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Going to Vegas this coming weekend for our first school (Yahoo!), and it will be cool (below 60).  I know, I know, you guys on the east think that's a nice day!

There is quite a bit of good data on tires (on this forum).  The short reminder is tires do not work cold, and have to be flexed to warm.   Meaning tires warm from the inside out (if one doesn't have tire warmers).  Most school bikes are ridden in both groups, but one doesn't know the other rider, so if not fast, might never have warmed the tires.  Very first thing to do is put your hands on the tires, get an idea of how warm they actually are.  A rule of thumb would be if the tire feels cool to you, it's COLD.  If it feel's warm (even quite warm) then it's WARM.  If you can't hold your hand on it, then it's HOT.  

There are some cold days, tires never warm fully!  Track temp, wind, sun can all affect the overall grip.  Often later in the day traction goes DOWN as the temp goes down, or sun comes off the track.  Another factor is if a rider pulls in, talks to his coach or for any reason is not on-track, when he/she goes back out--cannot go at max pace, tell the tires are re-heated.

These are reminders that we'll give the students this coming weekend, but same applies for road riding too!

Best,

Cobie

 

 

 

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Cobie- did you jinx me or did I fail to heed the warning? Since I don’t believe in jinx there must be another explanation for my getoff this morning. LoL

 

Now, just to regather my mojo (confidence).

 

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Let us know what happened?  What was the temp?  How long into the ride?  What kinds of roads ridden?  What kind of bike?  What tires.

We just did the school at Vegas, in the mid-40's on day 2.  I was quite impressed with the Q-3+...did even better than I thought.

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Cobie,

Here's a post that I was working on but decided not to publish it...that is until you asked (minor edits made).

Hotfoot- Sorry for the short response above. I'd intended to PM you about it later and just forgot. I didn't want to go too much into an answer at the time because I still want to maintain a modicum of online privacy & anonymity and I was still raw about the embarrassment. Confession being "good for the soul" and all that jazz. I hope you understand the fountainhead of my tepidity. 

A lesson (story) and question on confidence

This Friday morning I learned that 50F is still too cold to ride. I saw that we would have a break in the cold weather, I decided to commute to work. I had been watching the forecast a couple days and Thursday was warmer than forecast so I reasoned I could relax my 60F minimum. Data indicated that at 6a it was 50 at a local weather station and the forecast high for the day was 60F.

Preparing for the day, I went online last week and renewed the registration sticker and verified my insurance policy’s coverage status: FULL COVERAGE. I’ve got a lot going on with 9 motorcycles and 4 riders in my household - it’s too much to keep it all in my head. Life and maintenance was simpler with one bike and one rider. Knowing that I purposely over-inflated the tires while garaged, I pressurized the pump and readjusted the tire pressures on the Q3+ to 34F/36R Thursday night.

I hadn’t ridden my CBR1000RR in 2018 but about 100 miles or so, spending all year racing my stock XR100. And besides, just because I’d entered it into Bike of the Month doesn’t mean it’s a garage/trailer queen. It’s meant to be ridden, right? Right!

Well, I didn’t make it off my street when the rear tire broke loose in the right turn about 15MPH. Too much lean angle and not enough Joules (heat) and I witnessed it sliding and rotating away from me in the intersection of my subdivision, coming to rest on the footpeg and frame slider. The distance of my trip was approximately 200 feet from my driveway. My post-accident review Sunday Morning revealed the effect of the rising slope of the adjoining street on the right side was adding lean angle. Plus, I also know that I began to crack the throttle a tad too early on the rev-happy I-4 engine. We have the kind of pavement that looks like pressed rocks with deeply visible gaps where water, sand, or what may have been present...salt granules like to hide.

My heart sank. And I could feel my back already begin to tense up. I didn’t even feel like picking it up for fear that I would be in horrible back pain later and the horror of the damage to my baby. I mustered the courage to find that the crash protection on the bike did its job. <$50 and she’ll be good to go!

However, I still needed to get to work. I went back home and changed my pants (LoL). I made the foolish decision to not wear my riding jeans and tore a hole in my corduroys and skinned my knee.

So I bandaged my knee, changed into my riding jeans and back out I went.

But it wasn’t the same. Something happened to my mojo...

This isn’t my first experience putting a bike down. But it’s a different experience with this bike because it’s my favorite. I think it’s because I put a lot of time, energy and money into customizing it to make it uniquely mine. I have wanted this bike for years before I bought it- even denying that I wanted it, until when it was offered to me preowned at a price I couldn’t refuse.

My commute to work was tentative. And I don’t like the way I felt about it.

My ride home was at 10p was uneventful and it felt like I had good traction. I wanted to put the crash behind me more than I was able to at the moment. I'll address that later... 

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Jaybird, very similar thing happened to my wife this last Sunday afternoon.  Two intersections from our house I watched her go down on a right at a stop sign she rolled through - it was about 60F at the time.  I came up behind her, got off my bike and she said, "I don't know what happened, the front tire just..."  I replied, "Yeah, cold tires sweetie..."  She said, "Oh, I never knew tires could be cold."

She scraped up her knee, a few scratches on her Triumph Street Twin (exhaust, bar ends, brake lever), and a scratch on her helmet but ultimately everything was OK.  She got right back on and we went on our way.  Spent Happy Hour at the bar (no drinks just half-price food) talking about what she could learn from it - biggest lesson was cold tires (and maybe not rolling through stop signs).  Lesson for me was I need to pass on more of my knowledge.  I couldn't offer much more as I wasn't paying that close attention until just before I saw her bounce off the pavement - luckily it was only at about 10 mph.

