The throttle grip should have some free-play before the initial reaction.
Failure to adjust the throttle’s free-play could result in dire consequences.
Here “Foreman” Oh answers about throttle free-play.
In this fifth instalment of TechTOC, “Foreman” Oh Kah Beng (KB) answers the question about throttle free-play and initial action.
Please keep sending in your questions and KB will answer them. You may enquire anything about motorcycles. The best question wins a complimentary session at Most Fun Gym (MFG) worth RM300.
QUESTION:
I need to twist my throttle a lot before there is any reaction, why is this so and is there any way I can fix it?
– Wan MT-09, Alor Setar, Kedah
ANSWER:
It’s quite normal to have some free-play on the throttle twist grip to compensate for throttle cable stretching. The free-play eases multiple steering manoeuvres at walking speeds, such as to move bike in tight parking spots or tight turns.
However, there is a tolerance for the amount of free-play . The general tolerance , for non-ride-by-wire bikes, is 3 to 5 MM of outer cable movement with the steering pointing straight and there should be still some tiny free play when handle bar is steered to maximum anti-clockwise (left) as this when cable is most stretched. If it’s too tight the bike will accelerate unexpectedly and cause panicky situations, as turning to one side will pull the on the cable. Chances are you could end up dropping the bike.
The method of adjusting the throttle free-play is quite universal for all bikes albeit with some specific variations, so refer to your Owner’s Manual.
Keep sending in your questions to me at TechTOC with Foreman Oh to stand the chance of receiving a complimentary session at Most Fun Gym.
Please visit the TOC Automotive College Facebook page or their campus (map below) or call call (+603) 7960 8833 for more information. Likewise, you can find more information about the TOC Bina Bakat Program here, or email info@toc.edu.my. Please click on this link for further information on the TOC Superbike Technician Course.
Please click on the links below for the previous editions of TechTOC with Foreman Oh.
“Foreman” Oh Kah Beng answers a good question about tyre wear in this edition of TechTOC with “Foreman” Oh.
It goes without saying that your bike is only as good as the tyres it wears. Tyre wear must be kept an eye on at all times.
QUESTION:
How do I know when is the right time to change my tyres? Manufacturers say when the threads are worn to certain depth but my friends say I could use them until they look like racing tyres. Out of curiosity, how does one check the wear on racing tyres?
Ahmad Sukri – Johor Bahru
ANSWER:
On street tyres, there are small “TWI” prints embossed on the outer edges of the thread surface to specify the locations of the respective “thread wear indicator.” Now, move your sight directly across the width of the tyre from the TWI print and you should spot a little “knob” which protrudes inside the tyre’s groove. If the surrounding tyre threads have worn down to this knob, it is time to replace the tyre. Allowing the tyre to wear beyond that indicator isn’t a good idea as there isn’t enough groove depth to evacuate water. This is considering normal wear.
As for a slick racing tyre, the wear indicators are signified by visible pin holes from left to right across the tyre.
There are other factors that you should also consider such as age of the tires (5 years from time of manufacture), signs of abnormal wear (one side worn more than the other), signs of heavy damage (parts of the thread peel off, for example), already patched too many times, obvious signs of deterioration such as cracks.
Just one word of advice, please remember to check your tyre pressure at least once a week. This is the time when you may pick up on the condition of the tyres, also.
Keep sending in your questions to me at TechTOC with Foreman Oh to stand the chance of receiving a complimentary session at Most Fun Gym.
Please visit the TOC Automotive College Facebook page or their campus (map below) or call call (+603) 7960 8833 for more information. Likewise, you can find more information about the TOC Bina Bakat Program here, or email info@toc.edu.my. Please click on this link for further information on the TOC Superbike Technician Course.
Here Foreman Oh gives his answer on what causes it and how to remedy it.
The question for TechTOC with Foreman Oh Kah Beng today is about squealing disc brakes, something that none of us like. What could be the cause and what would be the solution? TOC Automotive College Motorsports Consultant and Most Fun Gym Principal Instructor, Foreman Oh Kah Beng answers.
