MAIN BEARINGS FAILURE, MUST CHANGE

rabno

i will say that the doc is bang up to date with what is accepted practice. ball left and roller right. the ball is because the rollers still can't cope on the left. the roller on the right is because it can!

we wouldn't hesitate to swap if that was what was required. i've stripped an engine to the left before and it was only a problem because i'm right-handed.

now, moving on.....
i took my first tentative steps today in machining the bearing housing and its relieved! a bit like me. i've also had the crank done by hand as well. thanks to thomas for the sound advice.

i'll start a seperate thread on it once i'm happy with the first results. let you all know.....

regards

Taffy

Well thanks for the replys, by the sounds of things after the rebuild my 450 (with me riding) should last "forever" . Ill let yous know how i get on (might be a month or 2 yet till its totally rebuilt and back in the bike ) Im just waiting on the bearing inner extractor coming, since tbh im scared of hurting the crank trying to get them off without it :lol:

had a chat with DCR a couple of days ago and he ran through a lot of stuff. the "pull to the left mod" was an idea of his father's! i have stripped a 450 that has a pair of 206EC/VC025s in. i would imagine these are the bearings that thomas has talked of before. KTM crate motor?

THE EC REFERS TO OPTIMISED INTERNAL CLEARANCE
WITH MODIFIED ROLLER END/FLANGE CONTACT.

PHA= INJECTION MOULDED CAGE
OF POLYETHERKETONE (PEEK), OUTER RING CENTRED.

THE PH WITHOUT THE A = PEEK INJECTION MOULDED CAGE WITH ROLLER CENTRED.

i've heard ECP/C3 HVC058 and ....EC548 come up here.

here is an idea i'd just like to throw into the ring?

the pressure side is the left yes? but it's the right side that gets the bearing that can take the loading? surely this is wrong?

lets go back to the DCR mod for a moment. the crank is pulled in hard to the left against the inner race of the ball-race bearing? on the right, the roller is laft to axially expand and contract without the shoulders of the rollers rubbing or banging. but all the same, its the ball that centralises everything right?

so what if a ball was put on the right and a roller on the left. they'd be the right way around for the loading they were going to take? swedish steel i belive was the first on this thread to mention the 'pull hard one way' and oddly enough went for the right side pull.

there's a choice of either a sleeve again as in the DCR idea with a larger ID of oil seal (includes an oil stopping 'O' ring) and the sleeve could be made to go up to the back of the flywheel as the form of keeping the crank pulled right.

orsecondly,to leave the crank to float and stay between the ball and the rollers shoulder as they are designed too. If we take the pulling of the crank to one side to be in order to stop the shoulder of the roller banging then maybe the lower shoulder roller would suffice and with the following mod we might reduce the flex/harmonic problems?

too much flex in the left side here or harmonics etc?

so how about this?
the balancer is still a good idea right but in the wrong place? its in the way even because as you saw in my photo above a large strong well placed spacer would be a good idea but the balancer is in the way.

small rollers can cope with speed/load all-in-all better than big rollers right? (i'm asking BTW?)
so why not pull the pair of ball races out of the balancer/single row and the 3mm spacer (if you run the single row) and then fit the inner race from a roller bearing having shaved the width down to the 12mm. the shouldered end should be the end sliced off.

the next task is to find an open caged needle roller similar to that in the clutch OR to find a really thin caged roller with just an outer race (they do make them!). at present the OD of the C/B bearings is 48mm but it looks to me like there is plenty of metal there. could a roller run directly inside? i don't think so, so an outer race is required. there is no hardening in the C/B itself. but then those needle rollers run inside the clutch basket? i don't know enough about it technically.

this way you get the roller on the left and the ball on the right, you keep the balancer and you are trying (i said trying!) to make the gap twixt crank flywheel and bearing rigid?

to be honest what is stopping two rollers being used with this more rigid system?

this is just a few ideas at once so some of them might have mileage?

regards

Taffy

Taffy said:

swedish steel i belive was the first on this thread to mention the 'pull hard one way'

Click to expand...

