Follow the Arrow on Tires - Always?

From the February 2011 issue of “MotorCyclist” magazine

The magazine has a section called the “MC GARAGE”, each issue has a feature titled “FAQ”. The February 2011 issue addresses the arrow imprinted on motorcycle tires.

FAQ – Follow the Arrow

Q: Why are motorcycle tires directional? Is it purely for water evacuation or is there some other, less obvious reason?

A: The tread patterns on most modern high-performance street tires work better rolling in one direction than the other. The front is optimized for steering and braking; the rear for putting down power. Pumping water away from the contact patch is another facet, as noted, but there’s another reason to heed those directional arrows: The rubber that is now your tread started out as a long flat strip before being vulcanized to the carcass and joined with a diagonal splice. More contact area makes said diagonal joint stronger because, when mounted correctly, predominate rotational forces push the joined edges together instead of trying to pull them apart. Since most of the braking forces are applied through the front tire, that splice runs in the opposite direction of the one on your rear tire. If you were to use the same tire at both ends and the arrow only indicated the drive direction for the rear, it would be best to mount the front so that it spun the other way.
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Wow, that is sort of a difficult piece to comprehend. I think the take away here is if you are running a tire designed for the rear tire position in the front tire position of your bike, you should check the directional arrow and make certain you are actually rolling against the arrow not with it.

x

No I think it really only applies if you are, as some have, using a tire meant for the rear of a bike as a front tire. If using a tire meant for the front in the front position - follow the arrow.

I don't really know why anyone would use a rear tire as a front, but some do. I thought it was an interesting article although highly confusing for it's length.

Wish I had looked - https://www.silverwing600.com/t1391-double-darkside?highlight=double+darkside

This thread discusses 'briefly' the concept of the use of a tire designed for the rear as a front tire. Lots of words, but not a lot of clarity or reason to do it (in my opinion).

jdeereanton wrote:

No I think it really only applies if you are, as some have, using a tire meant for the rear of a bike as a front tire. If using a tire meant for the front in the front position - follow the arrow.

OK. That's logical.

JD,

A lot of the old Brit iron had wheels the same size. I've come across tyres that are specified 'front or rear fitting' before and they have two directional arrows (obviously)....... The 'Dynepr/Cossack combo's' spring to mind as well - all three of their wheels/tyres are the same, as is the spare - however performance (on road) is not really an issue with one of those beasties

I spoke to a tyre fitter about this and his advice was never to fit a tyre designed for a front wheel to the back and visa versa - tbh I sort of figured that one out for myself a long time ago but he quantified it by saying that manufactures of modern tyres, for todays high performance machines, use different compounds in differant parts of the tyre depending on its fitment.

Is there any time, even in an emergency, when you would find it necessary to fit a rear tyre to the front??? Rather than wait delivery of a replacment? Generally speaking, over here most of the tyre places I know can get the relevant item within a couple of hours - over night at the latest.

Besides, a tubless tyre repair kit is always on my bike - just in case I do get stuck in that 'one horse town, full of single toothed, banjo playing, closely related, locals'......

Skippy wrote:

I spoke to a tyre fitter about this and his advice was never to fit a tyre designed for a front wheel to the back and visa versa - tbh I sort of figured that one out for myself a long time ago but he quantified it by saying that manufactures of modern tyres, for todays high performance machines, use different compounds in differant parts of the tyre depending on its fitment.......

Absolutely no argument from me on that. I can think of no reason to fit a tire designed for the rear position on the front, or to fit a tire designed for the front on the rear.

In the link above there is a reason cited - about tread depth:

"..... as I recall the rear had around 2.5 to 3 times the amount of tread depth."

I have to say based on observation and measurements on a commercially available tire (yes, a very small sample size), this is not possible. I have a new front tire in my garage and I measured it last night as close to the center as possible, measured close to 5/16" or 0.3125" at the deepest. For the above to be true the tread depth of a rear tire would have to be 0.78125" (2.5x) to 0.9375" (3x) or a bit more than 3/4 to almost 1" deep.

Another statement regarding the ability of a rear tire to shed water - it does it better. If that were the case why wouldn't tire manufacturers just use that sipe design on the front tires? Or, is it because they are hoping that through negligence they can entertain lots of law suits and make people rich through jackpot justice?

I think the article points to a reason not to use a rear tire on the front and merely gives a work around if it is used. Although I do not know their intent. As for me the tires designed for the rear are always used on the rear and tires designed for the front are always used on the front. Others may have different ideas and that is their perogative.

I would also always follow arrow.

But in the US with no laws to prevent weird stuff on bikes with tires, like car tires, etc. stuff goes on.


Point: Bikes and scooters used to have wheels/tires that were interchangable, one I have had BMW with Sidecar, HD '66 brandnew sidecar outfit, Vespa-----with those didn't seem to matter which direction tire went------great way to even out wear and finally run the near worn out on sidecar.

John Grinsel

Yeah bikes used to have tires that were interchangeable, those same bikes for the most part had much less powerful engines, and ran at much lower speeds. I've ridden my SW scooter at speeds my 59 Triumph 650 couldn't even reach. The brakes on modern bikes including the SW apply more stress on tires than many bikes 30-40 years ago. Developments in tire engineering have made modern tires a lot different than those of the past. I firmly believe there's a reason motorcycle tires are different than car tires. Somehow I just can't believe it's a plot to sell bikers shorter lived tires to increase their sales. I know the Darksiders will defend their choices to the end but I still use motorcycle and scooter tires on my bikes, I put the dot next to the valve stem and make sure the arrows point the right direction. But then I'm a pretty conservative fellow.

Talking of tyres!!!!

Metzeler have just annouced that they are relaunching the 'Feelfree Wintex' tyre (daft name). Its aimed at riders who use their machines all year round.

Quote MCN; 'it has a mass of sipes (groves) cut into the main tread blocks to give more grip, allow the tyres to warm up quicker and give good water clearance. The range has now been extended to cover bigger sizes'

Sounds like just the thing for those us lucky enoungh not to get buried under snow and ice - (other than once in every qtr centuary or so!! )