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My next set of tyres?.....??? (gpx250)

Discussion in 'Riding Gear and Bike Accessories/Parts' at netrider.net.au started by gpxkermit250, Sep 5, 2010.

  1. Hi All, been researching myself into late night - red eye oblivion on tyre options for the hardest bike in the world to buy for: 1998 gpx 250 with pissant 16" rims.. : ) The Netrider search function on this topic has been a worthy companion till about 3am this morning but I still cant seem to make up my mind.

    Would love to smash a set of 150 on the rear to fatten up the backside, but after just having a look, my existing battle ax 130/19-16 is only a matter of mm clear from the swing arm on the right hand side, alas. This makes me wonder how on earth people have been able to make this happen on this type of bike?? I think perhaps that is because the later model Ninjas come with a 17"inch - different swing arm clearance. Any hoot....I currently have 100/90-16 on the front

    So, can anyone offer some advice based on their own experiences as per the above and below.

    What has a higher or lower profile tyre done for your handling, peg scraping etc? Is the difference between 90, 80 or 70 series enough to change the look that much on the back. (ie, the current higher 90 profile does seem to fill out the rear end better with my rear fender taken off and replaced by oxford bracket, but if a 70 series changes the world in other ways it may be worth looking at at and not being so shallow on looks?

    I currently have BT45s and they have been pretty good. (from my previous GT301s which made me feel like I was riding around nude and vulnerable). Its my own fault via very very hard breaking and enjoyment of wet/dry weather compression locks mixed in with too much commuting and not enough twisting that my middle tread is bald el baldo with plenty available on the sides. The wear bar as arrived so they need replacing asap.

    Im working through some positive self talk to overcome my need to trash tyres and fry chicken strips on my next set, but would still like a tyre that offers reasonable wear and grip etc..

    Im looking at the same again with the BTs or perhaps some Pirelli Demons 130/70-16 & 110/70-16.



    The more I think about it the more Im getting further and further away from knowing where to start!

    Thanks in advance, Greg

    ps - some pics of the bike to give perspective on current tyre size/look with rear end modification

    http://s825.photobucket.com/albums/zz171/gregis00/GPXkermit250_SEP2010/
     
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  2. I had a BT45 on the back of my Hornet and replaced it with a Pirelli Rosso...demon..sports... something...

    No idea what it's name is but they're much better than the Bridgestones.
     
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  3. Since the bike will be just for general road use the best advice I can give is to replace them with factory recommended tyre brand.

    If you have a service manual they should be listed in there, possibly on the tyre placard if its still on the bike.
    Or even ask a tyre shop what the standard tyre should be.

    Definitely do not change the size away from factory unless you know exactly what you're doing.
    They're designed to be that size for a reason and changing them without properly accounting for the new size could mess up the handling.

    My 250 had the wrong size rear tyre when I got it (120/80/18 when it should have been 110/80/18).
    Thats only 1 step up from factory but due to the mismatch the sides of the tyre would never reach the ground even if the bike was layed completely down.
    I too had the brilliant idea of fattening up the rear a bit more but had the same swing arm clearance issues. Once I went down a size to how it should be the bike just felt so much more stable tipping into corners as the curvature was correct for the style of bike.
     
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  4. jeez, thanks for the pronto responses : ) yeah, it seems leave it to the experts who want to sell the right tyre not just sell a tyre - ie, ask plenty of questions and keep it to factory standard as possible.

    My Dunlop was a 120 on the rear and no way did it bald in the middle like my 130, and I havnt changed riding styles at all. That could be an omen for perhaps assesing the width as well, not just the height. I do like the look of the 130 though and going back to a cheese cutter with no fender could be a struggle. But your right, factory guidlines as a priotity consideration, cheers, G
     
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  5. If you're worried about flatspotting the centre and do a lot of straight line riding you should ask your tyre shop for a dual compound tyre.

    It should feel pretty much the same as the standard one in every way being a little bike.. basically means the centre of the tyre is a much harder compound than the sides, so it lasts a lot longer but still provides top grip levels mid corner.


    Also tbh, when I went from a 120 DOWN to a 110 rear tyre, it actually looked wider, because instead of curving up so much at the sides it was a proper fit and the sidewalls sat where they should.

    PS: I love the colour of your bike (y)
     
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  6. +1 to DragonCypher about not screwing with the recommended tyre sizes. Tyre cost per km on a 250 is half that of a 600 / 1000, and 250s have so little torque that a 130 section on the rear is more than enough.

