Changing tires?

[Promethean]

How can one tell that the time has come to change the tires on the bike? Is there a simple test?

[DJ Down Under]

Most tires have wear indicators...that's a start...what type/brand do you have?

DJ

[Promethean]

They're Michelin Macadams. Wear indicators? How does one identify them?

[Acacia]

Ab,

Look at the rain grooves in the tire. Between these rain grooves there should be a little ridge/bump/bridge every odd groove. Those are the wear indicators. Your motor car tires should also have them too. Once down to those as far as the DOT is concerned, you are required to change the tire. Some put a penny there and the head of Lincoln should once clear of the tread it is time I guess about 1/32" of the rain groove should remain

Most experiences indicates that once near there in wear - the soft motor cycle tire does not last too long - particularly if you ride hard.

We has 3 tire at the TX Hill Country ride wear quickly once near there , neccesitating the ride to slow pace.

[arkline]

You might also consider that tires that haven't been worn out but are older than around five years are becoming relatively less pliable on the road. There is a constant out-gassing that goes on with tires with each cool/heat/cool cycle they go through and the tire becomes a little harder every time the cycle is done. Sunlight and exposure to ozone and other such things helps the process along. I just replaced my tires because the date code showed the originals to have been manufactured in 2001. Five years is a long time for motorcycle rubber, although if you are parsimonious maybe they're okay, but they won't stick like new.

The date code is molded/stamped into the sidewall of the tire. Here's a link to a good source of info on decoding the markings on a tire:

http://www.ama-cycle.org/roadride/tires.asp

An older tire, properly inflated, will feel just a little woogedy in situations where a new tire will inspire confidence.

[DarthRider]

Ron -

The manufacturers recommend an approximate 5-year shelf life for new tires stored in climate controlled warehouses. (Gee, I wish Lance was here to argue this is so they can sell more tires!) This is best case for tire life, or close to it.

Out in the mud & the blood & the beer of the real world as you describe is worst case, or close to it. Many people just assume if the tread is "reasonably good" and the weather checks are not "too bad", it is good to go. Might be 10 years old or "hard as a wedding dick", no matter.

We met a guy last week on the Texas Hill Country ride on a very nice 1973 Triumph Hurricane with original tires!! And he was riding it as fast as he could...and bitching about what lousy tires it had. He said he is a motorcycle mechanic.

A moron I work with (in the motorcycle business!) has an old beater Gold Wing. It has had two completely bald tires for a month or so. I was going to hook him up with a tire deal but he said he already had a new set of tires, he was just waiting until it was convenient to change them, or until he "had to".
Last week the rear blew out just after he completed a corner in the rain!
He lucked out and didn't bite the big weenie, then later laughed that he was glad it wasn't the front or that it hadn't blown in the corner.

Some bozo on the old board was advising that it is OK to just slow down a little and "be careful" with cord showing on motorcycle tires and you could continue to ride this way until the cord patch extended all the way around the circumference of the tire.

There is no end to these stories, many involving people who should damn well know better.

Dave

[BobFV1]

How can one tell that the time has come to change the tires on the bike? Is there a simple test?

Abhijeet - all modern tires have TWI's (tread wear indicators) - not sure where they are on the macadams. The Macadams are an older model of Michelin tires, now discontinued, I believe. I had a pair on my Roadster and I thought they were great.

I consider tires as safety equipment and I change them early and often, whether or not the TWI's indicate they should be changed. When I teach the ERC I have to inspect the bikes and you should see some of the crap tires people ride in on. There is a lot of variation on tire life, depending on load, riding style, etc, and while there are stories of tires lasting 12 or 15K miles, I never get more than about 8K max out of any set. If you see wear, your tires have over 5K on them, and you are "not sure" about them, consider putting a fresh set on for the new riding season - Just like an insurance policy...

[Promethean]

Thanks gents.

Now that I understand what TWIs are, I took another look at the rear tire. The rear tire TWIs are almost worn out. They might last 2-3 weeks at most. I have over 6,000 miles on the bike with the original tires. I don't think I'll push my luck anymore.

I've already sent in my check for the Mojo lever.....I have to get the rest of the tire changing kit together. As soon as I have these, I'll order the Z6s.

Amazing, how quickly you begin to accumulate tools and such once you start working on the bike.

Does anyone have recommendations on an inexpensive air pump/compressor?

