ktk_ace
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Posts posted by ktk_ace
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Any potential cons using this method?
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this is PURELY theoretical and not trying to be sexist but if COG has a formularic pattern,
then it could explain why riders who are more top heavy (esp women) prefer lowered front bikes, it offsets a part of their COG on the stock settings, how much im not sure.
Im sure Im taller than hotfoot but with a lanky light build , i actually prefer a slightly taller front end , maybe my COMBINED COG of a similar bike+rider might be actually the same as hotfoots lowered front build.
there almost certainly can only have one "Sweet spot" range in a formula governed with constants like gravity and mostly fixed variables (wheelbase,power output,tire sizing) imho
Ha ha, I WISH I was top heavy.
I'm sure those who know me are giggling at the image...The center of gravity is usually lower on women than men, actually, and women are often shorter and lighter, which makes shifting weight by hanging off more challenging for women in general. But, we have the advantage of light weight, flexibility, and being a lot smarter overall... (hee hee)
Regarding lowering the front, I think it is just preference on how stable you want the bike to feel in corners and how much effort you want it to take to turn the bike. I started OUT lowering the front as much as possible mainly just to get the bike as low as possible because I am so short. But I also learned that I liked the way they handled with a low front. My husband hates riding my bikes, they feel wobbly and nervous to him. To me, his bikes feel totally planted in corners and more stable under braking but I have to push a lot harder on the bars to turn them and I can't get them turned as quick.
Interesting comments on wheelbase - on my SuperSingle we just shortened the wheelbase significantly by moving the rear wheel forward, and lowered the front an additional 5mm (I had already lowered it 5mm), and the net result was much sharper handling. We tried lowering the front ANOTHER 5mm but at that point it started to wobble on corner entries.
Hotfoot :
oopsies XD, thanks for the data ^^"
Then Theoretically it should be more akin/closer to variable COG % as a value in correlation to the bike's weight.
In layman's terms it means your weight : the bikes weight , and as you pointed it out (the example of you vs your husband) ,: >>
having less leverage when the % is lower = more understeer while the bikes bone stock with stock settings ,hence the need for lowering of the front
Lowering of the front , I think besides the lowering of COG , also decreases total wheelbase length (its trigonometry) and makes the rake/trail values change... (< not 100% sure, just started dabbling with chassis dynamics)
I love a great discussion ^^
@Stroker, im not sure about the RSV4R esp the APRC , BUT I do know that the KTM RC8R and 1199 Panigale's back suspension linkage has knobs to directly adjust ride height !
(seen them both myself and knows how they work, havn't seen the RSV4's so called chassis/engine adjustability ; eg how it works)
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Back to topic :
Im sure the S1000RR 's longer wheelbase and slightly relaxed rake/trail + TC makes quick turn almost impossible 'cept when tires are not warmed up properly and with TC set to really really low or off
(I presume in racing, its off/ set to low?) .
The way you've phrased this makes it sound like you perceive Quick Turn as a all or nothing kind of technique, which I don't think it is, as Dylan stated previous in the thread the technique is to steer as quickly as possible for the conditions, you can always turn the bike quickly, and quicker steering action always has benefits on your line, you cannot however steer the bike as quickly at 150 mph as you can at 15 mph, the massive increase in gyroscopic force to be overcome means no matter how strong your upper body strength you cannot throw the bike down as fast as you would be able to at a much slower speed, A raked out chopper might not steer as quickly as a Moto 3 bike, but you can still use the quick turn technique to steer "As Quickly As Possible" and carve a tighter line that someone who steers the same bike at a much slower rate.
I assure you, after watching Joe Roberts and School Coach James come through the 4,5,6 sequence at Streets of Willow at full tilt, the S1000RR quick turns just fine
AH DANG!!! i misworded it bad ...
it should have been " makes quick turn almost impossible to be overdone" , thanks for pointing it out and I apologize for the literature blunder !!
