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Offline nightowl

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Dunlop Roadsmart 3, strange experience
on: May 10, 2020, 02:01:41 PM
Wanted to share the strange and unexpected experience with my set of new Dunlop Roadsmart 3 tires with you. About 500 km ago I had to change front and rear tire, coming from the standard Dunlop Sportmax GPR300 that always worked fine for me. As some of you might have read in my other postings I'm using my bike regularly on the Autobahn, i. e. riding it at 170 km/h plus to get to other riding areas.
Anyway, having checked my tire options for the change I ended up with the Dunlop Roadsmart 3, front and rear. After the change I went for the first ride and immediately felt a strange "light" feeling on the front wheel. My usual turns around home felt weird, undefined, uncomfortable.  The rear, btw., felt (and still feels) "normal". O.k., I thought, those are new tires, let's wear them in a bit first and then judge again. But it didn't get better - it got worse. I went riding the Roadsmarts the first time on the Autobahn. Nothing special to observe - until I hit ~ 140 km/h! Reaching this speed and passing through it the front suddenly started weaving and wobbling with the handlebar significantly moving. What surprised me is that this movement was clearly not associated with road but rather with speed conditions. And that it WAS NOT the kind of effect that I know very well from high speed Autobahn travel when you get an impulse from e. g. passing the flexible road gaps of bridges. And where this impulse causes a short wobble and weave which disappears immediately and by itself having passed the gap in the road.
I have reproduced this effect now several times since it happened first. It gets much worse when reaching 180 km/h plus. And I'm not trusting higher speeds than 200 km/h anymore (don't get me wrong on this: not that this has ever been a pleasure or necessary but I NEVER had any unsafe feeling on the bike beforehand riding at higher speeds. Which is now clearly the case!).
What finally caused this posting here is my yesterday's "test" ride with introducing small impulses at the handlebar at 140/160/180 km/h. At 140 impulses do not disappear themselves but still can be calmed pretty easily with the handlebar. At 160 I'm feeling already very uncomfortable with the reaction of the bike. And I don't want to retry this at 180 km/h - for a moment I thought the handlebar movement would increase even further and drop me off (with or without a tank slapper).
Anyway, what I tried so far is varying the front wheel tire pressure. Which made the "light" and undefined lower speed riding feeling of the front wheel disappear (and I already thought I was fine) but did not change the higher speed behaviour. I also reopened the clamping of the front axle to make sure that nothing is distorted there - but also with no change to the better.
Anyway, kind of last thought is that I let the tire service recheck the front wheel balancing (although it does not feel to me that this might be the cause of the problem). And I will call Dunlop tomorrow and hear if they have any further ideas.
So much about this experience with my new tire set. If I can't get rid of this bike movement I will quickly go back to the Sportmax GPR300 tires or something else. Need to get my base trust to the bike behaviour back which is currently not there anymore.
Comments, especially other experiences with the Roadsmart tire, are higly appreciated!
Last Edit: May 10, 2020, 02:11:57 PM by nightowl

Offline Evangelos K

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Re: Dunlop Roadsmart 3, strange experience
Reply #1 on: May 10, 2020, 03:35:38 PM
This is my guess, coming from a similar situation (another bike, Bridgestone S21). I might be completely off.

The new tires have a very hard carcass and no flex.  Did the improvement come by lowering the tire pressure?
The S21 that came stock on my CBR gave me a MOFO of a tank slapper at about 110m/h, thankfully it was at the track, because it was so violent that I lost ALL FRONT BRAKE pressure due to the calipers retracting all the way in because of the violent movement...  We are talking brand new tires with 700mi on them.

I learned the hard way that tires can be the cause of what, otherwise, to someone not as experienced, could seem as suspension issues.  I was chasing ghosts (suspension) when it was the BRAND NEW S21's.  A new set of Q4's (what a  waste of brand new set of OEM tires - but they were simply unacceptable) cured EVERYTHING.  What you described could very well be a case of the same.

PS:  Before I resolved my issue, I also took a spill when the front S21 washed out on me (again, at the track).  And, NO, I should have known better by then, and now in hindsight, it was the tires and not "user error" LOL. Those S21's looked like brand new after 3 track days, when they should have been obvious signs of use and "shred."   I had the time of my life on the Q4's at the next track day.


