Need new tires = NEED HELP

Being the curious animal that I am, I still plan on doing a measurement when I get some time. Empty heads and inquiring minds want to know ...

I am curious too, since I have not measured them as well.

wgelhar said:

I have read just about every thread on tires. I have a few questions that still remain. I have a 1991 ST1100.
Stock tire
F 110/80/18
R 160/70/17
I know everyone knows that and it is posted over and over, but i am having a difficult time finding a Matched set of tires.
I also have read that for the rear it is ok to go 170/60/17, but there is not a tire made that works front and rear.
Looking at Bstone T30 GT Rear = 170/60/17, but what front tire? Bstone T30 None GT? are they 2 different of tires to run together?
Mich. PR4 ... same story, what front tire ?

Can I go 120/70/18 on the front to run PR4 or T30 GT?
Is there a big difference in the T30 GT and standard T30 ( which comes in stock sizes )
Sorry for so many questions. 1st year with the bike. Love riding again.

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Metzeler still makes their Z6 radial in the proper front and rear sizes you want, if you haven't bought yet.

I am running the Bridgestone BT30F 110/80/18 and BT30R 160/70/ZR17 non GT on my 1991 and 2000 St1100. I am on my third set and get about 9k miles. These should be readily available.

paulcb said:

No need for a matched set... people run mixed all the time. Tires are like oil... opinions vary wildly. FWIW, I'm running a Bridgestone Exedra G547 on the front and a Michelin Commander II on the rear of my '01 ST11. I got the Exedra at a good price and bought the Commander for long life. I run beads in both.

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+1 . But don't mix a bias tire with a radial.

As far as calculated diameters go, sometimes the calculated numbers don't match the spec/measured diameter. Take a look at some tire spec sheets. But there is a big difference between 0.7 inches & 0.1 inches (?).

I like the BS Exedra Max (120/70 radial) . It doesn't cup like the BS 023's did ( really bad ). And an Avon Storm 2 ( 160/70) on the rear. Might try the Storm 3, next.

Jim Van said:

+1 . But don't mix a bias tire with a radial.

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Any particular bad experience? Just curious as I have thousands of miles doing it with no issues at all. I can't find a radial rear that will get me to and from the West Coast or Alaska so I always run a bias rear and a radial front on those trips.

Uncle Phil said:

Any particular bad experience? Just curious as I have thousands of miles doing it with no issues at all. I can't find a radial rear that will get me to and from the West Coast or Alaska so I always run a bias rear and a radial front on those trips.

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Phil : Interesting. Thanks for that info. I have never mixed bias & radial. That's just the general wisdom I have heard on several forums. What about a bias on the front and radial on the rear ? Do you think that would be a problem ? Now that I think of it, I might have read one way is OK, but the reverse, not. I'll see if I can find that article, again.

Found this at Revzilla :

" Interestingly, for some manufacturers, a mix of bias and radial tires are factory equipment. You’ll see the mix with radial rear and bias front tires, but we do not know of any combinations in reverse. Anecdotally, folks have run mixed tires with success in the past. However, most riders doing such a thing are usually aware of what they’re doing, hyper-vigilant about the fact that something negative could occur, and experimenting with a specific performance characteristic as an end goal. With that said, RevZilla does not have a problem with a mix of radial and bias-ply tires, as long as that mix is in keeping with the OEM recommendations, and the tires are in their correct OEM positions (Bias front, radial rear). "

Found this at the Dunlop site :

" Bias and radial tires have significantly different dynamic properties. They deflect differently, create different cornering forces, have different damping characteristics, as well as other differences. In order for radial tires to be introduced into the two-wheel market, it was necessary to change certain characteristics of the motorcycle. The introduction of the radial tire led to such things as modified frames, wider wheels, new steering geometries and suspensions. Therefore, it is recommended that a motorcycle be used with the type of tire construction that it came with originally. If a change is to be made, then it should only be done if the motorcycle or tire manufacturer has approved the change. Above all, do not mix bias ply and radial tires on the same motorcycle unless it is with the approval of the motorcycle or tire manufacturer. "

The ol' "don't mix radial and bias" is a carryover from early car tar days. Technically, there's no reason _not_ to do it on a bike if the bike seems to like it. I have mixed bias/radial and also radial/bias in the past. The _only_ time I've had a problem was a new Michelin rear with a well used Avon on the front. Don't recall which models of each. Went back and got a new front and no more problem. I often buy what's on sale when/where I need it and just go. Bought a Metzler something-something 120/70/18 front for $75 mounted and balanced back at first of April. Mounted on my stock 3" rim, it felt fine and did the duty, but with only ~5000 miles, it's toast.

I'm currently running a Michelin Commander II (bias) on the rear and a Michelin Pilot Activ rear (bias) on the front of STick with the newly straightened 3.5" wheel originally from lipSTick. Hasn't been out'a the garage yet so I'll do a report soon's I rebuild the rear brake caliper in a few minutes (hours?) (days?)