QUESTION:
My brakes are always squealing when I apply them. I have tried cleaning them but it still happens.
— TAN SUAN HOR, Melaka, Kawasaki ER-6n
ANSWER:
May I assume that you clean your brakes (disc brakes?) with commercially available brake cleaner solutions? You may try to do so if you are not already. Spray onto the discs directly and wipe off the residue. Be careful to not spray onto painted areas such as the rims and leave it on!
Cleaning brake discs – Courtesy of rideapart.com
However, if you have already done so and they still squeak, the discs are most probably “glazed.” Sand and dirt picked up during rain storms will get trapped between the brake pads and discs. Then as you brake, enough heat is generated to embed the sand and dirt into the discs. This is glazing. As such, you need to either “skim” the discs if they are within their wear tolerance or replace them altogether if they are not. There are workshops who provide this service.
Glazed brake disc
Other conditions that can cause brake squeal are worn pads, broken securing clip (which holds the pads in place at the back of caliper), pads with insufficient insulation or insulation shims, and no surface cut (which is common on motorcycle brake discs).
Parts of brake pads
Hence, you may also try different brake pad compounds. Those with high metallic content (usually those marked “FOR RACING”) will scour the discs and squeal. Keep an ear out when a racing superbike comes to a stop in the pits.
Keep sending in your questions to me at TechTOC with Foreman Oh to stand the chance of receiving a complimentary session at Most Fun Gym.
Please visit the TOC Automotive College Facebook page or their campus (map below) or call call (+603) 7960 8833 for more information. Likewise, you can find more information about the TOC Bina Bakat Program here, or email info@toc.edu.my. Please click on this link for further information on the TOC Superbike Technician Course.
Our new column, TechTOC with Foreman Oh seeks to assist you with your technical questions or issues with your motorcycle.
The winning question earns the sender a complimentary session at Most Fun Gym (MFG) worth RM300.
Prizes are also available for 2nd and 3rd placed questions.
We have been featuring the TechTOC with Foreman Oh column for a couple of weeks now and we’ve received a few interesting questions. Please click here for the first and here for the second column.
We’ve received many enquiries from our readers and followers in the past and although we attempted to answer every question, we couldn’t answer all due to our heavy schedule and time constraints.
But we now have “Foreman” Oh Kah Beng, also known as “KB” among his friends and “Sifu” by his students (us included).
We’ve featured KB and his current Most Fun Gym (MFG) motocross school extensively, as we discovered that riding in the dirt has immensely improved our riding skills. Please click on the link below about MFG.
As we’ve also written before, KB was the very first Malaysian GP rider, who raced on classic race bikes such as the two-stroke TZ750 against other GP greats such as Wayne Gardner and Ron Haslam. And won. Please click on the link below to read more about KB.
To refresh, KB has now been appointed as the Motorsports Consultant at the TOC Automotive College (TOC) due to his racing, wrenching and coaching background.
Not only that, the riders and even the mechanics of the TOC-HKM Toyo MSBK team are undergoing MX training at MFG in order to upgrade their skills.
So, since TOC and KB are providing motorcycle-based training, who better to answer your questions than the legendary Foreman Oh Kah Beng himself.
But it gets better, because in the interest of training more riders the fundamentals of handling a motorcycle:
The winning question receives a complimentary training session at MFG, coached by KB himself. Don’t worry about the motorcycle and equipment, as MFG will loan you the appropriate riding gear from head to toe and put you on the bike corresponding to your skill level. The package is worth RM300. Yes, absolutely free!
The 2nd-placed question will win you 2 tickets to the 2018 Pirelli Malaysia Superbike Championship (MSBK).
The 3rd-placed question will earn you a coveted Most Fun Gym t-shirt.
Please send in your questions now (PM us at https://www.facebook.com/BikesRepublic/), but please be specific about the issue(s) you are facing, and include your full name and your city of residence. So, start typing!
TechTOC is a weekly technical column moderated by “Foreman” Oh Kah Beng (KB).
