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Bearing suitable for sideways load
Daf - 24/3/17 at 08:37 PM

Completely off topic from cars, but I need a bearing that's suitable for taking a sideways load in both directions but is still quite thin. I'd like to make something similar to the child bike seat in the link below. I could use a pair of tapered ones but that's going to end up quite fat and the one in the link looks very thin. Can anyone who knows more about bearings than me offer any advice?



http://www.mac-ride.com/


deanspoors - 24/3/17 at 09:08 PM

Not sure what you mean by sideways load? bearings are generally categorized by taking either radial or thrust, or a combination of both.

Whereabouts do you require the bearings for the application?



Dean


nick205 - 24/3/17 at 09:15 PM

quote:
Originally posted by deanspoors
Not sure what you mean by sideways load? bearings are generally categorized by taking either radial or thrust, or a combination of both.

Whereabouts do you require the bearings for the application?



Dean


Have to agree, I can't see in the photo where you'd need a bearing?

I tried an over the rear wheel child's seat. Certainly a weight to ride with, but left you space to ride more normally.


Daf - 24/3/17 at 09:42 PM

The bearing is needed where it joins the steerer tube because handle bars turn but the bar doesn't! So I need a bearing suitable for taking the load of a child downwards.

I have a child seat for behind me but on a mountain bike it really upsets the balance and messes with the rear suspension. Plus I'm hoping my son will feel a bit more involved than just being plonked behind me.


deanspoors - 24/3/17 at 10:17 PM

In which case, where there is only a singular axial load a taper roller bearing would probably be best, such as http://www.indiantradebird.com/admin/members/8184/images/0_0c739ae7.jpg

or for a thinner bearing a single row angular contact bearing, like so;
http://img.hisupplier.com/var/userImages/2011-10/12/104927465_Single_row_angular_contact_ball_bearing_s.jpg

Dean

[Edited on 24/3/17 by deanspoors]


Daf - 24/3/17 at 10:23 PM

In theory yes, but if I hit a bump it might bounce off. Is there such a bearing that does this in both directions but is still quite thin? A pair of these bearing would probably be too fat.


deanspoors - 24/3/17 at 10:28 PM

put a washer above the bearing to stop that happening, otherwise a deep groove roller bearing will take a certain amount of axial load, you'll probably be able to calculate the load and check against a bearing spec sheet.


Daf - 24/3/17 at 10:32 PM

Deep groove roller bearing is what I'm after, best weigh my son and crack my calculator out. Advice much appreciated 😃


deanspoors - 24/3/17 at 10:40 PM

I think you'll be fine with a deep groove roller bearing, if it's going to be around 1.25" ID to go over the bicycle stem then I would have thought that sort of size bearings would be good for 100's of kilos axial load.


Daf - 24/3/17 at 10:43 PM

It's semi fail safe, should the bearing fail it will only drop 20mm or so there's no danger really (other than my riding!)


bi22le - 25/3/17 at 12:24 AM

A 4 x child weight (+ mass of equipment) would be a good start for dynamic loading.

Also if your making a fresh design could you not bolt to the bike cross frame to aid rigidity and help take some loading off? Even if its just a saddle/ rest as the max loading of the bearing near the head stock will be downwards.


Daf - 25/3/17 at 06:34 AM

quote:
Originally posted by bi22le
A 4 x child weight (+ mass of equipment) would be a good start for dynamic loading.

Also if your making a fresh design could you not bolt to the bike cross frame to aid rigidity and help take some loading off? Even if its just a saddle/ rest as the max loading of the bearing near the head stock will be downwards.


I could do but my bike is carbon and I don't know of t's a good idea to start loading the top tube half way along it.


harmchar - 25/3/17 at 10:02 AM

I was thinking swapping the bearing idea for a Rose Joint. But you might get too much movement and the seat might tip depending on how rigid the fixing at seat post is. Hope that make sense.