BritBike Forum logo
BritBike Sponsor BritBike Sponsor BritBike Sponsor
BritBike Sponsor

BritBike Sponsor

BritBike Sponsor
BritBike Sponsor BritBike Sponsor BritBike Sponsor
JWood Auction JRC Engineering dealers JWood Auction
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
Two Alpha
Two Alpha
North Coast, BC, Canada
Posts: 619
Joined: April 2011
Show All Member Profiles 
Shout Box
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Random Gallery photo
Who's Online Now
202 registered members (79T140E), 2,176 guests, and 561 spiders.
Key: Admin, Global Mod, Mod
Newest Members
GabrielSoren, JoshP, spikey45, trevor's, myshootingstar68
10077 Registered Users
Top Posters(30 Days)
NickL 87
koan58 85
Lannis 81
Stuart 61
Popular Topics(Views)
504,148 mail-order LSR
Forum Statistics
Forums34
Topics66,033
Posts639,137
Members10,077
Most Online3,995
Feb 13th, 2017
Like BritBike.com on Facebook

Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
A65 crankshaft end float #489866
05/12/13 8:33 am
05/12/13 8:33 am
Joined: Jan 2012
Posts: 109
sussex
J
jamie weeks Offline OP
BritBike Forum member
jamie weeks  Offline OP
BritBike Forum member
J
Joined: Jan 2012
Posts: 109
sussex
I am re building an A65,when checking the crank end float without any shims or the shim cup, it is 6 thou ,so I have fitted a 3 thou shim to make the tolerance 3 thou.But this is without the shim cup and from the calculation of subtracting the number on the crank from the number on the cases it should need 17thou approx.I have obviously fitted the thrust washer etc and checked with a dial gauge,it turns nicely.Is this commom ?
thanks jamie

Support Your #1 BritBike Forum!
Membership Type! Free
Member
Premium
Member
Premium Life
Member
Vendor
Member
Site
Sponsor
Recognition No Premium Member Premium Life member (5 years) Vendor Member Site Sponsor Membership
Post commercial threads No No No Yes Yes
Custom title No Yes Yes Yes Yes
Upload avatar & photos No Yes Yes Yes Yes
Link avatar & photos Yes Yes Yes Yes Yes
Private Message Storage: 10 100 100 100 100
Length of signatures 255 600 600 600 600
Removes this very advert island between post 1&2 No Yes Yes Yes Yes
Price Free $12.90/year $105.00 No End
$55.00/5 years
$210.00/year
($17.50/month)
Email
Click on button >>
  Premium Member Premium Life member Vendor Member Site Sponsor Membership
Re: A65 crankshaft end float [Re: jamie weeks] #489882
05/12/13 10:34 am
05/12/13 10:34 am
Joined: Sep 2004
Posts: 706
Farnham, Surrey, UK
gunner Online content
BritBike Forum member
gunner  Online Content
BritBike Forum member
Joined: Sep 2004
Posts: 706
Farnham, Surrey, UK
AFAK as long as you have the correct end float with everything fitted together you should be ok.

I believe the way to check end float is to put a dial gauge on one end of the crank, zero it and then lever the crank sideways. If everything is correct the dial gauge deflection will be 3 thou which shows the correct number of shims have been fitted in the cup.

Although you can calculate the theoretical number of shims needed based on the previous endfloat & cup thickness, its the final fully assembled reading which counts.


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Re: A65 crankshaft end float [Re: jamie weeks] #489912
05/12/13 3:27 pm
05/12/13 3:27 pm
Joined: Aug 2001
Posts: 4,176
Santa Barbara, California
KC in S.B. Online content

BritBike Forum member
KC in S.B.  Online Content

BritBike Forum member
Joined: Aug 2001
Posts: 4,176
Santa Barbara, California
I had an experience lately where even though I thought I had everything together right, and it's not my 1st motor rebuild, I somehow had the thrust washer not seated in it's proper spot. If it is rotated, as when you lift the crank and turn it while fitting, the washer can stick to the crank and fall back in the wrong spot. The result is it is sitting High, and takes up too much space. If not too late, and you are really concerned, it might be worth checking that. Mine was SO obvious, that I had to take it apart, and found the problem.


Down to 1 BSA, 2 Triumphs, 1 '56 Chevy
Re: A65 crankshaft end float [Re: jamie weeks] #489967
05/12/13 11:49 pm
05/12/13 11:49 pm
Joined: May 2013
Posts: 283
Missouri
B
BSA Nut Offline
BritBike Forum member
BSA Nut  Offline
BritBike Forum member
B
Joined: May 2013
Posts: 283
Missouri
I agree with Gunner...total dry assembly of the lower end is the best way to check for correct end play. Math is good in some instances, but proof is in the pudding, as they say. Dry fit the crank in the two halves, bolt them up,set a dail up on a tang from the case. Measure,adjust, and finally assemble.

