Hi,
before you invest some efforts, time and money (tools) into building something on your own, I would like to just comment that the bashguard used at the nice Cannondale picture above is not so special.
Just search for a bash guard for a Trial bike.
E.g. Onza has it Armstrong bash guard or even complete cranksets with BCD94 including a bash guard
(this is post Onza Retrobike peak times, rather stuff from this century from what ever is remaining from this former iconic brand)
here is a cheap one I had also a while ago from DDG
Brand: Onza or DDGModel: DDG 22 Tooth in Stainless Steel for 5 arm CrankModel: DDG 32 Tooth in Alloy for 5 arm Crank. Black or Silver Anod.Price includes UK DeliverySEE PICTURES BELOW FOR DETAILS
www.rockandrollbikes.com
or another nice looking one at ebay
32T Max chainring size. Gusset Saw Ring Bash Guard has never been installed, but markings on the guard from storage. Item has been marked as "used". Gusset Saw Ring CNC 6061 Alloy. Trials type bash ring.
www.ebay.co.uk
silver also in saw blade style
94mm BCD protects up to 32t chainring.
www.ebay.co.uk
Another very nice looking one is currently offered at carousell, but with a LX crankset (and a bit pricey)
last but not least, my favorite, i had the chance to buy this a while ago and have used it for the shortened compact crank on a kidsbike build with a 32T chainring
but this is not for sale, nor I do have an idea who has produced it.
Some of those trial bashguards like the one at the Onza cranks from what i can see also at the Cannondale bike, are protecting very small change rings (<30T) mounted than on the inside of of the crank (not the middle position with 94mm BCD but the 58mm inner position).
So if you want an bash guard exactly like the Cannondale you have to run also a very small chain ring only.
E.g. this one is in my opinion too small to protect a chain ring at the middle postion
<p dir="ltr" style="margin-top:0; margin-bottom:0;">This is an old Mission bikes trials bashring, 94bcd fitment. </p> <p dir="ltr" style="margin-top:0; margin-bottom:0;">3mm thick stainless and 118mm outside diameter.</p> <p dir="ltr" style="margin-top:0; margin-bottom:0;">Any questions, please...
www.ebay.co.uk