This Is Why Your Motorcycle Has a Redline | The Shop Manual

This Is Why Your Motorcycle Has a Redline | The Shop Manual
Need a tach? Check out some here: rvz.la/3yAnyQd
Redline, rev limit, rev ceiling… Whatever you call it, every engine has one, and it’s there for a reason. In this episode of The Shop Manual, Ari explains why engines have a maximum allowable speed, and what happens if you exceed it.

[@RevZilla]

Check out this article about redlining on Common Tread: rvz.la/3jGvcoe

[@Kenkalsi]

Hi brother, one question. Royal Enfield 650 have cam and its like euro6 so why it has very low rpms not like hondas and suzukis.

[@joylonsequeira5067]

Do a video on RPM drops slow or hangs when revved or while shifting gears.

[@antdx316]

Is overreving down (money shift) the same as overreving up or are the positions of the valves different depending on where the actual throttle position is?

[@savage22bolt32]

I don't understand why you added background music. I want to hear what you have to say. The music ruined it for me.

[@user-in8bz3kd7d]

Is it the technology in the Speed ​​movie? That technology has bothered me for three years and I have been wondering.

[@mikep.5517]

Just remember that the ECU rev-limiter won't protect the engine if you're at a high enough RPM and speed and downshift to a lower gear and overspeed the engine mechanically.

[@willspeakman2461]

Very true but its quite common for the rear to lock up which helps prevents over reving.

[@marcandres4254]

@@willspeakman2461 However, many bikes have anti rear lock mechanisms, so damage is not prevented.

[@zackiaryruddick701]

Isn't that what a slipper clutch is for?

[@mikep.5517]

@@zackiaryruddick701 The SC can help reduce the chance the rear tire will lock (possibly resulting in a loss of control) under those conditions but there's no assurance the engine will not still be overspeeded.

[@zackiaryruddick701]

@@mikep.5517 ok thanks for the info

[@hotchihuahua1546]

One thing to note . An engine may have a high red line but may produce peak power below that redline . Knowing where that peak is on a dyno and shifting to the next gear at that point will allow you to accelerate just as quickly if not quicker that pushing it to redline . It also gives you a safety buffer in case you miss a shift .

[@Kathisbuecherstapel]

one thing to note is, you dont use your powerband right if you shift at exactly peak power. so you wont use the quickest acceleration your bike has to offer. please look for the video "When To Shift Gears For The Fastest Acceleration" by Engineering Explained here on yt. its a great description for the topic, also applicable for bikes.

[@gaiustacitus4242]

@@Kathisbuecherstapel I don't have to watch the video. You get the best acceleration when the shift leaves the engine in the middle of the peak power band for the next gear. When you shift before that point, the engine has to fight its way back up to peak and you lose precious tenths of a second with each gear change.

[@dazeen9591]

​@@gaiustacitus4242 both of these are wrong if you are referring to horsepower with "peak power". Your horsepower band doesn't matter for shifts. It's the torque curve that acts as your accelerator. You ought to shift past the peak torque only when a higher gear would offer you more torque than a lower gear.

[@valebliz]

@@dazeen9591just no.

[@dazeen9591]

@@valebliz literally yes lmao you know nothing about engines

[@SALTxTHExWOUND]

Funny I just topped out the new 2022 Honda grom, those bikes live at redline 😂

[@allisonburgers2289]

My 2015 sure as shit does

[@Steve69419]

Trynna squeeze everybit out of them underpowered tired little things

[@allisonburgers2289]

@@Steve69419 yeah but at least you dont need to brake for corners

[@niteninja0133]

Thats because it has absolutely no power

[@ironryomwest]

Funny... I was gonna say that with my 125cc...

[@TheSoullessJoker]

hands down RevZilla made a good decision when picking up Ari !

[@videoheap]

I did a rev limiter party trick 2 weeks ago on my r6. Floated a valve, dropped it into cylinder 2, and am rebuilding the motor now! Cool trick huh!

[@Lukas32398]

how many kms/miles did it have back then and what year is your r6 from? nonetheless pretty cool that you get to rebuild it yourself, must be a tedious job

[@patfuryy]

Nurses must love Ari, his arm is a vein paradise

[@JoshuaTootell]

My ex wife used to poke at mine all the time. Drove me nuts.

[@robertg.durant8489]

You are probably thinking about the veins in his shlong too

[@Keyxn]

@@JoshuaTootell bro my brain read this and instantly went "and thats why she's an ex" 💀

[@ryancraig2795]

The other difference between the Harley engine and the Honda engine is that the reciprocating parts in the Harley are much larger and heavier. One cylinder on the Harley is larger than all 4 on the Honda put together.

