I'm in the market for a new rear tire (previous post).  My front tire is a Cheng Shin, which is probably not the best quality.  But it still has plenty of tread, so I don't want to change it yet. 

If I get a quality rear tire (i.e. an Avon AV46), would the rear tire upgrade be compromised by having the Cheng Shin up front?  In other words, would I be better off just getting a less expensive rear tire or just replace both tires?

Thoughts?

I currently have a BT39 sticky front and less sticky IRC RX-01 rear with no problems, they're both bias ply tires

If they're both bias ply ( or radial) then it's ok if not then

P.S. av46 is radial I think so it's not a good idea to mix it with Cheng Shin, better replace them both

Dude ... cheng shin is horrible for GS, even worse for front, The only 17 rear they make - barracuda V still wore in 5K ... I mean WTF is the point of running Chinkshit if it doesn't  last as long as concrete ...
Anyway, what chengshin the barracuda V was OK... but I ran a rear not front.
Cool.
Srinath.

The Cheng Shin tires came with the bike.  I know they're crappy.  I guess what you're saying is that a Cheng shin with tread is worthless.  So I guess I'll replace both.

new tires (set) is like riding a new bike.......

Toad Rider, what kind of Cheng Shins came on your bike?

Treating yourself to a new set would be best like werase says, would be like a new bike.   

Just checking AMT, a new 140/80/17 AV46 rear only is about $110 plus ship and you can get an OEM size set of Roadriders for $125 or OEM G spec BT45 set for $138 plus ship.  Not worth messing around with the old Cheng Shin front.

Shrinath, there are quite a few 17" front and rear Cheng Shin tires like the Barracuda V and the Hi Max, and the Marquis rear 130/90/17.  Thought you used to like those Marquis rear for their long wear?

The only Cheng Shin front I might consider running with a radial rear would be the Hi Max which is coppied from the Metzeler Laser type front tread pattern and only if it came on the bke.   

As far as mixing bias and radials, a bias front with a radial rear can work OK, a radial front with a bias rear should be avoided.  Bias front/radial rear combos I've run are GT501/Z2, Lasertec/AV36, and my current Lasertec/RoadAttack which remains my favorite but I think I'm gonna cheap out and go to the Roadriders next.