Full Suspension Big Block Mini-Buggy Build

[SquidBonez]

Been doing some test riding before I finally paint it to make sure there's no welding left to do. After throwing a chain I decided to add a storage bin to the side to bring extra chain/masterlinks/tools with me in case of a breakdown. But the biggest addition is a spring loaded adjustable chain tensioner.


Not only do I have the slots in the engine plate for adjustment, I now have this spring loaded tensioner to actively tighten the chain as it wears. The tensioner itself also has multiple spring/idler wheel positions to allow for different spring strengths/sprocket sizes. Obviously you still need to keep an eye on you chain, but this at least will take up the slack that happens between adjustments. Hopefully this prevents any future chain-related issues. And if not, I have my storage bin to hold my tools to make any on-the-go repairs.

 

[Master Hack]

That will help a lot. What is the blue material? I made one outta 90D polyurethane, but it wore out quickly. Then i switched to an idler sprocket. End of problem. Don’t underestimate the required spring tension.

 

[SquidBonez]

That will help a lot. What is the blue material? I made one outta 90D polyurethane, but it wore out quickly. Then i switched to an idler sprocket. End of problem. Don’t underestimate the required spring tension.

Some sort of high density plastic. Got it off Amazon. As for the spring tension I believe it will be enough, but if not i have multiple holes to allow for different size/length/strength springs. Gonna try this one first because I had it on hand.

 

[Master Hack]

Since l'm a cheap scrounger, l used a spring from the neighbors old trampoline. It took 3 tries to settle on the right tension.

 

[lug-nuts]

The spring from a cheap wood clamp works good too, and theyre only a couple bucks for clamp.

 

[lug-nuts]

The spring from a cheap wood clamp works good too, and theyre only a couple bucks for clamp.

inside pic showing
the spring

 

[SquidBonez]

Just working out the kinks before paint. Also got this set of tires (square setup rather than staggered). 19x7-8 all the way around. This allows me to rotate my tires and also gives a more neutral handling/eliminate understeer. Haven't tried them out yet but these tires will be better on the trail. Also they are a lot lighter than the old rear tires so they should free up a bit of power.

 

[SquidBonez]

Been having big issues with chain tension. The spring loaded tensioner seems to actually exacerbate the problem rather than help, so I've ditched it (still holding on to it in case it becomes useful later). I thought I may have had my chain set too tight, but that doesn't seem to be the issue.

The chain I'm using is D.I.D. #420 gold chain, but I'm thinking I need to go bigger. I could go to #428 chain, but I think I'm going to jump up to #530 motorcycle chain for extra peace of mind. I'd rather overdo it than underdo it. I may have to space out my pulleys to fit the larger sprocket, but it seems like it might work. While #530 sprockets are hard to find for go-kart applications, #50 industrial chain sprockets are the same exact size as #530 and are relatively common. Downside is now I have to remove my axle to do gearing swaps (had a split sprocket before) and I am back to relying on manual chain tensioning.

Now just waiting on parts...hopefully this fixes it. Has anyone else had issues with chain stretch with big block engines?

 

[Master Hack]

Yep, had problems with #420 chain. Switched to #40H and solved that problem.
40H is substantaly stronger than 420. Same pitch so sprockets don't need changing.

 

[SquidBonez]

Yep, had problems with #420 chain. Switched to #40H and solved that problem.
40H is substantaly stronger than 420. Same pitch so sprockets don't need changing.

#40 chain will fit pitch wise, but doesn't it have tons of side to side slack as it's wider than #420? Also apparently this D.I.D. gold chain has a higher tensile strength (4930lbs) than the #40H I could find (just above 4000lbs on average). Do you know where to find strong 40H chain?

 

[Master Hack]

40 is a little wider, but not a lot. Doubtful you could tell the difference at a quick glance.
l don't remember all the detail BS cuz i'm old and did this yesterday....
l had similar problems and talked to these guys and end of problem.
don't know if the difference is USA chain vs foreign, 40 vs 420 or what.

Nitro Chain - Premium Industrial Roller Chain & Sprockets | Industry-Leading Performance

www.nitrochain.com

 

[Denny]

40 is a little wider, but not a lot. Doubtful you could tell the difference at a quick glance.
l don't remember all the detail BS cuz i'm old and did this yesterday....
l had similar problems and talked to these guys and end of problem.
don't know if the difference is USA chain vs foreign, 40 vs 420 or what.

Nitro Chain - Premium Industrial Roller Chain & Sprockets | Industry-Leading Performance

www.nitrochain.com

Are you jerking our chains, man?

I’ve waited years for the right time to use that!

 

[Master Hack]

I set ya up! Yer welcome.

 

[TNThomas]

I think your chain tensioner should be mounted such that it applies tension on the top chain, not the bottom. The bottom chain should naturally have most of the slop picked up from the tension force of the jackshaft sprocket pulling on it. It's the top section that's just flopping around since it's essentially being "pushed" by the jacksfaft sprocket. One idea would be to mount some sort of bolt with a wheel on it in-between the links. That way you could fine tune the tension via threading in/out the bolt.

Check these folks out, tons of size options for chains/sprockets, this is who I went with.

Nitro Chain - Premium Industrial Roller Chain & Sprockets | Industry-Leading Performance

www.nitrochain.com