Is one thou to three thou what they recommend on these? I dont have a manual in front of me at the moment.

wink

Re: A65 crankshaft end float [Re: BSA Nut] #489973
05/13/13 12:21 am
05/13/13 12:21 am
Joined: Oct 2008
Posts: 4,880
Gnashville
DavidP Offline

BritBike Forum member
DavidP  Offline

BritBike Forum member
Joined: Oct 2008
Posts: 4,880
Gnashville
Originally Posted By: BSA Nut

Is one thou to three thou what they recommend on these? I dont have a manual in front of me at the moment.

wink

0.0015" to 0.003"


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
Re: A65 crankshaft end float [Re: DavidP] #489976
05/13/13 12:26 am
05/13/13 12:26 am
Joined: May 2013
Posts: 283
Missouri
B
BSA Nut Offline
BritBike Forum member
BSA Nut  Offline
BritBike Forum member
B
Joined: May 2013
Posts: 283
Missouri
Thanks David...knew that was close.

Re: A65 crankshaft end float [Re: jamie weeks] #489997
05/13/13 1:51 am
05/13/13 1:51 am
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
Mark Z Online content
BritBike Forum member
Mark Z  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
I agree with KC that something is amiss. The shim cup is about .018" thick, there should be at least that much clearance.

"...total dry assembly of the lower end is the best way to check for correct end play."

To elaborate on this:
Assuming this is a drive-side roller bearing crank ('66 or later, you didn't specify the year), you should have the crank sprocket and alternator rotor mounted, and the rotor nut torqued down when checking the end play, in order to squeeze the shim(s) firmly against the bearing inner race.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 crankshaft end float [Re: jamie weeks] #490079
05/13/13 7:14 pm
05/13/13 7:14 pm
Joined: Oct 2007
Posts: 1,520
Auckland NZ
Ignoramus Online content
BritBike Forum member
Ignoramus  Online Content
BritBike Forum member
Joined: Oct 2007
Posts: 1,520
Auckland NZ
other things I would be looking for on disassembly (and yes you do have to start again) as Mark and KC said ....if the motor was designed with a shim cup thickness and you are hitting spec without it something is wrong.

the things to look out for ;
Inner bearing race is hard up against the web, and not sitting on a kind of wear mark "lip" where either a race previously spun or a shim cup skidded or what ever

that if you haven't checked the outer race (assuming post 66 crank here) is firmly bottomed out in the case you could loose .016 there easy

third a good alternative to fitting everything up on the crank (alternator ect) is use a piece of pipe and a washer to load the bearing inner race

let us know what you find

Last edited by Ignoramus; 05/13/13 7:16 pm.

"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Re: A65 crankshaft end float [Re: jamie weeks] #490271
05/15/13 2:32 am
05/15/13 2:32 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
You may well have a crank that was not part of the original case assembly. I could never get those numbers to work for setting endplay. When measuring with a dial indicator make sure you tighten the rotor nut so the whole assembly is sandwiched up tight against the crank cheek.

Mr Mike

Re: A65 crankshaft end float [Re: jamie weeks] #490287
05/15/13 7:06 am
05/15/13 7:06 am
Joined: Oct 2008
Posts: 4,880
Gnashville
DavidP Offline

BritBike Forum member
DavidP  Offline

BritBike Forum member
Joined: Oct 2008
Posts: 4,880
Gnashville
Just wondering, how does one properly tighten the rotor nut without assembling the whole primary drive?


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
Re: A65 crankshaft end float [Re: jamie weeks] #490329
05/15/13 2:41 pm
05/15/13 2:41 pm
Joined: Aug 2001
Posts: 4,176
Santa Barbara, California
KC in S.B. Online content

BritBike Forum member
KC in S.B.  Online Content

BritBike Forum member
Joined: Aug 2001
Posts: 4,176
Santa Barbara, California
Just find a clean piece of wood, and stop the crank from rotating. As use certainly still have the cylinder off. Find something to use as a spacer on the crank, to replace those parts. That way you do not need to keep installing the gear and rotor each time you tighten the nut. I have a cut off piece of pipe........ works fine.