[@jerm1027]

It's not the size per say, but rather the piston head speed (going back to inertia). As Ari stated already, Harley's have a similar, but slightly slower piston head speed, but assuming they are the same speed, since Harley's are under-square (i.e. longer stroke than bore), the piston head has to travel a greater distance, thus needs more time to do it at the same piston head speed, which translates to lower RPM redline. Honda CBR engines are over-square (short stroke, wide bore), thus the piston covers less distance. It's less efficient combustion, but you can have way more power strokes, hence the high-power rev-happy nature of oversquare engines.

[@ralphlouismendoza1977]

the Harley engine is just plain old design and inefficient.

[@andrewwilliamhorton789]

@@ralphlouismendoza1977 got that right….way overpriced boat anchors lol

[@rgh622]

@@andrewwilliamhorton789 Jelly much, LOL. Not everyone can afford an American classic, broke boi..

[@kristopherbell7158]

@@rgh622 harley needed a goverment bailout to compete with honda. Enoguh said there.. I like harely but i feel it's WAY overpriced..

[@MTNPANTS]

I love how Ari looks legitimately surprised by the amount of damage when he throws that old engine case 🤣

[@adityayitda]

Hey Ari, I hope it wasn't a big fall, can see your arm healing. Safe riding. Cheers!

[@ptacosnipe]

Really slick animations and visuals in this episode, nicely done Revzilla and co.

[@AriH211]

Thanks! We had a help from an animator on staff. I love how the animations came out.

[@manedwolfwithagmailaccount1478]

@@AriH211 this is a brilliantly presented and very professional video, as a new rider I highly appreciate it

[@Redmenace96]

I know the basics, but Ari and RevZilla usually give me something to think about. Great cycle channel. My VFR had a 11,500 redline? 90% of the time I was between 3 and 4.5k. 7k and you were at 100 mph. Took it to 10k for a brief time, and was ready to go back! I needed a track day to find out what that machine could do.

[@MrBulli69]

Surely you rev your engine to accelerate?

[@The_RC_Guru]

@@MrBulli69 he wasn’t really utilizing any of its potential.

[@corujariousa]

Ari, thanks for another Shop Manual video! I really enjoy all of them.

[@ThatMT09]

Finally another shop manual video! Always good to see you Ari!

[@ronaldtartaglia4459]

2:36.... no valve springs in my motor...😊, man you cover all angles. This upload is good for me. It allows me to believe there will be another common tread soon. I am in constant fear that you and Zack will be separated again...... constant......😥😥😥😥

[@TheThunderwars]

Some bikes live at redline. My 1977 CB Twin's redline is 12.000 rpm,but I frequently push it to 13.000 or even 14.000 where points ignition just can't sustain spark. It was absolutely advised to stay at 12.000 rpm all day(The manual stated that 12.300 rpm was an acceptable cruising rev) and even short bursts up to 13.000 were included in the manual. Small bike, high revs : all the fun with no fear of tickets.

[@ronalddaub9740]

I'm not impressed

[@andyboyd7511]

Love seeing Ari at the top of my feed. Instant watch and like. Thanks Ari!

[@philipbyrnes7501]

As usual, concise, clear, curate and well presented Ari, thank you. One of the best explanations I’ve seen presented, 11 out of 10 mate 😎👍

[@murraehaynes3182]

Nicely done👍…great explanation of the circumstances around rapid spontaneous disassembly events!

[@robertnewton9548]

Great job explaining this. I sort of knew this intuitively but having it demonstrated in detail like that really brought it home.

[@argieessex]

Fortnine levels of production quality and topic choice.

[@LTVoyager]

With far better than Fortnine technical credibility.

[@dimanxgermanist1327]

The animations are great quality, a true visual treat, thanks!

[@jamesbonanno3359]

Great class on redline. Excellent teaching style. You keep it simple, but explain a lot of good information at the same time.

[@MrHugemoth]

At the Vespa shop I worked at in the 70s we used to demonstrate engine durability by running it wide open in neutral for a full tank of fuel.

[@onanysundrymule3144]

Wow, really, a two stroke I presume, and the inbuilt ducted cooling alone sufficed? Kind regards.

[@taohawaii]

Very refreshing to just hear the facts, all the facts, and nothing but the facts. Thank you.

