changing down gears

[brettski]

hey guys,
is it ok to change down gears without using the clutch. some1 was tellin me the other day its sweet to do it, but jus wana no if i will stuff up ya bike.
thanx guys

 

[daniel40]

you should always use teh clutch when changing gears

 

[z50kid]

u can chane up without a clutch to just way smoother with any u can rev down

 

[Flarry]

Never change gears up or down with out the clutch, you'll crunch the gearbox, extremly stupid idea.

Whats so hard about using the clutch?? It makes riding so much easier, you have so much more control, and just pulling in a lever is very little effort.

 

[mechanic-man]

it is a better idea to use the clutch going down, but you do not have to use the clutch going up.

 

[mechanic-man]

Daniel40 and flarry,yes you should use the clutch going down, but it is not nessescery going up. still i only go up without a clutch when racing. but it will not wreck you gear box.

Ben.
Wooooot 100th Post!!! haha

 

[Flarry]

Unless the engine is the moving the exact speed that everything is alligned it will wreck your gearbox.

But wont it sill wreck your gear box going up?? How is it possible for it not to?

 

[FREAKS_UK]

Im new to the pit bike scene and i took my 125cc pit bike up a country lane this morning wanted to give the gears some speed and i noticed that i could change gears UP without using the clutch it sounded smooth and did not seem like it was gonna wreck the gear box BUT i had to use the clutch to change back DOWN the gears but im not sure how it works and why you have not goto use the clutch to change UP the gears would be better if someone who knows alot about engines and gearboxes could reply to this post and put all our minds at rest cheers...

 

[Flarry]

Sure you can change gears without the clutch but the engine is still connected to the gear box and the gears arent spinning at the same rate so they will clash and do damage to your gearbox.

 

[geezus18]

i always clutch it down gears..then you have the oppourtunity to giv it a quick rev before you let the clutch out to give the bike some extra revs going down so you dont lock the back wheel up! Im just wondering if its bad to flat change these bikes...when im goin hard i just pin the throttle and never let it off when i change gears, just use the clutch!

 

[pascal125]

yeh, i usually use the lutch, much easier too. when riding mi bro's 110 mini it doesn't hav a clutch, it is HARDER to change gears and also it is very hard whne u r still revvin it, so the only difference between the two is you move 4 fingers and pull a lever for 1 second, i don't see the big deal, the gear box may also last another 10+ hours

 

[mech_eng_matty]

It is not a law that u have to use your clutch on changing up through the gears. It is commonly called a "motocross change" when u keep the engine pinned and just snap the gears thru with a little flick of the clutch while doing it. Thats how motocross riders do it and while it does put extra stresses on the gearbox it is not the worst thing in the world.

A motorbike gearbox uses dogs to engage the gears rather than being a direct mesh from gear to gear. This means that one gears face has a male dog on the side of it, the mating gear has a female hole on the side of it, when you shift the gear, the shifter forks move the gears on the gear cluster and it is the dogs that engage together rather than the teeth on the gears. What happens when u use the clutch is the engines gear (which spins at the same speed as the engine) gets disconnected from the gear cluster which stops the driving force of the bike, when u shift the gear and release the clutch the engine gear re-engages to the new ratio selected and away u go. When not using the clutch to change, the engine gear is still driving the first ratio (say second gear) when u hit the shifter the fork moves the gears to engage the third gear which is spinning at a different speed hence the dogs have to undergo more stresses in order to engage (and it is harder for them to do so).

Therefore, using the rationalle, when changing down gears (say from third to second) your engine revs increase because second gear has a taller ratio than third gear. When u try and do this without using the clutch the gearbox has to try and engage the dogs of a slower gear with a faster gear while the engine is still spinning and driving the bike forward. This WILL increase the wear on the dogs on the gears and it will increase the stresses the dogs incur to a certain degree however it is not impossible to do it.

I realise this is very long winded and probably doesn't make a great deal of sense so i'll try and sum it up pretty easily.

On a well made japanese, austrian or italian bike, the gearbox can change up without the clutch all day every day. On a cheaper chinese made engine, it is still capable of doing it however the quality of the manufacturing/materials is not quite as high so the likelyhood of your gearbox breaking is increased. I always on anybike use the clutch to change down gears whilst giving the throttle a "blip". This Blip attempts to match the engine revs to the revs the engine will produce when the lower gear is engaged, this makes the dogs mesh a little easier and minimises wear to the gearbox. this is also used twofold to stop compression lockups of the wear wheel when u realease the clutch ina lower gear (as someone previously mentioned).

