Tires, I know "not again"

A 110-100 18 and 80-100 21 are effectively the same tire size as the ones mentioned above and should work just fine. I have even used a 140-80 18 (same as 120-100) on a 110-100 size rim.

Hi there bksavs,It helps to understand what the numbers mean on the side of your tires when you want to change sizes .The first number (in your case 130 )refers to the distance in millimeters from the outside of the tread on one side of the tire to the outside on the other.The second number refers to the height of the tire as a percentage of the width.In your case 80 would be 130x80%=104 mm.So therefore the width of the tire is 130 mm,the height is 104mm ,and of course the last number is the diameter od the tire(inside) or the rim size which for reasons I cannot explain is still in inches..ie..18.So if you use your calculator you can see that 140/80-18,is very close to 130/90-18,is close to 120/100-18.Mainly these ratios(aspect) refer to the shape and height of the tire as well as the width.Do not assume that the manufactures just put tires on a new bike because they were the best deal for them on the day.A lot of time goes into selecting the sizes of the tires that go on a new machine..nsman

Choosing a compound is always difficult for a guy that is not prepared to change tires as the surface he rides on changes.michelin 12 series tires in all the compounds soft-medium-hard are good tires.the s-12 is awesome on hard pack only you will rip most of the knobs off in one day.I would recommend the m compound and see if the traction will balance with an acceptable wear life.I agree with your conclusion ,stock sizes are best...nsman

My two cents,

nsman, thanks for the great info on tire size and aspect ratio. Even though actual tire height can vary depending on manufacturer. The michelen S-12 is about the lowest profile of 90/90-21. At least that has been my experience in searching for a low profile tire recently.

And I totally agree about the stock tire size having been thought out by the engineers.

I recently went to the mich 90/90-21 S-12 front, and 140/80-18 rear on my 2004 550. The tires seem to work pretty good, although I suspect there is some knob roll over on the hard terrain that I ride on, but, on the soft stuff they work well.

My tire of choice for riding out here in the desert's of Souther California has been the Pirrelli MT18. I find that they not only work good in sand/soft conditions, but, also work well in the hard pack and rocks. And speaking of rocks....... The size and type of MT18 I run is the Heavy Duty, 100/80 front and 120/100 rear. These tires have a tall side wall that is relatively stiff to prevent pinch flats. I run these tires at 12 to 13 psi cold front and about 11 to 12 psi cold in the rear. I also run that green slime stuff in my heavy duty bridgestone tubes. Yeah it's a pain changing tires with those 4mm thick tubes, but, I only have to do it when the tires are worn out

You just need to do a littel experimentation to find out what works best for riding and your pocket book. Those michelins work great, but, they're kinda pricey. The pirrellis work good and they're easier on the ol pocket book. And I have friends who really like the Kenda Carlsbad, they wear good, and they're pretty cheap. Another friend of mine runs the Maxxis IT tires and he is happy with them.

I have been experimenting with different tires for a while and I think that the Pirrelli's are the best working, price friendly, and flat negative tires around.

Hi DalEo,yeah for some reason the tire manufacturers all have different calibrations on their micrometers.Tires are a very personal thing,last summer Ryan Lochhart (I believe he finished 6th in the 125 class a few weeks ago at the vancouver supercross)showed up at our local harescramble .I was checking out his yz250f after he won the race and was surprised to see he was running kenda millvilles,I asked him why he was not using a more premium brand and his answer was simply that they worked o.k. and as far as he was concerned the most important thing about tires is a brand new set every race....nsman

The S-12 "climb" on the walls in deep tracks. The side knobs are rotated 45 degrees. Many use M-12 front and S-12 rear. I have used M-12 and they have less grip than the Enduro Competition tires. You need to be careful on stones and hard roads.

The problem with the sizes is that the companies measure the tires in different manners.

Never tried Trelleborg but there are some about the sizes,
http://www.trelleborgtyres.co.uk/
http://www.werproducts.net/mitas-trell_home.html
http://www.cgs.cz/

Hi Mikst,

Thanks for the trelleborg link. There is one tire there that looks allot like the now defunct dunlop 752.

After years of testing different tires I had settled on the 752 for the area that I ride in. And, of course, 3 months later dunlop quit making them :evil: Just like they quit making the K-139 which was THE tire for desert racing/riding as it had a very stiff side wall and would stay on the rim even when flat.

I forgot to mention in my previous post in this thread that I had run the dunlop 739AT desert tire for some time. This before switching to the 752. What I found was that the 739 did not work very well at pressures above 10 or 11 psi, AND! they didn't last very long.

You know, I can deal with a tire not working very good, but, lasts a long time. Or, I can deal with a tire that works great, but, doesn't last very long, but not both.

