An open response to John Milmont's article titled: Stop and weight! A 50:50 weight distribution is not ideal. (http://automotivethinker.com/chassis/stop-and-weight-a-5050-weight-distribution-is-not-optimal/)
Just to clarify a few misunderstandings on the part of many commenters...
All the points made by the author about the benefits of a rear-biased weight distribution on a RWD car are CORRECT. To summarise:
- Better acceleration as weight is over the driving wheels (rear). This can also help earlier corner exit. However, this is purely from the consideration of traction and doesn't take into account centrifugal forces acting on the car through the turn.
- Better braking because brake force is distributed better between front AND rear, instead of being more front-biased.
Now there's a whole lot more involved in engineering a car's handling attributes than simply looking at linear traction (frictional forces acting parallel to the longitudinal axis of the car). This is one reason why even mid/rear engine sportscars don't have their engines positioned all the way back.
There IS a context in which 50:50 weight distribution is IDEAL. If we are to consider ONLY the lateral (centrifugal) forces on a car during cornering, the ideal weight distribution would be 50:50. This is the weight distribution which would provide neutral stability in a car going through a constant radius turn, at a constant speed. As you increase the lateral forces (increase cornering speed), a front-heavy car would lose traction at the front, causing understeer. A rear-heavy car would oversteer. a balanced weight distribution would do neither as it would lose traction at the front and rear equally. These 3 characteristics translate into the steering stability of a car when it loses traction mid-corner.
see this picture:
http://image.slidesharecdn.com/basicaerodynamics-110324082120-phpapp02/95/basic-aerodynamics-35-728.jpg?cb=1300955896
- understeer = positive stability. when you reduce speed, the car will return to the original turning radius
- oversteer = negative stability. once you start to oversteer you continue to oversteer. This is neglecting the dynamics of counter-steering.
F1 cars are en excellent case study of how engineers try to find the best weight distribution taking into account ALL the variables. The loss of traction at the rear during cornering, is what will allow the centrifugal forces to rotate the car and destabilise it mid-corner. But the acceleration and braking benefits of a rear-heavy car ARE desirable. Amongst MANY design features that they encorporate to achieve the best possible lap times, a few basic principles applied are:
1. rear-biased weight distribution to improve braking + cornering.
2. aerodynamics to put more downforce on the rear driving wheels, and hence improve linear traction.
3. long wheelbase so that the lifting effect of the rear end during braking is minimised. A longer moment arm creates a larger counter-moment against this lifting effect to keep traction on the rear wheels.
4. the longer wheelbase also reduces the angular velocity of the oversteering car about its normal axis by increasing the radius of the rear end from the normal axis. This means that that recovery of control by counter-steering or regaining rear traction is easier.
5. Wider tyres on the rear to improve traction.
So in otherwords, although rear-bias weight distribution is not ideal for steering stability, they use other design features to remedy this problem such as suspension tuning (compression, rebound, etc), and steering geometry (wheelbase, track width, toe, camber, etc.).
However, for a road car, many of these features on F1 cars cannot be used as extensively.
Road cars need to meet passenger safety requirements, and have geometric limitations to accommodate passengers, luggage etc. Extra wide tyres are also far too expensive to be used on street cars, and most importantly the drivers are not professionals. The average joe cannot be trusted to effectively regain control of an oversteering car, so much so that many manufacturers use electronic stability controls and differentials which make rear-wheel drive cars behave like front-wheel drive cars. So in these applications, a 50:50 weight distribution IS ideal - such as the Mazda MX-5 Miata.
My credentials:
- Currently 2nd Year Bachelor of Mechanical Engineering
- Graduate with Bachelor of Aviation Degree
- Always been good at mechanics (physics)
- Car lover
Monday, June 22, 2015
Saturday, June 20, 2015
MUST VISIT Spots in Wakayama
Train cafe
Beach cafe
Sobo
Ta9mi
Cannery Row
La Trampista
Pan Cake Labo
Yaichi Sushi
Yufuin burger
Japan's MUST VISIT Chain Restaurants
Freshness Burger
Gusto Family Restaurant
Gyu kaku
Komeda Coffee
Mos Burger
Coco Curry House
Sushi-ro
Ebesan
Royal Host
Bikkuri donkey
Kuala Lumpur's Best Cafés
My opinion of cafe's in KL. Numbers represent ranking - lower is better.
