Spec'ing a single tire

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Tony
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Re: Spec'ing a single tire

Post by Tony »

Would be nice to see some feedback/data from someone who tried new tires early and late in the season to see if the phenomenon is really over. From what I have heard it is still around.

As to the kickback to the club I would think that it would be incumbent on the organization that wants to impose a spec tire tire to contact the manufacturer rather than to expect the manufacturers to read a somewhat obscure forum and decide to make us an offer. If Bridgestone et al have left the Canadian scene (largely due to the Rotax and obligatory Mojo situation) they might be very interested in a way to return to the market.

I believe that there is a lot of preparatory work to be done before imposing a spec tire, in a size that is not sanctioned by ASNCANADA, on a class. Nobody has even presented the manufacturer's pricing for the various compounds and sizes involved.

In the current economic climate we should be looking to minimize costs to the racer whilst maximizing the performance for the dollar.

If the best tire is the Mojo 7.1 D2 and it is also the most economical then there is absolutely no advantage in mandating its use.

Team 75
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Re: Spec'ing a single tire

Post by Team 75 »

At the end of the season old tires were faster in the Senior Rotax

samk
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Re: Spec'ing a single tire

Post by samk »

Eastern Canada is using Vega Blue for 4-Stroke as well as micro and mini max classes.

I did some quick price checking and on average, Mojos are about $20USD/set more expensive. The Vega blues are softer and I like the idea of a harder tire for the younger classes. MG has a pretty good tire, the Vega didn't seem to fall off as much as the mojos. I know the Vega rains are awesome!

It simply costs too much to switch a club over to a new brand and in this climate, everyone is looking for a deal. As much as I would love to see a different brand, I don't think this year is the one to do it in.

Tony
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Re: Spec'ing a single tire

Post by Tony »

I am not suggesting that we switch over to a new tire for 2016.
My point is that we haven't done our homework to spec a tire at all in 2016.

It has been fairly conclusively demonstrated that 7" tires at 55" width is faster than 6" at 50"
It has not been demonstrated that 7" tires are faster than 6" tires at the same width and compound.

ASN specify the 6" tire rim width for senior four stroke racing, if you travel in Canada you are likely to have to use the narrower 6" rim widths.

No one has contacted the manufacturer(s) to try to lower the price should the club/ region specify a tire. If we do specify a certain tire in 2016 what would the incentive be for that manufacturer to give us a break on pricing for the following year.

The Mojo brand of tire does not work well out of the box and therefore requires practice time to make them fast (while practice is always a good thing it does not come cheap and may not be available to all. It is not clear yet whether this unique to Mojo tires or the same for all brands

Yes 90+% of the club will race on 7" Mojo this year - if the people proposing this as the spec tire think it is the fastest then what is the advantage of making it a requirement?

If we acknowledge that a spec tire potentially lowers costs for all then why not work toward that in 2017 after we have a chance to contact manufacturers and arrange the best possible pricing for our members, on the most suitable brand of tire.

phil
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Re: Spec'ing a single tire

Post by phil »

I don't see how any tire manufacturer would compete with the price of "free" which is what the majority of the four stroke class pays for tires, fresh out of the discard pile. I am not sure the supply will keep up with the demand in the future as the Rotax class are maybe running them a little longer, so we may have to draw from Edmonton. As for the new tires being slower, it really only took two or three sessions to be up to speed, which would be race one on a race day, and then they are good for 1/2 of the season, so I don't see that as any issue at all. I also have not witnessed any tire in the class other than Mojo for a long time, so someone would have to go out of their way in purchasing another brand. The open tire rule was put in to allow competitors to run whatever used tires they may have lying around, not for someone to seek out an advantage by testing 15 different ones to find the fastest. I really don't care at all if we leave it open, but starting a tire war doesn't benefit anyone - especially the club.

Tony
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Re: Spec'ing a single tire

Post by Tony »

I am only guessing here but I would think that two to three sessions equate to two to three heat cycles which may well mean an entire race event - they might be ready for the final by that count; at which point a front runner may well be starting from the back of the pack IF the tires are ready by this stage.
I wonder what percentage of the four stroke class buy their tires from the discard pile, my guess is that it is a minority and no one has suggested here that they should not be allowed to do so in 2016
And I am not suggesting that we start a tire war - want to pick the right tire at the right price should we choose to spec a tire, and on the evidence to date see little need to do that (other than to further reduce the cost of new tires by getting a subsidy from the manufacturer - which we will not be likely to get for 2016.
And even this advantage becomes moot if people are buying tires from the discard pile.

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John Kwong
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Re: Spec'ing a single tire

Post by John Kwong »

The discussion of spec'ing a tire for Briggs was mostly brought up for the Alberta Shoot-Out so that for this year we would have rules uniformity between the two clubs for these particular events. Whether CKRC goes the extra step to change from the current "open" tires rule for Briggs Senior for CKRC club racing remains to be seen. EDKRA switched to 7.1 Mojo D2 and 55" width for their club last year and appear to be happy with the change.

