Date sent: Sun, 21 Nov 1999 21:45:12 +1100 From: Kevin Couter To: 80_series@sgiblab.sgi.com Subject: Re: [80] siping tires Send reply to: 80_series@sgiblab.sgi.com Davin Lim wrote: > John Borchers wrote: > > > > All right, I hate to appear so damned ignorant, but what the hell is > > siping?!? That is a verb I am not familiar with, here in AZ. > > Hi John - > > Siping (rhymes with typing) is a process of putting thin cuts into the tread > blocks of the tires, usually in a pattern perpendicular to the direction of > travel. Most siped tires I've seen have the cuts spaced between 1/4" to 1/2" > apart. > > Though it can be done using a sharp utility knife, it's safer to have a tire > shop do this because the machine they use is fast, and can control the depth > with good precision. Typically it only runs $10-$15 per tire, so it's not > worth the hassle to risk doing it yourself. > > The theory behind siping says that it provides a few advantages: > > 1) Increased number of "biting" edges to help aid in snowpack/icy conditions > 2) Increased traction in wet conditions since tendency to hydroplane is > reduced 3) Increased traction on smooth rocky surfaces since tires can more > effectively conform to the surface irregularities. 4) Greater durability due > to better heat dissapation characteristics > > Personally, I have siped tires (BFG AT's) and really like the way the perform. > I believe the claims 1-3 above. In the snow and icy conditions, they're still > not as good as a true dedicated snow tire, but good enough to make me not > worry about general winter driving performance. > > I think the greater durability argurment has yet to be definitively proven. > Some people swear that siping makes tires last longer, while others claim it > makes the tires more vulnerable to "chunking". My own experience says the > durability is just fine, but have no hard data to know if it's better or worse > than non-siped tires. > > -Davin You left out how Mr Sipe invented / developed / originated it! From: "Willem-Jan Markerink" To: 80_series@sgiblab.sgi.com Date sent: Sun, 21 Nov 1999 19:20:47 +0100 Subject: Re: [80] siping tires Send reply to: 80_series@sgiblab.sgi.com On 21 Nov 99 at 21:45, Kevin Couter wrote: > You left out how Mr Sipe invented / developed / originated it! On a shoe, in a Chicago butchery, no less....8-)) The odd thing is that in Europe nobody knows it by that name....in both Dutch and German it is called 'lamellen' (same as for blinds in front of a window). Not sure what name Pommies use.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] From: "Willem-Jan Markerink" To: 80_series@sgiblab.sgi.com Date sent: Sat, 20 Nov 1999 20:25:59 +0100 Subject: Re: [80] siping tires [chat] Send reply to: 80_series@sgiblab.sgi.com On 19 Nov 99 at 23:23, Doug Miller wrote: > I'm no tire engineer, but I do know enough that siping is not a freebie > improvement that the tire companies don't know about. The claim for > improved life is very tough for me to swallow. Siping tread blocks allows > them to squirm around more than the engineer designed. This movement is > wasted energy, and the energy manifests itself in more heat and wear. No, it's the squirming inside a solid block that creates heat....siping make the block conform better to the road, with less heat production. All reports I have seen sofar indicate less wear, and this includes fleet-owner reports from government agencies. For them it's simply a matter of cost. Tires > do come from the factory with siping, but it's often at all angles and would > be impossible to duplicate on a siping machine. You can sipe twice, once 30 degree from one end, and a second time 30 degree from the other side. Still not a true winter-tire zigzag-sawtooth pattern, but always better than a solid block that acts as a piece of soap. -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] Date sent: Sat, 20 Nov 1999 17:42:08 -0700 From: "Davin Lim" To: 80_series@sgiblab.sgi.com Subject: Re: [80] siping tires [chat] Send reply to: 80_series@sgiblab.sgi.com Willem-Jan Markerink wrote: > > On 19 Nov 99 at 23:23, Doug Miller wrote> > > I'm no tire engineer, but I do know enough that siping is not a freebie > > improvement that the tire companies don't know about. The claim for > > improved life is very tough for me to swallow. Siping tread blocks allows > > them to squirm around more than the engineer designed. This movement is > > wasted energy, and the energy manifests itself in more heat and wear. > > No, it's the squirming inside a solid block that creates > heat....siping make the block conform better to the road, with less > heat production. All reports I have seen sofar indicate less wear, > and this includes fleet-owner reports from government agencies. > For them it's simply a matter of cost. Here's a another *very* anectodatal piece of information regarding tread wear and siping. Again, I'm still a bit skeptical about the the possibility of treadwear being *improved* with siping, but here's the information anyways: A friend of mine has an equipment sponsorship by the company that makes the BFG tires (isn't it Michelin?). Since he gets his tires for free, he's able to experiment with things more easily than you or I. A coupl of years back, he had a each of three tires in a new set of four MTs (285-75R16's) siped at different depths varying from 1/8" to 3/8", and left one