Tires.... discussing tread types & patterns.

[BajaRon]

I know. A very overworked subject. My hope is that by taking some of the confusion out of the equation. Everyone will have a better understanding of what they should be looking for and not have to rely on someone else's opinion.

The Spyder and Ryker machines are special animals in may ways. This is very true when talking about tires. I hope this is a help.

The following only applies if we have gotten past the ever present Car Tire vs. Motorcycle Tire discussion.

There are 4 basic tire tread designs.

Symmetric is just another way of saying 'The Same'. This tread pattern is the most common. This tread may be the same all the way across. Or, looking from the center of the tread, each half is a mirror image of the other.. This allows tire rotation in either direction and does not require dismount/remount if you move from one side of the vehicle to the other. These are NOT 'Directional'.
Tire2.jpg
Though these may not be ideal for the Spyder/Ryker. They will work on both the front and rear of these bikes and can be mounted to run in either direction.

Asymmetric is just another way of saying, 'Not The Same'. Where the tread pattern changes across the face of the tire. There are many reasons for this but one of the main ones is to give a stiffer construction to the outside of the tire (which takes the most abuse in turns) to increase cornering stability. This design also allows for tire rotation without dismount, remount as they are not 'Directional'. These can also be run in either direction. But they must be mounted so that the side designed to be on the outside is correctly oriented.
Tire1.jpg
Asymmetric tires can work well on the front of the Spyder/Ryker. But not on the rear. When mounted on a single rear wheel. The back of the bike will corner better in one direction than it will in the other. This is not a good idea for a Spyder/Ryker rear tire.

Directional or Unidirectional tread is designed to roll in only one direction. It will be a mirror image as looking from the center of the tread. Usually incorporating a distinct 'V' pattern. This design is engineered to enhance hydroplaning resistance by moving water away from the tire more efficiently than most other tread designs. These must be dismounted/remounted on the wheel if you want to rotate them to the other side of the vehicle. Like the Asymmetric tire. These must be mounted for correct orientation.
Tire3.jpg
Generally speaking. This design gives the best traction in wet and standing water situations. Though there are a few non-directional tires which will also give excellent wet traction.

Tires which are both Asymmetric and Directional generally will incorporate some form of the 'V' pattern above. But it is offset to one side of the tire tread. These are typically special application tires. I don't know of any that will fit the Spyder or Ryker stock wheels so I did not include a picture.

General 'Rules of Thumb'

Typically, you will trade improved traction (especially wet traction) for a higher mileage tire. A long lasting tire has to use a harder compound which will not grip the roadway as well.

I do not recommend 'Summer' tires in any format for the Spyder/Ryker. Unless you are only going to be riding when pavement is 70 degrees or above. Once the pavement begins to cool, (especially as these summer tires begin to wear) they tend to get slick. It is not so dramatic in a car because of the additional weight. With the relatively light Spyder (especially in the rear) the difference can be pretty dramatic.

If you ride when the pavement is 40 degrees or less, Summer Tires can be very slick, no matter how good or dry the pavement is. This tire compound is specifically designed to give extremely good traction with warm or hot pavement. They are a 1 trick pony. For most of us, we need a good 'All Season' tire.

At the very least. If you're running a 'Summer' tire. Be aware of these tendencies.

[BLUEKNIGHT911]

Thanks Ron for that dissertation ...... However you left out the most important factor concerning Auto tires & Spyders/Rykers. .... Let me simplify it for the readers. From what my schooling & training (concerning tires) has taught me .... The single MOST important factor is ....PSI .... There are quality tires, mediocre tires, and then there are terrible tires - ie. Kenda tires, which have weakly constructed casings. Tires are basically TWO parts, the tread and the casing. The casing construction plays a large part in how the tread will wear.... If the Casing is weak - the tire will balloon at relatively low speeds. This is why the Kenda/Kanine's have Abnormal wear in the center of the tread.... PSI is not really a factor in this wear, only the Casing is a factor. As far as today's Auto tires goes (used for a Spyder/Ryker) ... the real difference between High end and Lower end tires isn't as much as one would think. The real difference might be 3%. .... And the tires cost isn't any guarantee of performance. To sum up ... Nobody has RACE quality tires on their Spyders or Rykers .... WHY - because they aren't available in our sizes .... Tread pattern has such a small effect - one would need very sophisticated equipment to separate one style from another ... What matters Most is the PSI you use in them (Auto tires)....... Good luck, ride safe - ride happy ..... Mike

[Peacekeeper6]

I know the tread patterns of both Continental DWS 06 and Michelin Cross Climate when I see them. The other tire, I have no clue.

