The Husaberg 550 and 650 are infamous main bearing killers. The culprit is the crankshaft, because it is weak and spreads to the shape of a banana when picking up revs. I'm planning on making a tougher crank. It will require you to remove the counter balancer. The left crank web will be thicker, to be able to hold the crank pin better. The right side will have a taller shaft to accomodate a second main bearing in the flywheel compartment. A spacer/bearing cage will be mounted at the right side and then OEM flywheel/stator/cover.

Crank, pin, bearing cage will probably cost 700€.

I'm not doing this with any commercial interest, just fix a known problem and make fellow Husaberg enthusiasts happy!

With this thread I just trying to see if there is any interest in such an improvement?

Original von Flo
Hey Mats!

That sounds very interesting !! How much stroke does your planned crank have? I would like to keep my 644ccm.
Do the bearing seats have to be adapted (e.g. milled) ?
At the end of the year I would buy such a kit.

Does your race bike run well?

Cheers
Flo

Hi!
The plan was to make a 80mm stroke with 35mm pin and maybe a 70mm stroke for the 550 (with 35mm pin though). The 644cc crank with 82mm stroke and 32mm pin, is IMO too weak configuration to try to improve.

The bearing seats can be untouched, because the OEM bearings will be sufficient once the crank stops spreading.

Thanks for the interest!

Cheers, Flo!
I believe a 32mm pin is too weak. With that "bottleneck" in the design, there is no point in making a tougher crank.

The idea was to use an OEM rod. The 644cc rod is 135mm tall and the 628cc rod is 136mm. So, just mount a 136mm rod on this crank and you´ll be good to go! For my application I use a custom Carillio rod, 145mm tall. If however there is an interest in making exact copies to the OEM design, that can be arranged too.

I will make two cranks for myself in any case. I just wanted to give more people the opportunity if anyone's interested!

We have lots of design work and calculating the stiffness of the crank (Ansys), before I dare to estimate anything at all. I'll keep you posted!

We have done a lot of calculations/simulations during the winter/spring. We have found out that we would have to make extensive modifications to the crank shaft, to be able to reduce the bending. There is not only one single modification that will solve the problem. I have instead chosen to let the crank move freely and replace the main bearings for spherical roller bearings. They are a bit "over-kill", but they will allow the crank movement and cope with the radial stresses.

BTW: The look for 2016 is now completed!