Getting my Grandson his first kids kart

[Little B first year]

Hello everyone, my name is Kenny and I just bought my grandson Beau a used kids kart. I broke the sprocket hub/adapter trying to change out some worn out bolts. I believe I have a 1 inch axel and the hub/adapter is 6 holes. I am going to add a picture of the one I need to take off and am hoping someone can tell me what kind it is and what site to get it from. I have looked at several karting sites but have not seen this one. As you can tell I am brand new into this and am having issues trying to find what I believe is the right part. I would love to do the work myself to learn how to work/repair the kart as we go.

Thanks

Kenny

 

[Rat]

The only way to know for sure is a micrometer/vernier caliper, the angle and zoom makes it look like the axle is 1.25 inch with a 1/4" keyway. What I don't see is what you say is broken. It doesn't appear to be anything more than maybe a 40" wide "live axle" or solid axle

 

[panchothedog]

Not a big deal. If you can't find a exact replacement, figure out what the diameter is then go to Go Power Sports website and purchase either a 1" or a
1 1 /4" hub for your axle and they will have a sprocket that will have the same bolt pattern that mates up to the hub. Before you buy figure out if the rest of your equipment ( chain and sprocket on clutch ) is a # 35 or a # 420. It will be one of those two. Same website will instruct you how to tell the difference between the two. Probably someone will jump in here and tell you how much cheaper you can find it on e bay or Amazon. Personally I kinda like doing business with the shops that support the hobby, especially if I were new like yourself and possibly had some questions. Amazon doesn't know an axle hub
or sprocket from a vacuum cleaner. It's just a part #. Suit yourself.

 

[Functional Artist]

DIY round material sizing tip;

Try to see how well a 1" open end wrench fits over the axle
...if it's "pretty close" it indicates that it's probably a 1" axle
or
Another option would be to use a "big" adjustable wrench
...tighten it down to the axle size
...& then, simply measure the distance between the "jaws"

 

[Little B first year]

Thanks everyone, I just ordered a micrometer vernier caliper to help with the axel size. This is going to be an interesting venture for my grandson and I. I will probably be asking many more questions the more I get into it. I guess I have a Comer engine and my track mainly runs the Honda GXH50 but they said it is not an issue because he just needs some seat time. Thanks again for all the responses.

Kenny

 

[Rat]

Before you buy figure out if the rest of your equipment ( chain and sprocket on clutch ) is a # 35 or a # 420. It will be one of those two. Same website will instruct you how to tell the difference between the two.

^

#35 is 3/8"p x 1/8"w, being the only 3/8 pitch chain it has ZERO interchangeability.

40, 41, 410, 415, 420 are all 1/2" pitch in varying widths and very often interchangeable as needed but can create its own issues. An exple would be using a 41 chain across a pair of 415 sprockets... it will work but there are going to be wear issues, but this is something I'd consider a repair of impatience.
I have seen the extra link width used as a means to correct small misalignment issues that would otherwise eat up sprockets and chains

 

[Little B first year]

Hey everyone this Kenny again with a question. I measured my axel and it came out to 25mm (.984 inches) so I figured it was 1 inch axel so I ordered a 1 inch sprocket hub that is being delivered. As I attempted to remove the axel to get to the sprocket hub I decided to replace almost everything including the axel, brake rotor, axel bearing. My kid kart has a Grimeca brake but the pads needs replacing. I was thinking the system is still good if I replace the rotor and the pads. I called today (Prairie City by Sacramento) because I wanted to buy the parts local but they have a race today but did tell me they only have metric axels and he told me they could convert my axel to a 40mm maybe next week because of a race today. Should I consider switching over the entire axel to a 40mm and sending back the sprocket hub I ordered or find a 1 inch axel and buy the appropriate components? If so, does anyone know what sites to get the entire 40mm axel kit or the 1 inch axel parts? I want to get this kart ready and safe for my grandson Beau! Thanks again

Kenny

 

[Functional Artist]

Hey Kenny,
IMO 1" components should be easier to find & at lower cost than 40mm stuff

