[Kartbuilding] Fwd: Chassis Tubing Size (fwd)

Stephen Burke sburke at burkesys.com
Tue Feb 6 23:37:23 GMT 2007

---------- Forwarded message ----------
Date: Tue, 6 Feb 2007 10:39:09 +0200
From: Alrin Christians
To: Stephen Burke
Subject: Re: Fwd: Chassis Tubing Size

Hi Stephen

Thankyou very much for the advice.Much apreciated.


On 2/5/07, Stephen Burke wrote:
> Hi Alrin,
> I recieved your email and JPEG of your SolidWorks Kart model fine. It
> looks good!
> As for suspension - its a lot of hassle in my opinion. To get suspension
> working "correctly" it take a LOT of extra work. I had often though that I
> could easily modify my karts afterwards to include suspension - however I
> never got the time to trying it. My suggestion - is to get some nice sized
> wheels and let them take some of the bumps.
> I have used a Honda GX160 5.5hp - its an ok engine - but on its own - its
> limited to 30mph for a on-road/tarmac kart with a simple centrifical
> clutch. The Honda GX240 sounds like a better engine with more power. I
> still think you may need a "torque converter" (google for it) or a gearbox
> to give you a high & low gear ratio which is essential for an off-road
> kart.
> As for the diameter of tubing to use. First off - as I mentioned if you
> are running the kart off-road, and with no suspension, letting a little
> air out of the tyres will help soak up some of the bumps and punishment.
> If I was going doing some serious off-roading in the kart - I would go
> with 30mm diameter tubing. It all depends also on the weight of the kart,
> and whether the engine will take it. The 8hp engine of your should. The
> roll cage you have modelled up in SolidWorks will also help to transfer
> the load into the chassis better. I would add further members to the roll
> cage also - firstly to better support the ladder type chassis, and
> secondly to offer more protection if the kart did roll onto its side.
> So - go with the 30mm tubing for the main members. You can use 25mm for
> the cross members. Also - look into getting some sort of a gearbox or
> Torque Converter.
> Best of Luck,
> -steve
>   On Sun, 4 Feb 2007, Alrin Christians wrote:
>> Hi Stephen
>> My name is Alrin.(Cape Town-South Africa)In am busy building a semi off
> road
>> cart based on the free plans I found on you website.This is my first
> project
>> of this type so there is a lot of things I am not 100% sure of.I dont
> want
>> to use suspension in my design because as I said before,this is my
> project
>> of this kind and I dont want to make it too complicated.
>> Originally I was going to use a Honda GX160 5.5hp motor but I ended up
>> getting a Honda GX240 8hp motor.This motor weighs 60Kg.What worries me
> is
>> the tubing size for the chassis.In my design I used 25mm mildsteel
> tubing
>> (as sugested on you site).I also made the chassis a 150mm longer to
> place
>> the engine behind the seat.The overall dimensions of the chassis is
> 1650mm X
>> 700mm.What ads to this worry of mine is the fact that I wont use a
>> suspension.Will the chassis be able to take the punishment or should I
> use
>> maybe 30mm tubing or maybe even more?
>> Attached is a Solidworks JPEG of my design so far.I bought the engine
> this
>> weekend and I want to buy the tubing next,so I just wanted to make sure
>> about the tubing size before I buy the material.
>> You advice will be greatly appreciated.
>> Regards
>> Alrin

More information about the Kartbuilding mailing list