Actually, that was me, and it was about pulling it to the left (to the balancer side). Swedishsteel mentioned using some screws to lock stuff in place - altogether a different proposal in my view.

As for loading, both roller and ball are capable of taking the loading so it's not like one side can and the other can't. I know none of you like what I'm saying but the maths and the physics speak for themselves - you only need to calculate it to confirm my calcs too. Also, the evidence does not support the need for bearings that can take greater load as that's not where the failures come from.

Again, you have to remember that maximum loading on the crankshaft is in the upwards direction when the piston reaches top dead center on the exhaust stroke and the force is a function of mass & acceleration, not combustion.

Your assumption that the left takes more load needs qualifying and although the crank will experience a rocking couple, it doesn't mean the left has to take most of the load. You need to remember that the c/b is a rotating mass not reciprocal.

Tell me, are the edges of rollers radiused? You need to have a think about the evidence in front of you. Has anyone shown a failed main bearing with any chaffing on the shoulder? Isn't that what you would get if the rollers were rubbing prior to failure? Yes, you'd get some signs it was happening and then an exponentially rapid bearing failure Didn't enginehardware send some failed bearings to SKF to have a look at and yet they did identify such evidence?

The next is to consider what it takes to create a side load that would crack the shoulder in the way that it is doing. I'm not sure where you would find enough axial thrust to make this happen.

As for crank flex - if it were indeed crank flex, why aren't we seeing a considerable number of snapped crankshafts as that is what would normally be sitting there as evidence in front of us if it were the case. In the number of years we've been around there's been a handful but if the cranks were flexing in the way people seem to think by now they would have at least broken from fatigue :wink:

Yeah, I know, I'm being negative again, but the evidence doesn't support the direction everyone is going in and the futility in finding a solution tells us it's most probably in the wrong direction too.

As for the shoulder idea, I think it was Ben Ballard that first made up such a collar for his big bore kits. I don't know if they were very successful but it is always worth considering that any benefits attributed to the shoulder may just come from removing the balancer unit alone.............

And following a comment earlier - you do not have to re-balance the crankshaft if you remove the counterbalancer to save the bearings. You can run whatever balance factor you want to if you remove the balancer weight without undue engine problems.

Interestingly, the factories themselves (e.g. KTM and other singles manufacturers) trying different bearings out here there and everywhere rather than looking at fundamental design shows a couple of things. 1) they don't want to admit they got it wrong 2) they haven't got a fookin' clue what's going on either

All the best,
Simon

Roller vs balls!!!

Its hard to say what is braking the bearing, we had it over to SKF, they said dirty oil, we went away from the SKF std rollers and took the ones with extra hardend surface and so on.
What we have seen during this seson is that we dont have any failure since we installed the Ball bearing from the crate motor on the left side and the OEM roller on the right, We gave the journals a bit of a grind to fit the bearings.
We run with the 644cc crank who has the smaller dia on the big end grank pin, the 628cc works even better. approx 100hrs before overhaul.
One thing that might have improved lifetime is that we now run with anti hopping clutch, there is no peaks in the system.
And this, every one have to realize, that we have 75RWHP, not 52 as when we started.

We can discuss what we belive is causing the damege, but all of us- we really dont know, we just change and test agian and again and again, and if it works-FINE.

The 20mm bearing on the left side is perfect, specially if there is a modification like Ben Ballards with the seal attached outside, to keep the balancer in the engine.

All modifications are good if it increases lifetime, either way you do it, test it and let us know.

Secondly, on baby size std engines( 380-501cc) this dont matter, there is not enough power to brake the bearings.

//Thomas

swedishsteel said:

Hello again! Haven't been able to get this off my mind, did some thinking tonight :idea: but its maybe not as good as a think, I'm a little tired right now, so maybe tomorrow when i look at it with fresh eyes its becoming stupid, and I haven't confirm that this should go or if its place for it. But anyhow. I was thinking.

some fact you must obligate to get it work probably.

