This don't look good....

dragonfly · Oct 23, 2014

Just got my '73 MkV back on the road after a total rebuild. Everything seemed to be just fine till i discovered this deposit on the left side of the rear wheel. At first I thought it was just grease or oil but when I tried to wipe it off, I found it to be hard and brittle, a bit like melted plastic. There's even some on the spokes that is very fine like spider web. I checked closely under and around and don't see anything rubbing with no abrasion on the tire or chain..etc. My best guess is it's coming out of the brake housing but there's no plastic in there. Before I pull things apart to investigate, do any of you have an idea what's going on here?

http://img.photobucket.com/albums/v666/ ... 05d8f8.jpg

Bob Z. · Oct 23, 2014

Suggestion:
Put the bike on the center stand and rotate the rear wheel.
Check for sloppy movement/clunk sound between the brake drum and wheel hub.
Maybe the cushions have deteriorated due to age or drum bearing friction heat?

motorson · Oct 23, 2014

If that was my bike it would be coming from the chain oiler and it would be oil. look for melted plastic----stator, voltage regulator, fuse block. Shorted flasher unit? I don't know if the voltage simulator has plastic in it. Any thing rubbing on the chain? I assume the primary chain case is all closed up? Maybe a plastic bag melted onto one of your pipes. Any way, that is all I've got for now. Dan.

Rohan · Oct 23, 2014

Looks like grease/chain lube flung off the chain, but if its plasticy stuff,
think Bobs suggestion of the plastic cushions in the cush drive near the brake drum there should be first point of inspection.
Other reports here have been of some turning to mush....

Johnnymac · Oct 23, 2014

I once used some weird sort of chain lube that flung off and looked exactly like that.

auldblue · Oct 23, 2014

Might be worth having a look at the chain and any shit on it first.

J

dragonfly · Oct 23, 2014

Chain is new and pretty sure that's not it. I did replace the wheel bearing. Somethings is getting hot enough to melt. I now suspect the cushions.

CanukNortonNut · Oct 23, 2014

Dfly
There is the possibility that when you assembled the rear brake and tightened the dummy axle (short one) it could have over heated the wheel cush drive buffers because the brake shoes were dragging. :shock: Which in turn heated your rear brake drum to the point of melting the cush blocks. :shock: Check them out to be sure.
It is imperative that you tighten things in the correct order. When the rear wheel is together on the swing arm, loosen all axle nuts (like you are adjusting the chain adjuster to set the correct chain tension and wheel alignment).
1. Now first tighten the brake side wheel Axle nut but make sure you are standing on the rear brake pedal as you tighten to spec.
2. Then do the other side (long Axle) and bring it tight. I will stand on the brake here as well.
3. Ensure the adjusters are touching both nut and axle to ensure your rear wheel is tracking properly to your front.
By standing on the brake pedal you centralize the shoes to the drum. Drive down the road ¼ mile and stop and check the rear drum for heat. (Not Good if there is any) I would do this check anytime you disturb your dummy axle nut.
Regards,
Thomas
CNN

dragonfly · Oct 23, 2014

Thanks Thomas. Good advice for sure. I'm sure I did something wrong. Thnx!

grandpaul · Oct 23, 2014

I don't think a Norton rear brake can generate enough heat to melt cush blocks without exhibiting some SERIOUS external symptoms like bluing and binding.

It's likely dried original packing grease chunks from the new chain.

Thoroughly clean the chain in manufacturer-approved solvent, lube it with light modern lube and try again.

auldblue · Oct 23, 2014

Usually if there is something hot enough to melt it is accompanied by some sort of smell as in " holy shit where's that burning smell coming from is my bike going to burst into flames?

J

CanukNortonNut · Oct 23, 2014

grandpaul said:
I don't think a Norton rear brake can generate enough heat to melt cush blocks without exhibiting some SERIOUS external symptoms like bluing and binding.

It's likely dried original packing grease chunks from the new chain.

Thoroughly clean the chain in manufacturer-approved solvent, lube it with light modern lube and try again.

I have melted mine. Humbled... I learn from my mistakes. I try to give others my lessons learned.
Cheers,
Thomas
CNN

CanukNortonNut · Oct 23, 2014

auldblue said:
Usually if there is something hot enough to melt it is accompanied by some sort of smell as in " holy shit where's that burning smell coming from is my bike going to burst into flames?

J

You don't smell it when your nose is pointing in the wind. When you stop at a light it might become obvious.
But then it’s too late.

Mark · Oct 23, 2014

Yep!
Take it from me...........that bike is now just a hunk of scrap metal. Goop on the rear rim is a sure sign.
I'll give you 100 bucks for it. PM me with details and I'll arrange pick-up of the bike.

Tim_S · Oct 23, 2014

If you haven't figured it out by now ..it's your cush drive blocks melting....Pull rear wheel off and replace them all....

Tim_S

Nortoniggy · Oct 24, 2014

grandpaul said:
I don't think a Norton rear brake can generate enough heat to melt cush blocks without exhibiting some SERIOUS external symptoms like bluing and binding.

It's likely dried original packing grease chunks from the new chain.

Thoroughly clean the chain in manufacturer-approved solvent, lube it with light modern lube and try again.

A friend of mine melted his when negotiating a mountain pass in the Pyrennes. A lot of hard braking for a series of hairpin bends while two up and riding with spirit did it. There is somebody in Spain probably still wondering why their rubber dustbin lid had little square holes cut in it!

Ian

dennisgb · Oct 24, 2014

Tim_S said:
If you haven't figured it out by now ..it's your cush drive blocks melting....Pull rear wheel off and replace them all....

Tim_S

+1

If it really looks and feels like "plastic" that's what it is IMO.

dragonfly · Oct 24, 2014

Tim_S said:
If you haven't figured it out by now ..it's your cush drive blocks melting....Pull rear wheel off and replace them all....

Tim_S

Ok....but why are they melting? Something amiss?

Hobot · Oct 24, 2014

Too much drum shoe drag &/or too much wiggle room from bad bearings have melted mine during learning curveballs. Extra slack in drive chain also degrade cushions quicker.

pdl999 · Oct 24, 2014

Definitely the cush blocks melting.
I know because I was dumb enough to forget to depress the brake pedal to centralize the rear brake before tightening the axle after doing routine chain adjustment. You only make this mistake once!!

This don't look good....

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