Is anyone using the Girling floating/slotted brake rotor? Having issues.

Mine is Feb 74 and the bottom looks like it was ripped off by a grinder. The stock caliper that is.
 
Mine is the same as LAB's and Onder's, rough sand area's showing and ground off area where the spur was on the bottom. Not a die cast part but sand cast using a resin mixed in the sand mould and cores plus fine sand to improve the finish and final sizing.
 
Brithit said:
Back to the OP: I bought two of these from Classic British Spares several months ago for my MKIII, and sent them detailed pictures about having to file a small edge off of the bottom of the caliper. That was the first they had heard of it. Not much of a problem at all, and I like the way they feel. I had a replacement stock front disc on the bike, and always felt it had a slight pulsation I didn't like. Not enough to replace., but enough to jump at the chance to buy these when I first saw them. Not the first time I've had to do a slight mod on a new non-stock part on a bike, won't be the last.
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I'm with you. It's unfortunate but not all that big of a deal for me. Yeah they should correct it and inform people. Stuff happens, then you make it right and move on.

I wanted to understand the situation and decide whether to fix or return, and have done so, and I appreciate the helpful inputs.
 
it may have been a factory cost saving short cut instead of finishing the faces in the machine shop just rough the casting flash off with the abrasive wheel
some are machined smooth and some are not , if you have a caliper with the machined bottom face and radiused edge chances are it will fit with no modification
 
MichaelB said:
Yup, didn't make sense to me. I think it's a typo. Alloy, drilled stainless vs cast iron.
Here's another vender listing it at 850 grams.
www.ebay.com

Norton Commando front disc (Floating) Girling New. | eBay

Find many great new & used options and get the best deals for Norton Commando front disc (Floating) Girling New. at the best online prices at eBay! Free shipping for many products!
www.ebay.com
Sounds more corrrect.
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If one of you guys could weigh the disc, I will update my weight list of brake options.

Thanks,
Knut
 
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mdt-son said:
If one of you guys could weigh the disc, I will update my weight list of braking options.

Thanks,
Knut
Click to expand...
I don't have a very accurate scale. Usually I am thankful for that.

I would say 85 grams seemed about right. I could tell it was lighter but not that much. I mean a few holes, metal, a little alloy in the center, you can't be saving pounds, it's gonna be ounces. I would say grams to Kg but I'm American and failed the metric system back in '74 when we tried it. And in this case it's a more accurate comparison to my mind, less of a wide range. IMO unsprung reciprocating weight is a good place to save any little bit.
 
gpzkat said:
OK I can't help myself, now all the front end is done except making a braided SS line and settling on a tire choice. New 24.93" stanchions and fork internals in the Commando lowers. Spokes laced, it is original Dunlop rider quality MC275 rim. It is NOT dimpled 3x1. I laced it up without any problems, it's true and no hops, correct offset etc. I have done a couple Honda CB750 wheels before, this was tricky but not that bad. Spokes are original and due to budget I just cleaned them and painted with a stainless steel spray paint. I'll touch the spokes up, it was a quickie job as I knew they'd get dinged during assy. Got some rust preventer inside the rim as good measure, it's just light surface corrosion thankfully.

I have a drum WM2 wheel in similar shape, will sell that and quite a few other things soon.

Is anyone using the Girling floating/slotted brake rotor? Having issues.


Is anyone using the Girling floating/slotted brake rotor? Having issues.


Is anyone using the Girling floating/slotted brake rotor? Having issues.
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Nicely done,
What was your method?
 
If anyone wants to try sand casting one feel free, I've walked that route. We cast using a die even for our small batches. A modern resin bonded method was considered which would have been cheapest, but is not suitable even today. Considering the numbers cast back in the day what method made sense.
If anyone wants to see a modern resin bonded sand cast item and compare it against a die cast item then they can pop in and see me and guess what item was used what method. The difference is surprising.
 
Madnorton said:
If anyone wants to try sand casting one feel free, I've walked that route. We cast using a die even for our small batches. A modern resin bonded method was considered which would have been cheapest, but is not suitable even today. Considering the numbers cast back in the day what method made sense.
If anyone wants to see a modern resin bonded sand cast item and compare it against a die cast item then they can pop in and see me and guess what item was used what method. The difference is surprising.
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For those of us outside pop in distance, any chance of getting a couple of photos?
/Steve in Copenhagen
 
Mad Norton

if you are making small batches pressure cast must mean expensive tooling why not machine from solid billet and anodise
 
Madnorton said:
If anyone wants to try sand casting one feel free, I've walked that route. We cast using a die even for our small batches. A modern resin bonded method was considered which would have been cheapest, but is not suitable even today. Considering the numbers cast back in the day what method made sense.
If anyone wants to see a modern resin bonded sand cast item and compare it against a die cast item then they can pop in and see me and guess what item was used what method. The difference is surprising.
Click to expand...
Sandcast, you can see the grains and the mould part lines on the side they did not polish.

Is anyone using the Girling floating/slotted brake rotor? Having issues.
 
Some just can't see it. Dies can also have mould lines and they are also a massive give away - do you honestly think we would have spent money on a die when we could have had them sand cast using the latest sand casting methods. The finish can be anything, castings are usually blasted whether they are die or sand cast, unless asked for 'as cast'
 
Whilst on the subject of calipers, is there any chance AN could get around to correcting their Mk3 '12'/'12A' (and nut '14') rear caliper mounting 'bolt' errors?

andover-norton.co.uk

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk
(And not just the bolt in the 12A picture that should be of a set/hex. screw)


Also, my copy of the Mk3 parts book has the incorrect (longer) front caliper (06-7969 x2) hex. screw part number.
The nut 14-0403 quantity ("3") appears incorrect.
 
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gpzkat said:
I don't have a very accurate scale. Usually I am thankful for that.

I would say 85 grams seemed about right. I could tell it was lighter but not that much. I mean a few holes, metal, a little alloy in the center, you can't be saving pounds, it's gonna be ounces. I would say grams to Kg but I'm American and failed the metric system back in '74 when we tried it. And in this case it's a more accurate comparison to my mind, less of a wide range. IMO unsprung reciprocating weight is a good place to save any little bit.
mdt-son said:
If one of you guys could weigh the disc, I will update my weight list of brake options.

Thanks,
Knut
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I tried to get an answer. Vendor's reluctant reply: "The disc is not very light. 85 grams is probably correct."
If the stock disc is the baseline, the brake disc will weigh about 2305 gram, making it the heaviest aftermarket brake disc for Commando models by far.

Update: Another vendor was more forthcoming. The exact bare weight is 1990 gram. It's in the same weight class as Don's 12.5" floating disc.

Weight of front disc brake(s)

There has been some threads on weight of the front wheel, and the desire to reduce unsprung weight. It seems weight of the braking system has been left out of the discussion entirely. How does the standard disc brake fare weightwise vs. the TLS stopper? And how much does the available upgrades...
www.accessnorton.com www.accessnorton.com

- Knut
 
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I was really leaning on getting one, upon examining my current, lightened, hardly used disc.
Just can't justify it.
 
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