Very informative and educational post, BR.

[Little Blue]

....First off Thank You, BajaRon.

The Tire information was right on.
I am sure many people will have a better idea
of what tire(s) to choose for their Spyder.

I have learned a lot more about tires on this Forum.
So again 'Thank You'.

Stay Healthy. ....

[Jetfixer]

This should be a sticky.

[CloverHillCrawler]

Ron with the directional tire you state...

"I do not recommend 'Summer' tires in any format for the Spyder/Ryker. Unless you are only going to be riding when pavement is 70 degrees or above. Once the pavement begins to cool, (especially as these summer tires begin to wear) they tend to get slick. If you ride when the pavement is 40 degrees or less, they can be very slick, no matter how good or dry the pavement is. This tire compound is specifically designed to give extremely good traction with warm or hot pavement. They are a 1 trick pony. For most of us, we need a good 'All Season' tire."

Does this mean I should be pulling off my Quatrac's for winter? I was under the impression that the Quatrac's were a good "all season" tire that performed well under hot and cold conditions and they have a directional V tread pattern.

[lvmyspyder]

Thanks Ron, always great information from you. Ron and Forum - I know there are a lot of tire discussions that go on, but it is one discussion point that matters. I see where some are running a 225 60 15, not a 215 60 15 tire, specifically the General Altimax RT43. I got the RT45 after much deliberation, research etc. I did get it in the 225 60 15 size after comparing it with the current current OEM Kenda, which IMHO is a terrible product, both front and rear. Fronts came off with less than 500 miles, such a waste, but definitely one of the must do things to make this machine behave as it should and can.

Knowing many favor the 215 width, for those of you who are running the 225 60 15 in that tire, are you noticing any fitment issue? From what I can see and measurements taken, that size will fit fine on my '18 Spyder RT. I would like your real world experience of running that 225 60 series and what your bike is. Much obliged...

[BajaRon]

Ron with the directional tire you state...

"I do not recommend 'Summer' tires in any format for the Spyder/Ryker. Unless you are only going to be riding when pavement is 70 degrees or above. Once the pavement begins to cool, (especially as these summer tires begin to wear) they tend to get slick. If you ride when the pavement is 40 degrees or less, they can be very slick, no matter how good or dry the pavement is. This tire compound is specifically designed to give extremely good traction with warm or hot pavement. They are a 1 trick pony. For most of us, we need a good 'All Season' tire."

Does this mean I should be pulling off my Quatrac's for winter? I was under the impression that the Quatrac's were a good "all season" tire that performed well under hot and cold conditions and they have a directional V tread pattern.

The Veredestein Quatrac is an 'All Season' tire. And one of the better choices for the Spyder/Ryker, in my opinion. You're good to go all year around with that tire. The Quatrac is also pretty good in light snow. Though I don't recommend riding any motorcycle in snow. But if you do, let us know how it goes!

Thanks Ron, always great information from you. Ron and Forum - I know there are a lot of tire discussions that go on, but it is one discussion point that matters. I see where some are running a 225 60 15, not a 215 60 15 tire, specifically the General Altimax RT43. I got the RT45 after much deliberation, research etc. I did get it in the 225 60 15 size after comparing it with the current current OEM Kenda, which IMHO is a terrible product, both front and rear. Fronts came off with less than 500 miles, such a waste, but definitely one of the must do things to make this machine behave as it should and can.

Knowing many favor the 215 width, for those of you who are running the 225 60 15 in that tire, are you noticing any fitment issue? From what I can see and measurements taken, that size will fit fine on my '18 Spyder RT. I would like your real world experience of running that 225 60 series and what your bike is. Much obliged...

The 215/60r15 is a little bit taller and a little bit narrower than OEM. Diameter is increased about 5.5%, width is reduced by 3/8". There are many reasons for going with a car tire. The main selling point of a car tire is the very low quality of the OEM Kenda. Getting a slighty larger diameter tire also works to make the speedometer more accurate.
Tire5.jpg

The 225/60r15 retains OEM tire width while increasing diameter by about 1-3/4" (A bit over 7%). Some don't want that much change. I do not have any personal experience with this tire size. But I have not heard anything negative about running it.
Tire4.jpg

Some customers have complained of fuel mileage decrease with the new rear tire. You have to understand that your measured Miles Per Gallon will decrease by at least the percentage of increase in rear tire diameter. In other words. If you increase tire diameter by 7%. Your odometer will read 7% fewer miles than it did with the OEM tire. In any case. The only way to get an accurate MPG is with a GPS as it reports actual miles traveled. Whereas the rear wheel only calculates miles traveled by counting tire revolutions.