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Tell me you are still on soggy suspension and street tires
Yup. The situation has been like that since we began riding 30+ years ago on virtually every bike we've had. BTW, the only bike I've had regular issues with regarding front end grip was with the CB400SF on Dunlop Motard radials, and by than I had altered my riding to more mimic that of my brother; brake early and turn in after getting off the brakes. Very disconcerting. Now I'm comfortable with late, medium and early braking, and the old style diagonal tyres on my old Z650 stick fine from the first meter. Which I like. Ultimate grip isn't great, but I do not push events any longer, so I have no issues. Track oriented tyres, from my limited experience, do not stick well when cold and when temps get close to freezing they offer about the same kind of grip as 10 year old touring tyres. For my mild mannered riding, I prefer predictable tyres that offer similar grip from from start to finish, from cool to warm days. And I have never been able to break traction no matter how hard I work the handlebars to change directions.
I did a search on the Z650... mind if i ask if the wheels are spoked or forged ?
If its spoked.... the suspension is gonna take one hell of a beating from modern race oriented rubbers esp with the carbon sidewall Q3's imho.
the load capabilities are just off the charts compared to 10 yr old touring tyres ... Kinda like bow and arrow VS a magpul ACR tech wise .
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I've lowered the front on every race bike I've had. I like the bike to steer quickly and with less effort. The trade off is the bike is twitchier and less stable.Quick turning the bike seems to me to result in a lot less wear to the front tire compared to turning in slower and on the brakes; trail braking puts a LOT of load on the front tire, and turning slower tends to use more lean angle and/or have you leaned over longer. The most wear I ever put on a front tire was when I was experimenting with trail braking, trying to mimic the style of some of my competitors to see if I could gain anything anywhere by doing so. I really worked the front tire!
Although I am not qualified to comment in any way... I'll still do it
I have, up until recently, been braking late and turning with the front brake trailing, using more of a V-corner style, standing the bike up before accelerating out. If I overshot, I would brake all the way through a corner. I have not had any issues with front tyre wear or grip in general. My brother has always done most of his braking upright, turned in hard and been back on the throttle early. He has always had issues with front tyre wear and often lost the front. This is with street riding in mind.
Tell me you are still on soggy suspension and street tires
Had a turn on one of the shops really messed up scooters , no way in hell im gonna quick flip it, it just doesnt feel planted at all to the ground , its like .... its on ice for a lack of a better term to describe it
Back to topic :
Im sure the S1000RR 's longer wheelbase and slightly relaxed rake/trail + TC makes quick turn almost impossible (to be overdone *EDITED) 'cept when tires are not warmed up properly and with TC set to really really low or off
(I presume in racing, its off/ set to low?) .
But having one of the highest output of all the 1L engine streetbike sure sets some of the above off; its a see-saw of balancing how much stability you can trade off for more speed without having an accident ,
does that count as experience ?
newer GSX-R 1000's for a lack of a better term, because of the short wheelbase +no TC , makes it a weapon in the right hands( WSBK grade rider) and right racetracks (smaller /tighter turns)
but lethal to less talented/educated/experienced riders as what hotfoot said for a bike with a "lower" front ,more instability and twitch at some speeds/conditions (No TC= one less safety net)
info: 2014 GSXR 1000 1405 MM wheelbase , 2014 S1000RR 1432 MM wheelbase
Do note that the 2014 GSXR 1000 has an electronic steering damper to iron out some instability/twitch (what speeds and conditions I dont know) while the S1000rr has TC + longer wheelbase.
Im sure COG has some influence here but just cant find a pattern here atm...
Edit:
this is PURELY theoretical and not trying to be sexist but if COG has a formularic pattern,
then it could explain why riders who are more top heavy (esp women) prefer lowered front bikes, it offsets a part of their COG on the stock settings, how much im not sure.
Im sure Im taller than hotfoot but with a lanky light build , i actually prefer a slightly taller front end , maybe my COMBINED COG of a similar bike+rider might be actually the same as hotfoots lowered front build.
there almost certainly can only have one "Sweet spot" range in a formula governed with constants like gravity and mostly fixed variables (wheelbase,power output,tire sizing) imho
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Im interested in the track temp and which tires you are on... mind sharing?
