Article - Snow Chains Written by: Jonny Retro

Build Your Own RC Snow Chains..

As a kid owning my first RC buggies, I looked forward to snow, thinking I'd be able to rip around at great speed in it … and was massively disappointed!

Fast forward several years, as an adult (kind of), I thought of owning a "big wheeler" - a Wild Willy 2 - would overcome the problem of getting stuck every 30cm or so - but, sadly, no.

Making & fitting your own snow chains will improve things on a suitable (read as "big wheels & high ground clearance") - but don't expect them to let you drive any RC car in any depth of snow.

In best Blue Peter tradition - here's some I made earlier..

Things you'll need:

  • Two pairs of radio pliers (aka needle nose pliers) or similar for bending links
  • Small cable ties (aka zip ties, tube ties) - the tiny ones that come with servos are ideal
  • Cutters of some sort (aviation snips, etc)
  • Chain (more on that later)
  • A suitable car to fit the chains to - buggies, truggies and rally cars just don't have the ground clearance - so we're really talking about Tamiya "big wheel" vehicles - the Lunchbox, Midnight Pumpkin, Wild Willy (more the so WW2), Blackfoot, Monster Beetle, etc
  • Time - allow at least 3 hours for the 1st wheel, reducing to about an hour for 2nd & subsequent sets as you get more practice
  • And, ideally, some snow!

The first thing to work out is the quantity of chain needed - it'll probably be more than you think.

Work out where you want the chain to fall on the sidewall - on the VLB/Pumpkin/WW2 tyre there's a moulded line half way between the rim & the outside edge of the tyre - for this set of chains, I'm going to aim for half way between the rim and that line - 32.5mm from the wheel centre.
Circumference = diameter x Pi, so the figure I want is 32.5 x 2 x 3.142 = 204.23mm. I need twice that - 410mm with rounding - to do the sidewalls on one wheel.

The next aspect is a judgement call as to how many cross tyre chains your set is going to have - I'll be going for 12 on this set of Pumpkin wheels.

Measure the distance over the tread of the tyre from where the sidewall chain will be on one side, to the corresponding point on the other sidewall. I got a figure of 95mm, but I know from past experience that you need to add a little more to take into account the thickness of the chain (about 10 percent), so I'll call that dimension 105mm. 105mm x 12 = 1260mm, meaning I need 1260mm + 410mm = 1670mm (or 1.67m) per wheel.

Count the number of wheels you want to chain up - I'd only bother with driven wheels, freewheeling corners won't benefit from having chains. So, 1.67m x 2 wheels = 3.34m, I'd also add 5-10 percent on top for wastage, accidents, and links not falling exactly where you want them, etc.
Furthermore, as there's a strong possibility of the first attempt going so badly wrong that little of the chain is salvageable for a second attempt, I'd add a further 50% - so I need to go shopping for at least 5.4 meters of chain.

The second big thing is to actually get a supply of chain… I've yet to find a "perfect" chain for the job, so can't give any specific recommendations, other than to say the best place I've found is the "ubiquitous auction site" Dare I say it quickly.. ebay.
Chain sold as "jack chain" or "hydroponic lamp chain" (usually a figure eight with a ninety degree twist) is not suitable; "clock chain" is comparatively expensive, especially the stainless variety, but it is tough - good in actual use, but it's tough to work with.
I'd suggest looking for bulk jewellery making chain - it's cheap, easy to work, and is available in lots of sizes and colours - including pink, red, blue, black, or even purple anodised if that's your bag.

Make sure you check the size of the links - the bigger the links, the more functional & easy to construct your snow chains will be (though I wouldn't want a maximum dimension of more than 10mm) - but on the other hand, the smaller the links, the more scale the look - and the fewer clearance issues you'll have (something to consider, especially on the motor side of the VLB and Pumpkin).

The gold chain on the pics above is 9mm x 6.5mm - it works well, was easy to build … but it's not subtle, and it's certainly not scale.

This time around, I bought 20 meters of "silver" light chain with 7mm x 3mm links for just over £12.. Bling!

I like to start by making up the sidewall loops. Going back to the measurements I made earlier, I know I need sidewall chains with a length of just over 204mm. Measuring chain from the inside of the first link, I can see I need 43 links.

Work out which will be the final link to get the right length of chain - then open it up with the two pairs of pliers, pass that link through the other end link, then close up the loop..

Depending on the type of chain and size of link, you might find it possible to do the bending by hand - but remember, you'll need to do it over a hundred times for a pair of VLB sized wheels - your fingers won't thank you by the end!

Work out where you need to put the tread chains for even placement - my sidewall chains are 43 links long … Clearly 43 isn't wholly divisible by 12, so I'll have to join the twelve tread chains to the sidewall chain on a staggered patter every 3 or 4 links - quite arbitrarily I chose links 1, 4, 8, 12, 15, 19, 23, 23, 26, 30, 34, 38 and 41 to get an even spread. Chances are that it won't work out neatly for you either - you'll have to do some juggling too.

Next up, is preparing some of the tread chains needed - I need 105mm chains (24 of them), in my case 22 links is about right.

Here I've joined all twelve tread chains to the first sidewall chain (and tucked the loose ends underneath the tyre) - note the close up detail of one of the joins..

Join up 3 of the tread chains to the second sidewall chain, then another two, and so on, doing test fittings as you go..

You'll get to a point where it becomes awkward to get the chains on - in my case, when I'd got 9 of the 12 tread chains on - so don't take them off once you've got them on.

Here's a finished wheel with all twelve tread chains linked up both sides..

You'll want to remove your snow chains at some point - I've found the best way is to cut one of the links out of the inner sidewall chain, then use a cable tie to rejoin the cut ends to refit.

This is also the best way to deal with snow chains that are a bit loose, or become so during use (cheap chain like this does tend to stretch) - cut two links out & replace with a cable tie..

I do suggest you try to form the chains around something, or rig up some way of hanging them when they're not fitted to any wheels though - they can easily become a tangled mess..

Earlier, I mentioned that it may be worth over-ordering your chain… If I haven't made it clear so far - this can be a fiddly process, so try to view your first wheel as a prototype for getting the measurements right - not a chain to be used… that way if it all goes Pete Tong you won't tear your hair out.

Here's some pics of the finished pair of show chains on my basher Pumpkin..

I plan to try some other variations in the future - a set with an elastic sidewall (to get the chains on and off quickly), or with a wire loop or metal ring sidewall for more of a scale look.

As to actually using the things - the main thing to remember is not to spin the wheels up too much if you can help it - you won't get any grip, and the cheaper the chain, the more likely it is to stretch, and possibly even break… That said, the only failure I've had was after donutting my Brat on ice for 10 minutes!

Thanks for reading and have fun.. getting cold!

A big thanks to Jonny Retro for this article.

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