Espresso Lab Nu Sentral 2
Espresso Lab Nu Sentral 2
Nice, balanced but strong latte. Friendly staff. Salmon quiche was nice. Almost forgot the quiche. Water sold separately?
Lapis near burger king wangsa walk 2.1
Very friendly staff. Free water. Best atmosphere so far. Main food is delicious. Coffee is not bad but priced lower than mainstream cafes. The espresso lab was better. Cakes are nice too and priced lower than other cafes.
Big Apple Doughnuts Wangsa Maju AEON 2.2
Doughnuts are great for the price. Certainly better than mister doughnut and dunkin. Haven't compared it to krispy kreme. Coffee is also the best lf the 3. Ordered a Latte and there wasnt any froth. Milk wasnt thick enough. But the coffee serving for 7.50 was big. Served in a very cool looking cup. Te taste of the coffee was not bad. Bold tasting and enjoyable. Not the greatest food or coffee but fantastic value. Doughnut and very large coffee for RM10. I'm happy. No wifi. Atmosphere at this branch is not so great. Then again its a doughnut shop, not a cafe. There are nicer branches around though.
Coffee Mania PV128 2.5
Best service in any Malaysian business. Super enthusiastic and professional staff. Fantastic atmosphere. Very relaxing. Ideal for chit chatting. Very fancy looking cakes and deserts. Presentation is 200%. Mille Creppe's are their specialty supposedly. You'll be spoilt for choice on cakes and deserts. Latte was bad. Weak coffee, very milky, mostly just like hot milk. It wasn't even that hot actually.
Coffee Mania PV128 2.5
Best service in any Malaysian business. Super enthusiastic and professional staff. Fantastic atmosphere. Very relaxing. Ideal for chit chatting. Very fancy looking cakes and deserts. Presentation is 200%. Mille Creppe's are their specialty supposedly. You'll be spoilt for choice on cakes and deserts. Latte was bad. Weak coffee, very milky, mostly just like hot milk. It wasn't even that hot actually.
Dr.Cafe festival city mall. 2.6
Very nice atmosphere. Not cheap. Close to mainstream prices. Super friendly staff. Great service. Free wifi. Latte was weak. Choc mouse was nice but slightly too sweet for my taste. No free water.
Coffee Bean Low Yat. 2.7
Friendly staff. Wifi troublesome with logins and facebook page like etc. coffee was OK. Latte but a little weak tasting.
8 Ounce KLCC 4
Balanced taste. Served a latte-like coffee. 20% service charge?! For what?!
Espresso Lab Low Yat Plaza 1.9
Perfect flat white. Best coffee in south east asia. Friendliest staff and best service ive seen in a malaysian food business. Water served complimentary once i sat down. Professional attitude with all staff.
Secret Recipe Wangsa Maju AEON 3
Cake sucked. Mostly sugary cream. Chocolate part was low quality and mostly sugary vegetable fat. Coffee was served nice and hot, tasted balanced. But it was made like a cappuccino - thick 2cm foam on top with regular milk coffee underneath.
Coffee Planet Nu Sentral 5
Coffee: watery: almost like warmed skim milk coffee. Very high acidity. Shocked at first sip and thought it might have been made with spoiled milk. was served at slightly above room temperature- was able to just scull it down. price quite high for water. $7 for 330ml mineral water. Business off high traffic location.
Foods in KL
Best Cheese Naan
place called best cheese naan next to NZ near PV128. Indeed the cheese used is good quality cheese, rather than supermarket sliced cheddar. Very soft and lucious cheese naans. Tandoori Chicken - HUGE pieces and taste fabulously spicy and authentic at best cheese naan. Yummy cheese naan is yummy but a little too salty for my taste. its just cheese naan with sandwich chicken meat chopped up inside as well. Run by real north-indian people.