Dunlop D-211 GPAs, very warm/hot air temp (around 90F) with the sun shining. I didn't measure the track temp. Barber Motorsports Park is mostly right-handers and only a couple of significant lefts so it's challenging to warm up the left edge of the tire.
Benny
Thanks so much
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Unfortunately, I had an interesting lesson in overdoing a quick-turn at Barber the last day of CSS that I think is relevant to this discussion. Unfortunately it resulted in a crash.
I was riding hard attempting to catch up to my coach who was chasing another student and had the right side of my tires nice and warm as a result. However, the extreme left edge of my tire was still relatively cold (another of the many lessons from this crash) and I wasn't aware of that. Coming into the final (left) corner prior to the front straight, I quick flicked the bike in at a very high speed (both the flick and the entry speed) and almost immediately lost the front. Fortunately, nobody was hurt and damage was minimal.
The quick-turn lesson from this, after much discussion with several coaches, was: the fast rate of steering didn't DIRECTLY cause the crash, it was the cold edge of the tire once I got it there. The tire was able to take the FORCE of the quick-steering just fine, but the reason the quick-flick was an issue was that I didn't get the chance to feel indications that the tire edge was cold in time to stop leaning the bike over. Had I steered the bike more slowly, I would have been able to feel the cues the cold edge would have given me in time to prevent the complete loss of traction. The bigger issue was really my awareness of the cold edge on the less used side of the tire, but since this thread is about quick-turning, I thought the quick-turn lesson would be a good one. This is a big reason you don't quick-turn on cold tires... It's less because they won't take the force while steering, and more about giving yourself a chance to feel where the cold tire traction limit is before you exceed it.
Benny
Im interested in the track temp and which tires you are on... mind sharing?
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G'day mate!
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Its a Honda , what do you think?
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I would like to add that if your 150CC bike has a wheelbase of LESS than 1370MM , changing tires different to stock sizes can have huge effects on the handling alone ,
and most of the time detrimental if you dont know what you are doing.
Over/understeer and stability issues could arise easily.
happy reading:
http://www.risingsuncycles.com/bikespecific/suspension.htmPS. The ninja 250R has a 1400MM wheelbase and the CBR250 1370.
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Unless the ECU of the VFR becomes open sourced (both hard AND software -wise), I doubt you can actually know how it works inside, legally that is...
Technically , from a (very noob) programmer POV, the ECU has a built in "self learning" part (which is like RAM , parameters keeps changing depending on other paramemters)
its sort of like the butterfly effect ... if i can actually make out how every VFR ECU work AND CONSISTENTLY , I'd be headhunted for one of their departments...
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Yamaha is having a new frame/chassis being rolled out imho.
Looks like lorenzo and Rossi are adapting well to the new bike Watch out Honda!! -
im not sure if going up a hill counts or not > / \ (the type with a flat in the middle)
nearly wheelied up sideways when i QT to pass a slow motorist; ended up losing the front for 0.5 seconds, good thing im loose on the bars , bike tided itself upon landing.
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the front geometry looked waaay too steep
; did you by any chance lower the front OR lengthen the rear's height (as in making it higher) ?
rake angle geometry is a science im beginning to touch and my guesstimate is that the bike is too maneuvable at the expense of stability , giving way too easily due to a very small unwanted steering input.
I presume there was no steering damper too ? -
Well if its race grade , why not? WSBK level tc that is; saves 20% on your tire usage at that too.
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Depends on many factors imho...
On the superduke 1290 , twin brembo M50s? doable.On the norton commando... nah.
anything on a streetbike with no proper aerodynamic fairings and above 200KM/H = the wind will try to tear you off your bike
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Just on the speed and risk thing ...
When I attended my first CSS school, the Instructor blithely tossed out to the audience, "Well, no-one came here to ride slower, did they?!?"
