i have stockers on my bike right now...and the rear is almost gone...

so i'm planning on just changing the rear tire and keep the stock front....is this a bad idea???

what's the most economical tire out there??...for price and tire life?
BT-45s???

anyways...is that a bad idea???

The BT-45 is a good selection for both life and grip. Harder compound in the center for good life, softer at the flanks for good grip in the twisties.

Manufactureres generally advise against mixing tire styles, but I have yet to hear a report abot really bad problems resulting from this.

I'd say change the rear and slowly get used to the combination. If you get really weird behaviour you can still change the front as well.

You should be OK just changing out the rear to something like a BT-45.  I would recommend that you stay with the stock 130/70-17 size this first time around.  My thinking is to get used to the new compound and THEN experiment with sizes.  Especially if you plan to own the bike long enough to wear out several sets of tires.

Unfortunately for you (in your current situation) the front tire tends to last TWICE as long as the rear.  So ... be patient!

i was thinking about getting the 140/70 BT45s....
and keeping the front till around mid season when i can afford it...

are BT45s good economical tires??...anything better that'll last longer???

You can definitely go cheaper, and you can definitely get longer wear, but I'm not sure how many tires (if any) can give you both.  gsJack is the resident long-distance tire burner, and he maintains a text file with mileage and wear results for the various tire brands / models / sizes he has tried.  Check it out at http://members.aol.com:/jcprrp/97GStirelog.txt

A wide-open GStwin.com search for tire info will yield way more message threads than you probably have time to digest.  But here are a couple of good ones to start with:

GSJack? (tires again)

New rear rubber?

Meanwhile, here is what my own tire log reveals:


 Front Tire                 Miles
 ==============================================
 Stock (Exedra)              9,605
 BT45 110/70-17             15,409
 BT45 110/70-17              5,007 & counting (looks almost new)


 Rear Tire                  Miles
 ==============================================
 Stock (Exedra)              5,183
 Cheng Shin HiMax 130/90-17  9,616 (Should have replaced ~9,000.
                                    Also rubbed slightly.)
 BT45 130/70-17              8,406
 BT45 130/80-17              6,816 (Need to replace.  Too much
                                    straight-line riding?

I think this is the first time I've compared my results side-by-side with gsJack's.  Hmmm.... Time to look into radials, for sure.  The fronts don't seem to last any longer, but the rears (can) go twice as far!  They tend to cost more too, but if you get to skip a mounting & balancing charge....

do you prefer the 130/80 or 130/70???
why not go with a 140/70?

also...right now on my stockers...I have this flat spot right on the middle from riding on the highway too much (8000km on the tire) (almost all highway)...should i change it quick??....i has about 2mm tread on it...

if i do a lot of hwy riding...should i just stick with stock size??

I tried the 130/80-17 because it was cheaper than the 130/70-17 and because I (naively) thought that the extra diameter from the more rounded profile would translate to slightly fewer tire rotations per mile, and therefore more miles before changing.

As you can see from my tire log, I was wrong!  What happened instead was that the more rounded crown of the tire wore out faster, and now the tire wear indicators down the centerline are nearly gone, while I still have LOTS of tread left on the sides.  So, back to a flatter profile next time.

For whatever reason, I haven't been in a hurry to try a wider tire.  But if I go radials it looks like I'll HAVE to....  (Er, GET to?  :mrgreen: )

how bout the 14/70?...it's fatter...but just a big taller...
will it be better for milage and handling???

Better for mileage?  Probably.
Better for handling?  Possibly.

But I'm just guessing.  Anyone else?  With experience?  

Keeping the front is a bad idea only in that the stockers are such crap. Putting a "good" tire on the rear will make the crap factor on the front very obvious.

New tires were the best thing I ever did to my street GS. If you can afford a new front, do it, you'll notice the difference immediately.