Down to 1 BSA, 2 Triumphs, 1 '56 Chevy
Re: A65 crankshaft end float [Re: jamie weeks] #490330
05/15/13 2:50 pm
05/15/13 2:50 pm
Joined: Jan 2012
Posts: 109
sussex
J
jamie weeks Offline OP
BritBike Forum member
jamie weeks  Offline OP
BritBike Forum member
J
Joined: Jan 2012
Posts: 109
sussex
I have found the answer,the roller bearing outer was not fully 'home' in its rebate, have now pressed it fully home with a press,and have shimmed the crank with the shim carrier fitted to an end float of 2 thou,many thanks for all your help.I just felt it was not right and that proved to be the case. regards jamie

Re: A65 crankshaft end float [Re: jamie weeks] #490419
05/16/13 4:26 am
05/16/13 4:26 am
Joined: Aug 2001
Posts: 4,176
Santa Barbara, California
KC in S.B. Online content

BritBike Forum member
KC in S.B.  Online Content

BritBike Forum member
Joined: Aug 2001
Posts: 4,176
Santa Barbara, California
Glad you found it, and have that off your mind !! Your intuition was telling you right!


Down to 1 BSA, 2 Triumphs, 1 '56 Chevy
Re: A65 crankshaft end float [Re: jamie weeks] #491181
05/22/13 10:14 am
05/22/13 10:14 am
Joined: May 2013
Posts: 283
Missouri
B
BSA Nut Offline
BritBike Forum member
BSA Nut  Offline
BritBike Forum member
B
Joined: May 2013
Posts: 283
Missouri
When doing this, I was amazed by the amount of endplay prior to tightening the rotor nut. I guess this elaborates on BSA's issue of the bronze bushing not controling the side movement of the crank, which explains the centering effect of having bearings on each end.Improperly fitted, and the crank would drift in and out, with nothing to positively position the shaft.

Re: A65 crankshaft end float [Re: BSA Nut] #491516
05/24/13 1:09 am
05/24/13 1:09 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
BSA nut,
While many plain bearing engines have a floating crank, it would have been nice to have a ball and roller on the primary side to fix the crank to the left side. They did in on b50's, a roller bearing motor, and early A65's had only a ball bearing on the primary side.

Mr Mike

Re: A65 crankshaft end float [Re: jamie weeks] #491549
05/24/13 8:23 am
05/24/13 8:23 am
Joined: May 2013
Posts: 4,730
Rotherham - S. Yorkshire
Allan Gill Online happy
BritBike Forum member
Allan Gill  Online Happy
BritBike Forum member
Joined: May 2013
Posts: 4,730
Rotherham - S. Yorkshire
I had a little look at that idea Mr Mike, I wondered if it would be possible to fit a ball race directly next to the roller. This though would be trying to find a roller that is as thick as the spacer, removing the oil seal and modifying the crank case, it could work but it would be a lot of hassle.

Im getting my engineer to make me a version of the outrigger plate that Mark Parker uses. I have supplied him with a bearing, which needs a sleeve between that and the crank. The sleeve is for 2 reasons

1) to get a bearing of decent OD but slim (about 7mm) the ID is larger also.

2) with the belt drive kit I will be using, the whole setup comes very close to the case, and securing the outrigger properly to the crank, the end of the crank needs to be lengthened.


beerchug
Re: A65 crankshaft end float [Re: jamie weeks] #491687
05/25/13 2:15 pm
05/25/13 2:15 pm
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
You can fit a ball bearing in place of the roller. I did it on my Lightning. Works great. The still make those inch series ball bearings. Then you can throw the thrust washer in the bin. You give up some radial load capacity but for normal street use the ball is adequate and you don't have to fuss with shimming for endplay.

Mr Mike


Last edited by Mr Mike; 05/25/13 2:16 pm.
Re: A65 crankshaft end float [Re: jamie weeks] #491753
05/26/13 2:14 am
05/26/13 2:14 am
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
Mark Z Online content
BritBike Forum member
Mark Z  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
"...and you don't have to fuss with shimming for endplay."

Really, Mike? I thought I had read that shimming is still required, although you don't have to torque down the rotor nut to measure.

This is important to me right now because I'm in the process of rebuilding a '65 lower end, and staying with the ball bearing setup.

One thing I've been wondering through all this, how is the crank located with respect to the cylinder bores, by the drive side or by the timing side of the crankcase? I've noticed that my '65 crankshaft is shorter than my '66, from web to web outer, and the counterweights are thinner. Now either the ball bearing inner race stands prouder in the case than the roller, or the thrust surface of the timing side of the case is built up to make up for the shorter crank and the lack of a thrust washer.

