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brass caged crank bearing-ok or should I use a plastic cage

PostPosted: Fri Jul 28, 2017 1:52 am
by Scooterslag
Just in the market for a new set of crank bearings (main and flywheel side) now I've noticed scootopia selling a brass caged bearing, how do these fair in comparison with plastic caged bearings? its only for a stock 150 so its hardly going to be pumping out mad power - cheers Paul

Re: brass caged crank bearing-ok or should I use a plastic c

PostPosted: Fri Jul 28, 2017 12:46 pm
by Knowledge
I think some of the nylon caged bearings have an extra roller in them, but as you say, if it is a stock 150, you will be putting it under no strain.

A grown up may pop along later to confirm whether I am correct.

Re: brass caged crank bearing-ok or should I use a plastic c

PostPosted: Fri Jul 28, 2017 1:00 pm
by Scooterslag
Knowledge wrote:I think some of the nylon caged bearings have an extra roller in them, but as you say, if it is a stock 150, you will be putting it under no strain.

A grown up may pop along later to confirm whether I am correct.


Yes that's what I read somewhere, didn't know if there was any issues with it being brass other than less bearings in the track, thanks Paul

Re: brass caged crank bearing-ok or should I use a plastic c

PostPosted: Fri Jul 28, 2017 1:06 pm
by Phil D
I asked the chap at the bearing shop exactly this question,
He said plastic cages were better because in the event of the cage breaking up the resulting debris would do less damage.
It seemed plausible to me .

He also added they only sold quality genuine bearings and judging by the price I believed him. :lol:

Re: brass caged crank bearing-ok or should I use a plastic c

PostPosted: Fri Jul 28, 2017 2:33 pm
by Warkton Tornado No.1
With the advent of non-metallic cages, manufacturers were able to squeeze extra rolling elements in & thus increase the rating of any bearings, roller or ball.

In the case of virtually any Lambretta, the parameters in which the magneto bearing gets close to 'touching cloth' is not the load so much as the RPM of the motor, as grease limits the speed rating compared to oil. However, that won't be an issue with any near standard/road tuned motor.

Those of us that do use high revving motors should really consider the continuous ratings of any bearing that is crankshaft mounted as there will be a solution.

As safety is upper most in my mind right now :!: I hope I can be forgiven for reminding anybody that plastic caged rear hub bearings are really an example where they should not be used as if they pop out (as has happened more than once) then the results could be literally deadly.

Re: brass caged crank bearing-ok or should I use a plastic c

PostPosted: Fri Jul 28, 2017 4:02 pm
by Scooterslag
Thanks for the replies so the brass caged bearings will be fine then? just wanted to test the water before making the purchase, thanks again Paul