Coasting

[marks]

There is one long downhill that my son and I tend to ride with our engines off and in neutral. It means the brakes get a workout but is great run racing (well.. me trying to catch him - as usual) with no engines.

Are we damaging anything - are the gearbox bearings all getting lubed etc?

cheers


Mark

[Danger]

The gearbox is not engaged so I can't see any problem.

[Danger]

Although the powerband does need constant lubing.:shifty:

[merv]

Haven't checked my Yamaha out but all my Hondas have had pressure fed gearboxes as far as the oil goes so yes you will be running the bearings short of oil compared to when the motor is running - not a good idea in the long run. There is no load on the box in neutral so probably not a viscious thing to be doing but even in neutral the countershaft is spinning in its bearings in the casing and the gears are in constant mesh so spinning on the shafts while not connected through the dogs to be driving.

I used to run my bikes in Maori for a laugh back in the 70's but after pulling one apart and consulting a workshop manual I thought hmmm these things don't have the oil up at the level of the bearings so not a good idea.

I'd say "done that let's move on a be more sensible and try another trick". One thing to do is just have neutral races with your engine ticking over and oil pump working but no chance of using the power or engine braking.

[B0000M]

Although the powerband does need constant lubing.:shifty:

lol, yea look out you might stretch your powerband, but that would only be a problem if you're pressing the powerband button at the time!

:lol:

[marks]

I used to run my bikes in Maori for a laugh back in the 70's but after pulling one apart and consulting a workshop manual I thought hmmm these things don't have the oil up at the level of the bearings so not a good idea.

I'd say "done that let's move on a be more sensible and try another trick". One thing to do is just have neutral races with your engine ticking over and oil pump working but no chance of using the power or engine braking.

Thanks Merv

whats the "run my bikes in Maori for a laugh" mean?

dead engine races aren't the same if you are idling in neutral.

I did discover that a WR makes a hell of an expensive sounding noise when it dumps itself on rocks without the motor to hide the sounds... :blink:

[kevfromcoro]

whats the "run my bikes in Maori for a laugh" mean?
Think he means nothing working..ie.. the engine.....
Just thinking about freewheeling down a hill..
Well the chain is still conected and i suppose some of the gears are going around....not to sure if it is going to do any serious damage though....
not sure...comments please....
Personally..wouldnt go down a steep gradiant without some sort of engine braking.....

[merv]

When I was young it was always referred to as Maori overdrive or Maori for short. I am sure Motu would be up with that saying. You know our cuzzies are cunning people, so if you want to go faster down a steep hill you throw it in to neutral so you can go faster than the motor would let you. Most hills aren't steep enough for that of course, but hey its a good concept, right up there with the kotanga (Billy T James car aerial) and especially when we were riding A100s or SL125s.

My favourites back then when I was in ChCh were Mt Pleasant Road and Dyers Pass Road. Both had nice long runs with a lot of curves. Dyers Pass Road had a few flattish spots on the city side that needed a bit of physical encouragement.

Anyway back to the original point you will starve the bearings of oil and many of them are plain bushes on the shafts so not a great idea for longevity.

p.s. 5 posts to go and I hit 5,000 for about the third time on this forum, but then Spank keeps changing stuff and taking hard earned service from our record.

[NordieBoy]

Personally..wouldnt go down a steep gradiant without some sort of engine braking.....

That's how I feel about 2-strokes too :D

[Buddy L]

its a pain when the bike jumps into netural going a hill, and just takes off on you.
Always when you about to take that corner!

[CookMySock]

how do you get it in neutral ?

If you are moving along quickly (100k plus) and you are clutching and changing down and down looking for neutral, you will be overspeeding the gearbox quite dramatically, particularly if you actually get it in first gear.

DB

[merv]

You start a Maori race from a standstill in neutral and getting up to speed in the first place is part of the laugh especially if you don't condone pushing the bike to get it moving.

[Buddy L]

Ill requote that, when im riding my off road bike, on trails or a motorX track(slow speed). and the bike goes into netural because i have miss judged a gear change
Normaly happends between 1st and 2nd, or even 2nd and 3rd, somtimes 3rd and 4th. the bike just builds speed alot quicker then expected(on a down hill).

Iv'e had my zxr250 flat out changing between 5th and 6th jump into false netural on the race track, at 160+. Now that scared me.

[CDFloss]

When I was young it was always referred to as Maori overdrive or Maori for short...