I know, I'm raising two or three different questions at the same time. I guess the bottom line is, if the reference point for locating the crank is the timing side, then it would seem that shimming is necessary.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 crankshaft end float [Re: Mark Z] #491793
05/26/13 12:26 pm
05/26/13 12:26 pm
Joined: Aug 2001
Posts: 4,996
Stone Creek OH USA
R
Rich B Online happy

BritBike Forum member
Rich B  Online Happy

BritBike Forum member
R
Joined: Aug 2001
Posts: 4,996
Stone Creek OH USA
Mark

The ball bearing motors used a lot of different pieces. The housing for the timing side main bearing has a thicker shoulder, the crank is different (as you note), and of course the bearing.

You check "end play" with crank unloaded (no spacer, sprocket, or rotor). Same spec as the roller bearing motors. All you are checking is the running clearance between the shoulder on the TS main bearing and crank. Once you have your .0015" - .003" clearance, you are good to go.

When you assemble the primary, when the rotor nut is tightened, you have running clearance....I still call it "end play" even if it does bother/confuse some. The crank is locked to the ball bearing and has correct clearance on the TS. Seems to work fine.


Life is too short to drink cheap, bad beer.
Re: A65 crankshaft end float [Re: Rich B] #491848
05/27/13 12:28 am
05/27/13 12:28 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
Mark,
I do not understand Rich’s explanation. We have been around on this before and we’ll have to agree to disagree. Here is my explanation of converting a roller bearing motor back to a ball bearing. First I agree there are differences in the thickness of the flanges of the bush and possibly the crank width, however, the ball bearing and a roller bearing have identical dimensions. The ball once assembled locks the crank to the primary side. The only movement of the crank laterally is the minute running clearances of the balls in the race. This movement is imperceptible…maybe .0002” I insert the same cup and shims that was used on my roller bearing so that the I centralise the rod journals under the bores. This is not of great concern because there is plenty of side to side clearances of the rods on the journals and between the piston and the small end. Now as I bolt the cases together I have to be sure that when I tighten the cases there is some clearance between the flange of the bush and the right side crank cheek. But since I have removed the thrust washer altogether (.065” thick), there is plenty of clearance so you won’t put the crank in a bind as you torque up the case bolts and studs. There is no need for a thrust washer whatsoever…It’ll only rattle around. With a roller motor that clearance has to be .0015-.003” because the crank is NOT fixed on the primary side. It shucks back and forth limited on the timing side by the thrust washer and on the primary side by the lip on the roller bearing. There is no such movement with a ball bearing.

I do not know how else to explain it.

Mr Mike

Re: A65 crankshaft end float [Re: jamie weeks] #491866
05/27/13 4:29 am
05/27/13 4:29 am
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
Mark Z Online content
BritBike Forum member
Mark Z  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
I've read both of your explanations (twice), and I'm not so sure there's any real disagreement.

Nowhere does Rich say that the crank floats.

You both say that the crank has to be shimmed "so that the rod journals are centered under the bores" (in so many words), and that's what I really wanted to know.

It sounds like you may be saying, Mike, that if the clearance turned out to be something more than .003, that would be ok (i.e., because the crank does not float). But since in my case, the end play has to be measured and the crank shimmed, we may as well shoot for the .0015-.003 spec.

But I understand now your PREVIOUS quote, "you don't have to fuss with shimming for endplay." The key words here are "for endplay". I first misinterpreted that statement as "you don't have to shim the crank".

Ok thanks both of you, I think I'm back on track.

Last edited by Mark Z; 05/27/13 4:31 am.

Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 crankshaft end float [Re: Mr Mike] #491912
05/27/13 5:07 pm
05/27/13 5:07 pm
Joined: Jul 2009
Posts: 3,549
Vic. Australia
P
Pete R - R.I.P. Offline
In Remembrance
Pete R - R.I.P.  Offline
In Remembrance
P
Joined: Jul 2009
Posts: 3,549
Vic. Australia
Originally Posted By: Mr Mike
But since I have removed the thrust washer altogether (.065” thick), there is plenty of clearance so you won’t put the crank in a bind as you torque up the case bolts and studs. There is no need for a thrust washer whatsoever…It’ll only rattle around. With a roller motor that clearance has to be .0015-.003” because the crank is NOT fixed on the primary side. It shucks back and forth limited on the timing side by the thrust washer and on the primary side by the lip on the roller bearing. There is no such movement with a ball bearing.


What holds the drive-side ball bearing in place when the engine is hot?It's only an interference fit in the crankcase when the engine is cold.
Heat the crankcase to 100 C.,and see how tighty (or loosely) that bearing is held in position.