unsiped. He rotated his tires every 500-1000 miles. He guesses his driving was about 65% of mileage on road, 35% of mileage off-road, whereas the actual *time* spent off road was about about the 60% off road, 40% on road. He measured tread depth at each tire rotation. According to him (and I cannot verify the results, though I have no reason to believe he'd falsify results) the tire that wore to within 1/16" of the wear bars the first was the un-siped tire. The wear levels of the other three went from the 1/8" siped (most wear except for the unsiped tire) to the 3/8" siped tire (least wear incurred). I don't know how close the measurements were, so take this all with a large grain of salt as the experiement wasn't done under the most rigorous conditions. Do I believe this result is indicative of what we should all expect from siping? At this point, though I believe what my friend told me is in fact what he observed, I am still skeptical until more scientific results can be given. Like I said in an eariler email, I *do* sipe my tires and like how they perform, but am unwilling to make too many broad generalizations about the benefits of doing so. -Davin (skeptic at large...) To: Volvo303@yahoogroups.com Cc: Claes Hellbom From: "Willem-Jan Markerink" Date: Sun, 26 Mar 2006 20:17:57 +0200 Subject: [Volvo303] Tire-siping on a 6x6 with Suregrip or Trelleborg? (& tire-recovers, & bolt-centric vs hub-centric balancing) Reply-To: Volvo303@yahoogroups.com Just curious: Anyone experience with tire-siping on a Goodyear Suregrip or Trelleborg Cross Country? When investigating the concept of tire-siping[*] about 10 years ago, at the US-manufacturer, I learned that in Europe there were only a few machines located in Scandinavia, none elsewhere. So, now that I learned that I finally can have this same service done in Holland (hurray!), I was curious whether anyone in Sweden/Norway/Finland had (heard from) siping experiences with either Goodyear Suregrip or Trelleborg Cross Country. My main curiosity is whether it also has a significant effect on tire- noise, one of the least discussed aspects of tire-siping....grip, heat and wear are normally the main arguments, in descending order, noise is hardly ever mentioned, while that too is an inherent physical aspect in this context....just not sure how significant it could be, especially not since the Trelleborg seems already an improvement over the Goodyear.... Any comments or experiences? Also in the context of a 6x6 application, where the rear tires are much more subject to twisting? (question being: would tire wear then decrease or even increase?....:)) [*] cutting slits/sipes/lamellen into a tire with a machine (not the hand-grooving/hot-iron method!), even in a different/better pattern/way than a tire-manufacturer could in the normal molding process, see also http://www.sipers.com PS (winter)tires!: probably also have found a good lead on a small- scale tire-recover option in Holland, based on the Michelin XZL 9.00x16....a set of recovers in the same XZL-pattern has already been produced (for half the price of a new XZL!), and through some more European contacts I even know who the actual tire-manufacturer is....one that has had several winter-tire recover options in its program for years, but only for the larger truck sizes, 20" and taller. (have been trying to get a grip on who did the road/winter-tire recovers that are typical for some Swedish firefighters, but now I might have found the actual source (if not produced in Sweden itself)) (not sure yet if they can produce every thread-pattern of winter- tire, my personal favorite is the older generation Cooper Weathermaster, with plenty of voids (openings) between the (zigzag- siped) blocks (always hated the closely packed wintertires that stand no chance in deep slush), magnificent low wear, and still capable of climbing up icy hills where a pedestrian falls on his butt....:)) PPS: through the same source, I learned that at least for 6-bolt Land Cruiser rims, I finally can have those balanced on a bolt-centric machine, instead of the usual hub-centric....so my next research is finding out if they have an adapter for the 8-bolt Volvo rim as well....;)) (probably far less critical, spinning at a much lower speed, but since the tire itself is much heavier, *and* larger, it could still improve) (the person/vehicle in question still uses balancing-powder in addition to all that, another option in this balancing context (some use granulate, some very large tires even golfballs I believe, and the powder must be inserted through a special (temporarily) valve)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] To: Volvo303@yahoogroups.com From: Phil Movish Date: Mon, 27 Mar 2006 07:17:21 -0800 (PST) Subject: Re: [Volvo303] Tire-siping on a 6x6 with Suregrip or Trelleborg? (& tire-recovers, & bolt-centric vs hub-centric balancing) Reply-To: Volvo303@yahoogroups.com I would be careful having aggressive tires siped. I once had a set of BFG AT's siped at the time of purchase. They were fitted on a Jeep Grand Cherokee Ltd with full-time 4WD and a limited slip rear end. Simply put, it became a very dangerous vehicle to drive and brake at highway speeds, which I attribute to the siping. I don't know whether or not the full-time 4wd and limited slip diff contributed to the white knuckle problem ( it drove perfectly with the lousy Goodyear