[@5665gopher]

I already knew this but I just love watching these well made videos so much, keep it up chief!

[@MotoPumps]

Awesome graphics and explanation! One of the best I have seen and covered it well for all levels. Nice work!

[@AriH211]

Glad you enjoyed it!

[@marsipio1733]

I love these videos. I always learn something.

[@pmdinaz]

Always good stuff. Thanks Ari!

[@Gobbbbb]

Could you also do a video on engine load, and explain why sometimes it's better to be in a lower gear at high rpm (especially going uphills) for the engines health and the riders benefit, thanks. This was a very informative video.

[@glennbeleber8418]

Thanks so much, Man! Really helpful content. Ride safe!

[@simemo75]

Great video. Very clear explanation... Love your videos!

[@fitz235]

Thanks so much for taking the time to explain this.

[@not-fishing4730]

My first wife missed a shift while passing with my '80 Supra and it sucked a valve. Back then engines didn't have a rev-limiter. Yeah, it was buy - buy Supra and I ended up buying a minivan for my growing family.

[@allenhuling598]

Always well presented and full of valuable information.....thank you!

[@WindyTherapy]

Very technical but well explained and in a simple manner. Great job.

[@non-wx8qm]

Yup, he's very technical but good for me as a novice.

[@scottsspeedtriplechannel]

Good to have you back.

[@gronkgrunk]

Welcome back, Ari. Looking 100% now 💪🏼

[@heyyhari673]

That's a lot of new information which I've learnt today !! Appreciate your content 👍

[@jpalcouffe7515]

Very clear explanation, thank you.

[@iamtheiceman]

Another awesome and informative video. Love that CBR, too....except for that dash, of course...(but at least it has a fuel guage).

[@MauricioRafaelGonzalez]

Now more educated! Thanks for the drawings/images, it helps.

[@gothops154]

Love this series. Super informative and incredibly well done. Shout out to all the nerds editing and filming these off-screen

[@AriH211]

Credit's due to Spenser for filming, Stephen for editing, and Carmella for the great animations. TSM is a team effort!

[@epicmotorcyclechannel307]

@@AriH211 I was wondering where the animations came from! They're awesome. Must be nice to have an in house animator!

[@ecrusch]

Great explaination. Thank you brother.

[@harrisonjacobsen173]

amazing production quality, great video!

[@seth_iwant_toride]

Excellent breakdown!

[@88888888Rocket1]

Great explanation Ari … thank you 🙏

[@Jagknorr]

As a scrub who knows nothing about motors - this is very informative! I like it!

[@someguyontheinternet7165]

If you haven't heard of them already check out engineering explained or donut media on KZbin. They're both prodominantly car channels but the science behind engines is the same. Donut keeps it relatively simple with lots of jokes, and engineering explained has some jokes but also gets really really in depth which i love to nerd out on.9

[@atomicdmt8763]

thank you for (your service)! excellent info

[@gallagherrides28]

I’ve watched this video like 14 times in the time it’s been out. I still do rev bangs. I still do full throttle redline shifts and then just not shifty and ratatatatata. But god is the engineering of these awesome hunks of metal just great

[@AmritGrewal31]

Nice explanation, simple enough for most people to understand. 👍 However, just one correction that I'd suggest. 4:40 rather, piston acceleration, which is also directly proportional to stroke. Mean piston velocity isn't a good indicator as things can accelerate at less rate but for a longer time period to reach higher speeds. Force = mass × acceleration For a given piston mass, the higher it's acceleration, the higher would be the forces it has to endure.

[@waldkrause6878]

Awesome explanation! As usual, great content!

[@alvinkinds]

That’s some awesome information and thanks for sharing. 💯

[@hra]

U r awesome bro.. Just one guy I can trust when it comes to bikes....

[@tammyforbes2101]

I hate going any where near red on either of my bikes but there both built for low to mid range torque more then all out HP. GSX-S1000 and CBR300R both use torque to get you going! I usually shift it like 4k rpm on both of them! Cruise at 5-6k rpm on the highway. The CBR tends to run out of gear on highway so I don’t take it on there for more them like one exit! Winds it way to hard for my liking and that’s what the big bike is for it loves the highway! Eats it up!

[@theymusthatetesla3186]

....Excellent video! Very well explained.

[@iAndrezM]

very informative as always, i love you ari!