Back in SA I had a mate who drove a sugarcane truck (like a big-ass logging truck, but with sugarcane ;) ) - and he used to "race" other trucks down a very long downhill section called Van Reenans Pass, using his "Mexican Overdrive". :D Funny that there's also a kiwi version. :clap:

(Not sure why it was called Mexican overdrive though, must've been an American term, because I dont remember ever seeing a Mexican in SA)

[merv]

Mexican haha - priceless :devil2::banana:

[B0000M]

how do you get it in neutral ?

If you are moving along quickly (100k plus) and you are clutching and changing down and down looking for neutral, you will be overspeeding the gearbox quite dramatically, particularly if you actually get it in first gear.

DB

tadaa!! another road biker sounding like an ass

[Crisis management]

how do you get it in neutral ?

If you are moving along quickly (100k plus) and you are clutching and changing down and down looking for neutral, you will be overspeeding the gearbox quite dramatically, particularly if you actually get it in first gear.

DB

I think you will find motorcycle gearboxes are constant mesh boxes so the only thing you can overspeed is the engine if you let the clutch out......

[CookMySock]

I think you will find motorcycle gearboxes are constant mesh boxes so the only thing you can overspeed is the engine if you let the clutch out......so you agree that for a constant road speed, the clutch housing spins faster the lower the gear you are in ?

If for example, the top gear ratio is 1:1 and first gear is 6:1 wouldn't the clutch housing be travelling at the same speed ish ? So if the chain drive sprocket rotated at 2,000 rpm, then in top gear the clutch housing would be similar rpm ish. What would the clutch housing rpm be if the chain drive sprocket rotated at 2,000 rpm and you selected first gear ? (hint 6:1 ratio)

Will the clutch unit survive this rpm ?

DB

[takitimu]

Will the clutch unit survive this rpm ?

DB

You were talking about gearbox stress before, now it's clutch stress, keep this up & you might even get to talking about dirt bikes.

[Crisis management]

selected first gear ? (hint 6:1 ratio)

Will the clutch unit survive this rpm ?

DB

Dunno??? (technical term in case you don't recognise it) but the Hyobag sounds like an ideal candidate for a test.

Let me know how you get on. :innocent:


To attempt a serious answer...what is there in a clutch basket and plates that is likely to be so affected by the centrifugal force of high revs? The plates aren't likely to go anywhere and the basket is a light alloy casting not having a lot of mass.

Thats all I've got to say about it, this is essentially a thread about engine off racing downhill, why are we worried about the clutch?

[scumdog]

how do you get it in neutral ?

If you are moving along quickly (100k plus) and you are clutching and changing down and down looking for neutral, you will be overspeeding the gearbox quite dramatically, particularly if you actually get it in first gear.

DB


Just pull the clutch in, click-click-click down the gears until the nuetral light comes on, let out the clutch and your away...

EDIT: Is it REALLY that hard to figure out???

[DrewBroadley]

Just pull the clutch in, click-click-click down the gears until the nuetral light comes on, let out the clutch and your away...

EDIT: Is it REALLY that hard to figure out???

Yes, if you don't have a neutral light ;)

[scumdog]

Yes, if you don't have a neutral light ;)


Still managed to do it on my old 4-speed H-D that had no neutral light (or rev-counter, indicators etc etc), just had to be more carefull.

[vr4king]

Care Factor = 0

I was told once coasting on dirt bike(motocrosser) should never happen "if your not breaking you should be accelerating and vise versa"

[merv]

Care Factor = 0

I was told once coasting on dirt bike(motocrosser) should never happen "if your not breaking you should be accelerating and vise versa"

Hey we're not talking about GSXR frames here lol :crazy:

This thread started because marks was talking about coasting for the fun of coasting, which I call going downhill in Maori, and he was concerned about the effects on the bike. I've answered all that for him.

Otherwise sure, your comment about braking (breaking frames haha) or accelerating applies if you are trying to win a race with your engine going normally, but there is also fun to be had doing other silly things in your life.

[Danger]

Care Factor = 0

I was told once coasting on dirt bike(motocrosser) should never happen "if your not breaking you should be accelerating and vise versa"

He says in his first post that he does not have his engine running. Only moving part other than wheels and chain is his sprocket spindle and attached gear. Plenty of lube in the bottom of the gear box and no load means no problems in my opinion. Maybe we should send this one to Myth Busters. I'm sure they could blow his bike up somehow.:2guns:

[B0000M]

put it this way, ive never heard of anyone ever damaging anything on a dirt bike from doing this