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PostPosted: December 18, 2022, 1:44 pm 
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Joined: July 17, 2008, 9:11 am
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Location: West Chicago,IL
I need some advice on front geometry. To start out, my adult son has been playing with an old riding lawn mower (think free to maybe $50 on Craigslist type) for running over ice. He has changed the pulleys to get a top speed of maybe 15-20 MPH. The front beam axle has been destroyed so he will be making a new one. He was asking me about geometry. Lawn tractors are a strange breed for front suspension, for sure. Again, the intended use is on ice. My suggestion was to keep the KPI at 0, Camber 0, Toe in 0. The reason is there will be no grip to start with, and no appreciable lean in corners. I'm thinking keep as much tire as possible flat on an ice pond. One of his buddies is now building his own ice monster and another buddy is looking for one to join in the fun. I'm sure the 4tth will join in suit. It is going to become competitive instead of just fun.

Any ideas?

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PostPosted: December 19, 2022, 4:51 pm 
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Joined: April 26, 2008, 6:06 pm
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Location: Under the weather. (Seattle)
I'm guessing you're talking about where the rear axle is rigid to the frame, and the front axle just has a central pivot? I don't think I'd get rid of the KPI. It adds stability and reduces scrub. If possible I'd add some castor to add trail for additional stability and control. Alignment wise, 0 all around probably isn't a bad starting point... Of course, this is all just a WAG.

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PostPosted: December 19, 2022, 5:44 pm 
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Joined: January 2, 2009, 1:45 pm
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Location: Halifax, Nova Scotia
Speaking as an iceboater, ice is rarely a perfect as you'd like and having steering that wants to self centre is a great idea when you run across a rough bit or a relatively sticky bit of ice. Reduces unwanted pirouettes!

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PostPosted: December 21, 2022, 1:41 pm 
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As an old ice racer I'd say that tires are more important than anything else on an ice racer, more important than alignment (as long as the wheels point forward and tow out if you're running FWD), much more important than horsepower (unless the track is just long straights) is tires. You need the softest rubber that you can source for your ice racer and you should "tractionize" them, cut each tire block with a razer knife putting in as many cuts as you can. You don't want to cut pieces of the tire out creating sipes, you just want the tire blocks to be able to move around very easily. Good luck.

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PostPosted: December 22, 2022, 5:13 pm 
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Joined: July 17, 2008, 9:11 am
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Location: West Chicago,IL
Good Ideas. Thanks. I gave him a link to here for him to read. :cheers:

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“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766


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