planning on building a shifter kart

[new-guy]

so me and my buddy (mainly me since I'm the only one with money ) are planning on building our own shifter kart for fun over the summer. I have access to stick, Tig, and a cheap Mig welder so that shouldn't be a problem but i was wondering if anybody knew what type of material i should use to build the frame. Mainly the size and thickness. also if anybody would be willing to post plans or measurements of your shifter karts that would be awsome we were planning on throwing a rm125 engine in there if that helps.

 

[voided]

Make sure you plan axle size according to your sprocket selection and chain size... You find more split gears in 40mm 428 link then any others.. Also make sure shifter is not to long to actually shift itself from hitting bumps..

 

[DS13]

You've already seen my thread but take the time to use the search button and look at other threads before ya start. Also ask a lot of questions! Everyone here is cool and will help ya as best they can. If ya have any specific questions about my build send me a PM.

 

[OzFab]

Material size is relative to the overall size of the build. Having said that, you should get away with using 1" tubing with 0.0625" wall thickness...

Have you thought of entering your build in our build-off?

Happy building & welcome to the forum

 

[new-guy]

that's something I meant to ask about. the rm125 is a 520 sprocket, is there a 520 sprocket for karts or am I going to have to do a conversion somehow. also I think what I'm going to do for the shifter is have linkage connected to a pole that's sticking up from the floor so weight won't shift it. and for the tubing, me and my buddy both come in around 200lb's so you think we should go thicker then that?

 

[landuse]

Welcome to the forum. You should be able to get 520 sprockets for your kart, so no conversion should be required

 

[OzFab]

and for the tubing, me and my buddy both come in around 200lb's so you think we should go thicker then that?

No, if necessary, go larger not thicker. Thicker tubing may make it a bit stronger but it will also make it a lot heavier

 

[new-guy]

So I'm thinking maybe 1 1/4" on outside then on the inner frame have just 1" to keep down on weight and add a bit of stability. Also where can I get from hubs that can have a brake disk on them? I can't seem to find any. And what axle size generally has 520 size sprockets? Thanks for all y'all help so far this has helped a lot. Also how much is 1" and 1 1/4" chromoly tubing per foot? And how much for regular tubing in those sizes also? I'm on the east side of Houston if that helps

 

[new-guy]

Oops the tubing in .0625 size as mentioned

 

[DS13]

So I'm thinking maybe 1 1/4" on outside then on the inner frame have just 1" to keep down on weight and add a bit of stability. Also where can I get from hubs that can have a brake disk on them? I can't seem to find any. And what axle size generally has 520 size sprockets? Thanks for all y'all help so far this has helped a lot. Also how much is 1" and 1 1/4" chromoly tubing per foot? And how much for regular tubing in those sizes also? I'm on the east side of Houston if that helps

Chromoly tubing is gonna be expensive and you will probably have to tig it to keep it nice and shinny.

 

[new-guy]

I can gig decently and my dad can tig very well so I think I'll probably go with chromoly as long as the price isn't ridiculously higher then regular tubing. Does anybody know the price gap of the two atleast I your general area? Were trying to make this think like a race kart as much as we can without emptying our pockets to buy a frame

 

[voided]

I found it hard trying to find 520 split sprockets..

 

[DS13]

I can gig decently and my dad can tig very well so I think I'll probably go with chromoly as long as the price isn't ridiculously higher then regular tubing. Does anybody know the price gap of the two atleast I your general area? Were trying to make this think like a race kart as much as we can without emptying our pockets to buy a frame

A quick check on google showed chromoly tubing 1" outside .065 WT to be 50 cents an inch... EXPENSIVE

 

[anderkart]

You can buy #520 axle sprockets at these shops:
http://www.gokartgalaxy.com/shifter_kart_&_quarter_midget_sprockets_for_3.htm
http://www.qrckarts.com/store/index.cfm/category/18/drive-components.cfm

_______________


Here's some frame dimensions from my 1999 Beisse B3 model:
You'll find more pics/info in this thread: http://www.diygokarts.com/vb/showthread.php?t=3664

 

[new-guy]

I do believe I'll be able to get tubing cheaper through my dad's work because they bulk order metal so we might be able to get a deal hopefully. also I'll e able to borrow a tubbing bender so that's some more good news. also, anderkart, would you mind measuring some the angles on your frame for me, were trying to make this thing as competitive as possible without actually competing haha so I'm trying to base it of off the work that plenty of engineers already did for us. also do you know what castor (i think? maybe cantor) your wheels are at? and what size axle would y'all recommend for me? I'm 90% certain it's going to have a 1992 RM125 engine on it if the seller doesn't get caught up in work like last time. I'd like to keep the price down but i still don't want something that will bend or be generally be crappy.

 

[anderkart]

Sorry someone swiped my angle gauge so I cant take any readings, but if you have one you could probably take most of the basic frame rail-angle readings from the pic I posted.
Or you'll find some helpful info at this link: http://blog.kartbuilding.net/2007/07/12/free-technical-kart-drawings-fia/

You'll find lots of caster/camber angle info in this search link: http://www.google.com/search?source...or.r_qf.&fp=32371135d2c69783&biw=1024&bih=532

Most modern shifter racekarts use 50mm axles because they're the strongest, but 40mm (or 1-1/4") axles & hubs typicly cost much less, and will usually hold up just fine using motocross engines like yours.

Have you considered buying a used shifterkart instead of building your own frame?
If you bought something like this one: http://www.hachiroku.net/forums/showthread.php?t=31807 you'd end up saving lots of money, and end up with a much better kart. Notice that kart has front brakes? You'll find you really need 4-wheel brakes on a 125cc shifterkart...

 

[new-guy]

Nahh I don't really want to buy a frame. I kinda want this be one of those memory's I can look back on with my buddy. I do However plan on using front brakes. I'll steal the calipers Frome some rear brakes on dirt bikes but where can I get the inner hub that actully has the brake disk on it? The one the front wheel clamps onto. And I think I'll probably run about 12 degrees of castor.

 

[anderkart]

Cool, I'd sugest you call this shop for your hubs/rotors:
http://www.seventh-gear.com/store/contact.php