BDLJ
4653
On a car....
..the aim is to get the CoG as low as possible. You do what you can to reduce weight transfer, to get the most benefit from all four tyres. Low CoG is the starting point.
On a bike weight transfers are *massive*, the CoG is inherently high and can move about, so it's all about controlling it. The CoG has to be in the right place. The 'right place' depends on the bike - its purpose, its size, its mass, available grip...
Without writing an essay on bike dynamics (which allows me to neglect Moments of Inertia, steering geometry, spring rates and damping, tyre widths, chain to rear pivot location) CoG effects can be summarised as
Longitudinally,
A low CoG will reduce the weight transfer onto the front wheel under brakes, with a tendency to push the front tyre. (think of cruisers)
A low CoG will reduce weight transfer onto the rear wheel under acceleration (look at drag bikes)
A high CoG will have more weight transfer, with a tendency to want to lift the rear wheel under brakes
A high CoG will have more weight transfer under acceleration, wheelie time (think how easy it is to pop the front up on a dirtbike)
Transversely,
a higher CoG means less lean angle for a given speed and radius of turn (sounds wrong, but isn't)
Of course, the CoG on a bike is heavily influenced by rider positioning - a big mass sited a few feet above the ground - which is why you see riders clambouring all over bikes, this is to get the weight where you need it. Back wheel lifting under brakes? move back in the seat to get more weight over the rear. Front wheel not turning in? Hunch over the handlebars to get some weight on the tyre.
The above can be summed up as: ratio of height of CoG v Wheelbase. Long and low, stable. High and short, twitchy.
This isn't just from theory, ride a Harley
Next up, does a light bike go around a corner faster than a heavy one? 
Things that make you go hmmmmm...
Happy new year to everyone. Before the end of the year, I was lucky enough to rediscover a piece that I've always been attracted to, even though it surprisingly (to me) elicits "eh, not bad..." from those around me whom I'm stupid enough to ask. I've been...
Well, I can't address the timing results after your ride...
...because is this one day an outlier out of many days (45 minutes slow though is bizarre)? However, I will say I actually really enjoy this piece, especially in the white dial variant. To me, the dial is proportioned very well and it has useful complicat...
the watch started to ride out 7 minutes fast...
Which crept forward 2 minutes from my usual 5 mins fast setting, over the course of a week. When I finished the ride, 90 minutes later, it was 45 min slow. So it "lost" 52 minutes over a 90 min ride. It could have been a loose hands; it could have been th...
I'm intrigued by the gray dial
with white date. I admired this watch from the day it came out, but the red color--the red of the date, PR, and needle of seconds, was bright to my eyes, and it just didn't speak to me as I thought it would, and I really wanted it to--because I love the c...
I agree with you about the colors, Mostel, but
That doesn't bother me. I rather like the "splash of color" with the red. I agree the moonphase background is a bit too light blue, a daylight blue rather than a night sky. I didn't know they made this model with a quartz movement. Cheers, TM
It may be Love .
Time stops, when you're in love... That is a well known phenomenon, with GP watches. Hmmmm... I am generally not keen on moonphases except on Perpetual Calendars for a reason: I am tired of trying to set the correct moonphase each time I decide to wear th...
The moonphase on this watch is rather unique...
Hi, Nico, The moonphase disc is constantly moving, rather than by discrete one or two jumps per day - the disc is affixed to the mainspring barrel. So theoretically, it is accurate to the hour / minute if set correctly. I have heard all the arguments abou...
Happy Dragon Year to you, Thomas!
What is the top speed of that three wheels cool road runner? I am sure it is faster than Mr. Bean's three wheels car. That GP looks clean and the case looks very well executed. Have a great and healthy Dragon Year. Regards Ling
Rowan Atkinson, aka Mr. Bean, is quite a motorsport enthusiast...
And famous for his (crashing) McLaren F1, among other exploits. The Piaggio MP3 500ie is good for 90MPH; it's not a superbike but quite adequate for a city tourer scooter. Very heavy though, and the COG is rather high, so not that nimble. Loads of fun... ...
yes, do tell...