Is`s the left main that go for the most off time (maybe 90%)(just my thought)
It`s the inner ring that breaks (don't Want that mounting without the support for the flange)(can do it as Thomas do but you have to change the c/b(modified) and drive shaft for that) (can be done, and for me its the best solution that I heard of, yet) but you cant do it by yourself and need modified parts.
If its possible use the new c/b.

If you use a ballbearing on the rightside you get the axial steering but you still get lower rating on the bearing and its more difficult to assemble the engine.
Now I'm getting to my point, If you use a NU206 on the left side with out flange that problem cant happen, and its free floating in axial direction, the radial is the same as NJ.
Now we need some kind of bearing that can hold the crank in the axial way.
If we use a NUP206 and mount it as a standard NJ, you assemble the engine the same and use the same tools. But we lock the right outer-race with 3 countersunk screws on the inside off the block, so it cant move in the block.
and from the outside we mount the extra flange-ring on the crank.
But how is this going to stay there :? Well now come the question that I'm not sure off.
I was thinking outside off this ring its a seal-ring and then the flywheel. the seal is 25x40x7 if we make a spacer that is lets say id25xod30x x (don't know the space) a seal-ring that is 30x40x7 is a standard. Then this spacer can press the bearing flange-ring by the flywheel and you can shims this up to get a little clearance say 0,2mm (If you must I'm not sure)
I don't know how much axial float you need in the bearing ? but when you use ballbearing you don't have any, and when the crank trow in axial movement its freefloating in the left side and cant get stuck between the bearings. and this is be me the main reason that the roller-mains goes,

So what do you think about this???
Is it Plausible you think?? please have some thought off it.
Now im going to sleep, so good night.

Regards Patrik

Click to expand...

sorry simon but whilst swedish was on about holding the bearing with three screws he was clearly on about holding the assembly on the right! this is at the bottom of page 4.

it's not true to say that a crank has to snap if it's not absolutely rigid! nortons didn't break and neither did half the british bike industry... and there are more examples. there could be flex spread around the engine i don't know.

i said harmonics/flex but infact the cases are now lighter and some would say possibly weaker since 2003/4. a lot of things happened that year and not just the change to rollers!

many riders found that the shoulder had broken off the bearing when they next went to kickstart the bike. this tells me that they went onto heavy decel when crossing the line and there was reverse thrust through the engine as well as the fact that when the rod goes from the exhaust to the inlet stroke with a closed throttle that the loads are enormous on the entire assembly and of a different nature to this stroke when running WOT or partial etc.

maybe it doesn't like decel?

i can't agree with your view that the rollers should show wear and radiused corners when they failed. if they ran outr of axial space they snapped! and i would conclude that whenever these shoulders were about to go they came close but for a brief moment and then carried on as normal and then that momennt came again and was so fierce that it snapped them.

i believe that these shoulders 'always snap opposite the big end' has been mentioned. now if that's true simon how about you working out from THAT what happened?

my little idea above i believe is new because it tries to keep the balancer and to have far greater support from the shoulder of the crankwheel to the shoulder of the main bearing. i believe thomas when he says he wants the balancer (as do i) and i also believe this idea that the crankwheel is 12mm too far away from the bearing. my idea is to combat both, however i don't produce 80RWHP so i don't have that opportunity!

you say that both the ball and roller are easily up to it but clearly better results are coming with better bearings...... and as i recall, the bearings are meant to be laying down in a bath of oil and don't even mention an out of balance crankshaft..... and i believe the ceiling of revolutions i saw on these was somewhere around 8,000 revs and we're exceeding this! and what loading is it when you accelerate hard?

anon

thomas, i know that you have machined the cranks now for at least one year but would you say that your reliability fortunes changed when you both changed the bearings and machined the crank journals as well?

DCR alsop said that when they used the slipper clutch that things got better! so this seems to be part of it!

if i understand you correctly;

We run with the 644cc crank who has the smaller dia on the big end grank pin, the 628cc works even better. approx 100hrs before overhaul.

