Main Bearing Superblend installation
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ashman
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I use a old inner bearing to tap the new one on without any heat and maybe a little oil on it to help it go on the crank as for the outer I just put my case over the flame on my stove it don't take long to heat the case before the old bearing drops out , flip it over and drop the new one in then let it cool down.
Ashley
Ashley
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p400 said:
Hi p400.
It seems the rounding-up is in their favour ($44.58 to $45.00). We call this 'salami slicing' - no-one worries about a few cents but when you move millions of products the extra profit can really mount up. Should you complain, their admin costs to correct the overcharge will wipe out the price of both bearing (we call this 'keeping the bastards honest').
Ta.
p400
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Before installing the bearings, I thought I would get a feel for how true the crank was after being disassembled , cleaned, and reassembled.
So I set it up on my wheel truing stand, with the support as narrow as possible and the dial indicator as far to the outside as possible.
I see this being done on knife edges, rather than my narrow bearing, but it seemed reasonable.
Both side registered a couple of tenths out - .0002-.0004"
what is normally seen on this type inspection? on this type bolt together crank?
So I set it up on my wheel truing stand, with the support as narrow as possible and the dial indicator as far to the outside as possible.
I see this being done on knife edges, rather than my narrow bearing, but it seemed reasonable.
Both side registered a couple of tenths out - .0002-.0004"
what is normally seen on this type inspection? on this type bolt together crank?
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Anonymous
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Hi p400.
That sounds good but does your dial indicator have such accuracy?
That sounds good but does your dial indicator have such accuracy?
p400
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This is a cheap dial that has .001 marks, so I have to interpret what I see happening between two marks l l on the dial.needing said:
This crank rotating fixture is running on two ball bearings on each side, so I am getting the runout (external/internal) of these bearings as well.
I am happy that I do not see any runouts bigger than .0005".
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So all roller bearings since WW2 had barrel shaped rollers did they?? Well you learn something new every day on this web site which appears to contain as much MISinformation as other Norton / British bike web sites and Club magazines etc!!
As far as I am aware the drive side roller bearing employed up to Commando models was a bog standard Ransome and Marles ( R & M from here on) 8MRJA30 bearing which had 11 rollers of approx width and O.D. 11.12 mm They had a 10 mm wide parallel section with a very slight radius at each end. In use on the more highly tuned Commando Combat motors the crank flexed so much that the edges of the rollers were the only bits in contact with the inner and outer raceways which resulted in bearing premature failure often at around 4000 miles DRAMATICALLY helped by the advance retard units falling apart and staying fully advanced at all times,,, their construction was later improved!! To help overcome this rather serious bearing problem a plain fag packet was obtained and someone suggested slightly altering the shape of the rollers such that when the crank flexed more of the roller than previously was in contact with the inner and outer raceways. R & M then produced a new bearing with a designation 6MRJA30 with the MRJA30 stamped onto the side of the outer raceway with the 6 etched on. The inner raceway was stamped MRJ30. The bearing employed 13 rollers of width and O.D. approx 9.53mm but the parallel portion of the roller was approx 6 mm with a slight taper on each end reducing the diameter to approx 9.46 mm and on the edge a slight radius as previously. I believe the 'barrel shape' is known as logarithmic profiling. This is the 'Superblend' bearing originally employed for Commandos.
Interestingly the load capacity of the earlier bearing was greater than that for the 'superblend' bearing....
8MRJA30 Dynamic 41,900 Newtons .....Static 35,200 Newtons
6MRJA30 Dynamic 35,800 Newtons .....Static 31,000 Newtons
Some of us actually talk to bearing manufacturers to learn the facts ........... and have removed the rollers from various new bearings and measured them 9with micrometer and OLD knackered eyes to try to find out what was actually going on. Well it kept me amused for a while......
Now another bearing company was FAG... who had an office just down the road from Norton.....and could, so I was told by several ex NVT Gentlemen friends, supply cheaper bearings....... FAG produced the roller 306 bearing in a std form and a high capacity load form and by that time had changed their roller shape (as did various other bearing manufacturers) This high load capacity FAG bearing had a designation of NJ306E the 'E' indicating EXTRA load capacity which were Dynamic 50,000 Newtons and Static 48,000 Newtons. This bearing employed 12 rollers of approx 12 mm width and 11 mm in diameter with an approx 8 mm parallel portion reducing at each end to approx 10.97mm. Funny thing is that every Fag bearing I have looked at taken from motors has wear markings on the rollers right out to the edge of the superblending whereas on the R & M bearings it stops just short of the edges......Perhaps its all down to the very slightly greater barrel shaping of the R & M rollers????
I believe Norton tried another manufacturers bearing at the same time as they did the R & M bearing because in a cellar in Birmingham there were a pile of SKF steel caged roller bearing that we were told had come out of Norton.....There were two types , one a std designated NJ306 and the other a high load calacity version designated NJ306E. All the boxes wer marked 1972. The rollers were all the older non superblended version.