Just like a 900 pound door that moves with a finger because it is hinged just right, with well machined and well lubricated hardware... So, Mr. Engineer, how high is too high and how low is too low? I'm not an engineer; I just know that a bike with a lowe...
On a car....
..the aim is to get the CoG as low as possible. You do what you can to reduce weight transfer, to get the most benefit from all four tyres. Low CoG is the starting point. On a bike weight transfers are *massive*, the CoG is inherently high and can move ab...
Very interesting details, thanks...
that's the sort of detail I was hoping for. In thinking further about the issue(s) I think nimbleness might be a misleading term; yes, one can feel a difference in the shifting of weight from left to right, right to left, between a higher COG and a lower ...
Smells...
...like getting caught behind a row of livestock trucks on a blazing hot day on some winding country road? One of the few times I'd much prefer to be cocooned in a car with the recirc. button ON. You're pretty much bang on with the balance point, particul...
Hi TM,
best wishes, and good to see you drive a ........bike.... the mountains in Switerland are great for that, maybe next time we can make a nice combo... Best, Michel
You might get bored...
Waiting for me, but yes, would love to try it. I just had my first "cold weather" ride that day - the temp ranged from a balmy 60F down to a VERY bracing 39F on the shadow covered stretches in the canyons. BURRRR...quite an experience, though, going throu...
No idea why you stopped the time but....
Hi Thomas, Happy new year my friend. We all needed a new year and now we got it. Let's do some good out of it. I have no idea (of course) why you stopped the time but I can say that I love this watch and if I was not a Patek Philippe forum moderator in ho...
May 2012 bring all that you wish for...
And more, my dear friend. Yes, most likely the GP needs a service, but this is not what is indicated by the sudden "loss" during the ride. Since the ride, and after correcting the time setting, it is back to the pre-ride rate. So there was something speci...
Your black speeder passed a wormhole?
Well, a watch showing such a weird timing is of course a case for the service center, but it could be a simple case of a magnetized spring (but then it should have been minutes too fast, not too slow). Regarding the Laureato itself, it is one of the most ...
Thanks, Marcus, I remember you are a fellow "trekkie"...
Hi, Marcus, There's actually nothing so weird about the basic normal condition timing - it probably needs a service to clean and regulate; it's been several years. The loss of time during the ride is hypothesized well by the sub-threads below. I too wish ...
Piaggio, Thomas?
I like it! Not crazy about the watch, though I agree with you -- the power reserve is an underrated feature, even on an automatic! Health, please health, and happiness for you and your family in 2012. All the best, CaliforniaJed
Yep, and thanks.
Unfortunately, it looks like no such luck; some pretty serious carry over issues from 2011...(actually goes back quite a few years... :-( ) Cheers, Jed, all the best to you and your family. TM
Perhaps...
Hello Thomas, Assuming you were not kidnapped by aliens (and held hostage for 23hrs 15min) it could be a resonance effect from the bike you're riding. At say 28,800 bph this is area 8 beats/sec and might be near the natural frequency of the bike/road vibr...
Not just the balance wheel....
...anything in the watch could be affected. One culprit could be the escape lever getting excited and mislocking. Or the mainspring could get all buzzy and not paying out properly... Which brings us to: Vibrations at the handlebars: The main source of vib...
Good ideas, Nomer, Ben...
Hi, I've worn other timepieces while riding the MP3, no noticeable problems. And as noted elsewhere in this thread, once OFF the MP3, no issues with that GP Laureato Evo either. So something about the MP3 and that GP. Cheers, TM
I have a different name for it...
A friend had couple of these in his shop (I think the 250 and 500 versions?). After both of us came close to crashing our brains out on them, we call them something rather....particular.
Perhaps a novice bike rider ...
... such as myself would find it easier than someone who is used to a typical motorbike? They do look interesting and I will add it to the Segway as transport to experience sometime. A
Yes and No
They are interesting. I like trying out bikes with weird front ends (I have an Italjet Dragster with single sided swingarm front suspension) so was keen to see what the MP3 felt like, especially given it shares the engine with the 500 Aprilia Scarabeo (a ...