Click to expand...

that the 35mm big end is actually helping with the reliability of the mains yes?

this might indicate that the crank is weak across the big end area? i'll await to hear what you say.

if i may still quote DCR he said that he felt that the later cranks (pork chop) aren't as well made as the earlier ones?

as i see it they went through thre cranks

full circular wheel with two huge holes
full circular flywheel with no holes but an internal 'pork chop'
pork chop crank.
i don't know when any of these started although i can guess!

the rule over the years has been to over engineer things till the problem goes away and in a way this is what is having to happen here.

regards

Taffy

Taffy said:

sorry simon but whilst swedish was on about holding the bearing with three screws he was clearly on about holding the assembly on the right! this is at the bottom of page 4.

Click to expand...

I know taffy, you really don't like to accept it when I actually come up with stuff and this is again a point that I made sometime ago :wink: - whether you like to accept it or not, you seem to have a problem with most things I say and you really hate to acknowledge the things I've added over the years particularly when a lot of it initially contradicts your thinking :roll: :lol:

Taffy said:

it's not true to say that a crank has to snap if it's not absolutely rigid!

Click to expand...

Nothing is entirely rigid Taffy :roll:

Taffy said:

i said harmonics/flex but infact the cases are now lighter and some would say possibly weaker since 2003/4. a lot of things happened that year and not just the change to rollers!

Click to expand...

I have always been the one saying that it is not down to one fookin' thing. Most often I've been the only one...... :roll:

Taffy said:

many riders found that the shoulder had broken off the bearing when they next went to kickstart the bike. this tells me that they went onto heavy decel when crossing the line and there was reverse thrust through the engine as well as the fact that when the rod goes from the exhaust to the inlet stroke with a closed throttle that the loads are enormous on the entire assembly and of a different nature to this stroke when running WOT or partial etc.

Click to expand...

Tell me then, when is exactly peak load on the crankshaft taffy?

How is it that difficulty starting the bike is after heavy deceleration? It doesn't add up and you've clearly not seen the occasions where failure was on the race circuit.......

Taffy said:

radiused corners when they failed. if they ran outr of axial space they snapped! and i would conclude that whenever these shoulders were about to go they came close but for a brief moment and then carried on as normal and then that momennt came again and was so fierce that it snapped them.

Click to expand...

Again you've misunderstood what I'm saying - the rollers are made with radiused corners to prevent digging in and if they dig in there is usually some sign that that has happened.

If SKF have looked at them and come to the conclusion the problem is non-specific, it tends to support my position. :wink:

Taffy said:

i believe that these shoulders 'always snap opposite the big end' has been mentioned. now if that's true simon how about you working out from THAT what happened?

Click to expand...

I've asked for some evidence to back this up but there never has been. Nobody has been able to support an assertion such as this.

Taffy said:

you say that both the ball and roller are easily up to it but clearly better results are coming with better bearings...... and as i recall, the bearings are meant to be laying down in a bath of oil and don't even mention an out of balance crankshaft..... and i believe the ceiling of revolutions i saw on these was somewhere around 8,000 revs and we're exceeding this!

Click to expand...

That is simply not true Taffy. The problems can be resolved as both I and Lineaweaver have shown without "better" bearings.

The bearings are not meant to be in a batch of oil and in fact only require a small amount. If they are lying in a bath of oil then operating parameters change.

It is the self-aligning bearings or wider bearing that have the lower maximum revolutions, not the usual ball or roller.

Taffy said:

and what loading is it when you accelerate hard

Click to expand...

That really depends on a number of things but if you're talking about crankshaft load it has to do with rpm, conrod length, stroke and mass of the components

The fact of the matter is that it is perfectly possible to get these 650 engines running reliably and cheaply and I have had 650s now for 7 years and I've never had a main bearing failure. One of my engines I have kept standard by choice and the other was tuned to bits. I have run my engines at some of the fastest road racing circuits in the UK without fail.

What I do know is that when producing 60-65 horsepower at the back wheel, which most of our visitors keep their engines at the problem can be solved and I've seen more 650s than you can shake a stick at being fixed easily and simply.

I know that you want to keep the balancer and I think what you are doing is laudable but, quite frankly, you may have you head stuck so far inside the box it's preventing you from seeing outside it, particularly since you seem to ignore the evidence right in front of you.