Ha!Ha!Ha! Big guffaws of manly laughter ... And true, of course. But until that moment, I hadn't even thought about being there to ride quicker. I was there to learn to ride better. Which for me meant - and still means - with more control, with more consciousness of what I was doing or should be doing. So, in fact, actually reducing the risks inherent in motorcycling.
So I'm with Eric. Motorcycling for me is not a speed thing. Frankly, I have as much fun on my little bikes as on a track bike. I learnt a long time ago that I don't like going over 140mph. To be honest, I just don't see (or process the visual signals) well enuf. But nailing that bend just as it should be nailed - ah, there's the buzz! Hell, I can even laugh myself silly on a push-bike.
Just my 2 cents worth.
Craig
I'm in the program to ride better too ; thou i would say 75% safer/better/control wise and 25% faster/more speed as part of my overall objective.
The traffic and pedestrians are are effin' nuts fyi, the law heavily biased against pedestrians doesnt help either.
Less SR's triggering = more control + bigger portion of 10 dollars to spend on emergencies.
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My stock brake is going fine after 20K miles (no rebulids so far, only bleeding and cleaning)
so i think the lube isnt really necessary , it might just be icing on the cake for all i know
Just my 2c -
Welcome! My old hometown is just south of MY, Wish i could visit Sepang someday
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^^^ yea
I wasn't advocating that anyone do that, it was meant more for the funnies.
I bought a used $100 200cc off brand dirt bike just to beat to death. It has taught me plenty that I used on the track for reasons Hotfoot has already mentioned above. The shotty suspension has me really relaxed on the street bike. I try not to crash my yami dirt bike too hard, parts are expensive when you need them often and broken bones hurt, even in dirt.
Yes, I knew that was meant mostly for entertainment.
I had not yet seen your post, it popped up while I was typing my reply to Stroker.Is that actually you in the photo?
Naw, that is not me but I would love to try that one day. Maybe on a bike that is older and cheaper.
Seriously though, I am in the dirt for the obvious reasons but for the subtle ones as well.
Staying frosty between races/track time.
Keeping visual skills on par.
Keeping decision making skills as fast as possible.
Keeping fitness and endurance high.
Keeping passing skills more "aggressive".
Trying to hit the rutting every time helps me with consistency.
I had an interesting thing happen to me last weekend. I blew a corner on the track and ended up in the grass runoff area. Normally when this happens to me, there is a "sharp" change in thinking. This time, there wasn't, the transition from tarmac to dirt was more blended together. Difficult to explain but totally cool to feel. As I took the "shortcut" from turn 2 to turn 5 lol, there was mud, bumps, the drain ditch and I still had to scrub off some speed/downshift, all the while keeping my head straight enough to not crash and reenter the track safely.
FUN!
Im also interested in knowing the pros AND cons of dirt riding in relation to racing , esp on tarmac/asphalt surfaces.
WHo better to ask than someone who does both??
Does it give you arm pump on the track later as dirt tracking makes use of a lot of upper body movements?
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Normally in the dry I get my braking and downshifting done before my turn point and then flick the bike into the turn. Standard CSS stuff.
In the wet for some reason I do things slightly differently. I get my downshifting and the majority of my braking done before the turn point and then gradually trail off the brakes in the turn. My turn in is a slower pace than the quick flick that the school teaches because of the reduced traction. My logic is to stretch the time on the brakes so that I can use them longer at with less pressure.
This might be the wrong way. But with no "wet" training I was flying by the seat of my pants. If anybody has some tips please share as I would love to improve my wet track riding. Some of the most fun I have ever had was on a wet track.
I would be uneasy doing the no brakes drill in the rain. In my opinion using the brakes produces a more predictable entry speed than rolling off the throttle. With the limited traction entry speed is more critical and sudden last minute braking to correct entry speed is more of a traction risk than light brakes.
I have lots of article on wet everyday riding but not racing in the wet so bummer me too.
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I'm sure those who know me are giggling at the image...
How Do You " Read " Tire Wear?
in School Questions/General Discussion
Posted
Thanks for the link, pretty comprehensive imho~