2018 Triumph Tiger XRx
2017 Honda CBR1000RR ABS
2013 Triumph Street Triple R

Offline nightowl

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Re: Dunlop Roadsmart 3, strange experience
Reply #2 on: May 10, 2020, 05:33:35 PM
Great, thanks for this input! I can obviously not refer to track day usage but what I also noticed is close to no noticeable wear and tear during those 500 km. The GPR300 looked much more worn after only 200 km compared to the Roadsmart after 500 km.  So I'll keep your comments well in mind and will also mention this limited initial wear and tear to Dunlop when I call them.

Offline nightowl

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Re: Dunlop Roadsmart 3, strange experience
Reply #3 on: May 10, 2020, 07:11:15 PM
Forgot to answer your question: yes, the improvement came by lowering the tire pressure.
Went down 0.3 bar and this did the job for the lower speed conditions. I'm just very unsure how much lower I can go to look for better higher speed behaviour until the tire starts flexing thus introducing a different negative effect to the bike's stability that way?

Offline Evangelos K

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Re: Dunlop Roadsmart 3, strange experience
Reply #4 on: May 11, 2020, 02:50:19 AM
OK, with  “legal reservation” LOL, I PERSONALLY, don’t have an issue getting the front down  to 30PSI.   I can go and say, again, how stupid the “cookie cutter” 36 and 42 PSI settings are,  but there is plenty arguments around.  My front usually is set at 32PSI, again, I , ME, don’t have an issue with dropping to 30. 

However, in your case, even if helpful, it could still be a bandaid. 
2018 Triumph Tiger XRx
2017 Honda CBR1000RR ABS
2013 Triumph Street Triple R

Online Hillie

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Re: Dunlop Roadsmart 3, strange experience
Reply #5 on: May 11, 2020, 03:24:38 AM
0.3 bar is just under 4.5 PSI, a notable difference. I always start with the "cookie cutter" pressures, but if there's a need for change, I'll do that without doubt.

Offline kes2463

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Re: Dunlop Roadsmart 3, strange experience
Reply #6 on: May 11, 2020, 01:49:04 PM
I have a pair of Dunlop Roadsmart 3s & have done about 1000 miles on them. What chalk & cheese, to me they have been fantastic, they inspire so much more confidence.
 I weigh 108kg & have had the suspension set up for my weight. The tyre pressures are set at 33F 39R & I don't carry pillion at all (occasionally camping gear  :001:).
I haven't had any problems that you describe & have had some spirited riding (160-210kmph) at times although on normal roads (non-autobahn) I tend to be mainly 100-150kmph).
Be you, not the image of you that everyone else says you are.

Offline Markymoto

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Re: Dunlop Roadsmart 3, strange experience
Reply #7 on: May 11, 2020, 03:29:50 PM
I’m running a set of these on my BMW, now with ~9K miles on them. They have been fantastic. We’ve toured through the Appalachia’s, Adirondacks & Green Mountains 2up. No problems. Had the bike up to 80+ mph on the interstate many times. Rock solid, wet or dry. I run them @ 36/42 psi. Getting an additional 1,500 miles over the Pirelli Angel GT.
In fact I’ve just purchased a second set & will have them installed shortly. I’ve tried many of the top tier tires & for me these seem to be the best performance/ price value...
Laissez les bon temps rouler!
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Offline nightowl

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Re: Dunlop Roadsmart 3, strange experience
Reply #8 on: June 07, 2020, 06:45:46 PM
Hi to all - wanted to share the outcome of this topic and especially the answer of Dunlop with you. The result is as clear as embarassing because the answer from Dunlop says: "Your bad riding experience is exactly the reason why the Roadsmart 3 tire IS NOT APPROVED for the Z900RS."
So on the good side this confirms that my strange riding experience was real :062:. And on the other side it teaches me to more properly look for the relevant tire approvals before just buying :192:.
Anyway, lesson learnt. And for those of you that might have other bikes where the Roadsmart 3 is approved: I have a tire set with a mileage of ~ 1.200km available for sale in 2-3 weeks (after I have swapped to approved :002: new tires - either back to the OEMs or to the Pirelli Angel GT 2.)