I agree and disagree with BDLJ's POV...
of course, I'm not gifted or experienced like he is with all things automotive... But within my humble, limited range of experience and even more humble, limited technical knowledge, The MP3 is SLIGHTLY more "stable" than a two wheeled vehicle. It is NOT ...
Sphincter tightening is all part of motorcyling Thomas
and i'm glad you experienced it. it shows you were pushing yourself to your limits in the UK they do 50cc and 125cc versions of this bike and London is full of them as people have the impression they are easier to ride than a 2 wheeler. when you get to 50...
Indeed, Graham, you must!
like watches, it all depends on what you are after with the experience. The "trikes" seem to me really a solution for a question no one asked - it is marginally more stable than a bike, but with a whole host of other issues, but does not have several of t...
Micro Heat Pockets
I remember one ride years ago through the desert at night in which I experienced a series of rapid changes in temperature and humidity as I rode through the communities in and around Palm Springs, and I know exactly what you mean, Thomas. Smells, too can ...
rent one and let's go for a ride some Sunday...in fact, we should start a
PuristSPro riding (and driving) group. A ride (or drive) every two weeks or once a month... Ah, I can smell the coffee and morning brisk air now...
Thomas, I so want to say yes to this
...but I'm not sure I can do it. Let me mull it over. At worst, though, ride on over one weekend morning and I'll pull the espresso! Best, CaliforniaJed
Thanks for the educative comments ...
... TM and BDLJ. While I expected the bike/trike to be heavier than a standard bike, it was the balance and stability that I assumed would help a beginner rider. And for some reason I have always been nervous about supporting the weight of a heavy 2-wheel...
make no mistake, Andrew...
the extra wheel / wider track up front does add to the perceived "stability" at low speeds and at a stop - it feels more "balanced" and across a wider tilt range less unlikely to "fall" (tilt past the "point of no return") but the additional range of supp...
Thumps up from me for the GP, but
why is this not posted on the GP forum? Best Ztirual
Because the post was not about GP but rather about...
the potential behaviour of watches while riding a motor vehicle with harmonic vibrations, which then has the potential to expand to other wear environments like golfing (acceleration / deceleration, hard shock if taking a large and deep divot); shooting "...
Can I barrow your GP?
Hi TM, Happy New Year. Can't wait to hear more about your driving impressions of the Piaggio MP3. We should take out the GP and see the effects of firearm shocks. Maybe a PPro range day? Regards, ED-209
Needs service. +15 seconds was your first hint, -45 minutes is your second.
You're welcome. _john
Uh, Thanks?
ummmm... Now the question is, why do those things indicate a need for service? curious minds want to know... BTW - After the ride, now on day 3, it's been spot on for the past 3 days (including checking every 12 hours or so, so half day variations haven't...
Perhaps vibration ...
... should be included in the routine testing of watches in addition to shock testing? While if have no additional explanation for the cause of your observations, now that you have demonstrated that the watch runs accurately off the bike, you now need to ...
Oh, so pithy and cute is not what you were looking for? Ahem...
Hello Thomas, It may not need anything at all, but the company surely didn't intend for it to be +15 s/d when new nor of course to lose 45 minutes on a bike (or, er, whatever...) ride. And although they may consider themselves content with the outcome of ...
Thanks, John! Exactly what I was looking for...
Hi, john, I wasn't looking for an answer (you know me well enough to know that, right?) but rather discussion. Your comments were exactly what I was looking for. "If you speak with a watchmaker who has extensive experience with the caliber (unlike myself)...
So much in common... ;-)
Hello Thomas, I hope we get to meet again in 2012! The GP Evo 3 watches are as you said 'about how easy it is to wear' I do like those series a lot! I am just hoping that someday I’ll find one configuration will suit me, great watches. Scooter, another ch...
Thanks, my friend! The Gilera Fuoco is the same spec and basically the same vehicle
as the Piaggio MP3 here in the US; Max Busser and I talked about this several months ago. It is lots of fun, and quite handy... All the best, my friend, hope to see you again in 2012. TM