tire pressures on older Airheads
My comments here are for ROAD tires (NOT off-road types or usage).
Modern design tires require higher pressures than stated on the label under the seat on old Airheads, or in the Owners Booklet. Use the classic old pressures only with original type tires. The only "classic" tires you are likely to ever purchase are the Continental RB2 and K112. They give the Classic Ride; and handle well-enough, if you use the book values for TWO-UP and/or HIGH SPEEDS. Those pressures are way too low for modern tires. On all other tires I have ridden on, and there are a LOT of them, using such low values as higher twenties to lowest thirties will cause mushy unstable handling, with a feeling of the tire rolling sideways off the rim...
Do NOT use the pressures printed on the tire as your standard pressure. Those are MAXIMUM designed pressures for the tire carcass.
Modern tires may....or may not!....give the old rule-of-thumb of 6% pressure increase from riding awhile. The belted tires and stiffer sidewall types generally do not work so good in that regard...and measuring is critical anyway. The effect is more magnified with very hot asphalt in very hot Summer conditions, up to 10%, but NOT all makes/models of tires!
As a fairly accurate general rule, if you ride solo, and weigh under 180 (or thereabouts), try 32 front and 36 rear as the absolute minimums, whether on a naked lighter BMW, or a heavier RT. The very BEST handling might be with 35 or 36 Front, and 40 Rear; but that is only for those that push rather hard into the twisties. I have found that 33F/38R is a very good compromise, most will like those pressures. Pressures are always measured with the tire cool....not right after riding...and NOT after heating up a lot from sunlight.
If two-up, and/or you weigh considerably more, or you are doing higher-speed traveling, I suggest about 35 or even 36 front, and around 40 rear, or even a couple more pounds in the rear.
All my comments on pressure values work well whether you are using metric sizes of, say, 90/90 or 100/90 front and 110 or 120 rear; or, inch sizes of, say, 3.25 or 3.50 front and 4.0 rear.
NOTE that some tire manufacturer will give honest recommended pressures for their tires, and others will offer-up only what BMW might have specified, long ago. Some don't even offer any guidelines, except the maximum printed on the sidewalls. I can only speculate as to the reasons.
There is an article at this URL, that discusses tires by brand and model, pressures, and lots more for your reading pleasure:
http://bmwmotorcycletech.info/section5.htm
BMW used to do extensive factory tire testing and made recommendations on tires, as well as pressures. I do not remember any tires for the early Airheads being tested and published by BMW since maybe the early or mid eighties.
Certainly BMW has not published anything at all on tires/pressures since the mid-nineties, then only for the last Airheads, and were no changes. You MIGHT want to glance at the R100R type pressures, however.
In MY opinion, all the Owners Booklets have the WRONG (too low) pressures for ALL models of BMW Airheads, up through 1985. EXCEPT if you have the Classic Tires. From 1986, the pressures were more accurate for real-world modern tires. Some brands and models of tires have been in production for a very long time. Almost none of the original Classic Ride type tires are now available, at least in the USA.
snowbum
MOA 17058
My comments here are for ROAD tires (NOT off-road types or usage).
Modern design tires require higher pressures than stated on the label under the seat on old Airheads, or in the Owners Booklet. Use the classic old pressures only with original type tires. The only "classic" tires you are likely to ever purchase are the Continental RB2 and K112. They give the Classic Ride; and handle well-enough, if you use the book values for TWO-UP and/or HIGH SPEEDS. Those pressures are way too low for modern tires. On all other tires I have ridden on, and there are a LOT of them, using such low values as higher twenties to lowest thirties will cause mushy unstable handling, with a feeling of the tire rolling sideways off the rim...
Do NOT use the pressures printed on the tire as your standard pressure. Those are MAXIMUM designed pressures for the tire carcass.
Modern tires may....or may not!....give the old rule-of-thumb of 6% pressure increase from riding awhile. The belted tires and stiffer sidewall types generally do not work so good in that regard...and measuring is critical anyway. The effect is more magnified with very hot asphalt in very hot Summer conditions, up to 10%, but NOT all makes/models of tires!
As a fairly accurate general rule, if you ride solo, and weigh under 180 (or thereabouts), try 32 front and 36 rear as the absolute minimums, whether on a naked lighter BMW, or a heavier RT. The very BEST handling might be with 35 or 36 Front, and 40 Rear; but that is only for those that push rather hard into the twisties. I have found that 33F/38R is a very good compromise, most will like those pressures. Pressures are always measured with the tire cool....not right after riding...and NOT after heating up a lot from sunlight.
If two-up, and/or you weigh considerably more, or you are doing higher-speed traveling, I suggest about 35 or even 36 front, and around 40 rear, or even a couple more pounds in the rear.
All my comments on pressure values work well whether you are using metric sizes of, say, 90/90 or 100/90 front and 110 or 120 rear; or, inch sizes of, say, 3.25 or 3.50 front and 4.0 rear.
NOTE that some tire manufacturer will give honest recommended pressures for their tires, and others will offer-up only what BMW might have specified, long ago. Some don't even offer any guidelines, except the maximum printed on the sidewalls. I can only speculate as to the reasons.
There is an article at this URL, that discusses tires by brand and model, pressures, and lots more for your reading pleasure:
http://bmwmotorcycletech.info/section5.htm
BMW used to do extensive factory tire testing and made recommendations on tires, as well as pressures. I do not remember any tires for the early Airheads being tested and published by BMW since maybe the early or mid eighties.
Certainly BMW has not published anything at all on tires/pressures since the mid-nineties, then only for the last Airheads, and were no changes. You MIGHT want to glance at the R100R type pressures, however.
In MY opinion, all the Owners Booklets have the WRONG (too low) pressures for ALL models of BMW Airheads, up through 1985. EXCEPT if you have the Classic Tires. From 1986, the pressures were more accurate for real-world modern tires. Some brands and models of tires have been in production for a very long time. Almost none of the original Classic Ride type tires are now available, at least in the USA.
snowbum
MOA 17058