And as a side note, I see in some of the dirt bike rags that they tell you, that you can get more time out of a tire by switching it around so get a sharp knob face. That's great, except what happens when you try and stop? I'll tell you, they don't stop worth a crap!!!! I found this out the hard way at a National Hare & Hound. I will only do this again if I am totally desperate, and I mean desperate. The people who suggest this have A) never done it or B) it has been so long since they did do it they can't remember. C'mon, does anyone really believe that magazine editors ride with worn out tires because they can't get freebies?

I have always liked the S-12's but the wear to fast, I have been running the MAXXIS IT's front and rear and really like them, sometimes I will run the M-12 on the front. I ride Woods, hard pack, rocks and sand. I am going to try the new MAXXIS Desert Tires at Moonrocks, NV in Feb.

Kraig

Hi DaleEO,

Yes, have heard about switching it around. This one who told me I trust. He goes a few hours and then switch and then a few hours more. The switched tires is for practice only. However, there are people who have almost no threads at all and they go very fast despite that.

Before, when Trelleborg made the tires in Sweden the Winter friction models with spikes were the best you could find. They lasted many times more than the other. Today I don't know for sure but they are still very good. The other brand Mitas, which is the same company, uses the similar rubber compound I have been told. The thread is a little different but people who use then like them. One thing you must remember is that the Winter friction models are *******s to work with. Gloves is a must, sweat and bloody knuckles are common.

Hi Mikst,

A friend of mine switches his rear tire around after one weekend/ride, so the knobs aren't too rounded off yet.

I can't imagine trying to mount a spiked tire!!! Ouch!!!!

My current favourite rear, and has been for the last few years, is the Mitas C02. Works in all conditions around here and lasts forever. Since I can't get Dunlop 755s for the front any more I've been trying a few different ones. The Dunlop 756, although similar, doesn't give the same confidence. Michelin S12s rip apart in a day or less, although stick well until then. I'm currently on my first Bridgestone M401 front and so far so good. Almost the new grip of the S12 but no knobs ripped off yet and hasn't deteriorated at all. I'll probably buy another.

Also I use Bridgestone Ultra HD tubes that allow for low pressures, 8-12 psi with no flats.

Cheers
Steve

As usual, my memory isn't what iot was. I'm on a BS M201, no M401 at the moment. Comments above are the same though. Its funny how the soft terrain tyres seem to work best on my rock gardens.

Merry Christmas
Steve

tyres

My 2 cents worth. I to love the Dunlop 752 front, which we can still get here in Tassie, and as for a rear???? Have tried most brands, they all wear out way to fast. The Pirelli Mt 16 is a good all rounder and you would also be amazed at how long and how much grip you get from a buggered Mt32 rear. I have a Maxxiss int/soft on at the moment but these are very hard to fit especially the first time. I also run Pirelli heavy duty tubes with "never flat".
# A hint I have learned to help fitting a tube into a tyre( you might all ready be aware of this??) is to use lots of baby powder and fit the tube into the tyre first, then lift the part of the tube up with a tyre lever so it protrudes out, then fit the rim into the tyre and drop out the lever, do up the valve nut and off you go! I also have the valve aprox 5 spokes away fron the rim lock. Before I fit another tyre I preheat it on a shed wall first or with a heat gun in Winter, this is probably the best trick I have picked up so far, you wont believe how much easier it is to fit a tyre!
Hope this helps someone.

tyres

My 2 cents worth. I to love the Dunlop 752 front, which we can still get here in Tassie, and as for a rear???? Have tried most brands, they all wear out way to fast. The Pirelli Mt 16 is a good all rounder and you would also be amazed at how long and how much grip you get from a buggered Mt32 rear. I have a Maxxiss int/soft on at the moment but these are very hard to fit especially the first time. I also run Pirelli heavy duty tubes with "never flat".
# A hint I have learned to help fitting a tube into a tyre( you might all ready be aware of this??) is to use lots of baby powder and fit the tube into the tyre first, then lift the part of the tube up with a tyre lever so it protrudes out, then fit the rim into the tyre and drop out the lever, do up the valve nut and off you go! I also have the valve aprox 5 spokes away fron the rim lock. Before I fit another tyre I preheat it on a shed wall first or with a heat gun in Winter, this is probably the best trick I have picked up so far, you wont believe how much easier it is to fit a tyre!
Hope this helps someone.

You can also fit a plier on the rim. This helps the tire to go "deeper" in the rim which makes it easier to fit as well.

plier?

Mikst, how do you do that? Do you mean something like a "vice grip" pair of pliers? I reckon Berg rims are an absolute pain as they are so deep?

The Exel rims Husaberg uses are good but if they are deeper than other Exel rims I don’t know.

Couldn't find any photo of this so I hope I can explain it.
The idea is to make the rim cushion to go deep in the rim. You fit adjustable lock pliers in the rim. The pliers prevent the tyre to stop on the “rim shoulder” so the rim cushion goes down in the deepest part of the rim (there the spokes are fitted). This gives that it is easier to fit the tyre. I got this hint from a guy who rides with bib-mousses so it works for that application as well.