Reducing thrust loads when using CVT

[coachgeo]

Saw this in another thread discussing a Crank with badly knackered bearings

i have seen lots of failed bearing that look like that, there are a few things that will cause it,

-was your engine new or used?
- what condition are the rest of the parts in the engine like?
- do you use a cvt?
-too much thrust load on on a ball bearing not an angular contact bearing (cvt's cause excesive thrust load back and forth as the belt shifts the action is not perfectly linear).........

Sooo.... with this comment it leads one to think.... ok.... how does one intending to use a CVT best plan to deal with these thrust loads to avoid premature wear on bearings.... or do they plan on more routine bearing replacement in maintainance plan.

[Stuart]

Probably not connected but I've heard if you run engine's without enough or any load it leads to glazed bearings and ultimately bearing failure. Is this true I wonder? And could a CVT (operating the way it does) increase the likelyhood of this kind of failure if it doesn't provide proper loading? Are they too kind to these working diesel engines?

[coachgeo]

hmmmm.... don't think you would consider it being used at no load... but instead as being used at a more "constant" load more like a genset. A constant load at optimum point in the power band at that. With that in mind a bike w/ an engine coupled to a manual tranny load would be considered cyclic (unload, load, unload load.... thru the gears)??

[DieselFly]

As the Punsuns are sold in both vertical and horizontal shaft and the end case seems to have all of the vertical mount holes and ears it would make me think there is no difference. This said there must be enough bearing surface to take the weight of the crank and any loads from vertical shocks (Dead bodies in the lawn) I have been building up an aircraft engine for a friend and was suprised to see the thrust bearing for the crank is just an oiled face on the aluminum crankcase that cannot be replaced. I will measure the end play on my crank and start monitoring it and report if I see any marked change.

Sean

[UAofE]

It could possibly be machined out to accept a traditional thrust bearing if/when the case wears down.

In my bike, we are planning to use an aluminum clutch spacer Tom designed to mate with the Enfield 4-speed manual and machine it to accept a sealed roller bearing.

[coachgeo]

On mine the Primary clutch we are using allows for the shaft to go thru it. Thus we are putting bearing on the shaft beyond the Primary that will be integrated into the engine/clutch belt cover