Is there any danger in getting close to redline?

Discussion in 'The Perfect Line and Other Riding Myths' started by davidb21, Nov 10, 2012.

  1. dirtrulz

    dirtrulz Been here awhile

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    I dont think I could handle being his engine builder and listening to that all that time, would make me cringe, especially since they usually raise the rev limiter also. Its a good thing he doesnt have to buy his own engines or bikes. Seems liek it would be better to land in a gear that isnt already tapped out rpm wise.
    #21
  2. High Country Herb

    High Country Herb Adventure Connoiseur

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    A friend of mine bought a brand new TU200 (2009 I think?), figuring he would save lots of money commuting on the highway. He pinned the thing everywhere he went, and kept the oil changed as suggested. After the dealer replaced the second motor under warranty, they told him they would no longer cover the bike if he rode it on the highway. He may have had bad luck, but there always has to be at least one cautionary anecdote, right?

    Most likely the bike will be fine, but I do think internal combustion engines wear out faster when ridden like that. I would recommend going one or two teeth smaller on the rear sprocket the next time you get a new chain, and using top grade motor oil. Cheap Walmart oil will get you into trouble running the bike like that.
    #22
  3. VozProto

    VozProto Type A ADD w/ OCD

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    The only bike I have ever had that sustained real damage from hitting the redline too much under load was one that I had modified the top end. Leave it stock and you'll be alright.

    The only thing I'll say is that if you are gettin on it, you've already surpassed your peak power by the time you hit the redline.

    Just re-read the OP.
    Perhaps a larger displacement bike is in order...
    #23
  4. NJ-Brett

    NJ-Brett Brett

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    Who makes a TU200?
    I never heard of one.
    My TU250 has 15,000+ miles on it so far with no issues.
    Hell, even back in 1979 I held my Bonneville wide open at 120 mph for 1/2 hour at a time often and I never had problems with it.
    I have always run every bike I ever had hard, and never blew anything up except the IT175 that always needed something after every ride, brakes, wheel bearings, crank bearings, reed valves, bore job, it was endless...

    Some older bikes, or older designs, would use oil when ridden hard at high rpm's.
    My TU uses no oil at all.
    Something like a TW200 does not seem to like doing 70 mph screaming for long, but its an old design and it lets you know its unhappy by making noises.

    I used to bounce even the Harley off the rev limiter often, no problems...
    #24
  5. High Country Herb

    High Country Herb Adventure Connoiseur

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    TW200, sorry.
    #25
  6. NJ-Brett

    NJ-Brett Brett

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    Yes, I had one of those, it was not happy running at high rpm's, but it never blew up.
    Its an old design.
    Its the one smaller bike I ever had that I would not trust to run at high rpm's long.



    #26
  7. randyo

    randyo Long timer

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    theres a safety margin in the manufacturers determination of redline

    my experience

    first bike, honda super 90, bought it used for like $50 it was a turd, every other kid in town owned it before I did. I had it about 2 months, no tach, but my bet is 80mph was faster than it was designed to go, but with a long relatively steep downgrade it would, till I heard a ticking noise, I just couldn't give it enuf fuel, it was thursty, so it began to eat solid food, valves, heads broke off, I tore it down, they were like marbles inside

    later in life, I had a Honda cb125s, I passed it on to my eldest son, withing a month it suffered the same fate as the S90

    move on, my 1982 Yamaha XV920R, no rev limiter, easily pulls 1500 past redline and still wants to pull, don't do it a lot, but occasionally, 60k no issues yet

    and finally, my 99 SV650, (gp shift)I admit, I have occasional brain farts, first one is I pull on to a nice stretch of open road, not a car in sight, time to practice a 1/4 mile run 1st gear to redline, click down into second, bring to redline and have second brain fart, ferget ya got gp shift, click back up into 1st, yes, shift into 1st at 70mph+ on a SV650, I'm sure I saw the tach past 13k maybe more the first time was not for long, I got clutch pulled in,

    second time, a year or more later, I was really spaced out for some reason, did almost the same thing, but never pulled the clutch in, I just rode out the skidding rear tire till the engine speed and tire speed matched, again it was over 13k for more than a split second though, as many as 10 seconds (on an engine with over 90k)

    ooh also a cage I used to regularly abuse, an '82 BMW 320i (e21) I loved to drift it on cloverleafs 500-1000 over redline, still ran strong with 460k original motor when it was rearended and totaled :splat, it was funnest car I ever had
    #27
  8. BikePilot

    BikePilot Long timer

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    Most 4 strokes will need valves adjusted more often the more time you spend at high rpms. It shouldn't hurt the engine though. I agree that it sounds like you badly need higher gearing. Don't flog it 'till it's warm, keep reasonably clean, good quality oil in it, keep up on maintenance (valves, etc.), and ride it however you like. These things are quite durable.
    #28
  9. NJ-Brett

    NJ-Brett Brett

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    I used to miss shifts during speed shifting my 1969 Daytona, since the trans was worse then most tractors/trucks/Russiaan bikes.
    Full throttle in neutral shifting at 8000+ rpm on a huge heavy piston push rod motor and nothing in the engine ever blew up, the trans was a different story, but it was a wimpy 1st gear story...

