Best shell bearings (2020)

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rotorwrinch said:
I have decided to join this existing thread rather than starting a fresh one that was so similar . I soon will be working on cranks and rods for Norton big twin roadrace engines. Some of these engines will have Nourish billet cranks and a couple will have modified stock cranks. Some journals will still be basically standard while some may have to be ground as much as -.020” and loose some hardness. There will also be a mixture of connecting rods. All that said, decisions will have to be made regarding hard bearing, soft bearing . That is where real insight and experience would be appreciated.

What rod bearings available now are aluminum backed and which are steel backed ? Of the bearings available now, are there any that are no-goes based on quality control or durability ? Has anyone actually compared the surface area to determine the hardness ?

The sharing of past battle experience is appreciated here. If the thread takes a wild turn, I will likely move it a fresh thread title. Thanks Motorheads and Thread Posters.
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All shell bearings are steel backed, its the lining that varies and the two main ones for a Norton are Aluminium/Tin which is bimetallic and the leaded bronze with plating called a Trimetallic.

If you ever see a Wassell shell bearing walk away. Other than that it comes down to matching the lining to the usage.

Aluminium/Tin is best used in a road engine, long life and does not get attacked by acid build up in the oil.

Best names for these are Glyco, Glacier.

Leaded Bronze with overlay plating is best for racing, higher fatigue strength for the higher forces but the soft surface overlay wear out quicker letting the acid get to the lead in the bronze so change the bearings often. Cast bronze is slightly better over sintered bronze on fatigue strength.

Mahle make the cast bronze, King make the sintered bronze. Glacier made sintered a long time ago, look for LC as a suffix on the part number.

Checking the surface hardness of a shell bearing tells you nothing, a soft overlay will give a low reading but the bronze underneath is what counts.

Nitride the crank to get the hardness back.
 
Glyco / Glacier / Vandervell are all great brands and top quality but you will be looking for NOS as they are no longer produced in these brands
King bearings are readily available for Commando and very good quality product , Wassell do not sell Commando shells under the Hepolite brand ( apparently Norton are low volume in comparison to Triumph )
Hepolite Triumph twin shell sets are highly rated by Franz & Grubb in the USA
 
kommando said:
All shell bearings are steel backed, its the lining that varies and the two main ones for a Norton are Aluminium/Tin which is bimetallic and the leaded bronze with plating called a Trimetallic.

If you ever see a Wassell shell bearing walk away. Other than that it comes down to matching the lining to the usage.

Aluminium/Tin is best used in a road engine, long life and does not get attacked by acid build up in the oil.

Best names for these are Glyco, Glacier.

Leaded Bronze with overlay plating is best for racing, higher fatigue strength for the higher forces but the soft surface overlay wear out quicker letting the acid get to the lead in the bronze so change the bearings often. Cast bronze is slightly better over sintered bronze on fatigue strength.

Mahle make the cast bronze, King make the sintered bronze. Glacier made sintered a long time ago, look for LC as a suffix on the part number.

Checking the surface hardness of a shell bearing tells you nothing, a soft overlay will give a low reading but the bronze underneath is what counts.

Nitride the crank to get the hardness back.
Click to expand...
OK, some info that will help define the decision process. As for having some of these cranks Nitrided, that becomes a bit more complicated. I agree that it would be beneficial if it was guaranteed to produce the desired results. While I have a closed loop with my crank grinder that allows me being part of the process and being basically that the stroke will be indexed, the journals will be in phase and the radiuses will ground properly. Since I do not have a heat treating/Nitriding concern that has been proven to properly harden the cranks, I am a bit leary . I have crankshafts that can be made servicable , admittedly with the possibility of a greater wear rate. There is a possibility that distortion and embrittlement could render a usable shaft unusable. The real quest would be to find a concern that is not put off with one off jobs and a lot of questions. Maybe someone in the States has already fought this battle and be willing to share their good fortune.

Thanks for insight. There is no substitute for having done it .
 
Frankie17 said:
Glyco / Glacier / Vandervell are all great brands and top quality but you will be looking for NOS as they are no longer produced in these brands
King bearings are readily available for Commando and very good quality product , Wassell do not sell Commando shells under the Hepolite brand ( apparently Norton are low volume in comparison to Triumph )
Hepolite Triumph twin shell sets are highly rated by Franz & Grubb in the USA
Click to expand...
Thanks Frankie,
I will have to go back through my shoebox of bearings. most of those are Vandervell from the time of bike manufacture. Bearings are seldom pristine when recovering old dealers stocks. I live in a humid part of the world and many of those old shops had rodent problems. None of that bodes well for the final finish on rod bearings. Some can be reclaimed with a microfiber cloth, but even that is wearing away @ the plating.

Have you any feedback from the bearings that Map Cycle has produced in the US ?
 
rotorwrinch said:
OK, some info that will help define the decision process. As for having some of these cranks Nitrided, that becomes a bit more complicated. I agree that it would be beneficial if it was guaranteed to produce the desired results. While I have a closed loop with my crank grinder that allows me being part of the process and being basically that the stroke will be indexed, the journals will be in phase and the radiuses will ground properly. Since I do not have a heat treating/Nitriding concern that has been proven to properly harden the cranks, I am a bit leary . I have crankshafts that can be made servicable , admittedly with the possibility of a greater wear rate. There is a possibility that distortion and embrittlement could render a usable shaft unusable. The real quest would be to find a concern that is not put off with one off jobs and a lot of questions. Maybe someone in the States has already fought this battle and be willing to share their good fortune.

Thanks for insight. There is no substitute for having done it .
Click to expand...
In the UK nitriding of single cranks can be done easily, it's charged by weight so take off the flywheel. The tool room at work used it extensively as it was a relatively low temp surface treatment that did not distort the tools so was done after final machine op. It will double journal life as a general rule. The first question you will be asked is what steel the crank is made from as it only works on certain steels. A Norton crank is made from the right steel but the code will not be recognised in the US.
 
I had oil pressure problems with the billet crank in my short stroke 500cc Triumph engine. So I had the crank re-ground, hard chrome plated then ground again. The final size of the big end journals was standard Triumph. I had been to a bearing supplier and took the rods with me. They went through their listings and found Morris Mini-Cooper bearings were the same size, but one thou of an inch bigger in ID, and one thou bigger in OD. So one thou more 'crush'. The bearings were a very hard grade of copper lead. I never had oil pressure problems again.
A Commando engine does not usually rev to 10,500 RPM.
I do not believe the Norton factory would have used big end bearings of a size which was not commonly available
 
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