GN250 front disc thickness check?

[Houseman]

Hi All,

Went for WOF on my 1987 GN250 yesterday (VTNZ Botany) and the picky buggers gave me a long list of things to deal to. Nothing too big, and all part of usual maintanance, so I guess I am just a bit miffed because I am hoping to sell her to get into a bigger bike (VTR Firestorm look like a god bike and they seem to be good value).

Among the list of things to be fixed which included number plate slightly off centre, high beam dash light out, rear brake adjusting nut needs tightening (about a 1/4 turn ffs!) there was the more serious front brake pads which I admit do need addressing.

Well I am pretty sure I can do the pads myself as have changed a few on farm bikes so should be no problem. But the WOF guys says I also need to make sure the disc is within manufacturers thickness spec. How am I supposed to prove that?? I can measure it sure, but if it is fine where do I get the bit of paper to prove it? Do I have to take a micrometer in to the WOF place?? If I go to a bike shop to ask for a quick sign-off, do you think they will charge me for it?

You would think they would just check it themselves and say yes/no.

Appreciate any suggestions.

[Squiggles]

That'd be there job to be looking for the min thickness stamped and determining if its up to it... Havent seen many ginnys manage to wear em down to below the limit, more that havent replaced the pads and have munted the disk.

[Madness]

It's up to the inspector to ensure the thickness of the rotor is up to manufacturer's minimum spec, not for you to prove.

Maybe they were just giving you a heads-up?

As Squiggles said, it'd be unusual for a GN to wear the rotor down past the minimum, unless you've been braking with the metal backing plate of yer pads.

[imdying]

Go somewhere else... they're clearly retarded. Ask him where the tick box on the WOF sheet is for rego plate placement, brake adjustment (which is not the same as performance), disc thickness, idiot signals on the dash etc.

[Katman]

Minimum thickness is 4.5mm

As has been said, tell the dickhead to measure them himself.

[Motu]

It's up to the inspector to ensure the thickness of the rotor is up to manufacturer's minimum spec, not for you to prove.

Wrong - it's up to the owner to provide specifications of compliance issues.That's the official stance on the matter,not an opinion.

[imdying]

What page of the wof manual is that on then?

[Motu]

You won't find it in the VIRM,although you will find mention of being able to charge for any extra time involved in an inspection,over and above that required for the inspection itself.Page 3-24,3.9...c.

So if the customer requires the AVI to look up or procure information and specifications,then they are allowed to charge for that time and materials.Testing stations will have practically no specs available,garages will have specs on cars,and motorcycle shops specs on bikes....but very seldom the other way around.If the customer is happy to pay these extra charges,then the information can be sorted - otherwise it's better if they do it themselves.

[Squiggles]

So if the customer requires the AVI to look up or procure information and specifications,then they are allowed to charge for that time and materials.Testing stations will have practically no specs available,garages will have specs on cars,and motorcycle shops specs on bikes....but very seldom the other way around.If the customer is happy to pay these extra charges,then the information can be sorted - otherwise it's better if they do it themselves.

So would charges be to find the minimum thickness or determine if the rotor is above the minimum or both?

[Motu]

Doesn't take much to measure then,so you would be charged for finding the specs.Of course that should be easy,on a bike usually marked on the rotor,but worse case senario it can take a lot of searching to find specs on an obsure vehicle - that is when the customer has to take it into their own hands and do the work themselves.

[koba]

I just got told to do the same, all I needed to do was measure the disk as it had a stamp. It was just over the minimum but I chose to replace the lot anyway, It is a lovely (But pricey) feeling having nice fresh brakes. 1987 - 2009 is a long time...

[quickbuck]

I just got told to do the same, all I needed to do was measure the disk as it had a stamp. It was just over the minimum but I chose to replace the lot anyway, It is a lovely (But pricey) feeling having nice fresh brakes. 1987 - 2009 is a long time...

Heck, you found new discs for an NC21?
Well done!

Must say it felt great when I got my new discs on the CBR... Shame the pads that came with them weren't up to the braking effort I was asking of them.

They didn't last long at all! Toast by lunch time at an HRCNZ training day!

Anyhow, back to the topic...
If you are taking your bike to a place for a WOF where they know nothing about bikes....
THEN DON'T!!!!

Go somewhere where they know what they are looking at.
At least then they will have a clue to detect faults!

[Houseman]

Thanks for all the help guys.

I fixed all the stuff myself and just told the guy I checked it and that it was fine. He wouldn't beleive me so I pulled out the service manual I bought with me to prove I knew what the min spec was. He ran his finger and thumb over it again a few times (I'm guessing to make sure it was 4.5mm not 4.4mm...) and said OK.

He then offered to buy the manual off me. Talk about mickey mouse...

Thanks again!

[FROSTY:Me]

Hang on a mo--you got failed ya wof for the NUMBER PLATE BEING OFF CENTRE??