[missouriboy]

BajaRon:

This allows tire rotation in either direction and does not require dismount/remount if you move from one side of the vehicle to the other. These are NOT 'Directional'.

When radial tires first hit the market, the recommendation was to never rotate them side to side, because once they are "broken-in" to a given direction they should continue in that direction for the life of the tire. Has that admonition gone away now with more modern radial tires?

[Peteoz]

Thanks for enlightening this little black duck, Ron……well there you go……I never gave it much thought, as I have never bought one, but I have to admit that I always thought asymmetric tyres were directional tyres to help shed water, rather than for added strength. You learn something new every day.

Pete

[IdahoMtnSpyder]

BajaRon:When radial tires first hit the market, the recommendation was to never rotate them side to side, because once they are "broken-in" to a given direction they should continue in that direction for the life of the tire. Has that admonition gone away now with more modern radial tires?

I can't say for sure, but I think it went away 30 or 40 years ago. I first used radials 55 years ago. That was the admonition back then.

[CloverHillCrawler]

The Veredestein Quatrac is an 'All Season' tire. And one of the better choices for the Spyder/Ryker, in my opinion. You're good to go all year around with that tire. The Quatrac is also pretty good in light snow. Though I don't recommend riding any motorcycle in snow. But if you do, let us know how it goes!

Can't tell you about snow as I live in an area that the road treatment destroys cars so the Crawler never sees the road once the treatment goes out on the roads and stays off until a couple of rains after the last treatment.

But the quatracs do handle wet packed sand quite well. I took it out on the beach at night just north of OC Md. Oct 14 ,where the sand was packed down by the tide so I could enjoy a smoke before continuing on with my ride on the coastal highway.

The crawler got a good bath after being in OC for the weekend to wash off the salt and sand.

[BajaRon]

Thanks for enlightening this little black duck, Ron……well there you go……I never gave it much thought, as I have never bought one, but I have to admit that I always thought asymmetric tyres were directional tyres to help shed water, rather than for added strength. You learn something new every day.

Pete

Most directional tires are considered symmetrical (as is the tire I used to represent that category) But you are correct, an Asymmetric tire (whether directional or not) attempts to combine improved water shedding with a stiffer outside tread area to improve handling. I highlighted the reason I would not recommend this tread type on the rear of the Spyder or Ryker without addressing other attributes. This is why, for the front of our rides, an appropriately sized asymmetric tire could be a good choice. But there is also tire compounds to consider. Which is something that we only lightly touched on.

Just know that a directional tire cannot be moved to the other side of the vehicle without dismount/remount because it must always spin in the same direction. Whereas, an asymmetric tire, while needing to be mounted with correct orientation on the wheel, can be moved to either side of the vehicle without dismount/remount. An asymmetric tire does not care which way it spins.

BajaRon:When radial tires first hit the market, the recommendation was to never rotate them side to side, because once they are "broken-in" to a given direction they should continue in that direction for the life of the tire. Has that admonition gone away now with more modern radial tires?

There is a lot about tires that I have not attempted to cover. I wanted to keep it simple. At least for the first post. But like other subjects. It can get pretty deep. There are a number of things that were once true. But are no longer. This is one of them.

But you are correct. Early radial tires suffered from cord separation when moved to the other side of the vehicle. This cased them to rotate in the opposite direction and there were failures. But this issue has been solved for a very long time. Radial tires, depending on tread design, can be rotated without issue. The reason you don't want to move a directional tire to the other side without remounting to the wheel has nothing to do with cord separation. But because the tread is designed to give best performance in one direction. Turning it around would give very poor performance.

[Peter Aawen]

BajaRon:When radial tires first hit the market, the recommendation was to never rotate them side to side, because once they are "broken-in" to a given direction they should continue in that direction for the life of the tire. Has that admonition gone away now with more modern radial tires?

I can't say for sure, but I think it went away 30 or 40 years ago. I first used radials 55 years ago. That was the admonition back then.

.....

