crank bearing

[Reelinfeele]

should the crank bearings have any play?

[Reinhoud]

Side ways, yes! Radial, a little, about a few hundreds of a mm. Hopefully someone here knows a more accurate number. 

[Jonboy]

Lateral play is inherrant because of the construct of the bearing, but there is positive location in the crankcase so this goes when you build the crankcases together. Radial play, not sure I agree with a little even if that little is a few hundreths of a mm, my feeling is that if you can detect play in the bearing simply by hand examination then its on its way

[arnout]

On 27-8-2016 at 5:12 PM, Reelinfeele said:

should the crank bearings have any play?

I checked the manual, but can't find any spec on it or how to measure it.. (there is a method described for checking the big end bearings however...)

For me the oiled roller bearings shouldn't have any noticeable radial play when you're trying to move them up and down.. Apart from that also check for any sign of notchiness on each bearing by gently and slowly spinning with your finger tips..

[Reinhoud]

To measure, you can put the crank in a lathe, or something else to hold it, and then with put a dial indicator on the bearing and move it.

I'll have a look with my crank, I've got 2 floating around.

[Reinhoud]

Just checked the bearings on the crank I have laying around, they have between 0.01 and 0.02 mm clearance.

[arnout]

On 4-9-2016 at 3:54 AM, Reinhoud said:

Just checked the bearings on the crank I have laying around, they have between 0.01 and 0.02 mm clearance.

Cool.. Nice bit of info..

[Reinhoud]

I'm not saying they're good or worn! Just reporting the clearances of the bearings on my crank.

[arnout]

 

6 hours ago, Reinhoud said:

I'm not saying they're good or worn! Just reporting the clearances of the bearings on my crank.

Noted, but the chance of all bearings being worn (out) is pretty slim (usually only 1 or 2 go bust).. And also with finding such a small variation, I'd reckon the clearance dimension you found would be pretty typical of bearings on a well used but good crank..