Damage at driving near redline when riding hard?

[imthatguy]

Hey guys,

Im part of a group of motorcycle enthusiast in Auckland who regularly ride SH22 from Auckland to Raglan together. Its a great ride and I really enjoy it but I find myself ringing the crap out of my little 1988 Kawasaki ZX-4 to keep up with them (they all ride modern 600 or 1000cc super-bikes). Im constantly near the redline to keep within the bikes power band and occasionally I find myself changing into the redline to cut speed / stabilise myself for the next corner ( doesn't have much engine breaking unless right up in the rpm range ).

How likely am I to blow something up running it that hard? Its not worth a huge amount, but I still get a hell of a lot of enjoyment from it so would like to know if Im going to seriously damage it running like that.

I understand the ZXR400 (which has the same engine) redlines at 14500 so Im not really sure why this is lower, can anyone explain this?

[AllanB]

A 400 IL4?

Used to being thrashed.

Mind you if you are up in the redline all the time like you say even on the 400 you'll be doing a pace no?

Blow on the pie to avoid burning.

Now everyone will come on and tell you to upgrade to a ZX14, but if that's not on the cards the best care for your engine is to give it regular oil changes with a quality motorcycle oil.

Alternatively slow down and don't try to keep the pace set by the larger bikes.

[Motu]

SH16 is a hell of a way to get to Raglan.

[Ender EnZed]

There is absolutely no need to be changing down into a gear that puts the rpm past redline. Use the brakes.

[imthatguy]

A 400 IL4?

Used to being thrashed.

Mind you if you are up in the redline all the time like you say even on the 400 you'll be doing a pace no?

Blow on the pie to avoid burning.

Now everyone will come on and tell you to upgrade to a ZX14, but if that's not on the cards the best care for your engine is to give it regular oil changes with a quality motorcycle oil.

Alternatively slow down and don't try to keep the pace set by the larger bikes.

Its definitely quote well maintained unquote by me, regular oil/filter changes, clearance adjustments, fluids regularly topped up, quality fuel etc etc.

Good to know it hopefully wont mind the abuse too much.

ZX14 definitely isn't an option at the moment but having a smaller bike has taught me some things I probably wouldn't have learnt with a bigger bike so I don't mind.

And I could but Im very competitive so thats where most of the fun is to be had!

[imthatguy]

There is absolutely no need to be changing down into a gear that puts the rpm past redline. Use the brakes.

Do do, and will do! However every now and again I slightly misjudge and it happens.

[Moi]

SH16 is a hell of a way to get to Raglan.

It's that new route via Glorit...

[Had the same thought myself...]

[imthatguy]

SH16 is a hell of a way to get to Raglan.

Good point, believe Im meaning SH22, will edit post - thanks.

[Motu]

I thought the go fast guys gave up on SH22, the lack of flag marshalls was causing some concern ?

[imthatguy]

You are possibly safer buying a bike like your mates. Having said that though you sound like many group riders who ride under pressure to keep up and if your mates had any consideration for you they would ride at a pace more suited to the speed of your bike in the interest of safety. One thing you dont want to happen is your bike dying during a multi vehicle overtake while trying to keep up. So either buy a bike that matches the speed of your mates or get them to slow down a bit and you would have a better chance of living longer if they do. Good Luck with what you decide.

Thank you! I appreciate that

We don't generally overtake vehicles much, as they are thankfully few and far between on that road, but thats a good point.

[Paul in NZ]

Are you in top gear? If not - maybe try a higher gear??

[Tazz]

If you're bouncing it off the limiter and or locking the rear when you're down shifting, then yes, you are doing it wrong. If you're down shifting and sustaining the high revs, then yes you are doing it wrong/'bad' for bike. Otherwise you're probably all good.

[caspernz]

You sound like you're trying too hard...

[OddDuck]

Grain of salt: I'm not familiar with the Kawasaki you're on. That out of the way... generally Japanese bikes are well engineered. The redline will be a genuinely safe engine speed. That said, forces on components like conrods etc get extremely high and it won't take going very far over redline to get into catastrophic failure territory.

It sounds like you're being careful with maintenance so that's good - but this sort of treatment is going to shorten the engine's life through wear and tear. The bike is going to start going through piston rings, then you'll have to start doing things like rebores and oversize piston sets (that said, it'll be at some pretty long intervals - crashing is probably more likely to write the bike off).

Options:

1) Accept that you'll see them head off, and you'll find them at the next intersection or rest point.
2) Bigger bike. Try a test ride or two and see if you're still happy with the current ride. I know I was amazed that I'd stayed with my 400 for as long as I had once I'd given a 750 a go.
3) Bigger front sprocket. Go a tooth up in size. Tolerate less torque for higher top speed at equivalent revs.
4) Different riding technique. Slower through the straights, faster through the corners than a bigger bike. Better tyres will make a difference, I'm running Bridgestone S20 Evo's and I've never felt more confident banked over.
5) More horsepower on current bike. Airbox / chip / exhaust mods etc... although this will torpedo the resale value of the bike (some dealers won't take it as a trade-in at all), it can get stupidly pricey, and chances are pretty good that the factory got it right anyway.

Hope this helps.

[imthatguy]

Grain of salt: I'm not familiar with the Kawasaki you're on. That out of the way... generally Japanese bikes are well engineered. The redline will be a genuinely safe engine speed. That said, forces on components like conrods etc get extremely high and it won't take going very far over redline to get into catastrophic failure territory.

It sounds like you're being careful with maintenance so that's good - but this sort of treatment is going to shorten the engine's life through wear and tear. The bike is going to start going through piston rings, then you'll have to start doing things like rebores and oversize piston sets (that said, it'll be at some pretty long intervals - crashing is probably more likely to write the bike off).

Options:

1) Accept that you'll see them head off, and you'll find them at the next intersection or rest point.
2) Bigger bike. Try a test ride or two and see if you're still happy with the current ride. I know I was amazed that I'd stayed with my 400 for as long as I had once I'd given a 750 a go.
3) Bigger front sprocket. Go a tooth up in size. Tolerate less torque for higher top speed at equivalent revs.
4) Different riding technique. Slower through the straights, faster through the corners than a bigger bike. Better tyres will make a difference, I'm running Bridgestone S20 Evo's and I've never felt more confident banked over.
5) More horsepower on current bike. Airbox / chip / exhaust mods etc... although this will torpedo the resale value of the bike (some dealers won't take it as a trade-in at all), it can get stupidly pricey, and chances are pretty good that the factory got it right anyway.

Hope this helps.

Thanks for the concise reply.

Granted its not great for the bike, but I get the feeling the bike was designed to be ridden a bit like that. All the interested power happens over 10k and anything below that feels asthmatic. Also good point about writing it off, its been crashed a few times but Ive fixed it up each time and try to learn from my mistakes

As for going slow, thats not really the point. The challenge is to keep up because I know they have been riding for much longer and have faster / more modern bikes.
Bigger bike is in the works but wont be happening for the next few months at least.
I could.. But to be honest Im not sure the bike needs more speed, the suppension has a hard enough time keeping the back tire in contact with the ground as it is..
Oh I definitely do that, straight line speed is boring on that bike anyway. Much more interested in catching people in the corners.
Have looked into, but honestly not much point on a small capacity bike like mine, they were actually released with a racing manual, but even in full race trim they only produce aprox 80hp and with not great reliability..