Saturday, October 04, 2008

A New Rear Tire for Maria

Today I spent almost five hours changing out my first and possibly last tire on Maria, my 2004 R1150RT. Long story short: The larger tire she use in the rear are apparently much harder to work with in terms of removal from the wheel and definitely for emplacement of the new tire onto the wheel! It seems, in retrospect, that it was much easier when I did my first ever tire swap on Brigitta's front tire: LINK.

I'd been noticing the thread level of the rear tire on Maria approaching the TWI (Tire Wear Indicator) mark along the center portion of the tire. This is where it spends most of its time in contact with the pavement since I've been doing a lot of highway riding and apparently not enough curves since the sides of the tire still had plenty of thread left!

You can see the middle TWI is almost flush with the top surface of the thread.

Mike O, my wrenching guru, had taught me the valuable lesson of not waiting to see actual wear bars or try and get a few more hundred miles out of a worn tire. There's just too much riding on it! I really don't need to be hydroplaning on a 612lb motorcycle while in the rain!

So today, I went to the dealer and came home with a new rear tire for Maria. The dealer was apparently very busy or booked up in their service dept since I'd not even gotten a reply email from this past Monday when I asked when they could schedule me in for a tire change. Oh well. In fact, I had a short conversation with a LT rider who'd had to wait three weeks for an oil change!

Bringing home the new tire

No problem I said to myself, I can do it, I'd done it before for the first time ever while replacing Brigitta's, my 1987 R80, front tire. No sweat. Hah.

I placed Maria on her centerstand and secured her front wheel to the centerstand so it would not collapse forward accidentally as I worked on her. It's worth it, here's how I know: LINK

I made sure to only use the tools I normally carry with the motorcycle I am riding so that I know I'll have all the necessary tools with me in case of a breakdown on the road.

I would take the tire spoons on long trips

I took off the four lug nuts with no problems using the above lug nut wrench. I'd added a T45 Torx wrench to my toolkit and used it plus a metal tube that I believe goes with the spark plug socket to add leverage to the small Torx wrench while removing the mounting bolts for the rear brake caliper:

Note that there's plenty of brake pad left

Once I had the rear brake caliper assembly off, the rear wheel came off easily enough with a bit of wiggling back and forth. I let all the air out of the tire by removing the valve stem and pulled it out between the final drive and the exhaust pipe. (It's a tight fit, removing the air helps)

So here's the old tire, the outer edges of the tire seem almost new don't they. I really must get in more twisty road time with the new tire!

I got 13,039 miles out of this one, not too bad

So I mentioned it took me five hours at the beginning didn't I? The above actions took less than 30 minutes. The next four and a half hours were a titanic struggle on my part, with much help from my loving wife, to A. remove the old tire from the wheel (what a booger it was) and B. Put the new tire onto the wheel, fail after several attempts to get both sides under the rim, take the wheel back out (painful), try it with brake rotor rim being the "in place" side this time, still much pain, struggling and swearing involved.

Finally, figured out the trick which I thought I'd been doing all along. You have to really and truly collapse the opposite end of the tire from where you're working the edges inwards. Its not enough to push on it a little, you really have to push it down to take the pressure off the opposite side. I finally spooned the edges into the wheel. Success!

Another 30 minutes to seat the bead (it took 47 lbs of pressure and two loud pops). I'd already put in the 2 ounces of dynabeads and replaced the valve stem. I let all the air out and put the tire back onto Maria's final drive assembly, torqued down the lug nuts to 77 ft/lbs. The rear brake caliper went on next, and its own bolts got torqued down to 29 ft/lbs. I used the torque values from my Clymer Repair manual. I filled the tire back up to 40 lbs PSI.

I'd been riding Maria with 40 PSI in the front tire and 42 in the rear tire. These values having been given to me by the Beemer dealer I bought her from back in Sturgis. I am going to try 38 in the front and 40 in the rear as I'd see the wear patterns on the front and rear tires seeming to indicate too high a pressure. We'll see.

Got geared up, took her out for a few miles spin and everything seems to be fine. Got no new vibrations coming from the rear. The tire didn't fall off at high speed. I took her up to max normal cruising speeds and a bit beyond and the tire did just fine.

Given the time involved, I am not sure I'll personally change tires on Maria again unless there's no other choice. Its a lot harder than on Brigitta's thinner tires. Still, I can't forecast the future, I may be stuck with time on my hands, an unsafe tire on the motorcycle, new tire on hand, and the dealer too busy again.


Conchscooter said...

If I got 13,000 miles out of a rear tire i would make no changes to the air pressure. I'm lucky to get 8,500.

Anonymous said...

You really don't want to change your own tires without the right equipment (curved levers, a wheel holder, good tire lube, rim protectors, a bead breaker, etc.)
I applaud your efforts to use just the toolkit on your own bike, but I can't see doing a tire change on the road. IMHO, the only tire repairs that are feasible on a trip are the sticky strips or the stop n go plugs, both of which I've used with good results without having to dismount a tire.

Charlie6 said...

yeah, having good tools helps a lot but the job can be done with toolkit tools, and a good set of tire irons/spoons plus noted tire bead breaker.

a wheel holder would be nice along with dedicated rim protectors. After yesterday, I might be looking at such an investment. Still, knowing I can do it is a good thing for one's confidence. Already plenty of practice patching holes.

the only scenario I can picture that would lead to a tire change on the road is getting a tire so damaged the patch kit won't cut it, and its easier to go get a tire than towing the bike to the tire source. Assuming of course I packed the tire irons. : )

if I can limp in to a tire shop, you bet they'll get my sense taking wrenching too far when one is away from one's own garage.

irondad said...

Congratulations on the eventual success. You're a braver man than me. I just pack a tire plug kit to get me to a shop.

Wait a bit. With the downturn in the weather, shop time will be more plentiful. Another bonus to riding through the Winter ( as much as you can past the ice and snow, that is! )

Jack Riepe said...

Dear Charlie6 (Dom):

I have two desperately busy seasons each year and just passed through the second and final one for 2008. I tuned into your blog and was surprised to see I'd missed a bunch of new pieces.

Chances are better that I would try and remove my own gall bladder before I'd have a go at changing tires. The club I belong too -- the Mac-Pac -- has lucky in that a member has donated a room in his factory as a tire changing room. The club asked members to contribute and bought a tire changing machine. Members who did not contribute are asked to do so the first time they use the machine.

It is still a do-it-yourself operation, but one of ther old hands will usually volunteer to walk you through it. This reduces the ordeal to about 90 minutes. I have a buddy in the Adirondacks, Lee K., who owns 7 BMWs. He bought a tire changing maschine on his own. He figured it paid for itself in the first year.

Fondest regards,
Jack Riepe
Twisted Roads