[Dallara]

Abhijeet...

Help me out here. What kind of pump or compressor are you asking about?

If it is something you want to carry on the bike at some time, great... Those are good things to have, and I have one called an "Airman Sparrow" I sometimes carry onboard in a saddlebag, and always have around in the truck or trailer when they're along to top off a tire.

But...

If you are talking about a compressor to use when you change your own tires at home and you are going to have to seat the tire bead, well... That's an entirely different kettle of fish. You may can get the little emergency compressor to do it, but it won't like it and you take a chance of burning it smooth up.

What you need then is a *real* compressor - one that is capable of moving sufficient volume at the necessary pressures to seat the bead properly. So often people forget to consider VOLUME of air delivery when looking at a compressor, and only look at pressure. Volume is especially important if you have a tire with really stiff sidewalls, as whe you try to air up the newly mounted tire some air escapes from around the bead of the tire while it is down in the mounting groove in the center of the rim. If you can't deliver enough volume you will never be able to get this to pop out and seat against the rim.

For tire remounting yuou honestly need a *real* compressor... A good rule of thumb is one that delivers about 5.0 CFM or more at 50 psi. You can get away with less CFM if everything is *right*, but it's a good place to start. Another way to look at it is that if it will run your air tools it is enough to seat a bead, but also remember you want to run air tolls at higher pressures and less CFM.

Ideally you don't want to use more than about 50 or 60 psi to seat a bead. Some people use more, but the tire manufacturers don't recommend it, and it shouldn't really be necessary with a properly lubricated rim and bead and the tire in the proper position.

Besides, seating tires at big pressures is inherently dangerous... Don't ask me how I know, but let's just say I have witnessed what can happen when somebody tries to seat a recalcitrant bead with a big compressor at about 120 psi and 25 CFM - Not a pretty sight, and it was lucky somebody didn't at least go to the hospital - besides wiping out a perfectly good, new tire.

You can pick up nice, relatively small, horizontal home compressors on wheels for about $200 to $400, and they are a great investment, as you will find more and more uses for them. Mind you, ones that small aren't for using big air impact guns, but work great for light die grinders, buffing wheels, air brushes, and air ratchets (though I never use air ratchets or air impacts on motorcycles any more...).

Just something for you to keep in mind, and I hope it helps.

Cheers!

Allan (Dallara - NACD)


WARNING! I know of no air compressors that are equipped with ABS, so remember that you are operating them at your own risk, and no doubt considering the NHTSA's data they are unsafe to operate on any roadway since they do not have ABS.

[Promethean]

Allan,
Thanks for the explanation. You saved me from making a blunder.

Yes. I'm looking for a compressor to use for changing my tires at home.
Where should I look for one? Do you have recommendations as to the brand / make etc.?

Thanks again.

[socalrob]

Abijeet,

I've had a set of Z6s & a set of Michelins (I'm sorry, can't remember the name, but they are the current model BMW dealers recommend, sport touring tires.) My problem with the Z6s is that they really don't have tread wear bars that are usefull as the tire has a solid stripe down the middle, so you don't really know when its at the wear limit. On top of that, the Z6 is a dual compound tire, with softer sidewalls for cornering & harder center for highway mileage. I was very carefully watching my rear tire, & in the course of 150 miles it went from "looks ok" to a "crap, I need a new tire, got an appointment with the dealer" to "I'm not sure I'll make it to the dealer, theres a steel belt showing all the way around". And I swear I was being carefull. The Z6s seem to reach a point at which the tires evaporate in a few miles (the soft underbelly compound?).

After that experience I had the Michelins put on, which are also dual compound, but they have tread accross the center of the tire, hence they have TWIs on the center of the tire, hence I can actually determine the tread wear. I really like the Michelins, have actually been grinding my peg feelers once in a while, am happy with the way they turn in, and all in all, I will stick with the Michelins in the future just to avoid the Z6 wearout problems.

[geechie]

The Z6s seem to reach a point at which the tires evaporate in a few miles (the soft underbelly compound?).

My experience tends to bear this out as well. Went from, "Looks like I can get another couple hundred miles." to, "Holy crap! Get SW MotoTires on the line. QUICK!!", in a day or so.

If you think they're getting pretty worn, change 'em out. Now.