    I think the rev limiters or red lines are set a bit low, and most motors have the power drop off well before red line, and even the Harley guys often bump up the rev limiter 1000 rpm's without issues.

    Maybe you shorten the life of the motor some, but bikes are about fun.
    #29
  10. Foot dragger

    Foot dragger singletracker

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    Thanks,you said it for me. "only a mighty air cooled beemer is tough enough for the feared redline"
    A manufacturer puts that redline where it wants,they build the engine and tune it. If it cant rev to redline regularly theres something wrong.
    Ive seen what happens when a airhead is spun a little too hard.
    Not much worth saving usually.
    #30
  11. VxZeroKnots

    VxZeroKnots Long timer

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    :clap
    #31
  12. Pantah

    Pantah Red Sox Nation

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    Offroad race bikes don't even have a tach. You shift them when they run out of breath. Heck, my Yam WR250R is often at the throttle stops for long periods. If it won't hold the speed in 6th, I go to 5th. If still won't hold I go to 4th.

    I didn't have a tach on my 950 KTM either because I installed a roadbook holder that had its own dash system. I don't think I ever revved that thing too high, though. I now have a 690R. It has a tach, but I rarely look at it for shifting. The few times I have I noticed I'm pretty much on its red line when I'm pushing it.

    My sons use quick shifters on their road racers and they very often shift after hitting the limiter. It's little burble in the howl as they go through the gears.
    #32
  13. gmk999

    gmk999 ____ as a Rotax

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    Don't you want one one tooth smaller? more tire rotation per rev.
    #33
  14. Homey

    Homey Been here awhile

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    There are two main issues with running over the redline on a stock engine. First is the reciprocating mass and the second is valve float. The issue with reciprocating mass is more of a long term issue of wear and tear. Valve float is more immediate. At higher engine speeds the valve springs simply cannot keep the tappet on the cam shaft resulting in the valve staying open. Depending on the engine design this can result in a bent valve (if the open valve comes into contact with the piston) or just a reduction in horsepower. Most manufacturers have a pretty good buffer on the top end of the RPM curve so it's usually not a big problem to run a little into redline on occasion or up to redline frequently. The only issue with running continuously at or near red line is engine cooling. The engine will run hotter so it's important that the oil and coolant levels are maintained with fresh fluids.

    Many smaller engines and singles do not have a redline because the power drops off long before the engine gets to a point where it becomes a mechanical issue.
    #34
  15. Grreatdog

    Grreatdog Long timer

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    What could possibly go wrong in the valve train?

    Oh wait..... I recognize that shape..... :lol3

    [​IMG]
    #35
  16. mattness

    mattness Adventurer

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    my 2009 vmax is about to turn 14k miles, of absolute thrashing. its on its 6th or 7th oil change. no problems so far. i think its actually gotten faster.

    redline burnouts through intersections...


    10+ miles of 5th gear wide open throttle..... at LEAST 40 times.... it'll be 30 degrees out and I'll be freezing cold, at 150 miles per hour, i can feel the heat coming off the motor and blowing straight out past my legs. This puppy can burn some fuel.


    shifting at redline and riding a wheelie out in all of the first 3 gears...

    if this bike can handle it im sure it wont hurt yours. (redlines at 10k)


    oh and one note, my bike has ALWAYS been able to warm up. It has never been out of neutral without the heat gauge at the 25% mark. and within the first 5 miles or 10 minutes of every ride it doesnt go past 5k rpm.
    #36
  17. B.Curvin

    B.Curvin Feral Chia tamer

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    If you want to lower RPMs at a given speed, smaller in the rear or bigger in the front.
    #37
  18. wmax351

    wmax351 Been here awhile

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    Some bikes are built for it. Some are not.

    The Royal Enfield will burn spark plugs, and then pistons, followed by other stuff if redlined (ish) for too long.

    BMW K bikes are over engineered. For the 2 valve bikes, power drops off past redline. There's no reason to go past 8500 rpm. The valves don't allow enough flow. Better off shifting. But they don't mind it at all. I ran my K75 at 7000+ rpm for 3000 miles in 80-100 degree weather this summer. Didn't miss a beat. Burned a bit more oil. But still within the normal range.
    #38
  19. Qwik

    Qwik Adrenaline Addict

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    Ever seen Gary Rothwell ride? He sits on the Rev Limiter for a LONG time. His bikes last quite a while.
    #39
  20. NJ-Brett

    NJ-Brett Brett

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    Back in the day, I used to abuse my Triumph that way.
    Never had a problem with it, it managed to do a 9000 mile trip around the US and cross the Mojave desert in July when it was 126F. Lots of full throttle long interstate runs on that bike, and plenty of tickets.

    I had a LOT more problems with that bike when I did not ride it then when I abused it badly.
    I think most bikes are made for hard use, except Royal Enfields and maybe Urals...
    And I would rather ride something they way I want and have to fix it once and a while then ride around like an old woman.



    #40