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When 2psi = 8psi


SwampNut

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Not sure I have any actual questions, just an exercise in discussion and some WTF.  The Zero is super sensitive to tire pressure, and also has a recommendation that's unusual to me.  They recommend 36/36, with no mention of other pressures for load or anything.  Tires are really standard sizing, Pirelli Diablo Rosso 3.  When they get down to 34, you can feel it a lot.  I left the other day at 33/34 and it was like pushing a truck's steering wheel to turn.  Also got a little rear slip cold just in the neighborhood.  I let them get to 32/33 and it was horrible.  Weird shit.  I'm used to fine tuning subtle changes with 2-4 pounds and seeing a massive problem when I'm down 6-8 from ideal, and even more below the recommended pressure which is often way too high.  I'm considering trying 38.

 

Steering on this bike, at recommended pressure, is easy, neutral, and comforting in how it stays put.  Easy to drive with no hands, unless you let the pressure drop.

 

 

Tire Inflation
WARNING: Under-inflation is a common cause of tire failure and

may result in severe tire cracking, tread separation, bead unseating from wheel, “blowout,” or unexpected loss of motorcycle control, causing serious injury or death.

 

Front Tire

Rear Tire

36 psi (248 kPa)

36 psi (248 kPa)

Tire pressure should be checked and adjusted to the proper inflation level before each ride. Tire pressure should be checked using an accurate gauge when the tires are COLD.

Note: A COLD tire is defined as one that has not been ridden on for at least 3 hours.

Note: Always install the valve stem caps after adjusting the tire pressures.

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3 minutes ago, The Krypt Keeper said:

How much psi does it rise once up to temp in the Arizona sun? Does it feel better once up to temp? 

 

The riding pressure change seems to be up about 3 psi, but I have only casually observed that and not carefully noted it.  While rising temp means more pressure, it also means softer rubber, so in theory, they actually balance out.  I can't say that I've actually noticed a change, and now realize that I haven't given it enough thought.  When I've left with the tires a little low, I notice it right away, but then my brain just filters it out as the way it is.

 

Max pressure is like most sport tires, 42 for both, with the front showing that for a 520 pound load and rear for 805 pounds.  The bike is 518 wet, there are accessories, my fat ass, and occasionally Moriah's much slimmer ass.  Interestingly the front is made in Germany and the rear is made in China.  The rear was replaced at a local shop, front is OEM.

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2 minutes ago, SwampNut said:

 

The riding pressure change seems to be up about 3 psi, but I have only casually observed that and not carefully noted it.  While rising temp means more pressure, it also means softer rubber, so in theory, they actually balance out.  I can't say that I've actually noticed a change, and now realize that I haven't given it enough thought.  When I've left with the tires a little low, I notice it right away, but then my brain just filters it out as the way it is.

 

Max pressure is like most sport tires, 42 for both, with the front showing that for a 520 pound load and rear for 805 pounds.  The bike is 518 wet, there are accessories, my fat ass, and occasionally Moriah's much slimmer ass.  Interestingly the front is made in Germany and the rear is made in China.  The rear was replaced at a local shop, front is OEM.

Monitoring and adjusting the PSI little by little for the best happy medium and even different pressures in each tire 1 at a time to note differences. 518lbs, (is it really wet being electric?) never would have guessed that weight for the bike. For some reason I had around 400lbs or so in my mind.

 

Don't forget that the tires profile will also change with wear. When you swap out the old tires and get fresh ones, they make bikes feels as if it lost 50lbs and handles amazing. Another issue to play tricks on your mind as you test out pressures. 

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5 minutes ago, The Krypt Keeper said:

is it really wet being electric?

 

LOL, I knew I'd get that question.  That's how they spec it.  There are a few fluids, and technically, electrons have mass.  So when I talked to a guy at the local training facility, I asked him about opportunities to charge on site, since it's a long ride there and then I'd be on the course half the day.  "And I'd rather not fill it beforehand, so it doesn't weigh it down for the class."  I think I have to apologize for the brain damage I gave him.

 

For size and weight, consider it an electric Blackbird, but with the weight lower in the chassis.  Really all around it's an electric XX.

 

5 minutes ago, The Krypt Keeper said:

Don't forget that the tires profile will also change with wear.

 

Front has 900 miles and rear has 100-some.

 

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29 minutes ago, SwampNut said:

 

LOL, I knew I'd get that question.  That's how they spec it.  There are a few fluids, and technically, electrons have mass.  So when I talked to a guy at the local training facility, I asked him about opportunities to charge on site, since it's a long ride there and then I'd be on the course half the day.  "And I'd rather not fill it beforehand, so it doesn't weigh it down for the class."  I think I have to apologize for the brain damage I gave him.

 

For size and weight, consider it an electric Blackbird, but with the weight lower in the chassis.  Really all around it's an electric XX.

 

 

Front has 900 miles and rear has 100-some.

 

An electric XX, if as comfy as the XX that sounds like a lot of fun. 

 

weigh it down for class :lol:

 

Mileage isn't bad, might also not be the tire choice you are after. We all fall in love with a tire brand and easily hate others at well. These might simply not give you the performance you are seeking or expecting. 

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1 hour ago, The Krypt Keeper said:

An electric XX, if as comfy as the XX that sounds like a lot of fun. 

 

Possibly more, it's slightly more upright (I'm experimenting with twisting the bars forward), lower seat, lower CG.  Same stability and great all around feel.

 

1 hour ago, The Krypt Keeper said:

Mileage isn't bad, might also not be the tire choice you are after. We all fall in love with a tire brand and easily hate others at well. These might simply not give you the performance you are seeking or expecting. 

 

I've perfectly happy with them.  The variation with PSI is really a thought exercise, not a complaint.  It would be interesting to try a Zero with another tire, but that seems extremely unlikely.  Also my rental had almost 2k miles and the tires still seemed fine, and not flat, which is shocking for a bike in FL.

 

D1B590DA-3056-4ED6-9E2D-4487DC31599F_1_105_c.jpeg

 

9F8D8FA6-94D3-43AF-B3DE-6E3E8ED1B832_1_105_c.jpeg

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Well, this may have skewed my impression of it to be more negative than it deserved.  I'm pretty sure the rear was showing 30 on the TPMS, I thought that was a bit nutty, but I knew that you were playing with pressures so I let it go rather than think there was a problem.  This was when I rode it right before you were riding it and discovered the nail.

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Oh, it was steering poorly for sure.  I guess...you need to ride it again!

 

Yesterday I left at 35/36 and during riding it hit as high as 37/39 but mostly 37/38.  Not a big change.  Day was 80 and I was doing around 80-85 on the freeway, doing my best to piss off the battery.

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  • 3 weeks later...

This bike seems to lose pressure faster than most, or maybe I'm thinking that because it's so sensitive to the loss.  And it's cooling off slightly here so that may affect it too.  We even had three days of winter (barely over 70).  Anyway yesterday I rode at 33/34 and again felt it immediately.  It's crazy.  The bike is so super neutral, I suppose, that any change in carcass shape is super obvious.

 

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