MAIN BEARINGS FAILURE, MUST CHANGE

The new stock 80030019000 bearing is marked NJ206 ECP/C3HVC058 on the inner race and 206EC/DVC025 on the outer race...

ha! ha! now what was arnie's best remembered expression again? i can't remember!!!

regards

Taffy

then the best thing to would to take out the counter balancer put in the 20mm wide ballbearing and the OEM roller bearing on the right side..?

The thing that worries me about roller bearings is if the crank is flexing they will not like it. Where as with balls it will not matter. My other bike, dare I say, is a kl650r kawasaki has a roller on the left side and ball on the right, the clutch side. and that has 80,000km on it and and never been touched. I think the bearings are much larger on the klr.
I am interested in the JBS spherical roller replacement, it requires boring the cases, but the bearings will take flex, and higher load rated. Has anyone tried these?
I too can not understand why this has not been addressed by the manufacturer, spoils a really great bike.

spanner said:

The thing that worries me about roller bearings is if the crank is flexing they will not like it. Where as with balls it will not matter. My other bike, dare I say, is a kl650r kawasaki has a roller on the left side and ball on the right, the clutch side. and that has 80,000km on it and and never been touched. I think the bearings are much larger on the klr.
I am interested in the JBS spherical roller replacement, it requires boring the cases, but the bearings will take flex, and higher load rated. Has anyone tried these?
I too can not understand why this has not been addressed by the manufacturer, spoils a really great bike.

Click to expand...

I understand it has been adressed by the manufacturer??

Apparently?? the new KTM EXC-R engines no longer use the NJ roller series mains??- my guess would be the new 09 Berg engines will follow this example, that is if the KTM info is correct (from the previous link i supplied @ KTMTalk)

Taking a long time!

just a small point here. i pointed out to thomas recently that he should chop the middle of the cron on a 100mm (or whatever) piston out and fit it as a dummy during the rebuilds.

the gap between the two parts that the gudgeon pin goes through is called the "pin boss distance" and is typically only 23-25mm.

as things are set up, the left ball race centres the crank into it. so the right side takes the expansion. on the 650 its as much as 1.5mm and it would pay to get this balance right. if the first few engines are "just nice" then all is well...

i found some VC058/VC025s yesterday for just £31 each so i bought 12!!!! i've been paying just under that for lesser specs anyway....

regards

Taffy

regards

Taffy

Taffy said:

just a small point here. i pointed out to thomas recently that he should chop the middle of the cron on a 100mm (or whatever) piston out and fit it as a dummy during the rebuilds.

the gap between the two parts that the gudgeon pin goes through is called the "pin boss distance" and is typically only 23-25mm.

as things are set up, the left ball race centres the crank into it. so the right side takes the expansion. on the 650 its as much as 1.5mm and it would pay to get this balance right. if the first few engines are "just nice" then all is well...

i found some VC058/VC025s yesterday for just £31 each so i bought 12!!!! i've been paying just under that for lesser specs anyway....

regards

Taffy

regards

Taffy

Click to expand...

Then you only have to buy the TMB206JR2/C3 for the left crank case, then you have enough for 12 overhauls.

I can sell you these for 28GBP +VAT and shipping.!!!!

Have not checked the Pin boss distance yet!!

//Thomas

that £31 was inclusive for me thomas and the man said that prices go up this week!

i opened up a FE450 recently with the VC058s on both sides, as you said to me thomas: 'a standard bike will be ok for sure with them on both sides!'.

i forget where i had this chat but someone was saying that the '01/'02 cases and then the '07/'08 cases are the strongest. the earlier 'full circle' 644 cranks were better than the later 628s?'

regards

Taffy

I am sorry that I haven’t had time to read all this tread, hope I don’t run over old ground.

For those interested I have added pictures of the JBS Racing main bearing fix to my gallery. A brief description – we bore the cases to take steel liners, press and bond these in, affix with screws from the crank side, then install specially ground main bearings from the OUTSIDE of the cases and clamp these in place with the female nuts (no pun intended) that also hold the seals. Photos will make clear. OEM bearing arrangement 88kN – JBS over 140kN. OEM not tolerant of crank flex, JBS full tolerant of it. Basically the Husaberg crank is not stiff enough not to flex so we have to live with it, if you can’t stop a force get out of its way! Plus unlike other bearing mods to the Husaberg including our own early attempts you can run the balancer with this mod even though you have a 20mm bearing on both sides of the crank. No machining of the drive gear or rotor is necessary they both clear our mod and both sides retain their seals.

All parts are in stock for this mod and we have a special set of tooling for boring the cases turnaround about a week. Also 700 kits in stock inc – piston, liner, gaskets & studs.

As for which years of OEM parts are the best –

Cases - Personally I think that the 03 cases are the best they were the same basic casting as the 01 / 02 but they had the separate oil drain. The 01 – 02 – 03 cases are thicker than the later ones especially around the mains. However I personally consider all years of cases workable and would choose the later ones by virtue of the face that they have the Kokusan ignition rather than the SEM every time.