Indian Mamak/Kandar at PV20
Best chapati. Just fantastic. Their teh-C-kosong is also so good I'm always tempted to order two. Kopi-C-kosong also quite nice.
Pampas Burger
Across from Setiawangsa LRT. Awesome HUGE burgers. Comes with nice home-made dipping sauce. French fries are cooked well - little crunch on outside and soft inside - but standard cut. Good service, friendly staff. Coffees are meh.
place called best cheese naan next to NZ near PV128. Indeed the cheese used is good quality cheese, rather than supermarket sliced cheddar. Very soft and lucious cheese naans. Tandoori Chicken - HUGE pieces and taste fabulously spicy and authentic at best cheese naan. Yummy cheese naan is yummy but a little too salty for my taste. its just cheese naan with sandwich chicken meat chopped up inside as well. Run by real north-indian people.
Indian Mamak/Kandar at PV20
Best chapati. Just fantastic. Their teh-C-kosong is also so good I'm always tempted to order two. Kopi-C-kosong also quite nice.
Pampas Burger
Across from Setiawangsa LRT. Awesome HUGE burgers. Comes with nice home-made dipping sauce. French fries are cooked well - little crunch on outside and soft inside - but standard cut. Good service, friendly staff. Coffees are meh.
Indian Mamak/Kandar across from Hotel Sentral
Best roti canai cheese. So soft and fluffy. They put a bit of sugar in the thing too.
Best roti canai cheese. So soft and fluffy. They put a bit of sugar in the thing too.
Waffles at Wangsa Maju LRT
Just a bit of crunch on the edges, soft inside, no eggy smell, instead nice vanilla/pandan smell.
Fuel Shack, Low Yat Plaza
Awesome HUGE burgers. French fries are big and chunky, cooked right - crunch outside and soft inside.
Just a bit of crunch on the edges, soft inside, no eggy smell, instead nice vanilla/pandan smell.
Fuel Shack, Low Yat Plaza
Awesome HUGE burgers. French fries are big and chunky, cooked right - crunch outside and soft inside.
Wash face before or after shaving?
Shaving my face is more than just a grooming chore. It's actually an experience I enjoy. The feeling of warm water on my skin, the pleasant fragrance of the shaving cream, the refreshing sensation of the aftershave on my skin, all of it!
There is a non-consensus about various steps in getting the best possible shave. One of these is whether to wash your face before or after your shave. For most people this isn't a big deal and they will probably choose one method simply out of personal preference or habit, rather than any objective difference it makes to the condition of their skin after they shave.
Definitions are important! What do we mean by wash before shaving? With any type of "wet" shaving, you're going to rinse your face with water, before you apply the shaving cream and then put the razor to work. Washing does NOT simply mean splashing warm water on your face but washing with a soap or cleanser product of some sort.
Say NO to IRRITATION!
A good shave is, among many other things, one which doesn't end with razor bumps and/or acne breakouts. If you have sensitive skin (and all of us do to varying degrees), the primary cause of these problems is inflammation, which is what you experience as irritation. Inflammation can occur due to bacterial infection or simply from agitation or abrasion of the skin. Bacterial infection can occur from clogged pores containing dirt, dead skin cells and/or debris which carry bacteria.
REASONS to wash BEFORE shaving:
Firstly, to clear away dirt, debris and dead skin so that it doesn't get rubbed into your skin as you run the razor over your face. This reduces the chances of bacterial infection, and lessens the abrasion as you shave. But most importantly to clear away any oil which can reduce the effectiveness of your shaving cream. You'll notice that shaving cream lather will be denser and last longer on a washed face and this means that it can lubricate your skin better as your razor glides over it. Better lubrication means less irritation.