[@Blinkubus]

I wish I had never watched any shop manual videos, so I could binge watch all of them as if it was the first time lol

[@Jesusprayerwarriorbw]

Love ya Ari! Keep up the awesome content & miss ya on MCgarage

[@sinkmach1ne]

i like the shop manual, is highly educational

[@NateB240z]

@0.07.... Versys 650 dash!!! It might be the pocket protector of motorcycles, but I love it!

[@natzel3865]

is there a limit to vein size per inch of muscle? Does the heart get stressed at a certain point? Props to you my dude. Keep on trucking Ari.

[@richardmaximo2260]

Don’t know your name but happy to see you back on KZbin, since you are not on the other channel I stop look at it, you really explain things in a very easy understanding way for someone like me, who is trying to learn about motorcycling suspension acceleration and even mechanic, I’m refurbishing my fz1 and all this contents help me to educate my self so let me tell you, muito obrigado (many thanks) keep up the good work, subscribed...

[@riad_ahmed]

this guy pumps iron before every take. I like. i Respect

[@CarlosGarcia-lx6qn]

Liked even before watching, top quality content, aprecciate that Ari.

[@BruceWayne-dl4lu]

Same

[@Sage_Lucas]

Same

[@mikeguitarification]

Great video, thanks.

[@anumeetsingh6218]

This man's a gem.

[@HarmonicaMustang]

I redlined my Yamaha YBR125 once while I was learning, I downshifted one gear more than I thought, luckily I realised it and pulled the clutch in shortly after. What's exciting about it is with my weight it can sit at 60mph comfortably, but I was able to get up to 70 on a dual carriage way with tailwind on a downhill slope, and the tachometer was a hairline from redline. Luckily the few times I go on a dual carriageway I'm happy to sit at 60-65.

[@Logarithm906]

I loved that bike. Favourite moment was finally overtaking a learner, following a horse box, after many miles of trying to find a nice flat spot with ideal wind (sadly there were no dual carriageways). Then zipping off into the distance. Mate had a Ninja 250. That was kind of hard to redline, it was basically a turbine with the redline starting at IIRC 20k RPM (which apparently you can do with a four cylinder 250 cc engine).

[@laillahilaallah001]

Thank you Ari, With your videos over the years teaching me how to fix and maintain my motorcycle, I've finally finished my project. A Cbr500r that I got on Copart for $625 that I've restored to OEM and even added a few mods, namely a sprocket change that gave me taller gearing. A thing I learned from you in your sprocket video. From the hardest job i think of that is Replacing Forks to even the most basic of maintenance such as cleaning and lubing your chain. You've been there for me every step of the way. Because I've toiled over him (the motorcycle) for the better part of the last two years, I believe that the motorcycle is an extension of myself. Thus I named him Rawhide, a anagram of my full name. Thank you Ari, and I hope to see you enlighten even more people into the wonderful world on two wheels. Such as you did I

[@AriH211]

That's awesome to hear! Also, excellent screen name.

[@laillahilaallah001]

@@AriH211 thanks ari!

[@PRSer]

I watched the entirety of this video but understood only about 5% of the actual content... but I still enjoyed it very much

[@sendit7777]

Very awesome and very informational.

[@Mike40M]

Fun fact. My old Manx Norton race bike has a max 7800 rpm limit. Set by the factory to ensure that the engine could endure 226 miles at mostly open throttle at the Isle of Man TT. On short circuit races 500 more rpm was allowed.

[@amperstandheart]

It's always a good day when we can get some physics with our motorcycle instruction

[@keithr5591]

You look gorgeous. Do you ride?

[@yashsvidixit7169]

Obviously she rides

[@garyboyce6186]

Awesome as always

[@JETZcorp]

The red line on my 1974 400 triple 2-stroke is 8,500. I'm told the stock rotating assembly is good for something like 12,000 and probably more with modern aftermarket pistons. However, 8500 is the point at which acceleration ceases to happen with the stock porting, so there's no point spinning a stock 400 any faster. Of course it has no valves and it has triplicate ignition points that don't float, so well and truly you can't over rev it except via spectacular bonehead downshifting. It's kinda fun to just hold it wide open for 3 minutes revving as high as it can with no limiter, knowing it absolutely will not scatter. And despite all the legends about 2-stroke triples, it's quite happy to do that without seizing the middle cylinder, on just 80:1 premix.

[@Oedk1]

🔥🔥🔥 your the man bro love seeing your videos

[@ackermull6909]

Im not sure about other nations but in Malaysia, bike owners always install aftermarket ECUs or remap the stock one to get rid of the rev limiter.