Has it occurred to you that the problem you are trying to fix in the way that you're trying to fix it is like getting a square wheel to work too?????

At the end of the day, just as enginehardware says, who cares what somebody is doing if it works - that's what matters at the end of the day. My solutions have worked, plain and simple but if you want to continue running around in circles, go for it.

This post of mine kind of reflects the problem that we're seeing repeatedly and that is that you simply don't understand enough of some of the basics involved that so much of the time you misunderstand the answers having to have things explained to you. As such I always regret getting involved in this discussion ...... so now I'm going to fook off and do something constructive with my time - like maybe ride my dead reliable 650

All the best,
Simon

ok simon

where in this thread BEFOIRE swedish steel did you mention this. his is at the bottom of page 4?

no ifs or buts tell us? quote it if you like.

Taffy

thomas, i know that you have machined the cranks now for at least one year but would you say that your reliability fortunes changed when you both changed the bearings and machined the crank journals as well?

DCR alsop said that when they used the slipper clutch that things got better! so this seems to be part of it!

if i understand you correctly;

We run with the 644cc crank who has the smaller dia on the big end grank pin, the 628cc works even better. approx 100hrs before overhaul.

Click to expand...

that the 35mm big end is actually helping with the reliability of the mains yes?

this might indicate that the crank is weak across the big end area? i'll await to hear what you say.


regards

Taffy[/quote]

Yes we have more relieble engine when we changed our set-up for the bearings. the KTM ballbearing and the roller works fine together. The journals are adjusted so the bearing slides hard on with out heating then to 100 dgr Celcius.

The slipper clutch takes away the big negative peaks when braking hard on asfalt( Supermoto) improved alot for us.
We opened the high output engine 2weeks ago after 16hrs riding, no wear, we changed the bearings and its together again, according Team Husaberg they rides 20hrs then change bearings, pre-maintenence. Now we dont wait for a brake down any more, 20hrs is good enough for us.
It was only 4hrs before.

The local street racers in our town all rides Husaberg, i see these engines after 100-130hrs, all with broken mains, some tuned some just a other exaust system, they ride hard and bearly changes oil. approx 10-15 riders all 628cc(2005-2008)
The 628cc, 35mm pin is much better, flex is less i belive. Must be due to the larger dia.

The 644cc crank will NOT brake, the pin and journals is much stronger than the mains, to weld it helps reducing flex and twisting.
Sure its weaker than the 628cc, but for racing its good enough.
If everyone wants a "perpetum mobile" run for ever, no maintenence, Buy a Honda XR400.
Now the engine with its output are fine, just some pre-maintenence.
For Enduro, its OK, runs easier on the gravel, both acc and de-acc/braking.

//Thomas

cheers for that.

it was bundybear (an aussie?) or someone who years ago said that the big end needed to be narrower than the (20mm) for the diameter that it is/was (at 32mm). i hope that makes sense and at least the 35mm changes that ratio a little (35 to 20mm)?

maybe someone else can remember who said it so they can be credited with it?

i think you deserve a special thanks mate for sharing all the info. when i was a roadracer they wouldn't help you go faster, they wouldn't help your handling but nobody stood by just to see you break down and reliability tips were always shared!

all you need now are sherco cam sprockets and chain! LOL!!!!!

regards

Taffy

my engine (628cc '06) has been just rebuilt and has approx a k miles (35hrs). is there any important maintenance to the engine i should do?

pastullo said:

my engine (628cc '06) has been just rebuilt and has approx a k miles (35hrs). is there any important maintenance to the engine i should do?

Click to expand...

Why is it rebuilt after 35hrs, it should run approx 100hrs if its taken care off.

Change oil every 5-10hrs and check valve clearence.

When you open it next time, change bearing config and camchain to IWS, then it will run with out problems for the next 100hrs.
Rocker arm rollers, check and change if nesessary at 100hrs.

Use the bike and have fun.

