big end size?

Taffy · July 17th, 2007, 03:30 AM

just wondered if we run the same b/e size throughout and indeed what size is it?

regards

Taffy

Motoxotica · July 17th, 2007, 05:44 PM

i think all bergs crank pins are the same diameter at about 30 mm according to my yard stick but i am not a mechanic and dont work on them myself.dan

AUSBERG · July 17th, 2007, 06:36 PM

Originally Posted by Taffy

just wondered if we run the same b/e size throughout and indeed what size is it?

regards

Taffy

Taffy, I believe you will find early bergs 00,01,02,03s all share the 32mm big end.

Sometime in 05/06 the beefed up cranks started showing up for the 450 and 650- I know the 650 had a 35mm big end and believe the 450 may have also gone to a 35mm big end.

I understand the 550 may have kept the 32mm big end into its 05 0r 06 year- but not totally sure. (HHmmmmm- computer says nooo...?)

Looks like you are up for a bit of cross referencing of the parts books

Please whack it all into the doc when you find out for us. Ta.

regards ,
AUSBERG

Taffy · July 18th, 2007, 03:46 AM

KTM ROD LENGTHS

have long rods and spacer plates in stock. yes it does work and yes the cylinders stay perfect for much longer. the only problem is its a real tight fit in a 525 frame as everything is 8mm taller.
The 450 uses a smaller big end 32mm as opposed to 35.
Power wise we did pick up about 1.5 hp in the top with no other losses, but the state of the piston and cylinder after many hours was worth it alone.
I have
120mm rods , specials made by arrows
121mm rods std sxs 540/ 05
126mm std rod from stroker crank
129mm std 525 rod
131 falicon special not really worth it , you need a short piston , and a spacer plate and the cam chain is just a bit too tight.
134 mm falicon knife edge rod works well.
hope this sheds some light on what I've been trying over the last few years.
Ps, all the std ktm rods are too heavy, and i have been working with lighter rods of the same length with good results.

this is from a belgian on katoomtalk. i'm going to suggest that the 650 has a 35mm b/e but that the 450 and 550 stuck with the 32mm. thisbelgian can get lighter rods but in the ktm sizes he wants.

maybe simon or someone SM has a source for rods?

anyway i'll endeavour to find out about the b/e sizes.

regards

Taffy

AUSBERG · July 18th, 2007, 06:52 AM

Those KTM rod lengths are a good find Taff, but just to clarify the KTM big end sizes

RFS 525EXC & SXs = 35mm

RFS 450EXC = 35mm

RFS 450 SX =32mm (Same dia as early bergs)

That might save someone a bit of confusion in the future maybe

.

Taffy · July 18th, 2007, 10:03 AM

oh yeh that made things r-e-a-l-l-y clear (LOL)

regards

Taffy

popup · July 19th, 2007, 12:54 AM

taffy
i can tell you that my 01 650 definitely has a 32mm big end pin.
another thing worth noting, when they sent me a conrod kit,for a 03 model ,even though it was 1mm longer it was 12g lighter than my 01 conrod.they shaved 1mm off the width.
look in my gallery.
..weed..

Taffy · July 19th, 2007, 03:43 AM

that'll go in the doc i hope weed. trouble is, how is the '01 crank balanced? naughty not to stick to original weight. how come you get to be popup here and weed in the gallery? i know json's been losing it for some time but now he's lost it!

to be honest - who was having trouble with the 32mm big end anyway? do we have a record anywhere of a 650 b/e going?????

what i find interesting here is something that i think i've learnt because i hadn't thought about ti and something i really have learnt - and that's rare for me.

i should have twigged that with todays non-destructive testing that you can make a PRODUCTION con rod lighter and lighter and lighter. that gives you a realistic opportunity to lengthen the con rod which causes less thrust against the sidewalls, less friction etc and also a better mechanical advantage. ideally all rods would be a foot long and all the energy would go up and down.

what i think is new is that i think it causes less stress everywhere to have a longer rod and therefore that's why husaberg have got away with the 32mm b/e for so long.

this is why i'm interested in taller cases or do i go and see JBS about a cylinder spacer??????

regards

Taffy

Dr_C · July 19th, 2007, 05:45 AM

Cheers Taffy!
I think the Swedish motor manufacturer Folan is using 32/20 mm rods which are 140mm long. Perhaps Highland has something that fits too?

The Husaberg 650 rod length increased from 134 to 135 mm from 2002 to 2003. The motard I raced with in 2002 was equipped with a 135,5mm rod with "Rotax" stamped on it...

As the crank is bending, I cannot understand why KTM chose to enlarge the big end for the later Husaberg models? The crank halves are still of the same thickness, which makes the press fit even worse in handling the bending forces.

Taffy · July 19th, 2007, 06:10 AM

so you're saying what? the flywheels are the flexible bit? i don't think so! sorry, didn't follow you there? and how good are these folan rods? racing or production?

regards

Taffy