Re: A65 crankshaft end float [Re: Pete R - R.I.P.] #491922
05/27/13 7:52 pm
05/27/13 7:52 pm
Joined: Oct 2007
Posts: 1,520
Auckland NZ
Ignoramus Online content
BritBike Forum member
Ignoramus  Online Content
BritBike Forum member
Joined: Oct 2007
Posts: 1,520
Auckland NZ
Have you guys considered that if you remove the thrust washer (which I think is nominally 1/16th ) you will create a much larger "cavity" between the crank web and the bush end on the ts.

I cant see any way that wouldn't loose you a bit of oil pressure ....or oil flow to the big ends to be more precise

might be a bit theoretical but I will skip that mod


"There's the way it ought to be and there's the way it is" (Sgt Barnes)
Re: A65 crankshaft end float [Re: Mr Mike] #491963
05/28/13 12:16 am
05/28/13 12:16 am
Joined: Aug 2001
Posts: 4,996
Stone Creek OH USA
R
Rich B Online happy

BritBike Forum member
Rich B  Online Happy

BritBike Forum member
R
Joined: Aug 2001
Posts: 4,996
Stone Creek OH USA
Mike

Mark is NOT converting a motor. He is rebuilding a 1965 motor that had no thrust washer, was designed to run a ball bearing, and has a lot of different pieces than you are familiar with your one motor you rebuilt and converted.

The details of your conversion are useful for someone rebuilding a 1966 or later motor. But, none of that information is useful on a 1962 - 1965 motor, which is a different animal. If anything, the info adds confusion.

Rather than keep saying you don't understand what I am saying and we have to disagree, look at a 62 - 65 motor for once. Then maybe you will understand the differences. And understand the differences in set of the bottom end.


Life is too short to drink cheap, bad beer.
Re: A65 crankshaft end float [Re: jamie weeks] #491978
05/28/13 1:02 am
05/28/13 1:02 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
Rich,
You are right ...I am only speaking only of a conversion of a roller motor to a ball. If I was putting an earlier ball motor back together I would want to make sure that there was clearance so as not to preload the bearing when tightning the case which would result in almost immediate failure. So putting in some shim to centralise the journals under their bores is important but don't put in so much that it binds the crank. In a coversion from roller to ball there is plenty of clearance with the thrust washer removed. If I left the thrust washer in I would have to make sure that there was a clearance.

Pete, as the motor heats up it heats up fairly slowly and somewhat uniformly so as not to lose the interference fit. Additionally the coefficient of friction of aluminum is about twice that of steel so it likely gets a little tighter. I do not know why BSA did not put in a retainter plate like on a B50. They must have thought it was unnecessary.

Iggy, It is unlikley that removal of the thrust washer will have any appreciable effect on oil pressure. It is not pressed in there...just captured there.

Mr Mike

Re: A65 crankshaft end float [Re: Mr Mike] #491984
05/28/13 1:27 am
05/28/13 1:27 am
Joined: Jul 2009
Posts: 3,549
Vic. Australia
P
Pete R - R.I.P. Offline
In Remembrance
Pete R - R.I.P.  Offline
In Remembrance
P
Joined: Jul 2009
Posts: 3,549
Vic. Australia
You should have somewhere between 0.0015" and 0.003" interference at room temperature,say 20C.

Aluminiuum expands roughly twice as much as steel.
The difference is about 0.001" per inch diameter for 100 C. temperature rise.With 50 degree rise on 2-13/16 diameter bearing,you lose 0.0014" of your interference fit.Crankcases can,and do occassionally,reach 100 C.

Even if you had 0.002" inteference at room temperature,you could have less than no interference when the engine is hot.

Re: A65 crankshaft end float [Re: jamie weeks] #491986
05/28/13 2:16 am
05/28/13 2:16 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
Pete,
If you are correct these bearings would not stay in the case very long but most do. I for one would have like to see an additional retainer of some sort but the BSA system seems to have worked but requires very accurate machining to hold tolerance for an interference fit. HOWEVER, once that outer race move relative to the case, the case is junk.

Mr Mike

Re: A65 crankshaft end float [Re: Mr Mike] #491989
05/28/13 2:33 am
05/28/13 2:33 am
Joined: Jul 2009
Posts: 3,549
Vic. Australia
P
Pete R - R.I.P. Offline
In Remembrance
Pete R - R.I.P.  Offline
In Remembrance
P
Joined: Jul 2009
Posts: 3,549
Vic. Australia
Originally Posted By: Mr Mike
HOWEVER, once that outer race move relative to the case, the case is junk.

