WHY? Bias Ply? TIRES '91K100LT

[swbell]

Why does the rim on this cycle need the "Bias Ply" and not just the "Radial"?

I've been running the Metzeler Lazertec 110/80 m/c 58H on the FRONT. Found out that it should be a 110/90.... Is that true?

The Rear has been the Marathon ME880's 140/80 B17 m/c 69v. Heard also the it should be 130/90...Is that true?

Any other suggestions on Tires for this the '91K100LT?

What made the real bummer is I'm here researching tires rather than ridding this afternoon. Found the front tire flat on my pretrip inspection.

 

[swbell]

Another question: I was trying to find the leak and so I pumped up the tire. The air is coming out of the valve stem itself, not the inside guts, but the rubber on the side of the valve.

Do I have to take the whole tire off to insert a new valve stem?

At least it wont cost me a whole tire.

 

[Bobmws]

You should be able to break the bead and squeeze the tire together to change the valve stem.
Front should be a 100/90, rear can be either 130/90 or 140/80.
The rims are too narrow to fit radials.

 

[Paul_F]

Another question: I was trying to find the leak and so I pumped up the tire. The air is coming out of the valve stem itself, not the inside guts, but the rubber on the side of the valve.

I've learned to always have new valve stems installed when new tires are put on my K. For whatever reason, new tires leak air from the old valve stems.

 

[warredon]

I started using the metal valve stems several years ago and really like them.

 

[ol-Levi]

For the weight

I heard from the STL shop that radial tires are not as good loadwize. So had to mount a bias-ply on back wheel of my K1100LT.

Anybody have advice for radial-bias mix?? PR-2 on front, Metzler bias on rear????

I'm sure that's suspect, but rides fine.

 

[tourunigo]

(1992 K1100LT) I put a 120/70 ZR/ 18 ME880 on the front (radial) and a 140/80 17 ME880 (bias). Did not want a Laser on the front. Seemed to run fine two up with load. I know that this is counter to conventional wisdom but Is there a better set up than this? Maybe another manufacturer with a bias for the front? What's the worse that can happen with what I am doing with the mix? - Bob

 

[MysticRed]

I ran Mich PR2 front and and Avon Azaro rear on my LT. 2 sets with no probs. Then I found a cheap RS/RT rear wheel and now run PR2s front and back.

 

[pglaves]

Why bias ply instead of radials on that bike? Because in 1981 when that bike was designed those were state of the art tires. Can radials be retrofitted? Maybe.

Go to the major tire-maker web sites. Find a tire of the right rim diameter. Look at the sizes available and then look at the minimum (and maximum maybe) rim sizes allowed for proper fitment. Also look at the load rating compared to the "recommended" fitment tire.

If you find a tire of the correct size and load range to fit the rim (most radials are spec'd for wider rims) then ... maybe. The radial will not be the recommended fitment from the tire-maker. The OEM pressure recommendations from BMW will be too low. The steering geometry won't be the same (probably), and you may need a different shock and may need to fiddle with the fork setup because the tire's compliance alters suspension characteristics.

But a cautious trial of a set of radials might be worth it if you really want radials.

 

[MysticRed]

I'm just saying that Michelin makes a radial (PR2) to fit the front. Avon makes a tire (Azaro) to fit the rear and have been run by riders here and here. I have never heard a bad review on this setup, YRMV.

 

[lkchris]

I've been running the Metzeler Lazertec 110/80 m/c 58H on the FRONT. Found out that it should be a 110/90.... Is that true?

The Rear has been the Marathon ME880's 140/80 B17 m/c 69v. Heard also the it should be 130/90...Is that true?

The bike originally came with a sticker affixed under the seat somewhere that specifies correct tire sizes. The information on the sticker is "true."

In addition, correct tire sizes are shown in the owners manual--a BMW dealer can get you one if you don't have one.