Hello, I'm trying to repair an antique Roadmaster, I recall buying it at KMart 38 years ago. The crankset bearings have mostly fallen off. I found one
and ordered bearings from ebay but they're smaller than the one . The photo shows the solitary bearing and two from ebay.

I wish you luck in your endeavor.

First, there is no photo; with less than 10 posts you can't include photos on posts. The way around this is to create a photo album from your profile page, make a post saying that you did this, and then someone can retrieve & post it for you. Second, crankset bearings don't fall off, you need a photo to show what you are referring to (did the balls fall out of the cages maybe?). Third, ball bearings are usually a common size. Hopefully, you still have an old one that you can measure with a hole gauge or a good scale. (FWIW, the most likely size of those is 5/16".)
John

There were several different types of bicycles that were sold under the Roadmaster name. Your bicycle probably has a Ashtabula crank or what's commonly called a one piece crank. Where the left and right crankarms and spindle are the same piece of metal..

This link should help you.... https://www.sheldonbrown.com/opc.html

If it is a crankset that has crank arms that are removable from the spindle, then knowing a little more about the bike might help.

When asking for mechanical help, the best place for your thread will be the Bicycle Mechanics sub-forum.

Here is the picture you tried to post.




https://www.bikeforums.net/g/album/38070490

They upload to your album. Even though you can't post them in a thread until you have at least 10 posts or replies of your own here on BF.

A picture of your bike. Particularly the crankset and bottom bracket will be more helpful.

Welcome to BF.

Establish the size of the bearing that came off the bike and order that size. There are a few ways to measure and each is quite simple.

Thank you for your help and expertise.

the photo shows my bike on a table with the one-piece crank on the lower shelf.
Thank you for your help and expertise,

Thanks for the advice. Just 'eyeballing' the bearing against a metal ruler suggests 5/16th diameter.
kevin

pic assist:


For these one piece cranks, you'd be better off buying the whole bearing with retainers. Read here:
https://www.sheldonbrown.com/opc.html
See if you have 24tpi or 28tpi threading, and buy the corresponding bearings . For example here is a set for 28tpi:
www.ebay.com/itm/185657317335

I would just let the bike go. A K-Mart bike from 35 years ago isn't going to have improved over that time and those bearings are probably going to be worth more than the bike new. If you want to pump money towards it it is in the end your money but I would just move on. If you want a good project bike there are plenty of decent quality used bikes that could use some love or just get a new bike and you will be much happier with quality shifting and braking.

Yup. Sort of like "restoring" a blue and white record player from the '50s because you need a sound system.

No sure why people asked but here it is before tear down. I have a trainer for bad weather exercise. But I'd forgotten how noisy a fat tire bike is on the trainer. I'll have to find a street tire.

"...A K-Mart bike from 35 years ago isn't going to have improved over that time and those bearings are probably going to be worth more than the bike new..."

I bought six 5/16" bearings for $4.15 at Ace Hardware. I needed nine bearings to fill the holder. So with the ones I found in the dirt floor I have what I need to put the bike back together. And some left-over bearings if needed in future.

There is a quote feature which helps so people know who you are talking with. However yes I did say that and yes I stand behind it. It is a 35 year old bike shaped object from a defunct box store.

Just let the guy fix his bike.

I’m curious. What is the large, toothed disc that appears to be on the non-drive side of the rear hub?

Otto

Me too....

That would have been DIY motor related, I believe?

I didn't stop him, I cautioned against putting money towards it but I didn't physically stop them. If they want to dump money into a pit and burn said money that is their money to do so with. I would just suggest saving that money and using it for a good project.

Yes, I planned to add a motor to the bike. I got the back-tire sprocket attached before I realized the bike wouldn't accommodate a motor. So I ordered a DIY motor.

the engine will not be kind to the thin steel rear rim or spokes, and the brakes will be sadly inadequate for safe operation... but it'll be fun right up to the fail point!

i'd think you would want a better bike with double walled rims and far better brakes to be the platform of your engine install...

typically....
Motor = Electric
Engine = Internal Combustion power

electric motors can produce maximum torque from zero rpm... that will quickly trash the rear wheel..
a weak clutch on an I.C.E. will be more gentle on the wheel pictured, but will still wreak havoc on the old steel rim and spokes.
i've actually seen examples of those old stamped steel brakes that Bent Badly when they were over-used...
you have been warned.

all that said... i love the deep blue color, and i'd probably upgrade the seat, wheels and brakes, then ride it with a

I got the bearings greased and in. There's no dust seal? Should the bearings be finger-tight or should I use a hammer and chisel to tamp them in more?
[img alt="I got the bearings greased and in. There's no dust seal? Should the bearings be finger-tight or should I use a hammer and chisel to tamp them in more?


"]https://cimg3.ibsrv.net/gimg/bikeforums.net-vbulletin/1500x2000/img_0208_6a74980abab50ceb24beb310c29890361e00e324.jpg[/img]
I got the bearings greased and in. There's no dust seal? Should the bearings be finger-tight or should I use a hammer and chisel to tamp them in more?

[img alt="I got the bearings greased and in. Theres no dust seal? Should the bearings be finger-tight or should I use a hammer and chisel to tamp them in more?


"]https://cimg3.ibsrv.net/gimg/bikeforums.net-vbulletin/1500x2000/img_0208_6a74980abab50ceb24beb310c29890361e00e324.jpg[/img]
I got the bearings greased and in. There's no dust seal? Should the bearings be finger-tight or should I use a hammer and chisel to tamp them in more?

You'll be looking for a set of these. Single bearings probably won't work.

i needed three 5/16" bearings. These came in the mail yesterday.