the Front Forks are missing:
1) "Spring preload adjustment" - generally hex style and located at the top of the fork.)
2) "Compression adjustment" - Generally located near the bottom of the fork

Re: RE:Suspension advice on a CBR400, NC29

Posted: Tue Jul 22, 2008 11:03 am
by eddie v twin
Hi first of all are the tyres in good order ( correct tyre pressures ?) is the suspension in good shape ( nothin leaking or siezed ?) . if all is well you need to then set the static sag front and rear ( the amount the suspension moves and works )
Now while your doing this you need a pen and paper to make notes of settings

Eddie

Re: RE:Suspension advice on a CBR400, NC29

Posted: Tue Jul 22, 2008 12:05 pm
by marty400
eddie v twin wrote:Hi first of all are the tyres in good order ( correct tyre pressures ?) is the suspension in good shape ( nothin leaking or siezed ?) . if all is well you need to then set the static sag front and rear ( the amount the suspension moves and works )
Now while your doing this you need a pen and paper to make notes of settings

Eddie

Thanks for that Eddie.

Is there a web site that goes through this step by step?

I remember playing around with the suspension on the cbr600 - I made her a dog to ride in the end! I had to just reset back to std in the end!

Re: RE:Suspension advice on a CBR400, NC29

Posted: Tue Jul 22, 2008 1:42 pm
by eddie v twin
Hi try this link it shows you step by step, ( remeber when fiddling with suspension DO one thing at a time !!!! )


http://www.motorcyclenews.com/MCN/advic ... &R=EPI-683" onclick="window.open(this.href);return false;


Eddie

Re: RE:Suspension advice on a CBR400, NC29

Posted: Tue Jul 22, 2008 2:12 pm
by marty400
eddie v twin wrote:Hi try this link it shows you step by step, ( remeber when fiddling with suspension DO one thing at a time !!!! )


http://www.motorcyclenews.com/MCN/advic ... &R=EPI-683" onclick="window.open(this.href);return false;


Eddie

thats brilliant!


Thanks Eddy!

Will let you who How I get on. Will probably fiddle this weekend

Re: RE:Suspension advice on a CBR400, NC29

Posted: Tue Jul 22, 2008 5:49 pm
by eddie v twin
Hi no problem , sounds a bit like you have to much front preload especially if the adjusters are screwed in flush to the top nuts. remember when you start adjusting things to make notes so you can allways return back to them .


Eddie

Re: RE:Suspension advice on a CBR400, NC29

Posted: Tue Jul 22, 2008 7:33 pm
by parto
Hey Mate

Sounds like your front tyre has lost its profile, just because it has tread doesn't mean it's ok have a feel of your tyre if it isn't smooth i bet thats the problem.

Also check your headstem bearings they may be a bit loose as well.

Goodluck

Re: RE:Suspension advice on a CBR400, NC29

Posted: Wed Jul 23, 2008 12:39 pm
by marty400
parto wrote:Hey Mate

Sounds like your front tyre has lost its profile, just because it has tread doesn't mean it's ok have a feel of your tyre if it isn't smooth i bet thats the problem.

Also check your headstem bearings they may be a bit loose as well.

Goodluck

Hiya Parto,

ops, sorry should have said - I have newish Avon Vipers on the bike

Re: RE:Suspension advice on a CBR400, NC29

Posted: Wed Jul 23, 2008 12:43 pm
by marty400
eddie v twin wrote:Hi no problem , sounds a bit like you have to much front preload especially if the adjusters are screwed in flush to the top nuts. remember when you start adjusting things to make notes so you can allways return back to them .


Eddie

I'll try winding off the fork Preloads! The manual says, the standard setting is 3 rings. This is for the Jap market (less than 9 stone blokes.) I guess I'll start from here cause I'm only 9stone 4 Pounds myself!


The rear suspendion looks a bit iffy though. Its preload is wound up to max as well, and I get sod all sag/bounce when I get on the bike, and bounce up and down.


How much does a Rear shock cost?
Any decent brands I should go for?


Cheers
Martin

Re: RE:Suspension advice on a CBR400, NC29

Posted: Wed Jul 23, 2008 12:56 pm
by monkey
http://www.maxton.netspinners.co.uk/" onclick="window.open(this.href);return false;

http://www.wpsuspension.com/" onclick="window.open(this.href);return false;

http://www.ohlins.com/" onclick="window.open(this.href);return false;

EMC shocks

Nitron

Hagon


or just go on ebay and buy a cbr600 F3 shock, that will fit with a tiny bit ground off

Front fork internals are around £60-80 i think