Cranks – the bell crank is most defiantly better than the circular crank. Firstly the bell has a 35mm pin rather than the circulars 32mm pin. As stiffness increases as the 4th power of diameter this makes a huge difference, still compared to Jap bikes its small. Secondly the reduced stroke helps with this too, of course. As for shape cranks have been exhaustively studied by the Japs, for a given mass of metal the bell shape is the stiffest. If you are a nerd you can purchase these studies from various academic institutions, sadly I have them, all! Simply put more metal is in the places that are taking the force in a bell so it is stiffer and stronger. This is why I used a bell design for my 750 crank, BEFORE Husaberg OEM went that way!

i found your web site very informative ben and i will add all this stuff to the doc as its so impressive.

"As stiffness increases as the 4th power of diameter this makes a huge difference, still compared to Jap bikes its small. ". what does this mean?

good luck

Taffy

Taffy - Put in mechanical terms the above means that a shaft that twice the diamiter of another is sixteen times as stiff. So with the Husaberg the 35mm pin is about 9% bigger than the 32mm which means it is very approx 40% stiffer. This combined with the reduced stroke makes it more like 50% stiffer. We all know stiff is good.

ben

gotchya, and i had just an iea what you meant - all about measuring the surface area perhaps.

what CC engines are you running now? i know you went to 750cc and then came back a bit?

you probably knew this but the big end pin on ktms is the same but 4mm wider. might help in another project....

regards

Taffy

I didn't know that about the KTM, thanks.

I am desperate to get a rod with w 40mm big-end bore and 133 or 132 centre the rest I can cope with. Anyone know anything? I can of course have a rod made easily but minimum order is 10 off or you pay a huge sum for 1.

Any one?

well the 40mm pin is from the KTM 625/640 LC4 duke etc etc and its 65mm wide.

various rod lengths here but nothing to help.

http://www.husaberg.org/wiki/index.php/Engine_tuning

there is a belguin who frequents ktmtalk.com who is mustard on special engines. names gone for now but when i remember it i'll PM you with it.

trust you've seen that falicon make a 131mm i got some ariable timing camwheels off them in 2000 for my WR400. they are in clearance clearwater revival. sorry - got carried away there.........they are in clearwater florida and they have a website you'll llleeeeerrrrrvvvv.

arrow do con rods for katooms as well so try them. i think they are british.

134mm with offset bush?

come on ben, keep up at the back! you tell me all you know and i'll find the washers! LOL!!!!!

ben what is the ID of the rod and i may be able to come up with a pin between 36 and 38 for you.... there is a KZK bearing thats 38 x 46 x 20.

regards

Taffy

Taffy - The rod I seek is 40mm bigend BORE. I will be running either a 32mm or 34mm pin. I must have it at 132 or 133mm long I have no room in the piston. I have my own crank pins and big-end bearings made so there is no problem with that its just the rod.

I am just being impatient really, the answer is to use a custom rod I already drew it and got it proced, I am just holding off ordering 10 as that will set me back 2 grand. By the way - Arrow are British they make my 750 rod for me, they are simply put the best rods in the world.

Falicon are very good too. They made me a billet crank once upon a time. Where do you find the spec's of their rods I.e. this 131mm one? I can't find it on their website.

http://ktmtalk.com/index.php?showtopic=50582&hl=

this is a very old thread and you want top talk to this GWR fella from belguim although it looks like at 396 posts he doesn't hang around for long!

i got the centre to centres there.

you have a PM as there is some stuff i can't share too far at present.

regards

Taffy

Thomas do you have a SKF number for the 06250.60206 bearing...?

David Sorensen

No-angel said:

Thomas do you have a SKF number for the 06250.60206 bearing...?

David Sorensen

Click to expand...

TMB206JR2/C3.

Go for the KTM OEM, cheaper and dont have such tight fit as the SKF.

We have noticed during the past time that the quality of SKF varies, we had some problem 2 years ago.
But today we only use OEM parts.

//Thomas

to ben at jbs.
you never thought about enquiring at mx composite rods.that way you can use their rod (32mm big end hole with no bearing) might even save you some room for stroking?

well... main bearings failure ,must change
looks like they have.
if its going to be the same mains as the new ktm motor 450/530 ,which i can bet it would be.
still not over built by any stretch of the imagination, but still a bit better.
72od/ 35id/17mm wide/25.5kn x2 balls compared to the current std ball 62od/30id/16mm wide/19.3kn.
although the load rating is probably improved now that we know to use the hardened ktm crate engine bearing.
the potential for the new motor to have less problems in this dept should be improved,having a bit bigger mains/5mm bigger crank & external counterbalancer off the crank.
as for our current split case berg motor.there should be no problem with main bearing failure going ball/ roller set up,provided that its done correctly.when i say main bearing failure,i mean premature bearing failure like what is happening with the current roller /roller set up(breaking the flange off).everyone must realize that when this motor gets a couple of hundred hours of normal use (less for supermoto etc ) that there WILL BE a main bearing failure or counterbalancer failure...no ifs no buts & it doesn't mater weather you are using ball or rollers.the xr/dr's use a 90mm od/ 23mm wide main say no more.
i have to disagree with simon about removing the counterbalancer, thinking this will save the mains,it will not.the only thing that it will save is c/b bearing failure cause it is no longer there.
after removing the c/b from my motor i still had a main bearing failure(2x roller set up) with only 20 hours on the clock (cause ..no main bearing support),we are talking apples & oranges here cause simons running balls.
with the c/b removed on an unbalanced crank the vibration wasn't good. the more you reved it the more it vibrates.this has to have a detrimental effect on the mains,its only logical.
yuck... don't do it unless you are going to get the crank rebalnced.
..weed..