They always move when the engine gets hot.There was some discussion about this on the Norton Bulletin Board,a little over a year ago. Bearing Movement in Crankcase

Re: A65 crankshaft end float [Re: jamie weeks] #492057
05/28/13 6:18 pm
05/28/13 6:18 pm
Joined: Oct 2008
Posts: 4,880
Gnashville
DavidP Offline

BritBike Forum member
DavidP  Offline

BritBike Forum member
Joined: Oct 2008
Posts: 4,880
Gnashville
From that Norton post:
"Just to re-confirm what I had found in the past I pulled an old virgin 750 bottom end off the shelf and checked the end play. It had a tight .002 IN.- about right for a ball bearing.
I stuck it in the oven at 220 F. for one hour.
The end play was then .034 and I could move it back and forth by hand."

I assume that this increase also happens to our BSA engines once they get up to temp?


Stepping on others doesn't make you stand tall.

71 A65L "Zelda"
92 BMW K100rs "Gustav"
Re: A65 crankshaft end float [Re: jamie weeks] #492127
05/29/13 3:54 am
05/29/13 3:54 am
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
M
Mr Mike Offline
BritBike Forum member
Mr Mike  Offline
BritBike Forum member
M
Joined: Aug 2001
Posts: 3,871
Cape Carteret, NC
David,
I suspected the same thing and measured endplay on a roller motor. I then heated the whole assembled bottom end up in an oven. The endplay increased measurably with a dial indicator. Coefficient of expanison of Alum is approximately 2x that of steel. Based on that I would set the endplay at the bottom end of the limit, but, I have often wondered what gets hotter under normal operation the crank or the cases
Mr Mike

Re: A65 crankshaft end float [Re: jamie weeks] #492136
05/29/13 6:32 am
05/29/13 6:32 am
Joined: Mar 2011
Posts: 833
derby england
wak Offline
BritBike Forum member
wak  Offline
BritBike Forum member
Joined: Mar 2011
Posts: 833
derby england
im not sure im buying this, when you run the bike its air and oil cooled,i cant see the cases getting much hotter than the oil, and if its growing that much whats happening at the cylinder base,timing gears ,primary chain? not to mention piston and rod alighnment.if it expanded that much every time it cooled all the bolts would be loose.


BSA lightning
BSA B50MX
TRIUMPH TR6C
BSA BUSHMAN
BSA Gold Star Daytona
BSA Gold Star Scrambler
BSA Rocket Gold Star
BSA C15S
BSA Cyclone
Triumph T120
Triumph T100 Daytona
Triumph 5TA Trials
Triumph T100 Scrambles
Cheney 560 TT
Re: A65 crankshaft end float [Re: jamie weeks] #492164
05/29/13 1:24 pm
05/29/13 1:24 pm
Joined: May 2013
Posts: 4,730
Rotherham - S. Yorkshire
Allan Gill Online happy
BritBike Forum member
Allan Gill  Online Happy
BritBike Forum member
Joined: May 2013
Posts: 4,730
Rotherham - S. Yorkshire
My bike was running 018" of end float when cold, never checked it hot. The crank was perfectly fine when it was pulled apart. It probly didn't do the primary chain too many favours but if anything it probably worked in harmony with the wobble in the clutch basket laughing

I'm with wak though. If you just heat the whole engine then yes the cases will expand a bit, not at any great expanse though otherwise the cases would crack at its mounting points. When your running the motor, the moving components generating heat are made of steel, the oil flow is removing heat, some is transferring to the cases which is being cooled by air flow. The overall rate of expansion is probably fairly even. Run the engine for 20 miles and check it then!

I think as long as you have enough clearence so nothing nips up tight and not too much so that the engine throws its self apart there is little to worry about.


beerchug
Re: A65 crankshaft end float [Re: jamie weeks] #713676
11/03/17 1:04 am
11/03/17 1:04 am
Joined: Jul 2006
Posts: 467
just a guy from Jersey [Hopewe...
N
nert Offline
BritBike Forum member
nert  Offline
BritBike Forum member
N
Joined: Jul 2006
Posts: 467
just a guy from Jersey [Hopewe...
So, on a 1966 A65 roller type bearing, the crankshaft can still float with the spacer, gear, and rotor all tightened up? It doesn't feel like it. Or should I measure end float with out the spacer, gear, and rotor torqued up.?


keep your "oddies" lubricated, and carry a dime
Re: A65 crankshaft end float [Re: nert] #713705
11/03/17 12:12 pm
11/03/17 12:12 pm
Joined: Oct 2009
Posts: 444
new jersey usa
P
pushrod tom Offline
BritBike Forum member
pushrod tom  Offline
BritBike Forum member
P
Joined: Oct 2009
Posts: 444
new jersey usa
Everything needs to be torqued up. A pain but necessary. PRT

