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Main Area => General GS500 Discussion => Topic started by: hInstance on March 19, 2015, 12:02:14 AM

Title: Mixing tyre brands unsafe?
Post by: hInstance on March 19, 2015, 12:02:14 AM
I was reading the owners manual for my girlfriend's Kawasaki Ninja 250r and I was surprised when it warned against having different tyre brands on the front and back wheels. Is this really unsafe? Should this warning apply to the GS500 as well?
Title: Re: Mixing tyre brands unsafe?
Post by: prmas on March 19, 2015, 12:20:19 AM
It is not a case of avoiding different brands of tyre more of avoiding different construction types of tyre.
You should not mix radial and bias ply tyres although you can have a radial on the rear and a bias on the front without a problem. That mix is legal here in my state.
You should also obviously not mix design types, meaning a road tyre on one end and an adventre/off road tyre on the other end. That would result in dangerous handling.

Macka
Title: Re: Mixing tyre brands unsafe?
Post by: J_Walker on March 19, 2015, 01:21:43 AM
I for one mix tires sometimes depending on what I'm trying to get out of my bike, mostly the off road related stuff.
Title: Re: Mixing tyre brands unsafe?
Post by: hInstance on March 19, 2015, 01:22:42 AM
Whew, I'm glad you provided that information. My front tyre is the original OEM BT-045 and is still going pretty good. The rear OEM BT-045 has had it and I was planning to replace it with a Michelin Pilot Street Radial. From what you've told me it's ok to do that, have the bias ply BT-045 on the front and the radial Pilot Street on the rear.
Title: Re: Mixing tyre brands unsafe?
Post by: Janx101 on March 19, 2015, 01:29:52 AM
Just check your front tyre though.... My OEM one had decent tread left .. But was wearing flattish 'scallops' in the tread blocks.... Didn't realise how much minor vibration that was giving me till I put in the new front tyre... Smooooooooooth!
Title: Re: Mixing tyre brands unsafe?
Post by: prmas on March 19, 2015, 02:06:55 AM
Quote from: hInstance on March 19, 2015, 01:22:42 AM
Whew, I'm glad you provided that information. My front tyre is the original OEM BT-045 and is still going pretty good. The rear OEM BT-045 has had it and I was planning to replace it with a Michelin Pilot Street Radial. From what you've told me it's ok to do that, have the bias ply BT-045 on the front and the radial Pilot Street on the rear.

hInstance, I had exactly the same situation with the same combination that you mention. For a few days I had the BT45 on the front and the PSR on the rear (although it is a 140/70/17).
I did a track day at Phillip Island and destroyed the LHS of front tyre in 26 laps. It was well worn anyway (18.5K) but still had plenty of legal tread. The brand new PSR (fitted the day before) on the rear showed NO wear and very little scuffing after 26 laps. The bike handled really well at track speeds with that combo and I had no "clencher" moments.
I was the smallest bike there but not the slowest. I was able to cut inside several bikes on the tighter corners but was very slow down the straight into a strong head wind. A true 159kph was the best that I could do no matter what I tried. Even at that speed the tyre combo caused no problems. The ride home from PI however showed that the front tyre was nackered as there was quite a lot of vibration. The new PSR on the front a few days later made a huge difference.
The PSRs are a very good tyre but I don't think that they give as much feedback as the BT45s did. I have had a couple of unexpected rear lockups under heavy braking. I just did not feel it coming whereas I would have with the BT45s.

I also have Michelin Pilot Radial 4s on my Honda and my comments would be the same in that the grip is better that the old Michelin Pilot Active (bias) tyres but there is noticeably less feedback. These have now done about 3K and are showing almost no wear yet despite being on a much heavier bike. The old MPAs did 27K and still had another 2-3K left but the rear was squared off to the point that you could feel it when cornering. Actually, the rear one would have done another 5-6K treadwise but it was starting to feel funny.

Any input fro GSJack? I know your tyre preferences but comments would be appreciated.

Macka
Title: Re: Mixing tyre brands unsafe?
Post by: gsJack on March 19, 2015, 04:43:29 AM
I've mixed a lot of tires on the GSs over the past 15 years with mostly good results, I think the bias 110/80 Lasertec front with a radial 150/70 RoadAttack rear were probably the best all around handling tires I remember although I've used mostly bias Roadriders in recent years.

I've only had one mix I'd consider a bad mix, a bias-belted GT501 front with a Z2 radial rear.  Hitting a quick right then left I'd ridden many times the bike felt like it was falling out from under me when I transitioned into the left. It repeated a couple times and then wouldn't do it again, I was compensating for it I guess. 

I wouldn't hesitate to try your bias/radial mix but would work up to speed with it to be sure.  I was riding like Macka into my 70's but have slowed way dowm into my 80's maybe to a stop soon.   :cry:
Title: Re: Mixing tyre brands unsafe?
Post by: gsJack on March 19, 2015, 04:54:15 AM
http://img.photobucket.com/albums/v443/jcp8832/GS500tirelogs_zpse04c1f44.jpg

I tried to link my tire log in the above post but it wouldn't work with the Chrome browser I've been using.  Had to go to Explorer to link it, don't know why it used to work with Chrome.   :dunno_black:
Title: Re: Mixing tyre brands unsafe?
Post by: rg500gamma on March 19, 2015, 08:34:03 PM
 :cool:
Title: Re: Mixing tyre brands unsafe?
Post by: hInstance on April 19, 2015, 11:54:58 PM
This is also from the Ninja manual. Sound advice?

[attachment deleted by admin]
Title: Re: Mixing tyre brands unsafe?
Post by: gsJack on April 20, 2015, 04:52:59 AM
I would consider that sound advice although I didn't always heed it myself.  Years ago I ran them until the tread was gone in the middle of the back tire but have always replaced them when they hit the tread markers for the past 15 years and 180k miles I've ridden the GS500s.

90% of the failures is only a very small percentage of all tires now, I was more concerned about the lack of tread when I was riding harder and faster and more frequently in the rain.
Title: Re: Mixing tyre brands unsafe?
Post by: Iarn on April 20, 2015, 06:12:42 AM
Yes, that's very true. Never run any tire bald, you're asking for trouble. Reduction in traction, handling, stopping power. Very real possibility of the mesh underneath being exposed, blow outs under high stress situations because they're weaker. Don't do it.

Tires are way more likely to have problems in their last 25% of tread life. So if they're getting near the end of their life, inspect them more often.