spent all day in the shed today, with the double doors open, sun shining down, drinking coffee and getting greasy as hell.
good times!
The Single speed is now back in one piece, and the trance has been stripped down to component parts.
[img] 
[/img]
i even managed to make myself a top notch bearing press. i'm really impressed with how well it works, and how easy it is to use it to push bearings both out and back in (some of the bearings just needed a clean)
1x old QR + 1x old cup and cone axle, using cones to press in the centre of the bearings on knackered one + many assorted sockets to push bearings in at the edge and support the race from the other side.
the qr applies plenty of pressure, and they just slip out.
top!
[img] 
[/img]
anyhoo! ive got to replace a few of the bearings.
question.
as bearings only go round and round in one direction, why are they spherical? surely that increases the pressure on the race?
would cylinders or needle bearings not be better in most situations?
if not, why not? (for you engineers)
Two reasons:
a) although all the movement is in the radial direction, the bearings still have to resist axial loads (ie sideways loading of the swingarm). Roller bearings can't do this, as the raceway is flat - there's nothing to locate the rolling element.
b) Believe it or not, rollers are an order of magnitude more difficult, and therefore an order of magnitude more expensive, to make.
Also rollers have larger contact area and this can lead to higher friction losses?
Any rubbish has to be crushed under a cylinder, might move past a ball on a flat surface. So better performance and longevity in grime? Also a smaller contact patch so less friction (when new and perfectly set up)?
All guesswork on my part though.
That bearing press is genius. I think I have all the component parts lying around in the shed... a wee project for this week!
Easier to make harder materials into a sphere than a cylinder. Axial load carrying capacity is better with sphericals too.
yep, I'm liking that bearing press idea - certainly beats a hammer and a screwdriver
fair enough!
any suggestions of good places to get nice full compliment bearings online?
cool thanks 🙂
thats where ive been looking (as was at the top of google) but wondered if there were any specifically good places.
Now there is a fantastic bit of shed engineering right there. Good effort on the bearing press.