LipSTick has a Commander II on the rear and a Bridgestone BattleAx BT45r rear (bias) on the front. She needs new front brakes as well, all the parts on hand. STick will get the duty for my coming early summer trip, so no hurry to get this done. She has been to Mesa and back twice recently and seems to be running fine.

Jim - Lawyers and theorists are where that comes from! I've run all sorts of combos - bias R/bias F, radial R/radial F, bias R/radial F, radial R/bias F - You do stuff like that when you have take-offs and your own tire changer! ;-) In theory, if you rode right on the edge of the performance envelope and did a lot of track days, you might have some issues. But I know of very few riders that get close enough for it to matter. As I tell people - 'Don't tell the ST and she will never notice the difference'. Looking back, I've probably got over 100,000 miles on the bias R/radial front. And I'm sure George has way more than that!

I noticed a Metzeler ME880 is made in the proper size for my rear 160/70 but never see one on an ST.
The load and speed rating seem to be correct, is there something I'm missing? Other than it being a preferred tire for a Harley.

Since I have had very good luck with Avon Storm 2 Ultras, and they make exact OEM sizes for the ST11, I am putting on my first Storm 3D X-M (xtra-mileage). Hopefully, I will experience the extra 10 - 15% mileage over the 2s - which should calculate to about 13,500 miles on the rears (down to wear bars) and about 23K on the front.


Ray

Jim Van said:

Found this at the Dunlop site :

" Bias and radial tires have significantly different dynamic properties. They deflect differently, create different cornering forces, have different damping characteristics, as well as other differences. In order for radial tires to be introduced into the two-wheel market, it was necessary to change certain characteristics of the motorcycle. The introduction of the radial tire led to such things as modified frames, wider wheels, new steering geometries and suspensions. Therefore, it is recommended that a motorcycle be used with the type of tire construction that it came with originally. If a change is to be made, then it should only be done if the motorcycle or tire manufacturer has approved the change. Above all, do not mix bias ply and radial tires on the same motorcycle unless it is with the approval of the motorcycle or tire manufacturer. "

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That's the paragraph that's scared me off of experimenting with radial tires on bikes designed for bias ply, at least so far. One of these days I'll probably give it a try. I'm on my first set of new tires on the ST so I went with OEM Exedras to get a baseline. I do like the fact that bias tires generally last longer than radial.

Have to agree tottally with what Jin Van found. Some ten yrs. ago I had BT20's on bike, removed the rear and took it down to have a new 205 run'flat Dunlop put on(rear). Back home and on, I then rode bike down to have the front 205 installed next day, as it came in as orderd. I got 50+yrs. on bikes of ALL types, street and dirt, and I've never in my life had such an ill-handling of a motorcycle! I did run 205's, front and rear till the day they were discontinued. I DO tend to 'play' hard....just occassionally now, and the NOW discontinued BT23's ARE superb, in every way wet or dry. My other listed big 'tour' ride....it could care less what's on either end, as long as they aren't 'squared' off. So, with that, modern designed twin-spar framed bikes are a tottally different animal when it comes to tire matching. If one doesn't notice any difference, so be it, but I suspect that crowd's largest percentage of riding is just 'cruising' down the road without the occassional adrenaline rush 'pushing' things a bit in the twisties, as THAT's when mis-matched tires and modern frame designs WILL rear their ugly head.

I've run the ME880, didn't like it, made the bike feel like a truck. I'm very happy with the Michelin Commander II on the rear. I've used all models of the Avon since '93. Always liked them for handling, not for mileage. I'm old enuff and slow enuff, mileage counts more for me now.

I'm conflicted ..... can't decide which type of thread is better - an oil or tire thread ???

Jim Van said:

I'm conflicted ..... can't decide which type of thread is better - an oil or tire thread ???

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Conflict is stressful Jim...........does 'round' and 'slippery' reduce that conflict?.

George said:

I've run the ME880, didn't like it, made the bike feel like a truck. I'm very happy with the Michelin Commander II on the rear. I've used all models of the Avon since '93. Always liked them for handling, not for mileage. I'm old enuff and slow enuff, mileage counts more for me now.

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......pretty much the case with me also, but by the same token, I don't want the back-end feeling or looking like it needs a short skirt or 'booty' shorts if I decide for a 'short' to wick it up in the mountain twisties here.

George said:

I've run the ME880, didn't like it, made the bike feel like a truck. I'm very happy with the Michelin Commander II on the rear. I've used all models of the Avon since '93. Always liked them for handling, not for mileage. I'm old enuff and slow enuff, mileage counts more for me now.

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That confirms what I suspected, heard someone say they wear like Iron. Of course the trade off of Hard compound and less traction. I remember them on my Magna and when they were squared off it was apparent in the corners.

Brant said:

If one doesn't notice any difference, so be it, but I suspect that crowd's largest percentage of riding is just 'cruising' down the road without the occassional adrenaline rush 'pushing' things a bit in the twisties, as THAT's when mis-matched tires and modern frame designs WILL rear their ugly head.

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Yeppers, that's me - I ride like an old man