Most directional tires are considered symmetrical (as is the tire I used to represent that category) But you are correct, an Asymmetric tire (whether directional or not) attempts to combine improved water shedding with a stiffer outside tread area to improve handling. I highlighted the reason I would not recommend this tread type on the rear of the Spyder or Ryker without addressing other attributes. This is why, for the front of our rides, an appropriately sized asymmetric tire could be a good choice. But there is also tire compounds to consider. Which is something that we only lightly touched on

Just know that a directional tire cannot be moved to the other side of the vehicle without dismount/remount because it must always spin in the same direction. Whereas, an asymmetric tire, while needing to be mounted with correct orientation on the wheel, can be moved to either side of the vehicle without dismount/remount. An asymmetric tire does not care which way it spins.

......

There is a lot about tires that I have not attempted to cover. I wanted to keep it simple. At least for the first post. But like other subjects. It can get pretty deep. There are a number of things that were once true. But are no longer. This is one of them.

But you are correct. Early radial tires suffered from cord separation when moved to the other side of the vehicle. This cased them to rotate in the opposite direction and there were failures. But this issue has been solved for a very long time. Radial tires, depending on tread design, can be rotated without issue. The reason you don't want to move a directional tire to the other side without remounting to the wheel has nothing to do with cord separation. But because the tread is designed to give best performance in one direction. Turning it around would give very poor performance.

As has been mentioned above, that 'don't swap sides & the direction of rotation of your radial tires' thing has largely been overcome years ago; but as has also been mentioned, any discussion on tires can get pretty deep pretty quickly, and aside from the 'now not such an issue' cord separation thing, there are other reasons that you might want to at least consider carefully before just swapping your wheels across to the other side & thereby making them rotate the other way, and this applies particularly for tires that are lightly constructed &/or have errm.... let's just say 'less than the most robust' of tread support plies, like some OEM tires that all of us here should know of & many of us might dislike or even loathe!!

Once you've started wearing a tires' tread with it rotating in any one direction, it will create a 'set' in the wear on the tread blocks, and if this wear has been allowed to 'set in' for a reasonable length of time/saaaay, 500 or so miles, then it's gonna take a loooong time for that 'set' in the wear & any 'packing down' of the tread blocks to be 'worn out of/off the tread blocks', if that ever can be done on that tire!! And in the meantime, the ride & handling delivered by that tire is not going to be as 'nice or good/safe' as it really should be!! Usually, at least the comfort & feel of the ride will be verrry noticeably poorer; the safety thing, possibly not so obvious.... until you really need it!!

Still, with a modern radial tire, while swapping sides without flipping on the rim shouldn't be anywhere near as dangerous as it was back in the early days of radial tires, when many people persisted in running the same sort of pressures in their radials as they were used to running in their cross-ply tires (can you see anything familiar in this yet?? ) if you are running pressures that are heading up towards the top of or even over the ideal pressure range for that tire & the way you are using it under the load you are asking it to carry, it can be pretty uncomfortable at best & at the other end of the scale, because of its less than ideal contact with the road surface &/or in less than ideal conditions, it can even be somewhat dangerous! And it can continue to be like that for a verrrry looong time/many thousands of miles!

So it's still not an ideal thing to do, altho it's waaaay less of an issue down to an almost minimal concern on good quality well constructed modern radial auto tires than it is on any tires that are lightly constructed &/or have errm.... let's just say 'less than the most robust' of tread support plies &/or not so well made tires, especially if they're being run outside the usual limit of their ideal pressure range for their use/the load they're carrying etc! . So unless you're running some of those good quality well constructed modern radial auto tires, you still might want to consider things carefully before just swapping front wheels across to the other side without flipping them on the rims!

Hopefully that hasn't gone too far down the rabbit hole for anyone, cos it's reaaallly easy to get carried away in the subject, something that Ron really didn't want to do & a wish that I've tried to comply with in this little lot!

Ps: there are quite a few asymetrical treaded tires that have a traditional non-directional carcass with matching strength sidewalls & tread materials, so it's not always an issue to run an asymetrical tire on the rear of a Spyder, even if they might have an 'Inside' &/or an 'Outside' marked on their sidewalls - but you should check for that sidewall strength thing & any issues with even traction delivery before buying, because as Ron mentioned, those that do have one stiffer sidewall or differing 'thrust' &/or traction levels across the tread pattern/face can make your cornering more than just a little iffy when run on the rear of your Spyder!! It's juust not ALWAYS the case, and some asymetrical tires can work really well on any Spyder's rear end!

