New guy with questions

[Neo1975]

First, I would like to say hi to everyone. This looks to be a great forum. I am already enjoying looking at all of the pics on here, some really great karts.

I remember riding go karts and mini bikes as a kid. Recently, I came across a deal on a Manco Dominator 2 seater. This is my sons' first kart. They really like it, so I am glad they are getting to experience the fun of a go kart. It has a 5 hp Robin Engine. It is enough for the boys.

Anyway, it has a jackshaft, and I would like to convert it to a live axle. I have looked into the parts needed and have some ideas as to what it will take. The problem that I am having is with wheel selection. The tires on the kart are 145/70-6, and we have 4 new tires of the same size. Seems like they should go on a 6" wheel, but the wheels on the kart measure about 6.75" outside diameter. Do all 6" wheels measure like this? Will these wheels work for the given tire size: http://www.ebay.com/itm/220933808292?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649 . I know it would probably be simpler to go with a standard 4bolt hub and wheel setup, but the boys (me too) really like these. BTW, I plan to use a keyed 1" axle.

Any help is appreciated.

 

[r_chez_08]

Have you got pics of the wheels? Dunno if they would fit. I have some of these tires too. Common on 50cc quads such as Suzuki lt50's.

It would be cheaper getting just hubs depending on what rims you have.

 

[Neo1975]

The drive wheel is on a hex shaft. I want to convert to a 1" axle shaft. I am looking at the Douglas Q+ Aluminum Machined Wheels with Lightened aluminum hubs. These are the wheels http://www.dwtracing.com/products/kart/oval_kart . I can get them in 6x5 with 2.5" offset.

 

[OzFab]

There's usually a reason a jackshaft is used, removing it could be detrimental to performance.

Wheels are measured from where the bead seats, not the outside measurement. If you measure a tyre from edge to edge on the bead, you will see that it will measures 6". If the rim also measured 6", what would hold the tyre on the rim? The width of a rim is also measured from the inside of the bead lip (just FYI)

Have a look at these:
http://www.bmikarts.com/category/Tires--Rims-621
http://gokartgalaxy.com/wheels.htm
http://www.mfgsupply.com/gomini/gominiwheels.html
You'll find a large selection of wheels, some with hubs built in.

Post some pics of your kart so we can get an idea of what you're doing. Include pics of your jackshaft

 

[Neo1975]

I will try to get some pics. I understand what you are saying about the bead diameter of the wheel vs that of the tire. I didn't realize that is how the wheels are measured. That is what confused be. I saw a post (can't remember if it was on this forum-google search) of someone doing a live axle project on the same go kart. I know it will take some good planning. I will try to find the post of the project I read about.

 

[Neo1975]

http://www.diygokarts.com/vb/showthread.php?t=13393&highlight=dominator It was on this forum. It is similar, but the motor is on the right side of our kart.

 

[Neo1975]

Pics

 

[OzFab]

I did say there's usually a reason for a jackshaft but, in this case, the only reason I can think of is for ground clearance.

I thought I'd seen one here. Although they're both dominators, it's clear they are different models. The conversion on yours will be easier than Herky's, simply because of your existing setup. Can I assume the tube the axle is running in has bearings between the tube & the axle? What is the ID of the tube & the size of your axle? Potentially, from what I can see, you will have very little fab work to do

 

[Neo1975]

It is a 7/8 hex axle and the bearing outer diameter is 2.047". If I understand it correctly, I should be able to use the existing tube and change to bearings for a 1" axle. Should be as easy as changing from bearing 3941H to bearing SA305-16 from this web site: http://www.gokartsupply.com/bearings.htm . Then do some fab work to install a pillow block on the other side.

 

[OzFab]

That's what I was thinking... almost. You may be better off with a 2 bolt flange on the other side. A pillow block, in this case, would be very restrictive. If it doesn't line up with the rest of the axle, you'll have to cut & weld & grind & play around to get it to line up. A flange will just bolt up once you drill 2 holes, easy.

I'm a big fan of pillow blocks so, for me to suggest a flange, there must be something in it.

You may also need a collar or two to keep the axle centred, depending on what bearings you can get. Keep in mind that most axle bearings with the lock extension have a convex outer surface. They should still work but external contact area will be minimal

 

[Neo1975]

Thanks for all of the help. The flanges do sound like a simpler setup. Guess it is time to start gathering parts. I am planning on getting most parts from BMI Karts and Supplies. It may be a while, but I will try to post pics of the completed project.

 

[qtband]

I think I would get rid of the tube completely and use a flange mount on both sides (1861). The bearings will have allen screws in them to lock it to the axle. I like to line everything up, mark those screws, then drill a dimple in the axle for extra holding power. Keep the jackshaft, it allows for the smaller driven sprocket.

 

[mysteryboy28]

your jackshaft is actually a gear reduction (creates more torque, less speed). see how it goes from the clutch to a large sprocket to a smaller sprocket? you'll want to leave that intact, or get a much larger axle sprocket (causing a ground clearance issue) if you decide to ditch it.

 

[Neo1975]

Well, I don't want to run into ground clearance issues. I looked at the setup on it now to count the teeth on the sprockets. There are 11 teeth at the clutch to 24 teeth on the jackshaft. The smaller sprocket on the jackshaft has 10 teeth going to 28 teeth on the sprocket that drives the axle. I found a 28T sprocket on a holder with a 1"bore. It is for the correct chain (420 chain), but it has a 8mm keyway instead of the 1/4" keyway.

 

[Neo1975]

I think I would get rid of the tube completely and use a flange mount on both sides (1861). The bearings will have allen screws in them to lock it to the axle. I like to line everything up, mark those screws, then drill a dimple in the axle for extra holding power. Keep the jackshaft, it allows for the smaller driven sprocket.

I thought about getting rid of the tube, but I would probably need to place a 3rd axle bearing near the axle sprocket to keep from snapping the axle. It may be simpler to use the existing tube with bearings for a round axle.

 

[OzFab]

but, seriously, you won't snap a solid 1" axle. It may flex a little bit, but that's about it. I'd leave the tube, it'll only add strength to the axle

 

[Neo1975]

Just recently got back from vacation. I have all of the parts for the live axle conversion and new hubs and wheels for the front also. It may be a while on the conversion (need help, I can't weld) but I would like to get the front wheels installed. Does anyone know the torque specs for the wheel studs and nuts? I am using the lightened aluminum wheel hubs and Douglas Q+ aluminum wheels.
http://www.dwtracing.com/products/kart/oval_kart
http://www.bmikarts.com/item/Lightened-Aluminum-Front-Wheel-Hub-with-Bearings--600236-7209

 

[anderkart]

Does anyone know the torque specs for the wheel studs and nuts? I am using the lightened aluminum wheel hubs and Douglas Q+ aluminum wheels.

It depends on the size & hardness of your wheel studs,
heres a link to a handy torque spec chart: http://www.engineershandbook.com/Tables/torque.htm

PS: you can click on the metric chart from that page if you need it

 

[Neo1975]

Thanks. The link is very helpful.

 

[OzFab]

Just for curiosity's sake, can you post some pics of your front stub axles/steering setup; just want to check something out.