KB is now the Motorsports Consultant at the TOC Automotive College’s motorcycle racing venture and Principal Trainer at his Most Fun Gym (MFG) MX-school
Send in your technical questions, and the winner receives a complimentary session at KB’s Most Fun Gym MX-school!
We began with TechTOC last week, when “Foreman” Oh or as he likes to be called, “KB”, answered a reader’s query about engine operating temperatures (please click on the this link to read about it). This week, KB answers a good question about motorcycle suspension, namely the terminologies.
Question:
I always hear my friends talking about set up. Can you explain what is preload, compression and rebound damping?
— Wong Siew Seng, Selangor
Answer:
To answer your question needs to take up and entire article so I’ll try to be as brief as I can and cover only the basics.
The short answer is, preload is to adjust suspension sag. Sag (there are unladed and laden sag) is the name given to the amount of suspension travel used up when the bike settles under the bike’s own weight (unladen) and when the rider sits on the bike (laden). You alter its settings by rotating the collars or ramp clockwise, which loads the spring. It will cause the spring to push back on the collar, thereby reducing the sag and raising that end of the bike’s ride height at the same time. Move the collars up and the ride height drops.
But do not be fooled! The frustrating misconception is that altering the preload also changes your suspension’s stiffness (spring rate). This is totally wrong! You DO NOT change the spring rate unless you replace the spring. The suspension feels harsh when you add in too much preload as you have reduced the sag too much and the suspension sinks into its stiffer stroke. Think of sag as “freeplay.” However, too little preload is also a bad thing, as the suspension will have to much “freeplay” and compress all the way to its bump stop.
Before we proceed to the subject of damping, let us get this out of the way:
A spring if left to work alone (without damping) is prone “oscillations.” A compressed spring stores energy and when that energy is released, the spring will re-extend past its original length. When that happens, the elongated spring now stores potential energy and will recompress the spring when released. This process happens over and over again, the spring will “oscillate” until the energy turns translates totally to heat. You will feel the bike wallow up and down, like sitting on a motionless boat on a stormy sea – up and down, down and up, up and down.
Spring oscillation graph – hyperphysics.phy-astr.gsu.edu
This is where damping comes into play. Damping controls the movements of the spring.
Compression damping (marked as “COM”on the fork/s or shock/s) pertains to how “quickly” or “slowly” the wheel is allowed to push upwards when it contacts a bump. If you increase compression, the valves inside the fork or shock shuts off the flow of hydraulic oil or gas, thereby resisting the wheel’s upward movement. Conversely, if you decrease compression, the valves open up and oil or gas is able to flow more freely, hence the wheel comes up faster.
But DO NOT go to extremes. Just because you ride fast, it does not mean you need more compression damping. If you increase it too much, there will be too much resistance to the wheel’s movement, rendering it difficult to “soak” up bumps i.e. the suspension could not comply with road irregularities. This will cause the wheel to hop and lose traction. Additionally, a lot of bump energy is transferred to the rider. A bit less compression works for cornering at times, allowing the tyre to absorb the bumps and “dig” into the road (better mid-corner stability, too).
Rebound damping is opposite to compression damping. It regulates how quickly or slowly the wheel returns to its normal position after compression. Too much rebound will cause the suspension to “pack up,” as in it returns too slowly and that end of the bike will feel loose as the wheel stays up too long from its optimal position. Too little rebound, conversely, causes the wheel to be pushed back down too quickly (“packing down”) and the bike will feel harsh.
Too little rebound can be confused with too much compression but pay attention to whether the “hit” is felt immediately when you contact a bump or just after it. If it is felt immediately when you hit a bump, it is due to too much compression (or a spring that is too hard). Conversely, if the bump is felt after contacting it, it is due to too little rebound damping.
So, adjust the preload to obtain the correct sag (30 to 40 mm or 1/3 of total suspension travel) and ride height, compression damping for bump absorption and rebound damping for how the wheel returns after bump absorption. Understanding this will do wonders to the handling of your motorcycle.