Re: A65 crankshaft end float [Re: jamie weeks] #717050
11/29/17 12:58 am
11/29/17 12:58 am
Joined: Aug 2017
Posts: 3
Toronto Ontario Canada
6
69BSATONY Offline
BritBike Forum member
69BSATONY  Offline
BritBike Forum member
6
Joined: Aug 2017
Posts: 3
Toronto Ontario Canada
I'm learning as i go along.
Since the cases have to be assembled and pulled apart a few times to get the end float right
how do you guys install and remove the roller bearing without busting it. mine is very tight on the shaft.
I all ready ruined one and waiting for a replacement . At $ 100 bucks ???
Should I sand the shaft or the inner race ?
Thanks



69 BSA lightning

Re: A65 crankshaft end float [Re: 69BSATONY] #717054
11/29/17 2:43 am
11/29/17 2:43 am
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
Mark Z Online content
BritBike Forum member
Mark Z  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
Originally Posted by nert
So, on a 1966 A65 roller type bearing, the crankshaft can still float with the spacer, gear, and rotor all tightened up? It doesn't feel like it. Or should I measure end float with out the spacer, gear, and rotor torqued up.?


The rotor nut pulls the crank tight to the inner race of the roller bearing. With a roller bearing however, the inner race can "float" with respect to the outer race.

Not sure what you mean by "it doesn't feel like it" - I doubt you could detect 2 thou of movement without a dial indicator. Also, are you trying to check this on a fully assembled motor? It should be checked with the rotor nut torqued down, but without the crank pinion and oil pump installed.

Originally Posted by 69BSATONY
I'm learning as i go along.
Since the cases have to be assembled and pulled apart a few times to get the end float right
how do you guys install and remove the roller bearing without busting it. mine is very tight on the shaft.
I all ready ruined one and waiting for a replacement . At $ 100 bucks ???
Should I sand the shaft or the inner race ?
Thanks
69 BSA lightning


Wow, if you ruined a bearing (just the inner race, right?) getting it off, it was really on there! They're usually not THAT tight. Yes, I would do a bit of sanding, on the crank. Fine emery, go slow, wipe it clean and apply a bit of oil before test-fitting.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 crankshaft end float [Re: jamie weeks] #717089
11/29/17 1:33 pm
11/29/17 1:33 pm
Joined: Aug 2017
Posts: 3
Toronto Ontario Canada
6
69BSATONY Offline
BritBike Forum member
69BSATONY  Offline
BritBike Forum member
6
Joined: Aug 2017
Posts: 3
Toronto Ontario Canada
Thanks Mark z.
Will do that when I get the new bearing .

Re: A65 crankshaft end float [Re: jamie weeks] #717092
11/29/17 1:52 pm
11/29/17 1:52 pm
Joined: Aug 2001
Posts: 3,641
argyll. scotland, uk
gavin eisler Online content
BritBike Forum member
gavin eisler  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 3,641
argyll. scotland, uk
To get the shims correct it helps if an old main bearing is used, remove some material from the bearing inner bore ( a small flapwheel will do it) and outer shell to make trial fitting easy, as long as the width is the same as the new one this allows trial fits with no drama. its best to have tight/ snug final fit. I have had to resleeve a DS mainshaft so I am wary of removing material from this part.


71 Devimead A65 750
56 Norbsa 68 Longstroke A65
Cagiva Raptor 650
MZ TS 250
The poster formerly known as Pod
Re: A65 crankshaft end float [Re: jamie weeks] #717104
11/29/17 4:02 pm
11/29/17 4:02 pm
Joined: Jan 2004
Posts: 3,599
ca, us
D
DMadigan Online content
BritBike Forum member
DMadigan  Online Content
BritBike Forum member
D
Joined: Jan 2004
Posts: 3,599
ca, us
You need a bearing puller that clamps around the rollers with a lip behind. Something you would have if you did this more often.
If you use an old bearing as Gavin suggested you should measure the inner race width with a micrometer to be sure they are the same. Different manufacturers may have different tolerances.
I would not suggest doing anything with the crank to make removal easier. Since you do not have a bearing puller I doubt you have the equipment to do it properly.

Re: A65 crankshaft end float [Re: jamie weeks] #717151
11/29/17 9:01 pm
11/29/17 9:01 pm
Joined: Sep 2004
Posts: 706
Farnham, Surrey, UK
gunner Online content
BritBike Forum member
gunner  Online Content
BritBike Forum member
Joined: Sep 2004
Posts: 706
Farnham, Surrey, UK
IMHO its not unusual to find that bearings don't fit easily on to crankshafts or other shafts. Whether this is due to inaccuracies in BSA or bearing manufacturing is unknown to me, I guess you would need accurate measurement apparatus to find out where the problem lies.