    I've used Bridgestone BT-45s for 30,000 km. The rear is a dual-compound tyre but none-the-less I always wear out the centre with plenty left on the sides. Commuting and traffic-light grand prixs will do that. The first rear went 15,600 km, the second rear went 13,700 km. The third rear cost $177 fitted.

    The front tyre, on the other hand, gets scalloped out on the sides (probably due to my cautious cornering). The first went 14,000 km, and the second looks like it will exceed that (I haven't been hitting the twisties as much as I used to).

    In the dry, the BT-45s have never given me cause for concern, despite playing "keep up with the faster bikes" in the Black Spur. Your mileage may vary (YMMV). :p
     
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  7. GREAT COMMENTARY – ALWAYS HELPFUL TO HEAR IT…

    If you're worried about flatspotting the centre and do a lot of straight line riding you should ask your tyre shop for a dual compound tyre.
    AH YES… LAST SUMMER I RODE MY PUSHBIKE TO WORK MOST DAYS AND THE KAWAKA WAS VERY MUCH A WEEKEND TWISTY HOBBY HORSE. IT HAS BEEN THIS WINTER THAT HAS KILLED MY FUN AND MIDDLE REAR TYRE SO IVE DECIDED TO ENGAGE THE SAME STRATEGY THIS YEAR - GET FIT AND SAVE RUBBER… I WILL KEEP THE DUAL COMPOUND TYRES IN MIND FOR NEXT WINTER THOUGH. THAT COULD BE A GO ER..RUN TWO PAIRS, PROVIDING I DONT TRASH THESE NEW ONES BY THEN..


    Also tbh, when I went from a 120 DOWN to a 110 rear tyre, it actually looked wider, because instead of curving up so much at the sides it was a proper fit and the sidewalls sat where they should.
    AWESOME… THATS HANDY TO KNOW AS WELL

    PS: I love the colour of your bike
    THANKS! I HAD JUST SPENT 5 HOURS OF LAST FRIDAY DETAILING THE BAJEEZEES OUT OF IT (DOWN TO TOOTH BRUSHING FOOT PEGS AND COTTON BUD DASHBOARD TYPE CLEANING OBSESSION) AND FELT THE NEED TO TAKE ANOTHER TOTALLY UNNESSESSARY 20 PICS OR SO OF IT (TO ADD TO THE OTHER EXISTING 100S), SO THANKS… FEELING VERY PROUD AND DEVASTATED AT THE SAME TIME (THE NEXT DAY IT GOT VERY WET AND VERY DIRTY IN THAT FARK OFF MELBOURNE STORM)…

    +1 to DragonCypher about not screwing with the recommended tyre sizes. Tyre cost per km on a 250 is half that of a 600 / 1000, and 250s have so little torque that a 130 section on the rear is more than enough.
    YEP… AND SINCE POSTING THIS INITIAL THREAD HAVE SPOKEN TO SOME CERTIFIED TYRE FOLK AND THEY ARE ALL CONFIRMING THAT A 130/90 – 16 IS PRETTY MUCH AS STOCK AS YOU CAN GET WITHIN BOUNDARIES OF RANGE (IE, COULD GO TO A 120/8O, BUT 130 IS FINE IF IM THAT KEEN)

    I've used Bridgestone BT-45s for 30,000 km. The rear is a dual-compound tyre but none-the-less I always wear out the centre with plenty left on the sides. Commuting and traffic-light grand prixs will do that.
    AH YES.. THE TRAFFIC LIGHT GP ACTION… KNOW IT WELL… I ALSO KNOW THE ON PURPOSE HI REV LATE BRAKE TRAFFIC LIGHT INFO MERCIAL AS WELL…. IN FACT JUST ABOUT EVERY RED LIGHT LATELY HAS BEEN AN EXCUSE TO PRACTICE MY EMERGENCY BREAKING.. GOOD FOR SKILLS AND CONFIDENCE ON A SLIDE BUT BAD FOR THE TYRE OBVIOUSLY.. I THINK BECAUSE I KNOW THEY ARE SOON TO BE GONE, THE CARE/LOVE FACTOR DROPS OFF BY ABOUT 99.8%

    The first rear went 15,600 km, the second rear went 13,700 km. The third rear cost $177 fitted.
    OK

    The front tyre, on the other hand, gets scalloped out on the sides (probably due to my cautious cornering). The first went 14,000 km, and the second looks like it will exceed that (I haven't been hitting the twisties as much as I used to).
    SAME HERE… MY FRONT IS THE SAME..

