bearings

M cebee

can someone tell me how you measure the bearings on a kids bike

http://cgi.ebay.ie/Bicycle-Ball-Bearings-Retainers-1-4-Bmx-FREEPOST-/280283010421?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item41422b5575

these type of things

i looked at a couple of bikes and the retainers seem to be a different diameter

thanks

kona

M cebee wrote: »

can someone tell me how you measure the bearings on a kids bike

http://cgi.ebay.ie/Bicycle-Ball-Bearings-Retainers-1-4-Bmx-FREEPOST-/280283010421?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item41422b5575

these type of things

i looked at a couple of bikes and the retainers seem to be a different diameter

thanks

A micrometer or a vernier. Or you could tell me what part of the bike they are for and ill tell you the size you need.

Holyboy

kona wrote: »

A micrometer or a vernier. Or you could tell me what part of the bike they are for and ill tell you the size you need.

Whats the bets its from the BB;)

kona

Holyboy wrote: »

Whats the bets its from the BB;)

Was my first guess too

M cebee

kona wrote: »

A micrometer or a vernier. Or you could tell me what part of the bike they are for and ill tell you the size you need.

it's the back wheel

they're 20" wheels

so are they are a standard size then-back and front?

Holyboy

Damn, Kona we were wrong!!!!

To the OP, they will be 1/4" and you're better off putting in lose bearings,bit of grease in the cup and then 9 either side, the front are usually smaller but not always depends on the hub.

Just on the off chance its a cheap B.M.X. and has a 14 tooth freewheel (not trying to confuse the issue) it would have 1/8" bearings in the rear but if it's a standard kids bike then ignore this!

M cebee

hey can you explain that to me thanks

don't i need a cartridge for the bearings?

before i fit the cone and tighten locknut

kona

M cebee wrote: »

hey can you explain that to me thanks

don't i need a cartridge for the bearings?

before i fit the cone and tighten locknut

Nope as holyboy says, just do whats convienient, if the 1/4" bearings you have are loose, grease up and put them in. If the bearings you buy have a cage, just stick them in.
Make sure if your using a cage that the offset faces out. Cages are just there to reduce the amount of bearings needed and IMO are a waste of space as they fail like the above.

Have you inspected the hubs and cones for pitting?

Holyboy

M cebee wrote: »

hey can you explain that to me thanks

don't i need a cartridge for the bearings?

before i fit the cone and tighten locknut

Oh dear, cone and cup look in bad nick but it's hard to tell with the grease and dirt! First things first, do you have cone spanners? If not it's pointless trying to fit the bearings your self, best to just bring it to your LBS, if you do have them then you don't need the caged bearings,much better to fit lose balls ,after you put grease in the hub the bearings will stay in there them selves before you install the axle, if that makes sense?

M cebee

thanks for the replies

on further inspection it seems the cup is damaged

does this mean the wheel is a write-off


also i'm trying to get my head around this

the loose greased bearings are wedged between the cup and the cone

and that keeps them in place?

seamus

M cebee wrote: »

thanks for the replies

on further inspection it seems the cup is damaged

does this mean the wheel is a write-off

On a cheap wheel, a damaged cup means yep, the wheel is a write-off. Hard to see what you mean in that picture. Get a rag and some kitchen roll and give it a good clean out. Usually it's impossible to see damage under the grease.

also i'm trying to get my head around this

the loose greased bearings are wedged between the cup and the cone

and that keeps them in place?

Yeah, that's pretty much it. Sounds iffy, but there's a locknut on the axle which stops the cone from moving. So when it's properly adjusted, it all moves smoothly and the bearings sit in the cup, the cone sits even against the bearings, without pressing in on them, and it all spins freely together. The grease prevents overheating and seizing which in turn increases the life of all of the parts.

M cebee

ok thanks