Misc: Everything Else Brakes, Linings, Drums and Shoes

[davidd]

I would not buy linings from a supplier that could not cite the exact model of the lining and the coefficient of friction, both cold and hot, of the linings. There is no other way for you to document what works best for you. This is often done in letter code. The Green Gripper is "GF". The letter codes work as follows:

E=0.25-0.35
F=0.35-0.45
G=0.45-0.55
H=0.55-0.65

If a lining is labeled "GF" like the Green Gripper it has 0.52 cold and 0.43 hot. The first letter is the cold number and the second letter is the hot number. GF is fine for the street. If you were racing, you might want GG or higher because you need the hot performance to be pretty better than average. HH linings are available, but they require lots of heat and are usually too unstable for normal use.

If you have installed disc brake pads on anything the letter code is often displayed on the edge of the friction material in paint.

David

 

[Texas John]

David, Which ones are the GGW? The ones with .51 Coefficient?
How did you find that out?
Could the non-metallic ones be GGA?
Thanks, John

 

[Martyn Goodwin]

Yes the cost of new brake drums is very high, but where can I get some of the course woven linings to try as a cheaper option please
Matty

Have you checked out the cost of the new V3 brake drums? See advert in MPH

 

[vibrac]

Just go to the people who I get my race linings from (the nearest thing to AM4) and cover all the surface of my Velo clutch plates (who still uses cork?) they know a lot about linings and about serving customers
Saftek Friction https://saftek.co.uk/ Telford UK

 

[davidd]

David, Which ones are the GGW? The ones with .51 Coefficient?
How did you find that out?
Could the non-metallic ones be GGA?

Unfortunately, you have to work pretty hard to get brake lining information. The GGW is Green Gripper Woven made by ScanPac and their spec sheet gives most of the data. They also make GGA, which is Green Gripper Ariamid, that is not woven, but solid and it is not green (it is grey). The aramid lining does not have aluminum oxide in it so it is not as grippy. It is still in the range of AM4. However, I used Industrial Brake & Clutch in NJ. I asked them if they had ever used GGA. They did not know what I was talking about at first and then caught on. The owner had been using GGW for over 25 years, but had never seen GGA. It is worth calling to see if the lining you decide you want is in their supply chain.

Sometimes you can search specifically for the "J661 tests", which are the SAE designed friction tests used to compare friction materials. GGW is over 0.50 and GGA is just below.

David

 

[Matty]

I have had a chat with SAFTEK in UK who say they are aware of the problem with Vincent steel drums and will reline my shoes with a suitable woven material for my needs.
Afraid I did not enquire about the exact spec for the material but they say they have supplied it to several riders with no complaints.
Will have to dodge the virus when the linings are fitted to see if this is the solution - luckily I Iive out in the sticks and will have an excuse to pick up medication or shopping if I do not go far from home.

 

[Texas John]

David, My apologies for an unclear question. I was wondering how you determined that the linings on the McMaster web page you gave the link to were actually GGW? And which ones on the page specifically are GGW (the .51 coeff ones?) and if one of the others might be GGA. Because the McMaster site doesn't mention manufacturer. Well, as I look back, you did say "I think" so not an absolute. Perhaps they would inform one if asked.

 

[davidd]

I think McMaster would provide the material safety data sheet which would have the manufacturer. I read that folks were buying GGW from McMaster Carr. I looked it up and noted that they did not name the manufacturer. Frankly, I don't care to cure the lining myself before bonding onto the shoes and then curing the bonding agent. I prefer to have someone else do that.

David

 

[Roslyn]

Hi - Have just understood about the relative leverage of the two ends of the cam on the brake shoes and the reason for a small difference in leverage to the leading and trailing shoes.
So that is not my problem and will have to think of something else - tried the trick of slackening the spindle,
applying the brake and doing the spindle up again, some years ago to little effect.
I still wonder if it is really the material of the drums or if ribbed Shadow ones are the answer.

This however would be an expensive experiment unless I could borrow a front wheel with Shadow drums from somebody to try !!

I think your right on the money as the old linings as they do dry out with age and also the new materials used today still deteriorates when exposed to heat air and oil over time.

 

[Texas John]

David, Good suggestion - so I wrote McMaster about obtaining the SDS/MSDS information and I will see where that leads.
You were experimenting with some other linings a few months back; did you ever decide if you liked it better than GGW? May have been the Porterfield RD-4 linings? Did you ever try GGA to form an opinion of it? Every time you write about brakes and linings, I learn something but end up with questions!