    In the dry, the BT-45s have never given me cause for concern, despite playing "keep up with the faster bikes" in the Black Spur. Your mileage may vary (YMMV).
    CHEERS FOR THAT.. YEAH, I HAVE TRIED THE “KUWTFB”ITBS, BUT TEND TO SHITE MYSELF AND GET TARGET FIXATION ONCE THE REALISATION THAT IVE FOLLOWED THEIR LINE IN AND ITS WAY BEYOND WHAT MY SILLY SCARED LITTLE BRAIN TELLS ME I CAN DO…THE RIDE ENDS AND IM ALMOST THROWING UP AND MY MATES ARE QUOTING WORDS LIKE 'SAUNTER, MOSIE, LULL, ETC'... HOWEVER, IM LUCKY TO HAVE A FEW REALY TWISTY BACK ROADS AROUND WHERE I WORK, TO A POINT, THAT YOU DON’T HAVE TO ENTERTAIN MORAL DILLEMAS TO FEEL LIKE YOUR ‘APPRECIATING THE GENTLE AND CONTROLLED AND TEMPORAY LEVITATION TOWARDS TARMAC’ – BECAUSE EVEN ON THE SPEED LIMIT A HAIR PIN WITH SUGGESTED 20KM/H IS A HAIRPIN

    BIKE IS GOING IN FOR A SERVICE TONIGHT WITH NEW TYRES GOING ON THURS – DECIDED ON PIRELLI SPEED DEMONS 130/90/16 & 11/90/16 – NOT THE DUAL COMPOUND, BUT WITH CHANGE IN FORECASTED RIDING OVER THE NEXT 6 MONTHS THOUGHT I WOULD GAMBLE ON THE CHANGE OF RUBBER TO SOMETHING NEW.

    THANKS AGAIN. WILL BE HAPPY TO POST INTITIAL FEEDBACK ON HERE AGAIN AFTER THEY HAVE BEEN SCRUBBED IN IF YOUR INTERESTED.. CHEERS,.G
     
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  8. first advice. Get yourself some new mates before they put you in a situation that you cant handle and it causes you to Phuck up big time and you ride off the road and you bin yourself as well as your beautiful bike.

    You dont need 'mates' like that when your learning to ride.

    +1 captain slow re tyre advice.

    OZ
     
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  9. thanks Oz, funny you mention it. I was thinking alot about my last thread and then you send a very well timed reply. Over the winter period with lack of planned twisty riding that sometimes happens the group dynamic has changed from beyond thunderdome to the usual 2 or 3 of us that tend to gaggle along together at a Pensioners Insurance pace. I dont envisage keeping contact with all be it good blokes met on the odd ride who just seem to be at another level not conjusive to my own comfort. + No one forces me to try and keep up etc, so I need to be accountable for my own space and actions too. Good to re asses this from time to time. I need to do this with my own riding too coming into another season where all the hair pin and or cliff face corners skills are a bit rusty, but enthusiasm bursting : ) Might just Q up in the left hand lane with all the cagers 10 under the speed limit on the daily commute for a while, ...saving some precious grip on the rear as an inncentive to be nice..
     
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  10. Hows the grip now that we have scrubbed them in a little bit? well, in a word ridiculous!!! ridiculously good..... I dont know if it was just becasue for so long I was on balding tyres so I became used to feeling nervous all the time on corners (as I am anyway coz Im too over cautious and have no concept that when I think its curtains and I chop the throttle the bike is only at 36% handling capacity, dóh...damm SRs) or if these news tyres are just out of this frigin world compared the BT45s? Im trying to remember getting this horned up last time when I got my previous pair fitted? or perhaps im a better rider now, so when I compare "what speed am i now taking that corner at now etc" that this is not all the tyres but just my current perseption... well, anyway, for all the over analysing etc it doesnt matter.... the Pirelli Sport Demons are really doing it for me and I for as long as I have this bike, I cant see myself really opting for anything else. I know I should give it a thousand Kms and few twisties rides before making such grandiose statements, but meh, 250km so far and a trip to devils elbow last night is enough for me to know! Loved this thread too, thanks for gettting on it with your opions etc. Really helped me get motivated to make it happen.
     
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  11. metzler lasertec
     
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  12. Good to hear Greg, might give the Pirellis a go next time!
     
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