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Since that was a front tire crash, you might want to ask a few questions - did she have the wheel turned and touch the front brake right before it slid out? Were her arms stiff, adding more load on the front and/or restricted the movement of the bars?

Certainly makes sense that cold tires contributed to the crash, but even with that info I imagine it is very mysterious to her why the bike would go down at such a slow speed, probably a good idea to explore other contributing factors.

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Thanks Hotfoot, good points. I too suspect that she had some front brakes while turning the wheel. I’m constantly reminding her to relax her arms and shoulders. Come to think of it, that’s the second time I’ve witnessed her drop it on a low speed right (the first was on a deep sandy right off road and I know she was squeezing the brake while turning there).

She’s only been riding a couple of years because I love it so much, she scares the heck out of me sometimes.

Thanks!

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On 2/19/2019 at 5:57 PM, Jaybird180 said:

Preparing for the day, I went online last week and renewed the registration sticker and verified my insurance policy’s coverage status: FULL COVERAGE. I’ve got a lot going on with 9 motorcycles and 4 riders in my household - it’s too much to keep it all in my head. Life and maintenance was simpler with one bike and one rider. Knowing that I purposely over-inflated the tires while garaged, I pressurized the pump and readjusted the tire pressures on the Q3+ to 34F/36R Thursday night.

Glad to hear you're alright, Jaybird!  That's the most important thing.  And props to you for getting back on the bike the same day.  

One thing though, and maybe someone else will disagree with better info, but those pressures 34/36 seem very high to me.  A high pressure like 36 would result in a stiffer tire, which might have contributed to lower traction by reducing the contact patch.  Dunlops in general feel like they have a stiffer carcass to me, and I was running substantially lower pressures for grip.  Race Tire Services, which is the US Dunlop race tires distributor, suggests 28 cold or 32 hot on the Q3+ rear.  I was running Q3+ on my trackbike at 30 hot on the rear.  I even ran the older Alpha13 rear at 26-28 hot because it was sliding at 30 hot on a barely moderate pace so I can't even imagine how that would have felt at 36 cold. 

To get heat in the tire on a cold day, you can either go up or down in pressure from your norm.  At least that is what suspension gurus say.  I always go down, and just pay for the accelerated wear.  I used to ride in DC when it was 30-40 degrees on Pirelli Diablo Rosso IIs set at about 26psi cold. 

Again, most important thing is that you are safe and sound. 

 

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I'm just getting back to running Dunlops, but these are close to the pressures I used to run on D208s on the street. Yes, they feel stiff but I've also got quality suspension underneath me.

I know the conventional wisdom is to reduce pressure for more contact patch, but I like to make changes only after establishing a known baseline.

Good seeing you online again Apollo. Now that you're over there in the land of year-round riding.

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I hope the current D208 are something else than the Sportmax D208s I had on the CB400 back in 2013! Most slippery rubber I have ever ridden on, by a big margin. They were original equipment on the DRZ400 motard allso, and may have worked on 100F sunny days, be we do not get those here. Ever. 

Sport touring tires work quite well when cold, and also warm up much quicker in my experience, compared to sport rubber. Even touring type bias ply will out-perform sport rubber under some conditions. I'll bet that on a day with 20-30F, something like a set of Metzeler ME77s will offer a LOT more grip than any modern sport radial made. At least with street tire pressure. 

In short, there is nothing wrong with sport rubber, but they are made for a purpose. Riding on public roads at respectable (as in legal) speeds in chilly temps are not such a purpose IMHO. In fact, even on a hot day, at a sensible pace for public roads, I doubt any pure sport tire will offer the grip of a sport touring model. 

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20 hours ago, faffi said:

I hope the current D208 are something else than the Sportmax D208s I had on the CB400 back in 2013! Most slippery rubber I have ever ridden on, by a big margin. They were original equipment on the DRZ400 motard allso, and may have worked on 100F sunny days, be we do not get those here. Ever. 

Sport touring tires work quite well when cold, and also warm up much quicker in my experience, compared to sport rubber. Even touring type bias ply will out-perform sport rubber under some conditions. I'll bet that on a day with 20-30F, something like a set of Metzeler ME77s will offer a LOT more grip than any modern sport radial made. At least with street tire pressure. 

In short, there is nothing wrong with sport rubber, but they are made for a purpose. Riding on public roads at respectable (as in legal) speeds in chilly temps are not such a purpose IMHO. In fact, even on a hot day, at a sensible pace for public roads, I doubt any pure sport tire will offer the grip of a sport touring model. 

I was wondering the same thing when I read Jaybird's post. I don't know the models of street tires very well, but isn't that a very sport oriented tire?

Jaybird, are you able to get those tires warmed up adequately on a cold day for good grip? Have you tried measuring the tire temp (even just with your hand) after riding for a while to see if they are warming up all the way?

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The tires aren’t getting hot. I mitigate this by not street riding below 60F, which I violated in the above. I’ve read discussions on other boards about using a touring tire and I’m rethinking it but I don’t have a dedicated sport bike - double duty of track and street.

Racing season (we do mini-moto) starts soon and at both ends of the season it’s cold enough to rethink the weekend...but we need the seat time and last year my son needed the points at the last event and it was coooooold.

I worry about tire temps more than he does. A couple folks had suspected cold tire crashes but they were only the adults. The kids rode fine.

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Could getting an extra set of wheels be an option? You could have one with track tires and one with road rubber. 

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Of course, it’s an option.  But then I’d be forced to confront other realities about my time commitments and I’m not quite ready to do that yet (LoL).

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