Clutch freezing up

[p2im0]

-10F this past weekend when riding. After I got moving my clutch would get extremely stiff. After letting out the clutch lever it would take a a half second or so for the fluid to release and the clutch to engage. It's a magura hydraulic clutch in a Husaberg FE570 using mineral oil. I just rebuilt the slave and put fresh fluid in.

As soon as I stop and my coolant heated bars warm up the reservoir it's back to being buttery smooth and easy. My initial thoughts are moisture in the fluid, as the more I think of it I left the fluid in an open syringe for a week while I waited for a gasket.

I'll be changing the fluid next time I'm in front of the bike but wanted to see if this was an indication of something else.

 

[M5-]

It could actually be moisture in the pivot of the lever. If its that cold, which IMO is too friggin cold, throw a set of gauntlets on your bars they will keep in a ton of heat. Easy fast solution for super cold days and they are cheap to buy.


M5

 

[bighuckpunk]

I believe it's due to the mineral oil thickening in the cold temperatures. brake fluid becomes thicker at colder temperatures than mineral oil does. Warming up your master cylinder to make your clutch work again indicates that this may be the case. The hand guards sounds like a good idea. I would be interested in hearing if if that works for you. Good luck!

 

[eric82930]

Some mineral oil is real thick when cold. I was using 3wt shock oil and it's better in cold. Even kerosene works it's really thin.

 

[jacmmaxwell]

Baby oil works great in the magura. Sounds goofy but thin and very pure.

 

[p2im0]

Picked up some "magura blood", gonna flush it out and see if that fixes the issue.