Topic: Overwhelmed New Guy, First Hot Rod

[Chromie]

So my son comes home and says "Dad I wanna build a hot rod mower!"

I had a Murry Widebody behind the garage, so we pulled it in and tore  it down. Power washed the chassis and removed everything that was for the deck. Now we are ready to start the build. I've been reading on this forum all day and still I'm overwhelmed with options. I want to keep this as simple and cheap as possible until I see him stay interested. I also don't want to build a death trap for the kid. There are 5-6 of his buddies from School that are also building these rigs. (I talked to the Dads) and we all have 12hp mowers to start with, so it should be cheap, fair, safe and fun. Motors will stay stock for now, but anything goes for everything else. With that said. Where do I start with this thing? Should I just start with a pulley change? Here are a few pics of our progress. This is a father son project, so we want to do some upgrades but I don't think we need a full blown race rig. Where do I find the rules for racing for a 12 year old? Down the road we may want to race real races, so I would like to keep things within those rules.

[Toadworks]

Bottom line, the rules we use for the sanctioned clubs (ARMA, SOMA, USLMRA, WOO, etc.) have the safety of all concerned at heart. Building to the rules of one of those clubs affords a margin of safety and is a great way to teach young people about fair play. Even if you don't race on a national level the rules should still apply to your builds. Get the other Dads on board with one of the national club rules too. This way you can know that your son is racing against safe machines as well. The USLMRA offers two classes that use identical machines. One class, known as JP is for younger drivers, the other IMOW (International Mower Of Weeds) is for adults. The idea here is that one machine can be built for two people to race. A pretty cheap way for Dad and Son to share a Saturday. The other clubs offer similar classes, they just go by different names.

No matter what direction or set of rules you follow; There are three 'must do' items.

Steering. Stock steering simply WILL NOT be safe.
Brakes. Again stock brakes WILL NOT be safe.
Kill switch. With a tethered key.

There are many 'old school' tricks that are simple and effective. You do not need expensive hydraulic brakes nor do you have to have a complete custom front axle and steering assembly. This sport has developed many parts and pieces that are billet this and solid that, and that is fantastic. But a welder and some thought can build a safe, fun to drive machine.

Oh and simply changing pulleys, nah, not a good idea. The rules in USLMRA for both JP and IMOW have an 8 to 1 final drive ratio. With stock motors and stock RPM (another requirement in that set of rules) you will see speeds around 25 MPH. That is extremely hard on stock steering and brakes and they WILL fail.

Are there any clubs in your area? If so visit them, look over the machine to get ideas and search the database of knowledge on this forum. There are many folks here that will help as long as they know your build is safe and follows some sanctioned rules.
 

[Chromie]

thanks for the replies fellas, I most defiantly want to keep it safe.

I'm not sure if there are any clubs in my area or not. I hope there is. this is the first time my oldest boy wanted to do anything besides play video games or lay around on the couch. I see an op to spend more time with him, and want to take full advantage. Besides I think a racing mower would be a hoot for both of us. I'll do a little searching and try to figure out if there is a club near by and which rules they go by.
Is there one set of rules that is legal at every track? Seems like that would be the one to go with.
Where are you guys getting the brake parts?
What are you using for the kind of tranny we have?