The tale of the Commando main bearing failure problem was told by someone CLEARLY involved at the factory in Motor Cycle Sport January 1977 on pages 27 and 28 The heading on page 27 is ' VICIOUS CIRCLE... A cautionary tale in which it is shown that in Engineering, at least, nothing is as simple as it seems. The following story is based on a series of events that took place not long ago, at a motor cycle manufacturers somewhere in Europe. Only the names have been changed to protect the guilty.' On page 28 the heading is ' For life and reliability there is a threshold which cannot be crossed with impunity. Most bikes are there already'.
I would suggest you read it and I believe one of the many people I have over the years sent a copy actually published it on the web but I have not bothered to see if it is stil on the web.
A WARNING. Many years ago a certain British Bike spares emporium in London bought a VERY cheap pile of new brass caged boxed FAG NJ306E bearings ..... opened one box and removing the bearing inner I looked at the rollers expecting to see the slight barrel shape...there was non....I removed a roller and measured it proving my eye sight was still working......I phoned FAG who suggested they must of been a batch held by a dealer for a few years and that they had the old NON barrel shaped rollers. I assume everyone checks such things before fitting them ?? The dealer sold them all to Commando owners and I bet NON of them shecked.........
I even checked the RHP main bearing used on the D.S of later Triumph twins NUP306ETN which employed 13 rollers 12 mm wide and 11 mm O.D. with a 9 mm mm parallel portion reducing to 10.96 mm at the edges. Load capacity was Dynamic 57,000 Newtons and Static 53,000 Newtons.
All my measuring took place decades ago and the bearings could well of changed since then.
As far as I am aware the drive side roller bearing employed up to Commando models was a bog standard Ransome and Marles ( R & M from here on) 8MRJA30 bearing which had 11 rollers of approx width and O.D. 11.12 mm They had a 10 mm wide parallel section with a very slight radius at each end. In use on the more highly tuned Commando Combat motors the crank flexed so much that the edges of the rollers were the only bits in contact with the inner and outer raceways which resulted in bearing premature failure often at around 4000 miles DRAMATICALLY helped by the advance retard units falling apart and staying fully advanced at all times,,, their construction was later improved!! To help overcome this rather serious bearing problem a plain fag packet was obtained and someone suggested slightly altering the shape of the rollers such that when the crank flexed more of the roller than previously was in contact with the inner and outer raceways. R & M then produced a new bearing with a designation 6MRJA30 with the MRJA30 stamped onto the side of the outer raceway with the 6 etched on. The inner raceway was stamped MRJ30. The bearing employed 13 rollers of width and O.D. approx 9.53mm but the parallel portion of the roller was approx 6 mm with a slight taper on each end reducing the diameter to approx 9.46 mm and on the edge a slight radius as previously. I believe the 'barrel shape' is known as logarithmic profiling. This is the 'Superblend' bearing originally employed for Commandos.
Interestingly the load capacity of the earlier bearing was greater than that for the 'superblend' bearing....
8MRJA30 Dynamic 41,900 Newtons .....Static 35,200 Newtons
6MRJA30 Dynamic 35,800 Newtons .....Static 31,000 Newtons
Some of us actually talk to bearing manufacturers to learn the facts ........... and have removed the rollers from various new bearings and measured them 9with micrometer and OLD knackered eyes to try to find out what was actually going on. Well it kept me amused for a while......
Now another bearing company was FAG... who had an office just down the road from Norton.....and could, so I was told by several ex NVT Gentlemen friends, supply cheaper bearings....... FAG produced the roller 306 bearing in a std form and a high capacity load form and by that time had changed their roller shape (as did various other bearing manufacturers) This high load capacity FAG bearing had a designation of NJ306E the 'E' indicating EXTRA load capacity which were Dynamic 50,000 Newtons and Static 48,000 Newtons. This bearing employed 12 rollers of approx 12 mm width and 11 mm in diameter with an approx 8 mm parallel portion reducing at each end to approx 10.97mm. Funny thing is that every Fag bearing I have looked at taken from motors has wear markings on the rollers right out to the edge of the superblending whereas on the R & M bearings it stops just short of the edges......Perhaps its all down to the very slightly greater barrel shaping of the R & M rollers????
I believe Norton tried another manufacturers bearing at the same time as they did the R & M bearing because in a cellar in Birmingham there were a pile of SKF steel caged roller bearing that we were told had come out of Norton.....There were two types , one a std designated NJ306 and the other a high load calacity version designated NJ306E. All the boxes wer marked 1972. The rollers were all the older non superblended version.