REASONS to wash AFTER shaving:
When you shave, the razor blade not ONLY cuts your hair, but it also will scrape off a very thin layer from the top of your skin. This, and the abrasion of the razor against your skin can also cause inflammation. Also, any dead skin scraped off in this way can get dragged into your pores, causing infection if it is left there without getting washed away. Aftershaves which have an anti-bacterial effect can solve this for most people, but they can also dry your skin and they don't actually clear away the dead skin, meaning bacteria can grow on it later on.
PROBLEMS with washing BEFORE shaving:
By shaving with an unwashed face, the layer of dirt and dead skin protects the living skin underneath from the razor. This may reduce irritation caused directly by abrasion of the razor against your skin.
What about washing BEFORE AND AFTER:
Washing with a cleanser removes a lot of the moisturising oils from your skin and can make it very dry. The shaving cream can also do this. So what you end up with is three consecutive drying processes to your skin. Moisture starved skin on the surface dies prematurely leading to a faster build-up of dead skin for bacteria to thrive. Also, your skin will end up compensating for dryness with an overproduction of sebum (natural oils) which can end up clogging pores. Keeping your skin moisturised should be part of your regular skin-care regimen anyway. So if you do decide to wash before and after, make sure your skin is moisturised afterwards. Also, make sure you use a very gentle cleanser, and only scrub your face lightly on each wash.
CONCLUSION:
Everybody's skin reacts differently to any of these stimuli. What works best for you will depend on which specific factors inflame your skin the most. Is it the abrasion? Is it dryness? Is it bacterial infection? Is it removal of skin by the razor? You'll have to try each of these methods for several shaves to see what works best for you.
For ME, I choose to wash before and after. This way, I can ensure the best possible lubrication from my shaving cream. After the shave, cleansing clears away remaining dirt, dead skin, bacteria and depilated hair. Finally, I use a mild benzoyl peroxide cream (from acne.org). Benzoyl peroxide (BP) is an anti-bacterial (actually a mild bleach) which can also dry your skin. The particular cream that I use, however, is mildly moisturising and has a very low concentration of BP (2.5%).
After over 15 years of experimenting, I've found that this is what works best for me.
There is a non-consensus about various steps in getting the best possible shave. One of these is whether to wash your face before or after your shave. For most people this isn't a big deal and they will probably choose one method simply out of personal preference or habit, rather than any objective difference it makes to the condition of their skin after they shave.
Definitions are important! What do we mean by wash before shaving? With any type of "wet" shaving, you're going to rinse your face with water, before you apply the shaving cream and then put the razor to work. Washing does NOT simply mean splashing warm water on your face but washing with a soap or cleanser product of some sort.
Say NO to IRRITATION!
A good shave is, among many other things, one which doesn't end with razor bumps and/or acne breakouts. If you have sensitive skin (and all of us do to varying degrees), the primary cause of these problems is inflammation, which is what you experience as irritation. Inflammation can occur due to bacterial infection or simply from agitation or abrasion of the skin. Bacterial infection can occur from clogged pores containing dirt, dead skin cells and/or debris which carry bacteria.
REASONS to wash BEFORE shaving:
Firstly, to clear away dirt, debris and dead skin so that it doesn't get rubbed into your skin as you run the razor over your face. This reduces the chances of bacterial infection, and lessens the abrasion as you shave. But most importantly to clear away any oil which can reduce the effectiveness of your shaving cream. You'll notice that shaving cream lather will be denser and last longer on a washed face and this means that it can lubricate your skin better as your razor glides over it. Better lubrication means less irritation.
REASONS to wash AFTER shaving:
When you shave, the razor blade not ONLY cuts your hair, but it also will scrape off a very thin layer from the top of your skin. This, and the abrasion of the razor against your skin can also cause inflammation. Also, any dead skin scraped off in this way can get dragged into your pores, causing infection if it is left there without getting washed away. Aftershaves which have an anti-bacterial effect can solve this for most people, but they can also dry your skin and they don't actually clear away the dead skin, meaning bacteria can grow on it later on.
