Attention: TDR Forum Junkies Just received my new VanAlstine Tire Regrooving machine and, BOY is it cool! I learned a lot by talking to "Weir" from VanAlstine. What really sold me is that you can regroove recaps! A lot of times, the recaps are actually thicker than the original tread. Since our septic pumping trucks all utilize recaps, this will be a big money/time saver, since I automatically have fresh tires or recaps installed just before winter if tread depth is less than approximately 3/8" (12/32"). Legal limit is 2/32" on rears, but I never let my trucks get that low for safety/traction reasons.
So the magic question is "how deep can you go"? Well, based on my lengthy discussion with VanAlstine, and from what I've read, you want a minimum of 3/32" between cords and the deepest groove you cut. Depending on the tire manufacturer, and if it's been recapped, that means you can go somewhere between 1/32" deeper than stock, or a whopping 24/32"!!!!!
So, I've been practicing. Been picking up casings on the side of the road, (AKA Road Gators) and bringing them back to the shop. I have found that I can safely groove 8/32" (1/4") deeper than stock groove depth out of any recap that I've found, and still have at least 5/32" before hitting steel belts. I can go much deeper and still be safe on some, but I'm really just looking for the shallowest safe depth, and will use that as my mental "do not exceed" depth!
HOWEVER, that has been on the bigger truck tires. I have one casing that I found that seems to be from a 19. 5" tire (maybe even 16 or 17) that I can only go about 5/32" while leaving 5/32" safety margin.
NEXT, I learned another important lesson. DON'T BUY GEOSTAR TIRES!! Those came stock on our '07 NRR Isuzus. They are 19. 5" due to being a 19,500 GVWR truck. They wear funny, and quickly develop a hopping sensation. One tire I was playing with had 8/32" tread depth on most of the tire and BALD on other parts, along the same tread line! So I cut into it to get some practice and found that once I went 4/32" deep, I hit steel belts!! And these tires say "regroovable" on the side. I'm not sure how anybody could regroove them safely, and it isn't really worth the effort to only trim 1/32" deep and still only leave the MINIMUM 3/32" rubber gap. Never heard of Geostars? Me neither. Made in China, of course. The only regrooving I would consider doing to these is to change the pattern for more traction in the winter, since these tires are very highway oriented. If I still have some on the Isuzus this winter, I will probably do that, and probably set the depth of the cutter to be more shallow than the deepest factory groove, to keep them stable too.
I have pictures of what I've done, but I need my wife to download/upload pics from my phone, since I don't have a rat's *** as to how to do it!!
Regarding the Siper, apparently the guy I talked to forgot to include it or charge me for it. I think he spaced it off since we spent so much time discussing the "science" of grooving and siping. That should be here later this week and I will report on it as well. That machine is basically a tool that holds 1 to 13 razor blades, and heats them up so you can pull them across your tire. Depth is adjustable, although he recommends not going more than 3/16" deep and actually recommends only 1/8".
So the magic question is "how deep can you go"? Well, based on my lengthy discussion with VanAlstine, and from what I've read, you want a minimum of 3/32" between cords and the deepest groove you cut. Depending on the tire manufacturer, and if it's been recapped, that means you can go somewhere between 1/32" deeper than stock, or a whopping 24/32"!!!!!
So, I've been practicing. Been picking up casings on the side of the road, (AKA Road Gators) and bringing them back to the shop. I have found that I can safely groove 8/32" (1/4") deeper than stock groove depth out of any recap that I've found, and still have at least 5/32" before hitting steel belts. I can go much deeper and still be safe on some, but I'm really just looking for the shallowest safe depth, and will use that as my mental "do not exceed" depth!
HOWEVER, that has been on the bigger truck tires. I have one casing that I found that seems to be from a 19. 5" tire (maybe even 16 or 17) that I can only go about 5/32" while leaving 5/32" safety margin.
NEXT, I learned another important lesson. DON'T BUY GEOSTAR TIRES!! Those came stock on our '07 NRR Isuzus. They are 19. 5" due to being a 19,500 GVWR truck. They wear funny, and quickly develop a hopping sensation. One tire I was playing with had 8/32" tread depth on most of the tire and BALD on other parts, along the same tread line! So I cut into it to get some practice and found that once I went 4/32" deep, I hit steel belts!! And these tires say "regroovable" on the side. I'm not sure how anybody could regroove them safely, and it isn't really worth the effort to only trim 1/32" deep and still only leave the MINIMUM 3/32" rubber gap. Never heard of Geostars? Me neither. Made in China, of course. The only regrooving I would consider doing to these is to change the pattern for more traction in the winter, since these tires are very highway oriented. If I still have some on the Isuzus this winter, I will probably do that, and probably set the depth of the cutter to be more shallow than the deepest factory groove, to keep them stable too.
I have pictures of what I've done, but I need my wife to download/upload pics from my phone, since I don't have a rat's *** as to how to do it!!
Regarding the Siper, apparently the guy I talked to forgot to include it or charge me for it. I think he spaced it off since we spent so much time discussing the "science" of grooving and siping. That should be here later this week and I will report on it as well. That machine is basically a tool that holds 1 to 13 razor blades, and heats them up so you can pull them across your tire. Depth is adjustable, although he recommends not going more than 3/16" deep and actually recommends only 1/8".