George

[Dallara]

Well Abhijeet,

This may surprise you, but the compressor I have at home is what some would term a "no-name" brand. I got it decades ago specifically for doing airbrush work on everything from model cars, slot cars, R/C cars, and helmets. The brand is "American IMC", but it is actually made in Italy. It puts out a maximum of 100 psi, is powered by a 110-V electric motor (of which I can give you no specs), and has about a 6.0 CFM delivery at 50 psi, and has a 10 gallon or so horizontal tank. I have it dual-regulatored... One side of the block only allows about 50 psi by, and this side has two regulated, guaged outlets, too. One is set at about 20-25 psi for occasional air brush work (and often is used at less psi than that), and the other ope to the 50 psi. I use that outlet for checking and maintaining tire pressures on all my vehilces at home. The other side is set for 90 psi, and I use it for my die grinder and cut-off saw.

I have rarely mounted tires with it, but I have, and it worked fine. I have the local Kawasaki/Yamaha shop do my tires now, but the last time I did a complete set myself I simply used the compressors we have at the car store, which put out mega-amounts of CFM even at very low pressures.

Where to find a good, small garage/home compressor?

Well, you could always do worse than Sears. They usually have good to really nice ones in stock, and several friends of mine have Sears compressors. I hear Harbor Freight has some decent ones, too, but I know no one that has one. I would stick with electric motored ones, but you can get them run by gasoline engines, too, if you prefer.

I have done a lot of business with Northern Tool over the years, and their service is great and I have never had a problem with them. YOu can find them online at:

http://www.northerntool.com/

Here's one they have for $400 that is probably way more than you need:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200311705_200311705


Here's another one:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200317939_200317939

Here's another one that is probably a bit more than you need but looks like a good buy:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200007574_200007574


Oddly enough, Harbor Freight has one that looks like a dead-ringer for the little one I use in my garage, only without all the regulators, splitters, and dryer/water separators I have hung on mine. You can see it here:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90234


But remember, I haven't used any of those compressors, so just use them for guidelines. Shop around, do a little research, and I am sure you will find something that fits your needs exactly - for now and in the future. Like with anything else having ot do with tools, it never hurts to buy a bit more than you need, and that is especially true of a compressor. One of these days I am going to have a vertical tank, quiet rotary screw compressor with a huge tank standing in the corner of my garage so I am not limited to doing anything at home, but that's down the pike, and since I don't need it now It's not a priority.

What you want to try and achieve is the largest tank, with the highest CFM delivery you can get, capable of high enough pressures (but anything over 120 psi for home or motorcycle use is wasted) to operate the tools you want, that fits in the space you need and can run on the current you have available (big compressors can need 220-V, etc.).

Hope this helps!

Allan (Dallara - NACD)



WARNING! None of these compressors have ABS, so they should not be operated by soccer moms or stockbrokers or other subjects of NHTSA studies, nor hould they be used for transportation on public roadways. To do so without installing an overly complex and ludicrously expensive ABS system is taking your life in your own hands, and may God have mercy on your soul.

[Arby]

I picked up a quiet, light weight compressor at home depot for about 150 bucks. Plenty good enough for a home work shop.

And the advice about not exceeding 50-60 psi when mounting the tire is good information.

RB

[BobFV1]

Home compressor - let's see:

I prefer oil-lubricated to the ones that you don't have to add oil to, but that have cheap teflon (plastic) bits in them that tend to wear out.

The yellow, coiled plastic hose is a big pain in the ass compared to a rubber hose, but it is a lot cheaper.

Unless you have a place to keep the compressor stationarily mounted, make sure you get one with little wheels on it so you can roll it around rather than lifting it and moving it - those little suckers are heavy!

[Deans BMW]

Z4's and Z6's are an extremely fast wearing tire IMHO, tried them several times on my R1150R, the Z4's would last 3,200 to 3,400 miles, the Z6's (MEZ4 & MEZ6) about 3,600 miles. After trying LOTS of tires I have settled on Michelin Pilot Roads, worked fantastic on the Roadster and mileage appx 6,000.On my ST Pilot Roads give me just under 5,000 miles which I find fantastic considering the way the ST is run. Pilot Roads have been approved by BMW.

[Promethean]

Thank you gentlemen. My list of tools to buy seems to be growing rapidly.

I'm off to Harbor Freight to see if they have the items on sale. My Mojo Lever should be arriving shortly.