[lvmyspyder]

Know there is a lot of conversations about tires on this site and especially since the OEM Kenda tires leave so much to be desired.

I have appreciated the information share on this thread. It has made me realize that just because something might fit and its a good replacement, there are other things to consider besides just the fitment and why I will be sending back the 225 60 series if I can and getting the 215 60 series to true up the speedometer. It's also function rather than just form and even though I was looking at the stock width and would like to keep that, 3/8's is not much to give up to true up the speedometer and shrink that height and circumference a bit. Gaining that 1.75" in circumference seems a bit excessive looking at those size comparisons now as well.

Appreciate the information. Thanks much.

[BLUEKNIGHT911]

Know there is a lot of conversations about tires on this site and especially since the OEM Kenda tires leave so much to be desired.

I have appreciated the information share on this thread. It has made me realize that just because something might fit and its a good replacement, there are other things to consider besides just the fitment and why I will be sending back the 225 60 series if I can and getting the 215 60 series to true up the speedometer. It's also function rather than just form and even though I was looking at the stock width and would like to keep that, 3/8's is not much to give up to true up the speedometer and shrink that height and circumference a bit. Gaining that 1.75" in circumference seems a bit excessive looking at those size comparisons now as well.

Appreciate the information. Thanks much.

IMO, For the perceived benefit from what you are thinking of doing. It will be a waste of both time and money..... But it's Your Time & Your Money. Years ago Danicka Patrick ( the Race car driver ) owned a Spyder ( maybe She still does ?? ) .... I seriously doubt even She could tell the difference unless She read the tire sidewall. My opinion on the Total garbage Kenda's has always been - ride it until it wears out then re-place with an Auto tire, if you can ...... good luck.... Mike

[USAF]

I will be sending back the 225 60 series if I can and getting the 215 60 series to true up the speedometer. It's also function rather than just form and even though I was looking at the stock width and would like to keep that, 3/8's is not much to give up to true up the speedometer and shrink that height and circumference a bit

I didnt know the speedometer is not correct on the Spyders, So you are saying my 22 RTL is not accurate ? and if so, how far off ?

[rjinaz86323]

Thanks Ron, always great information from you. Ron and Forum - I know there are a lot of tire discussions that go on, but it is one discussion point that matters. I see where some are running a 225 60 15, not a 215 60 15 tire, specifically the General Altimax RT43. I got the RT45 after much deliberation, research etc. I did get it in the 225 60 15 size after comparing it with the current current OEM Kenda, which IMHO is a terrible product, both front and rear. Fronts came off with less than 500 miles, such a waste, but definitely one of the must do things to make this machine behave as it should and can.

Knowing many favor the 215 width, for those of you who are running the 225 60 15 in that tire, are you noticing any fitment issue? From what I can see and measurements taken, that size will fit fine on my '18 Spyder RT. I would like your real world experience of running that 225 60 series and what your bike is. Much obliged...

I have been running the General Altimax RT43 SL 225/60R-15 for almost a year on my 2018 F3 Limited. It has made 3 multi-day trips (2 were 2 up), which includes a fair amount of gear in the cases. I run them at 20PSI. I have not noticed any undesirable issues with this tire. It also makes my speedometer almost perfect to my actual speed. I live in Arizona, so they are exposed to some pretty high temps, but also include a lot of mountain riding so also some fairly cold temps.

[lvmyspyder]

Hey Mike, I appreciate your comments and insight on this forum and your last on this thread. I am pretty anal retentive when it comes to my Spyder and if I can eek out any degree of "betterment" on this machine, its a good use of time. I will be on on that rear tire for a while and if I can dial in the speedo closer to actual by going the 215 versus the 225, it will be worth the effort, or even if I have to order the other tire and try and sell that 225. In my head I was thinking stock width, that's a plus and its only slightly more than 3/4 of an inch on either side front to back - good to go...

On the fronts, the Kenda's had to go as no amount of effort with balancing, beads, air adjustments would make them run true.

I did as you suggest run the OEM Kenda on the back since new and have almost 10K on it now and it has another season in it definitely, but investing in a better tire at this point, the value of doing so will be there. It will also take a bit of doing to swap that out, so may as well optimize that effort for sure.

I agree with you though, other than the speedo and difference there as a visual, running the 225 versus the 215 would most likely be imperceptible.