The tale of the Commando main bearing failure problem was told by someone CLEARLY involved at the factory in Motor Cycle Sport January 1977 on pages 27 and 28 The heading on page 27 is ' VICIOUS CIRCLE... A cautionary tale in which it is shown that in Engineering, at least, nothing is as simple as it seems. The following story is based on a series of events that took place not long ago, at a motor cycle manufacturers somewhere in Europe. Only the names have been changed to protect the guilty.' On page 28 the heading is ' For life and reliability there is a threshold which cannot be crossed with impunity. Most bikes are there already'.
I would suggest you read it and I believe one of the many people I have over the years sent a copy actually published it on the web but I have not bothered to see if it is stil on the web.
A WARNING. Many years ago a certain British Bike spares emporium in London bought a VERY cheap pile of new brass caged boxed FAG NJ306E bearings ..... opened one box and removing the bearing inner I looked at the rollers expecting to see the slight barrel shape...there was non....I removed a roller and measured it proving my eye sight was still working......I phoned FAG who suggested they must of been a batch held by a dealer for a few years and that they had the old NON barrel shaped rollers. I assume everyone checks such things before fitting them ?? The dealer sold them all to Commando owners and I bet NON of them shecked.........
I even checked the RHP main bearing used on the D.S of later Triumph twins NUP306ETN which employed 13 rollers 12 mm wide and 11 mm O.D. with a 9 mm mm parallel portion reducing to 10.96 mm at the edges. Load capacity was Dynamic 57,000 Newtons and Static 53,000 Newtons.
All my measuring took place decades ago and the bearings could well of changed since then.
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J. M. Leadbeater said:
Yes, I noted that old BS cropping up here again - regularly too.
Same poster(s) every time too, some folks don't seem to be able to listen and learn...
And, if the rollers were barrel shaped, how would you ever fit them to parallel housings.
We have beaten this to death here, a number of times. Not again, again, again, pleeese...
p400
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heated the new FAG super blend inner races with 1500 watt heat gun used for various purposes (purchased at Lowes) and they slipped right on crank.
heated the alloy engine cases with oxyacetylene to 300F and the outer FAG bearings dropped right in.
air cooled all
assembled cases and find .022" float on crank....using same cheap dial.
should this be tighter? or does this meet spec?
heated the alloy engine cases with oxyacetylene to 300F and the outer FAG bearings dropped right in.
air cooled all
assembled cases and find .022" float on crank....using same cheap dial.
should this be tighter? or does this meet spec?
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Anonymous
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Hi p400.
I would recommend reducing the end float to say 10 thou while you have the opportunity.
Your gauge is fine (but once you quote figures smaller than the markings then it is really a guess done it myself)
Oh, great photoshop of the vise. :shock:
Ta.
I would recommend reducing the end float to say 10 thou while you have the opportunity.
Your gauge is fine (but once you quote figures smaller than the markings then it is really a guess
done it myself)Oh, great photoshop of the vise. :shock:
Ta.
lcrken
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p400 said:
Norton recommended an end float of .010" -.024" in 1971 in their first service note on Commando crankshaft bearings, and .010" - .020" in a later one in 1972. You should be fine with .022". On the other hand, this would be the time to get it down to .010" or so, if that sort of thing worries you. I get them down to .005" - .010", even though I know it isn't critical. The only situation in which I've ever seen it make much difference was in a race bike with a crank triggered ignition.
Ken
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hobot said:
Hi hobot.
A few thou (10 tops) either way? Nope, I'm not concerned.
Ta.
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Yep sir J.M. no completely flat rollers at least since WWII though what worked in automotive or air craft got exceeded by The Bad Manufacturing Errors of early Combats, mech adv to crank and maybe case bores too. Please explain how the 1971 and prior Commando which are almost as potent as a Combat to rev as high got away w/o SuperDuperBlends?
I found the original essentially flat type rollers in both my Combats, the first one was rather famous a few decades before I arrived as the hot hot to beat in several counties around and got reminded of it showing back up on it here and there. If a Combat is not lugged but kept mostly on the boil the bearings almost do not wear out and were still about pristine in both my hard run Combat before I got em.
My 1968 P!! dragster had plain roller on DS and ball bearing on TS with tach marked 9000 by builder which I always respected but hardly ever could stand it. Same in Ms Peel, No SuperDuper on DS and 11 ball on TSl. Rode 2000 miles often over ton with big winter shield after tach needle bouncing on both side of peg over rev event. Loss of wheelie power made me tear down, check and give my bud Wes the bearings now 8 yrs/ 15,000 miles in his 1971 that had seized on originals many dozens 1000 miles of use. Wes had a Combat that bombed in the 4000 mile mark in North Carolina so left with expert to go through it, afterwards he was able to out drag the 2smoke triples over the ton but they could catch back up and pass once out on open hwys.
Appreciate the details and experiences I lack but something does not compute on the SuperDuperblends worshiping as key to Norton Combat salvation. Norton had better advertising dept than accounting or quality control.
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