Rotors?

[XS1100_OEM4ME]

I have a bad pulsing under hard breaking on my 79 spacial. Cant see a pattern on ether rotor and am thinking of buying 80+ special slotted rotors, any non comp between years? Are they much better stopping to justify cost?

[DGXSER]

The later model special rotors have the slots in them for cooling. Pulsing as I am sure you know usually indicates a warped rotor. So, while stock in spec rotor for stock in spec rotor I would say there should be no performance change from one to another, if you have warped rotors, I think you will see better performance from ones that are not warped.

As far as compatibility and mounting, any year rotor of XS1100 will fit any year or model, including front versus rear.

[XS1100_OEM4ME]

Warped

Yes, I am sure at least one is warped, Yamaha claimed the "slot's" not only cooled under hard breaking but increased wet breaking times. Could all be crap and I could do a run out and maybe only replace one bad rotor but if the 80+ are a worth wile upgrade, I will pay up.

[DGXSER]

I have not compared them, and have not seen any info on here of a comparison, of the slotted versus non slotted performance. IMHO, I would think that unless you plan to put that iron horse through all the paces at some serious speed, that you would be hard pressed to see any increase in performance. Just my opinion though. But then, I am for anything that increases the braking on these beast. Hard call to make.

I do know there is a template on here somewhere of a drilling pattern to add holes to the solid ones. Would take a lot better drilling equipment than I own to put holes in those hard as Superman's skin SS rotors.

[XS1100_OEM4ME]

Thanks

I am guessing, do the run out, find the bad one and save $, the slot's do look cool, but my name is OEM, Would have made an exception if the diff. was worth it, seems not so as no "claim from member's" of a worth while gain. When it comes to stopping the beast, any "real" gain would have been considered!

[mro]

Not OEM but ...

any "real" gain would have been considered!

SS brake lines do make a noticeable difference.
As a caution tho,
it becomes easy to lock up the rear and not that hard to lock up the front which can lead to disaster.


mro

[foreda]

Slotted Rotors

I have a set of front slotted from 80+ I am probably not going to use. Let me know if you are interested.

[Rstyduck]

The slots are there to release the gases built up when braking hard.
Yes, slotted and drilled rotors do offer performance gains.
Maybe not on a bike driving by an old man but definatly on a bike driven by a crazy man.

[XS1100_OEM4ME]

Hi Duck

Yes, I am old, 50 to be exact. When I was in my 20's I owned my own busness, restored muscel car's. Owned a 1967 Z28, 1969 Camaro. 1970 Chevell SS 396, 1969 Vett, 1967 GTO, 1966 GTO with a 6 pack (turned low 11's at the track and then I drove it home) Rebuilt my first motor at 15, was port and poishing heads at 18. I my still know something about motor's even at this old age.

[TADracer]

Check this.

I take it you are talking about the front rotors but it might not be the rotors at all. Check the runout with a dial indicator to make sure but also try this.

Some specials will slightly bend the mounting bolt through the caliper with use and some dont. Before you spend a bunch of $ take the calipers off and check the bolt for straightness. You will notice it when you are undoing the bolt as the caliper will wobble slightly back and forth with the bend as you are unscrewing the through bolt. If the bolt is bent it will be only the threaded portion and will be just slightly off. If the bolt is bent you will hardly ever get it back into perfect alignment and it can cause a host of symptoms, one of which is pulseing.

Have had this happen to me more than once so every time I remove a caliper I change the bolt. They are easily found at a hardware store. Worth checking before you spend a bunch of money on other things.

[XS1100_OEM4ME]

Thanks

Thanks TA, I will check the bolt for true. Could be what is up as no uneven ware pattern on the rotors like I would expect from a warped one.

[cywelchjr]

The slots also do improve wet braking performance as they allow the water to get out from under the pads faster when braking with wet rotors (generally only a problem under really wet conditions, like heavy rain). So, if your not going to be riding in heavy rain, the only difference would be from the increased performance from cooling and the slots allowing the gases from the pads to get out from under them. I know that drill and slotted rotors on cars will give a measurable increase in braking power, something like 10-15% IIRC.

[yamahansolo]

I have 82 slotted rotors on my 79 they work real nice...

[Eveready1100]

Rotors?

Gidday mate,
As cywelchjr stated in his post, Drilled or slotted rotors make a big difference in braking in wet weather. I changed the plain rotors on mine for drilled ones in 2002 as I had been scared badly by the time delay in applying the brakes till they actually started to slow the bike. Sometimes it could take over a second to start working, which is bad if you're only 2 seconds behind the vehicle in front. I was probably spoilt by my previous bike (GPZ750) which had impeccable wet braking performance probably due to its slotted rotors and hi-metal pads.
Since fitting the drilled rotors to mine, it's much more predictable in the wet and feel much more comfortable riding in the rain (happens a lot over here)
If you've got the funds to get a set, (drilled or slotted), I would recommend you get them if you are an all weather rider

[jwhughes3]

Everready that is quite the driving light setup...

You have on your pic - do you have any issues with battery or charging system keeping up with the amps it draws? (It looks like a landing light for the Space Shuttle!)

John in San Antonio