New tires vs scrubbed in or used tires is not night and day performance difference. The Mojo tires are very consistent and last a very long time on our asphalt surface. I would be surprised if someone bought more than two sets of tires for Briggs in a single season. A racer would only have to Pre-Scrub two sets of tires through the season if they chose to.

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Rob Kozakowski
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Re: Spec'ing a single tire

Post by Rob Kozakowski »

Spec tires, where the fastest setup requires buying new tires every weekend is bad because all it takes is for 1 person to start doing that to gain an advantage, then everyone seems to follow suit, and in the end, the race results are the same, but our bank accounts see less cash in them. Is that what we want? I'd argue no.

To date, I think both CKRC and EDKRA have seen several great results with the D2 on the Briggs karts...

(a) there has been no advantage to having brand new tires;
(b) there is an ample supply of used D2 tires from the Rotax karts - whether free or very-near free;
(c) after an initial heat cycle or two, the tires remain very consistent for at least a half season;
(d) the grip levels provided by the D2 have made driving the karts a lot more fun than the D1; and
(e) it has opened up the chassis choices because a used Rotax kart will "work properly" on the D2, where they tended to be at a very real disadvantage with the D1.

At EDKRA, Briggs was new in 2014 and we started out 2014 to ASN spec's (50" width, 6" rear tires) and D1. While my K&K loved that setup, as a CLUB, we quickly realized that formula wasn't attracting people to the class, so mid-season, with the support of all the Briggs racers, we opened the rules up to also allow the D2, at the CKRC spec's (while also allowing the D1, for anyone who wanted to use up tires). That was probably the best decision we have made as a club and that proved itself with the numbers running Briggs at the end of 2014, continued growth in 2015, and the expectation that it will be bigger again in 2016.

In 2015, we continued to provide the option of D1 or D2. For 2016, we are going to D2 only because nobody ran D1 in 2015. That said, if someone shows up with D1, we'll let them race. We'd just rather spec the D2 because we don't want anyone (new or uninformed) to make the "wrong" choice thinking that D1 might be just as good as D2... the worst thing we can do is bring in a new racer, have them spend money on the wrong equipment, and feel they got ripped off... that's the best way to lose a new member just as fast as you gained him/her.

Tony
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Re: Spec'ing a single tire

Post by Tony »

In Calgary many people are reporting that new tires are around 1 (one) second a lap slower than used tires - and well used tires at that. I have heard numbers closer to 1.5 seconds.

This is infinitely better than new tires being even a few tenths faster than lightly used ones which as Rob rightly points out means that in a competitive class to remain that way you have to use new tires each race.

However the situation at Strathmore where new tires were at the end of the 2015 season still being reported as significantly slower than the well used ones that they were replacing is far from ideal. If we are to specify a tire it should be one that is consistent after the first heat cycle (practice on race day) until they are worn out.

Tires from the major manufacturers are built to homologation specs from the karting division of the FiA that are available at www.cikfia,com. They homologate tires for three or four years at a time, and in 2014 changed from requiring a certain elasticity or softness to the compound to mandating that when used on a particular type of kart they should last for a certain number of kilometers without a drop in performance (as I recall it is 150km for the Primes and more for the harder Options). Perhaps it is this change in specs (which are a very good thing and have lead to much lower tire costs at the club level) have lead to the current situation at Strathmore: a combination of the track surface and Mojo rubber compounds leading to them being slow out of the box. It is very possible that another manufacturer's compounds would be more consistent at Strathmore and would be better suited to being the spec tire, as well as being cheaper.

I don't think there is any doubt that Mojos work, but there is a lot of question whether they work well out of the box, scrubbing in an extra set of tires has a significant cost in travel and time. If people want to run Mojo D2 under an open format they can, and I believe that the vast majority of the class will run Mojo D2 at 7"

However while the 7" Mojos work, they don't work within the manufacturers pressure recommendations - so something is going on at the Strathmore track, Are the oils coming out of the asphalt as John suggests (in a track that had already been in the sun and overwintered) or is it the off camber nature of the corners (something that will not change)?

No one has shown that they work the best, nor that they are the cheapest. I think that the all options should be explored before we lock ourselves into a tire for what will likely be many years to come unless the Rotax program changes tire manufacturer again, or there are other supply issues.

A reasonable compromise would be to spec the 7" Mojo D2 tire for the Alberta Series and to leave the tires open for club series points while planning to make a decision for the 2017 season. During that time we can investigate the options including approaching the tire manufacturers / importers to see if we can get better pricing than we have at present.

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John Kwong
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Re: Spec'ing a single tire

Post by John Kwong »

A class meeting will be held prior to the beginning of the season to give the racers a chance to democratically decide what direction they would like to take with the tire rules for this class. For the time being a straw poll has been set-up to get an idea which way the class is leaning.

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