Wranglers the BFGs replaced), but I would be careful blindly modifying the tire design via siping without getting some info as the performance from those who have siped the tire of interest. To: Volvo303@yahoogroups.com From: "Willem-Jan Markerink" Date: Mon, 27 Mar 2006 18:00:12 +0200 Subject: Re: [Volvo303] Tire-siping on a 6x6 with Suregrip or Trelleborg? (& tire-recovers, & bolt-centric vs hub-centric balancing) Reply-To: Volvo303@yahoogroups.com On 27 Mar 2006 at 7:17, Phil Movish wrote: > I would be careful having aggressive tires siped. I once had a set of > BFG AT's siped at the time of purchase. They were fitted on a Jeep > Grand Cherokee Ltd with full-time 4WD and a limited slip rear end. > Simply put, it became a very dangerous vehicle to drive and brake at > highway speeds, which I attribute to the siping. I don't know whether > or not the full-time 4wd and limited slip diff contributed to the > white knuckle problem ( it drove perfectly with the lousy Goodyear > Wranglers the BFGs replaced), but I would be careful blindly modifying > the tire design via siping without getting some info as the > performance from those who have siped the tire of interest. Well yes, that was the purpose of my posting....:)) (but more to learn about noise improvement, and whether the wear- argument still holds on the rear wheels of a 6x6 application) But if nobody has ever done this on a Suregrip nor Trelleborg, then there is no other option than playing the guinnee pig....')) However, the danger in your sample is that the siping was done at the time of first-mounting, so no proof that the non-siped tires would have done much better. Nor would I ever consider AT's as 'aggressive'....;)) (my Cooper Weathermasters might have a better void-to-lug/block ratio....) And the concensus about siping aggressive, solid-block tires, is that it is the best thing ever done in the wet/snow/ice grip department....from scary white knuckle behaviour to somewhat predictable....much more improvement than with normal tires. Btw, fulltime-4wd can theoretical become a argument/problem, when converting a parttime-4wd to fulltime....the toe-in setting of the front wheels is different, fulltime front wheels pull, while parttime front wheels are normally pushed (hence needing more toe-in). -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] To: Volvo303@yahoogroups.com From: David Giller Date: Mon, 27 Mar 2006 10:40:54 -0800 Subject: Re: [Volvo303] Tire-siping on a 6x6 with Suregrip or Trelleborg? (& tire-recovers, & bolt-centric vs hub-centric balancing) Reply-To: Volvo303@yahoogroups.com On Mar 27, 2006, at 7:17 AM, Phil Movish wrote: > I would be careful having aggressive tires siped. I once had a set > of BFG AT's siped at the time of purchase. They were fitted on a > Jeep Grand Cherokee Ltd with full-time 4WD and a limited slip rear > end. Simply put, it became a very dangerous vehicle to drive and > brake at highway speeds, which I attribute to the siping. I don't > know whether or not the full-time 4wd and limited slip diff > contributed to the white knuckle problem ( it drove perfectly with > the lousy Goodyear Wranglers the BFGs replaced), but I would be > careful blindly modifying the tire design via siping without > getting some info as the performance from those who have siped the > tire of interest. > ... > I wouldn't consider myself a tire 'expert', but I am a big believer of siping, especially on aggressive tires. But by 'aggressive', I think of MT tires with big, solid lugs like the Volvo stockers, BFG MTs, or your common Super Swamper. I've used siping on my local- brand MT tires on my Range Rover, and the tires are excellent performers. They find any grip that is to be had off-road, and run more quietly on-road than they did before being siped. I've got somewhere around 20k+ miles on them and they still have at least 80% tread left. BFG AT tires have a tread pattern that I wouldn't feel comfortable siping. The blocks aren't square, and they already have 'siping' molded into the tires at many angles. Since it's effectively already siped (which is a good thing), I wouldn't think you would get any more benefit from the dealer-cut siping. In fact, it makes sense to me that you were unhappy with the results... after being cut, those tires would basically have a bunch of 1/4" lugs, with little support in any direction. Solid-lug tires, when siped, don't seem to lose lateral stability, and the longitudinal fold-over of the siped lugs seems to actually help traction and treadwear. On the BFG ATs, I can see how the siping might have caused your bad results. I'd consider that the BFG is probably a special case that shouldn't ever be siped. To answer the original question, I'd expect that siping would work fine on all locations of the 6x6, and slightly improve tire longevity. Standard siping (90 degrees to the tread) probably won't affect the rear axle scrub at all, positively or negatively. If you were somehow able to sipe at a 45-degree angle, it might improve rear tire wear due to turning scrub, but that would be a speculation. It also might hurt lateral stability during braking. As far as noise is concerned, I can't speak directly to the Suregrip or Trelleborg tires. But I've found noticeable reduction in tread noise with at least several kinds of mud-type tire when siping, and if it were me, I would take the chance. Cheers, Dave