Here is a 1" x 40" steel axle @ BMI Karts for ~$43.00 (plus shipping)
https://www.bmikarts.com/1-Steel-Live-Axle_p_517.html

* Go Power Sports has a large selection of kart parts too

 

[Rat]

Hey everyone this Kenny again with a question. I measured my axel and it came out to 25mm (.984 inches) so I figured it was 1 inch axel so I ordered a 1 inch sprocket hub that is being delivered. As I attempted to remove the axel to get to the sprocket hub I decided to replace almost everything including the axel, brake rotor, axel bearing. My kid kart has a Grimeca brake but the pads needs replacing. I was thinking the system is still good if I replace the rotor and the pads. I called today (Prairie City by Sacramento) because I wanted to buy the parts local but they have a race today but did tell me they only have metric axels and he told me they could convert my axel to a 40mm maybe next week because of a race today. Should I consider switching over the entire axel to a 40mm and sending back the sprocket hub I ordered or find a 1 inch axel and buy the appropriate components? If so, does anyone know what sites to get the entire 40mm axel kit or the 1 inch axel parts? I want to get this kart ready and safe for my grandson Beau! Thanks again

Kenny

40mm is massive overkill unless you're running some sort of drag kart.

 

[anderkart]

Some of the guys trying to help here you don't realize your working on a European racing kart built for competing in the Kidkart class.

Do not attempt to change your axle to 40mm. The componets will be super expensive and I doubt if any of the 40mm axle bearing Cassettes would even fit into your frames much smaller sized mounting brackets.

You can order this sprocket hub thats made for 25mm racekart axles like yours. Your old sprocket will fit it.

1. 5700.00.12 Birel 25mm Sprocket Carrier, Cast Aluminum

25mm Sprocket Carrier, Cast Aluminum

cometkartsales.com

Check and see if your old Brake pads are the exact same dimensions as these:

Top Kart Kid Kart Brake Pads, Pair

Kid Kart Brake Pads (Pair)

cometkartsales.com

Chances are you can simply cleanup and re-use your old brake rotor using sandpaper and/or Scotch Brite pads.
But If your old rotor is warped beyond use, you might find a replacement here: https://cometkartsales.com/Metric-Brake-Discs/

 

[Little B first year]

Some of the guys trying to help here you don't realize your working on a European racing kart built for competing in the Kidkart class.

Do not attempt to change your axle to 40mm. The componets will be super expensive and I doubt if any of the 40mm axle bearing Cassettes would even fit into your frames much smaller sized mounting brackets.

You can order this sprocket hub thats made for 25mm racekart axles like yours. Your old sprocket will fit it.

1. 5700.00.12 Birel 25mm Sprocket Carrier, Cast Aluminum

25mm Sprocket Carrier, Cast Aluminum

cometkartsales.com

Check and see if your old Brake pads are the exact same dimensions as these:

Top Kart Kid Kart Brake Pads, Pair

Kid Kart Brake Pads (Pair)

cometkartsales.com

Chances are you can simply cleanup and re-use your old brake rotor using sandpaper and/or Scotch Brite pads.
But If your old rotor is warped beyond use, you might find a replacement here: https://cometkartsales.com/Metric-Brake-Discs/

Thanks you all for the input. I decided to buy a 1 1/4 inch axel and the components. I have a list of things I am going to buy including wheel hubs, axel bearings, sprocket hub. My next questions are about the chain and sprocket and if I would need to change them. When I bought the kids kart they gave me two extra 89 teeth sprockets. I tried measuring the sprocket with a 3/8 inch wrench and it is slightly wider then the teeth (see picture). I also have a 6 1/12 inch rotor that looks old and used and was thinking about replacing it but I only find 6, 7 or 8 inch rotors and not sure if I will need to have someone move the caliper bracket to fit a larger or smaller rotor. I was planning on using the same chain and sprocket if that is OK and if you all think the caliper is good I will need to find the brake pads to fit it (see picture). The pad fell out when I removed the caliper and it is in the picture but I think the Brake pads you reference from Top Kart Kids Kart look like they would fit my caliper. Thanks again for the info and the sites to reference.