//Thomas

Enginehardware said:

pastullo said:

my engine (628cc '06) has been just rebuilt and has approx a k miles (35hrs). is there any important maintenance to the engine i should do?

Click to expand...

Why is it rebuilt after 35hrs, it should run approx 100hrs if its taken care off.

Change oil every 5-10hrs and check valve clearence.

When you open it next time, change bearing config and camchain to IWS, then it will run with out problems for the next 100hrs.
Rocker arm rollers, check and change if nesessary at 100hrs.

Use the bike and have fun.

//Thomas

Click to expand...

change bearing config?
camchain to IWS?? sorry but could you please tell me more about that? are you speaking about using two different kind of bearing? what's IWS, a brand?

pastullo said:

Enginehardware said:

pastullo said:

my engine (628cc '06) has been just rebuilt and has approx a k miles (35hrs). is there any important maintenance to the engine i should do?

Click to expand...

Why is it rebuilt after 35hrs, it should run approx 100hrs if its taken care off.

Change oil every 5-10hrs and check valve clearence.

When you open it next time, change bearing config and camchain to IWS, then it will run with out problems for the next 100hrs.
Rocker arm rollers, check and change if nesessary at 100hrs.

Use the bike and have fun.

//Thomas

Click to expand...

change bearing config?
camchain to IWS?? sorry but could you please tell me more about that? are you speaking about using two different kind of bearing? what's IWS, a brand?

Click to expand...

The cam chain on your engine is made by DID, short lifetime.
The 2001-2003 chain is made by IWS, diffr part no. #200045-06 70L (650cc)
There have also been a Regina chain for the older Husaberg.
price is double from DID to IWS but the lifetime is also twice as long.

Your main bearings have part no 800.30.019.000 2pc. Roller bearing.
We change to the left main bearing to ballbearing part no 06250.60206

//Thomas

ok so next time i should use an IWS camchain and use on the right main bearing the OEM one, and one the left the 06250 60206?

Just thought id add that the shoulder broke off my left main, pretty much bang on opposite the bigend. Just noticed someone mention it!

can you add to this thomas? where did those shoulders break before? a long time ago when you had trouble before they became ULTRA-RELIABLE!!!!!

i have some bearings i've pulled out of keiran's and they are coded:
206ECP/C3 VC025

"it would seem that these bearings are now obsolete. The VC025 is the heat treated suffix for heavily contaminated environments". my bearing stockist.

i continue to find out more. he like me is a keen athletics fan and it seems to be my currency to getting information.

regards

Taffy

Taffy said:

can you add to this thomas? where did those shoulders break before? a long time ago when you had trouble before they became ULTRA-RELIABLE!!!!!

i have some bearings i've pulled out of keiran's and they are coded:
206ECP/C3 VC025

"it would seem that these bearings are now obsolete. The VC025 is the heat treated suffix for heavily contaminated environments". my bearing stockist.

i continue to find out more. he like me is a keen athletics fan and it seems to be my currency to getting information.

regards

Taffy

Click to expand...

The bearing with the ending VCO25 is as mentioned and with a extra hardend surface.
NJ206ECP/C3 VCO25 = 8000.30.019.000
Shoulders broke mostly on botton side and on occation at the top, cant say how many, but never on the side.

//Thomas

he started out by saying that the VC025 was a batch code (thus obselete) but i can't think that thats right.

top and bottom - never the sides! sounds like the crank with the old 32mm big end.

regards

Taffy

Now here is a public announcement for you.

I have had the privilege of seeing the insides of an ex-factory 650. And just for you I looked at the crankshaft.

Lo and behold there wasn't a counter-balancer, just the bearings as spacers. The crank hadn't been re-balanced and on one side there was a roller bearing (stator side), the other a ball bearing. By all accounts this was a perfectly reliable engine. There was also plenty of space for end-float........

No unnecessary engineering and nothing beyond the home mechanic who can rebuild an engine themselves..... sweet and simple

Although I have always just used ball bearings when rebuilding I'm quite satisfied with what I saw and I thought it useful to pass it along.

Now I'm truly done and as such I've also un-subscribed from this thread

All the best,
Simon