brake rotors

[dirt mcgirt]

anyone know if 89 rotors have a bigger diameter than 86

[Dave83]

86-89 are all the same

[dirt mcgirt]

well i recently got 89 hubs so i got new rotors i matched them up with my 86 ones and they have a bigger diameter just wondering if i got 400ex ones or something i did buy them used

[Dave83]

Sorry,I thought you meant the rear,but I think the fronts were the same diameter on all years too.The 86-87 style had 4 mounting bolts and 88-89 had only 3.

[dirt mcgirt]

no problem my fault shoulda posted that they were the front ones just wondering why these are slightly bigger in diameter also do you know if the mounting bolts on 89 hubs are longer than 86s havent had a chance to check yet.........thanks

[Dave83]

Bolts are all 6x20mm for all years.How much diff is there between the rotors you have?

[dirt mcgirt]

well my bolts from the rotors on my 86 hubs dont even come close to hitting the threads on my 89 hubs thats what has me wondering what i got

[Dave83]

The 400ex had larger bolts, 8x22 on earlier yrs and 8x24 on the later ones.If your bolts are smaller in dia than the hub holes,Id say you got the EX stuff.

[dirt mcgirt]

no idea how to post pics i would to show you them got them of ebay have seal markings that are the same as 89 seals ill figure it out i hope

[Dave83]

Exs had the same seals as the R on some yrs.check out the 8mm bolt thing.

[dirt mcgirt]

i will buddy thanks for your time

[C-LEIGH RACING]

I got both year models of rotors & both are the same O D as the other.
You might have a 400EX front end on the R.
Lot of pro riders used the 400EX spindles, hubs & rotors as a mod & then used an aftermarket caliper mount to use 250R calipers instead of the 400EX ones.
Neil

[deathman53]

I have that setup on my hybrid crf450r, my friend who built it put a complete 400ex spindle setup on, I recently bought the adpaters to use 250r calipers. I think the 400ex rotors are a larger diameter than 250r.

[dirt mcgirt]

yeah im thinking i got all ex stuff on there rotors are def bigger in diameter rotor bolts dont even start to thread in from 89 or 86..anyone know if using the 400ex spindles throw out the caster or camber or make the front end wider?

[C-LEIGH RACING]

I cant remember if it makes it wider, but I think the swap out mod was because the 400EX spindles not as heavy as the R, one piece aluminum.
Neil