 

[Rat]

I tried measuring the sprocket with a 3/8 inch wrench and it is slightly wider then the teeth (see picture).

Slightly worn, but that's a #35 chain sprocket.
Anything bigger would be 1/2" pitch (40, 41, 410, 415, 420) you could also check the tooth thickness because a #35 roller width a bit less than a quarter inch (0.188) wide

The roller chain pitch is measured pin to pin (or rivet if you prefer) that holds the links together, although the teeth can give you a close enough approximation to know or figure out what chain you need

 

[anderkart]

Looks like your old sprocket is a #219 pitch. That's the chain size Kid Karts usually have.

Try using a 5/16 wrench instead of a 3/8.

 

[anderkart]

Thanks you all for the input. I decided to buy a 1 1/4 inch axel and the components. I have a list of things I am going to buy including wheel hubs, axel bearings, sprocket hub. My next questions are about the chain and sprocket and if I would need to change them. When I bought the kids kart they gave me two extra 89 teeth sprockets. I tried measuring the sprocket with a 3/8 inch wrench and it is slightly wider then the teeth (see picture). I also have a 6 1/12 inch rotor that looks old and used and was thinking about replacing it but I only find 6, 7 or 8 inch rotors and not sure if I will need to have someone move the caliper bracket to fit a larger or smaller rotor. I was planning on using the same chain and sprocket if that is OK and if you all think the caliper is good I will need to find the brake pads to fit it (see picture). The pad fell out when I removed the caliper and it is in the picture but I think the Brake pads you reference from Top Kart Kids Kart look like they would fit my caliper. Thanks again for the info and the sites to reference.

Your welcome.

Swapping over to an 1-1/4" axle and all the related componets seems like an awfully drastic alternative to simply replacing your old 25mm sprocket hub... But if your committed to attempting this, I'd suggest you start by seeing if an 1-1/4" axle bearing will even fit your frames mounts, before spending money on any other 1-1/4' componets.

Have you been able to find any 1-1/4" axle bearings that fit your old metric/25mm bearing cassettes?

Or, have you found any 1-1/4" axle bearing cassettes that fit your frames smaller metric sized mounts?



Here's what most 25mm axle bearing cassettes look like:

 

[Little B first year]

Hy everyone, this is Kenny again. I took the kart down to our local track (Prairie City in Northern California) and found out that I bought a Track Magic kart. I ended up taking the axel out (that was an experience but a 5 pound hammer helped) lol. I took off all the parts and cleaned them. The axel is a 25mm so I bought and replaced a 25mm sprocket hub. I was going to use the brake hub and rotor that was on when I bought it but the problem I ran into is the brake caliper and brake pads. The Grimeca caliper must be old because I cannot find any replacement brake pads. Someone in the above threads recommended a 1 inch puck style replacement pad which I did order. The problem is that the replacements are flat and the ones I need are not (see picture below). I used a dremmel to try and put the shallow hole in them but that did not go so well. They did not fit so well and when trying to put it together the pads and assembly fell out 3 times loosing the 3 small bearings in them. The last time it happened I could not find one of the bearings so I called it a day.

I have decided to replace the brake caliper, rotor and maybe the brake hub. At least a newer caliper will have brake pads available. This is a kids kart for my 4 1/2 year old grandson Beau. I am thinking about going with a mechanical brake caliper (kart will only go approximately 27 mph). I have a brake hub that has 3 holes so of I decide to stay with that I would need to find a rotor to fit that. If I buy a new brake hub I can buy a 4 or 6 hole which brings me to another question, what size of the rotor do I need or does it matter? Is there a specific size rotor for a kids kart? After I get the rotor and caliper and brake hub figured out I will have to go to a fabricator to have a bracket installed. Does this sound right or does anyone think a different brake system is a better idea for a first timer?

I appreciate any and all help. Thanks
Kenny

 

[anderkart]

See if these pads are the size you need: https://www.kartbrakepads.com/product/577-0/