What's up with these front rotors?

Check out the rotors on this one
http://cgi.ebay.com/ebaymotors/ws/eBayI ... &viewitem=

Is this a home-made modification or aftermarket rotors?

That has got to be a LOT more effective than holes.

 

Looks just like my "new" Venture front rotors. Lots of slots.
But I think grooves that don't go all the way thru are better.

 

So those aren't stock for an '85 700? They sure look the part, I wouldn't have guessed. I think they're from a different bike rather than aftermarket.

TIME is right; "channels" are the current hot setup. However, I believe it's Audi, has teeny tiny holes in their channels (on the racecars.)

I can tell you that a drilled stock POS Yamaha front rotor does work a bit better than in its original form. The EBC floating rotor discs made with correct modern metals are the easiest way to completely upgrade the brake. But they're not slotted.

 

I've never seen an 85 with slots standard.

Also notice the big holes next to the mounting bolt holes (also not stock)...similar but different

With a good MC, pads, and SS lines both mine will lock up the front wheel so I'm not looking for any upgrades.
Or at least they will up to about 35 mph (I'm afraid to squeeze hard enough above that speed)

 

those arent factory on anything I have seen.

 

Those front rotors are exactly the same as mine.

I have an (Australiasian) 1985 XJ900. The stock rotors were slotted and vented but they were too worn to pass a "roadworthy" test after I got it together and ready to be registered on the road.

So...a visit to the wreckers turned up those exact same rotors. They're off a Yamaha model, possibly even in the 90's - can't remember - and they are the correct size (diameter) and have all the mounting holes in the right places. I think I paid around AUS$60 each (presses calculator buttons...), that's about US$75 each.

They were in good order and barely worn at all. Check around and you'll find that some later model Yamaha rotors can be interchanged on at least my 900, Rick's '83 900 and probably other XJ models like the 700.

Cheers.

 

Wow - can I borrow your calculator next time I buy something from the States?.... :lol:

Not sure what model they are off, but they are DEFINITELY Yamaha spec. I think the early FJ1100's had them (??)

 

They are also fitted to the UK/Europe model xj600 which is what I ride. Rear brake is a smaller diameter of the same design.

Hope they show up ok? You can see the rear fairly clearly.

 

They are exactly the same rotors as fitted to my bike, which I believe are the original rotors. The rear rotor, though, is the same as fitted to the U.S. XJ900RK. Yamaha probably didn't see any need to update it.

 

10 points for those who said they came of a yamaha. originally these were fitted to the xj 600/650, and 900r. they are the same size and spec for most seca models. these are the units that i changed to after having a near miss with the old solid ventilated units. bolt straight on and the stopping performance is something else. if you can find these and they fit your bike do youself a favour and grab them, you won't regret it.
sad to say i don't think they will fit the earlier maxims

 

10 points for those who said they came of a yamaha. originally these were fitted to the xj 600/650, and 900r. they are the same size and spec for most seca models. these are the units that i changed to after having a near miss with the old solid ventilated units. bolt straight on and the stopping performance is something else. if you can find these and they fit your bike do youself a favour and grab them, you won't regret it.
sad to say i don't think they will fit the earlier maxims