Although suspension settings are subjective as every rider has a different comfort zone and riding environment, personally, I always like to set both compression and rebound damping on the softer side, and work my way up, using the factory (stock) setting as the baseline. An overly soft setting is more forgiving than overly hard one, as the former is more pliant while the latter is harsh and unforgiving, which could lead to extreme occurrences such as tyre slides and tank slappers.
You can learn more about this in the TOC Automotive College’s Superbike Technician Course. Please visit TOC Automotive College’s Facebook page or their campus (map below) or call call (+603) 7960 8833 for more information. Likewise, you can find more information about the TOC Bina Bakat Program here, or email info@toc.edu.my. Please click on this link for further information on the TOC Superbike Technician Course.
You may also visit Most Fun Gym for off-road training, as it improves your riding skills for all riding conditions. Please call +6012-2072516 for more enquiries or to book an appointment.
TechTOC is a new weekly technical column moderated by “Foreman” Oh Kah Beng (KB).
KB is now the Consultant for the TOC Automotive College’s motorcycle racing venture.
Send in your technical questions, as the winner receives a complimentary session at KB’s Most Fun Gym MX-school!
Malaysian GP legend and now motocross instructor, “Foreman” Oh Kah Beng is no stranger to most of us. He was the very first Malaysian to have ridden in international GP events on 500cc 2-stroke machines in the 80’s, before moving over to the automotive industry where he was the head of Lotus Cars Malaysia and Driving Instructor for the Lotus community’s Performance Driving Program.
Growing up at his father’s motorcycle shop, he had learned about wrenching on a motorcycle from an early age. In fact, all his brothers are well-known technicians, too, including Sunny Oh and Randy Oh.
Lately, he is the operating his own motocross and off-roading as the Principal Coach, to teach riders the finer points of motorcycle control at his facility, Most Fun Gym (MFG). His students start from as young as four-years-old.
As TOC Automotive College makes a foray into two-wheeled education and racing, in addition to auto racing, it was only right that KB (as he likes to be called) plays the role of consultant to the racing project.
Please click on this link to visit TOC Automotive College to know more about their new TOC Superbike Technician Course. https://www.facebook.com/TOC.edu/
Here, we kick off the first installment of TechTOC, where readers such as you can send in technical questions regarding your motorcycle and KB will answer them. The best question earns a complementary riding session at Most Fun Gym! So get typing!
Kah Beng (far left) with Sebastian Foo and the TOC Automotive College MSBK Malaysia Superbike Team
Question:
I own a Harley-Davidson and a Ducati 1299 Panigale. What would be the ideal operating temperature for these bikes? I also own a scooter for my daily runabout, should the same temperatures apply to it as well?
– Muhammad “Don Ducati” Anis, Kuala Lumpur
Answer:
Motorcycle engines need to operate at a certain temperature range for the optimal thermodynamic efficiency. At this optimal temperature, the fuel-air mixture is in a state which is easier to burn efficiently. This efficiency translates to better power production, fuel efficiency and lower exhaust emission.
Courtesy of www.explainthatstuff.com
As an example, you may have noticed that familiar exhaust smell from a cold engine as it heats up. That is because the engine has not reached it working temperature.
Now, over to your questions.
The operating temperature range of a motorcycle depends on what type of motorcycle, which brand, whether it is Japanese or “continental” and if it is liquid- or air/oil-cooled, so please note that this is a general statement.
An air-cooled Harley-Davidson engine’s operating temperature correlates to its oil temperature. From what I understand, that is around 90o to 120o C on a 32o C day. It is okay as long as it stays below 150o C. The only way to tell is if you install an oil temperature gauge, sold by Harley as an accessory. (It’s a dispstick-like device which fits in the place of the stock engine oil filler cap.)
As for the Ducati 1299 Panigale, the operating range for Ducatis, including my Monster is around 90o to 105o C. Ducatis, Cagivas and most Italian bikes have traditionally run temperatures up in this range. Our TOC BMW S 1000 RR racebikes could hit close to 100o C in the heat (pun intended) of competition.
What scooter do you own? May I safely assume that it is from a Japanese manufacturer? The Japanese manufacturers adhere to lower engine operating temperatures, usually between 70o to 80o C, conversely.