Appreciate this forum, the input, experience and recommendations. I know my bike is the better for it. Quite frankly, I would have sold it the first Summer, but one of the members of this forum talked me into giving it a chance and no matter what else he had going on, always went out of his way to help with awesome guidance and recommendations and now I can't wait to get on this bike and ride it and I do at every opportunity. I have a 2008 BMW M3 that I positively adore, but since this bike continues to get better that car sits more and more.

[Peter Aawen]

I didnt know the speedometer is not correct on the Spyders, So you are saying my 22 RTL is not accurate ? and if so, how far off ?

If you are cstill running OEM Tires, then there's a good chance that your car speedo (& odometer, trip meter) is off too!

It's due to an International Agreement between governments, vehicle, & tire manufacturers et all (maybe in order to ensure that they can never be held accountable for some driver inadvertently speeding? ) that when they leave the factory, all vehicle speedo/odo's will read optimistically, ie faster than the vehicle's true speed/more than true miles travelled by anything up to about 10%, but they will never read slower/more than true speed/miles when they leave the factory on OEM tires run at OE specified pressures!! This is because (& I'm using my words to paraphrase a whole lot of weasel wording legal speak here ) it'd be to hard (more likely expensive! ) for manufacturers to make/use/install & test to confirm accurate speedos & odometers!

So the speedo/odo's on new vehicles are all made to read like that, only due to the number of potential variables involved, your Spyder &/or car's specific speedo/odo discrepancy will be showing your travelling faster than true/more miles than true with varying degrees of accuracy! Things like the ambient temperature, tire pressure, but& even variations in tire manufacture will change the EXACT amount that your speedo/odo is out by, but it WILL be out at least a little unless you've increased the rolling dia over that of the OEM tires, and it can be out by as much as about 10% (I think that right now, the 'allowed discrepancy' is actually something like 'up to 10% + 4kmh at an indicated 100kph') ie, you might THINK you're doing 100 kph cos that's what your speedo shows, but your true speed is anything up to 10% plus 4kmh slower, or 14 kph LESS than that - & possibly only 86kph! And your odometer/trip meter distance travelled can be similarly optimistic, but due to manufacturing tolerances, it might not necessarily be exactly the same discrepancy, just something within that range......

So if you ever wonder about how all those other vehicles passing you all the time apparently never get pulled over for speeding, it could well be that they weren't actually speeding, instead it's just that their speedo is a little (or a lottle! ) more accurate than yours!

And then there's the variation in actual tire sizes between the Nominal size printed on the sidewall, and their true/actual size to contend with too! Those OEM Kendas tend to be even more on the small side than most, and that doesn't help the 'accurate gauges/meters' case much, but it does mean that you probably don't need to return that 225/60 series tire lvmyspyder, cos it too will be making your speedo/odo more accurate than it was when you had the OEM 225/50 fitted! (or was it OEM 55?? Duz'n matta! ) As Mike said, there's probably very little real difference in looks, OR in your final speedo/odo accuracy between it & any 215/60 you'd replace it with anyway!! Either size will be better/more accurate than the OEM tire, and every other difference is small enough not to be of any significant concern, IF you even notice it!!

So for now, you really don't need to return/swap/sell the 225/60 if you already have, you really can run it safely in the knowledge that your speedo/odo is going to be more accurate than it was, and until you NEED to replace it cos it's worn out, you can simply.....


Ryde More, Worry Less!

[rjinaz86323]

With the 225 60 my Spyder speedometer matches my GPS speed.

[bigbadbrucie]

With the 225 60 my Spyder speedometer matches my GPS speed.

Don’t know if this still holds true, but a number of years ago my NEW THEN GPS came with a notice that it could be out by up tp 10% depending on the number of satellites it was able to connect with. Still true, or.....? Of course there is also the fact that “as your tire wears”, its rolling distance changes, hence your speedo accuracy changes. just my thoughts on this subject. Mike has forgotten way more on this subject than I’ve ever learned, so listen to the experts.

[K80Shooter]

I didnt know the speedometer is not correct on the Spyders, So you are saying my 22 RTL is not accurate ? and if so, how far off ?

About 3 mph.

[Mikey]

If it was 10 out there be some cause for alarm, less than 5, don't swet the small stuff!!

[Jetfixer]

For those interested in comparing stock sizes to other available sizes, here's a very handy calculator that will give you a graphical depiction of the differences and describe all the changes. (such as speedo change).

http://www.tire-size-calculator.info/