Also, its not clear to me what the ideal clearance between a crankshaft and bearing internal diameter should be. I'm aware that C3 clearance is intended to take up bearing compression when fitted into a crankcase housing and also tight fitting onto crankshafts. However what if both conditions exist, does this mean a bearing with even larger clearance is needed?

Where a bearing is a very tight fit on a shaft, my preference is to hone the inside diameter of the bearing so that its a nice tight sliding fit on the shaft. Its better to remove material from the bearing as these are easier to replace compared to crankshafts.


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Re: A65 crankshaft end float [Re: jamie weeks] #717158
11/29/17 10:31 pm
11/29/17 10:31 pm
Joined: Mar 2005
Posts: 10,057
Boston, Massachusetts
J
John Healy Online content
BritBike Forum member
John Healy  Online Content
BritBike Forum member
J
Joined: Mar 2005
Posts: 10,057
Boston, Massachusetts
Quote
IMHO its not unusual to find that bearings don't fit easily on to crankshafts or other shafts.


They were designed that way!

Quote
Also, its not clear to me what the ideal clearance between a crankshaft and bearing internal diameter should be. I'm aware that C3 clearance is intended to take up bearing compression when fitted into a crankcase housing and also tight fitting onto crankshafts.


It is not either or.

It is if both are a press fit you use a C3. Of course it depends on the press fit. The shaft and bearing dimensions are plus or minus about .001".

The problem with having the bearing a slip fit is, if the rotor nut comes loose the harder bearing wears the crankshaft. It can wear the shaft enough that it will need plating to restore the fit. So, while you can make it a slip fit, it isn't such a good engineering practice.


Re: A65 crankshaft end float [Re: jamie weeks] #717163
11/29/17 11:47 pm
11/29/17 11:47 pm
Joined: Sep 2004
Posts: 706
Farnham, Surrey, UK
gunner Online content
BritBike Forum member
gunner  Online Content
BritBike Forum member
Joined: Sep 2004
Posts: 706
Farnham, Surrey, UK
Thanks John, point well made and now understood.


1968 A65 Firebird
1967 B44 Shooting Star
1972 Norton Commando
Re: A65 crankshaft end float [Re: jamie weeks] #717170
11/30/17 1:00 am
11/30/17 1:00 am
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
Mark Z Online content
BritBike Forum member
Mark Z  Online Content
BritBike Forum member
Joined: Aug 2001
Posts: 4,279
Owego, NY, USA
I will defer to the advice given above. Using an old bearing with some material removed to test fit is an excellent idea. Also using a bearing puller, and sanding the bearing rather than the crank if sanding is needed (although it's easier to evenly sand an outer surface than an inner surface).

I was always able to get the bearings off the cranks on my A65s with just a bit of prodding.


Mark Z

'65(lower)/'66(upper, wheels, front end, controls)/'67(seat, exhaust, fuel tank, headlamp)/'70(frame) A65 Bitsa.
Re: A65 crankshaft end float [Re: jamie weeks] #718193
12/09/17 2:11 am
12/09/17 2:11 am
Joined: Aug 2017
Posts: 3
Toronto Ontario Canada
6
69BSATONY Offline
BritBike Forum member
69BSATONY  Offline
BritBike Forum member
6
Joined: Aug 2017
Posts: 3
Toronto Ontario Canada
Thanks for the advise.I do have one of those bearing pullers. This bike was sitting outside for 30 years and whoever worked on it last didn't shim the crank at all so the bearing was stuck against the crank side pretty good. Plus by the red ish color under the bearing they must have used locktite by the gallon.
I bought a bearing with shims and cup from CBS in California. Soon as it gets here I will compare widths . If they are the same I'll use the old one to set things up and use the new one on final assembly.

Thanks again

Page 1 of 2 1 2

Moderated by  Allan Gill, Jon W. Whitley 


Home | Sponsors | Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons | "OLD" BritBike Forum | DVD- Manuals & Parts books | BritBike Stickers & Decals
Upgrade to: Premium Membership | Premium Life Membership | Vendor Membership | Site Sponsor Membership
Powered by UBB.threads™ PHP Forum Software 7.6.1.1
(Release build 20180111)
Page Time: 0.117s Queries: 15 (0.007s) Memory: 1.3781 MB (Peak: 1.9370 MB) Zlib disabled. Server Time: 2018-02-23 00:42:27 UTC