[@Bugholeexcalibur]

I was just telling some friends today that my 92 Suzuki Intruder doesn't have a rev limiter of sorts so if I rev it too much I run the risk of hitting the valves with the pistons. They didn't believe me so this video will server as proof!

[@PetesNikon]

A lot to absorb in six minutes, but all this is entirely correct to this engineer's ears. Great advice. Go red at your own risk.

[@Jimblefy]

Super informative. Thanks :)

[@totspuertos1722]

Thanks 👍 very informative

[@gouharfayyaz643]

Awesome video bro very knowledgeable things 😀 👍

[@jetlag4free621]

Motolove! Love my own yamaha. Always putting up the good stuff like Delta Parole, Metallica, Alice In Chains and others when I am working on her. Moto is life

[@juha2031]

Very Thorough.

[@rahulsharma-qx2dh]

Very well explained 👌👌

[@comcastjohn]

Great info!

[@gaiustacitus4242]

I had a custom ordered Kawasaki KH500 H1F triple that was designed for racing. Unlike the commercial models, it came with a 6-speed gearbox and the tachometer started in the orange at 7,500 RPM and entered the red at 9,500 and maxed out at 14,000 (instead of 12,000 as on the commercial model). Well, I pushed it past the 14,000 until the tach needle bounced up and down against the stop pin and eventually broke the cable by this abuse. What limited the engine RPM was fuel-air starvation. The manual that came with the bike listed top speed in 1st gear at 15 mph, 2nd gear at 29 mph, etc., but this was the point at which RPM reached the red line. After some additional modifications, the bike was actually able to hit 52 mph in 1st gear, 87 mph in 2nd gear and topped out at over 160 mph in 6th gear (the speedometer cable also broke). I put more than 15,000 very hard miles on this bike, many of them with the needle buried deep in the red on tachometer, and the engine did not come apart. I did blow seals quite often and had to tear the engine down to replace them. I even had the engine seize once at more than 100 mph due to a lack of two-stroke oil in the reservoir. The rear tire locked up and I brought the bike to a stop in a controlled skid. If I'd been running The Tail of the Dragon, then I'd likely not be alive to tell the tale. I was quite surprised when the engine kicked over after cooling down, and it even ran about the same as before after replacing the top end. The red line is really just a recommendation. There is a margin for safety. On a four-stroke engine, the push rods typically fail and/or head gaskets blow before any serious harm is done to the engine. I've pushed a 302 small block Chevy to 12,000 RPM and those were the type of failures I experienced. Of course, you can't do that with the factory engine components installed. I was once young and fearless. Age and crippling injuries from my youthful exploits have taught me a bit of caution, but only a little bit.

[@vijayam1]

Lord's work. Thank you.

[@dls613]

Thanks. Great info her.

[@dmaxcustom]

This was neat. What a simple way to explain a very complex issue. Thanks.

[@Chrisuperfly1]

My 2012 Aprilia RSV4 Factory developed a crack in the CAM retainer, problem is you can't buy just the retainer you have to buy the whole head. I bounced it off the rev limiter more than a few times at the track.

[@ttmfinland_yt]

2 strokes having redlines might be true on larger street use bikes but with less than 150cc you will start losing power before the revs are too high for the parts to handle. For example my 88cc has its peak power (around 27hp at the crank) at 13.5k rpm and after that the power falls off rapidly. The bike will not rev over 14.5k even on neutral. Also it can handle these kind of revs throughout the lifespan of the engine.

[@digitaldazzle5836]

Damn that Honda looks beautiful!!

[@matteouccellani9657]

Love the Versys 650🥰

[@maruthigs1026]

Much needed video

[@loramattal7688]

Hi Ari! I am new to riding just 1 year but took the MSF first and have over 24K miles. I ride a 2015 R3 totally stock except tires, brake pads and a chain. I have maintenance my bike as per Yamaha suggests. I don't think I ride my bike improperly. Would revving a bike like this say no more than 11K RPM (just to accelerate at first but regularly doing so) cause it damage? I have put a little over 8K miles on it since June it had 650 miles and sat for over 4 years when I got it.

[@DansADV]

Well done!

[@zdravkoperesdeprado4127]

Now I understand why maverick viñales was fired from monster energy Yamaha 😂😂😂

[@AntaresSQ01]

Thank you, now i'm going to send this to my mom who refuses to rev her peugeot over 3500 RPM when redline is at 6500...

[@XtremeCoke]

its worth noting that redline is also a buffer zone under hard downshifting to protect engine from running into mechanical issues. ref term "Moneyshifting"