PROBLEMS with washing BEFORE shaving:
By shaving with an unwashed face, the layer of dirt and dead skin protects the living skin underneath from the razor. This may reduce irritation caused directly by abrasion of the razor against your skin.
What about washing BEFORE AND AFTER:
Washing with a cleanser removes a lot of the moisturising oils from your skin and can make it very dry. The shaving cream can also do this. So what you end up with is three consecutive drying processes to your skin. Moisture starved skin on the surface dies prematurely leading to a faster build-up of dead skin for bacteria to thrive. Also, your skin will end up compensating for dryness with an overproduction of sebum (natural oils) which can end up clogging pores. Keeping your skin moisturised should be part of your regular skin-care regimen anyway. So if you do decide to wash before and after, make sure your skin is moisturised afterwards. Also, make sure you use a very gentle cleanser, and only scrub your face lightly on each wash.
CONCLUSION:
Everybody's skin reacts differently to any of these stimuli. What works best for you will depend on which specific factors inflame your skin the most. Is it the abrasion? Is it dryness? Is it bacterial infection? Is it removal of skin by the razor? You'll have to try each of these methods for several shaves to see what works best for you.
For ME, I choose to wash before and after. This way, I can ensure the best possible lubrication from my shaving cream. After the shave, cleansing clears away remaining dirt, dead skin, bacteria and depilated hair. Finally, I use a mild benzoyl peroxide cream (from acne.org). Benzoyl peroxide (BP) is an anti-bacterial (actually a mild bleach) which can also dry your skin. The particular cream that I use, however, is mildly moisturising and has a very low concentration of BP (2.5%).
After over 15 years of experimenting, I've found that this is what works best for me.
Monday, June 1, 2015
3 Month REVIEW: JAVA X1-7S-D 14" Wheel Folding Bicycle
THE GOOD:
I've even had strangers come and have a friendly chat about the bike. Common things to hear are:
- Hey, nice bike!
- Where you get it?
- How much was it?
- (The most surprising one is) Does it have a motor?
THE BAD:
All the positive attention from others is all well and good but there is one deal breaker that makes me regret buying it. The manufacturer rates it to take up to 100kg riders. Problem is I've had a rear-wheel spoke break on me twice.
The first time was after about a month of riding. I took it back to the shop where I bought it and they fixed it for free. Nobody carries spares for 14" bicycle wheels so the wheel had to get sent to China or Taiwan (wherever the factory is) to get it fixed. So, it was almost a month until I got my bike back.
I figured I must have just been unlucky to get a bad wheel. But after 2 weeks of getting it fixed, a rear wheel spoke broke again! Not sure if it's the same one or a different spoke.
So, although its specified to handle riders of up to 100kg, I doubt the wheels have been tested and rated to withstand riders of that weight. What doesn't help is the uneven roads that put increased stress on the wheel when riding over them at speed. Still, the ratings/ specifications should be at most half of what the wheel is engineered/ tested to withstand.
BOTTOM LINE:
I figured I must have just been unlucky to get a bad wheel. But after 2 weeks of getting it fixed, a rear wheel spoke broke again! Not sure if it's the same one or a different spoke.
So, although its specified to handle riders of up to 100kg, I doubt the wheels have been tested and rated to withstand riders of that weight. What doesn't help is the uneven roads that put increased stress on the wheel when riding over them at speed. Still, the ratings/ specifications should be at most half of what the wheel is engineered/ tested to withstand.
BOTTOM LINE:
All in all, I purchased this bike as my main form of transport. Above all other things, I need it to be reliable - ready to go wherever and whenever I am. It hasn't even come close to satisfying that purpose. I consider every dollar I spent on it a waste.
I can at best, only recommend this bike as a recreational bicycle for children. Being able to fold it makes it possible to put it in your car and take it to parks etc. But if it's a mode of transport you're looking for, STAY AWAY!
Also, the fact that the product fails to perform to advertised specification (100kg riders) means I can't really trust Java as a brand.
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