Brake Rotor

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Cheesehead Commando

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Hi All-

The front brake rotor on my ‘74 850 MKII is warped, and I am looking for a replacement I found a few Norton parts sources that offer a stock-sized until that is made of stainless steel. Claims are lighter, better performance, and rust free.

Anyone purchase one of these units and can offer some feedback? I realize I can upgrade other ways with complete parts replacement but am hoping to keep the rest stock.

Thanks to all who respond!!

Tom
 
If you are confident that your wheel bearings are not loose, that your steering stem is properly tight, that your rim's run-out, axially and radially, are within spec, that your tire is less than 6 years old (5 is better) and not worn unevenly, that the rotor fasteners are torqued equally, then, yes, the rotor is probably warped. You can also add any wear of the stanchion bushings into the mix. It is an old motorcycle after all.

Assuming it comes down to rotor warp, which is far from uncommon, I suggest that you ship the rotor ff to Disk Brake Reconditioners in Illinois and for short money they will grind the braking surfaces relative to the mounting surface, drill the rotor, if you want, paint the center and return it to you You will have a stock part that is "seasoned" and much less likely to warp again.

If your hydraulic hoses are original get rid of them now, if they are over 10 years old get rid of them tomorrow, if they are over 5 years old change them out next week, and make sure that your caliper isn't seized on either side; think about stripping it and replacing teh seals, at least, and give the pistons a good looking over.

Whether you choose this service, or one like it, or purchase a new rotor be sure that you break-in the new rotor and pads with a lot of low speed stops without extended applications or "panic" stops, if you can avoid same. The more gentle heat cycles you can get through the less likely that the pads will glaze; a good break-in will insure that the brakes will be your friend if they are called upon to save your bacon.

For me having great brakes is a must, but ironic at the same time as I rarely call on them to step up, but when I do I know that they are there and will do their part to get me home on the machine to which they are attached, not to the coroners cooler.

Best
 
Cheesehead Commando said:
Hi All-

The front brake rotor on my ‘74 850 MKII is warped, and I am looking for a replacement I found a few Norton parts sources that offer a stock-sized until that is made of stainless steel. Claims are lighter, better performance, and rust free.

Anyone purchase one of these units and can offer some feedback? I realize I can upgrade other ways with complete parts replacement but am hoping to keep the rest stock.

Thanks to all who respond!!

Tom
Click to expand...
SS is not as good in the wet as iron, as for some reason the brake dust "clings" to the rotor giving delayed action compared with iron. Braking action is restored with wiping rotor with paper towel. Don't ask me how I know.
P.S. you can always get the c.i rotor zinc coated.
 
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You can check rotor run out with a small magnetic holder on spindle with a long rod inserted to hold a Verdict clock gauge. But if you haven't got or can't borrow one..........
 
I had mine ground by Truedisk in Michigan. Inexpensive, fast and Tom packed it for the return like a newborn.
 
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Scout63 said:
I had mine ground by Truedisk in Michigan. Inexpensive, fast and Tom packed it for the return like a newborn.
Click to expand...
Ditto. If it's not recoverable, he will say so. Unless there is a crack, I send them to him to evaluate/grind.
 
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When I bought my triumph I thought the front disc was warped
When I went to remove it two of the bolts were ultra tight and two were about right
There was rust under the disc under the two tight bolts
The bike was almost mint,no rust anywhere at all!!!
All was well once cleaned up
 
I too had Gary resurface/grind/refinish my front disc that looked awful, rusted, warped, etc. I wanted to keep original look so did not have him drill any holes, just keep it stock. Besides being a very nice guy and fun to deal with, he returned the disc very quickly and it looks fantastic! I paid for postage sending it of course but I think 2 years ago I paid him $65 shipped and it was well worth it. Great guy, fast turn around, inexpensive and beautifully done. Recommend him to consider.
 
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