Perhaps someone could add a slipper clutch to their mini to stop this problem of the rear wheel locking up after a change down! HAHAAHAHHHA.

I'm sorry this is so long, its a bit hard to try and explain without visual aids! If anyone has any more queries feel free to PM me and i'll try and explain it further (probably doesn't help that i didn't sleep real well last night and am not really thinking 100% clearly!!) HAHAAHHHA

 

[mechanic-man]

Old post but clear it up finally,
No clutch going up, you must use it when going down because what are you most of the time doing when ur going down gears? slowing down ie Braking. So when u brake u pull the clutch in yah? so there u go.

 

[darb110]

dam guys... so many ppl are saying its ok to shift up gears without the clutch?? guys you should never do this!! thats shocking for your gearbox i hate having to do any shifting without using the clutch. the only time i would ever resort to not using the clutch is when my cable has snapped or something... grinding your gearbox suxs and thats wats happin when ur not using your clutch basically.

just think of a car.. you would shift from 1st to 2nd without pushing the clutch in right?

 

[jayde156]

actually....i think its better to shift up gears without the clutch

with my first engine i used to clutch to change up gears during the run in and it stuffed the gearbox........grinded like 4 teeth off

if u use no clutch it is pretty much impossible to break ur gearbox because you are changing the gear up to a longer ratio so that means that it will turn slower and it is impossible to grind teeth off......you probably wont agree..but ive been riding pretty much all my life half of it with manual and ive never used the clutch to go up gears and when i did the engine broke down

 

[mad man]

Never change gears up or down with out the clutch, you'll crunch the gearbox, extremly stupid idea.

Whats so hard about using the clutch?? It makes riding so much easier, you have so much more control, and just pulling in a lever is very little effort.

it doesnt crunch the gear box fuck face

 

[Cactus Jack]

Cars are synchro mesh which means the teeth come out of mesh with each other - they use synchro cones and energizer springs to allow for remeshing of the gear teeth so you can smash teeth off if you don't use the clutch . Bikes are constant mesh meaning ALL the gears are constantly in mesh with each other - they just slide across the shaft in sets and use dog lugs to swap (simultaneously engage and disengage) already meshed gear sets . You CAN ride without using the clutch if you carefully match the revs to the gear speed but IF you stuff up you will round off the edges of the dog lugs and locator slots in the gears - then you'll have to live with the dog lugs popping out of the slots and hitting false neutrals all the time . Smashed gear teeth are caused by dropping the clutch at revs when there's too much traction - tooth play causes impacts and breaks brittle gear teeth off . A good quality transmission will have hardened AND tempered gears - whereas a cheap box will simply have gears which are hardened all the way through .

 

[pegleg]

Cars are synchro mesh which means the teeth come out of mesh with each other - they use synchro cones and energizer springs to allow for remeshing of the gear teeth so you can smash teeth off if you don't use the clutch . Bikes are constant mesh meaning ALL the gears are constantly in mesh with each other - they just slide across the shaft in sets and use dog lugs to swap (simultaneously engage and disengage) already meshed gear sets . You CAN ride without using the clutch if you carefully match the revs to the gear speed but IF you stuff up you will round off the edges of the dog lugs and locator slots in the gears - then you'll have to live with the dog lugs popping out of the slots and hitting false neutrals all the time . Smashed gear teeth are caused by dropping the clutch at revs when there's too much traction - tooth play causes impacts and breaks brittle gear teeth off . A good quality transmission will have hardened AND tempered gears - whereas a cheap box will simply have gears which are hardened all the way through .

This is why it isn't a good idea to be up or down shifting without using the clutch on these cheap Chinese engines. No matter how smooth it seems at the time, because the only thing that will be smooth is the gear teeth.

 

[coolmodee01]

i don't know mutch on this subject it's a good read
but the dog gears i find you can feel when the engage
from what a gather this is how the semi auto gearboxes work
i think??????
my diafo 110 has a 4 down gear box and at the mid point of each gear change you can get it to clutch
(and yes i do recognize that this is not a good thing)

in my opinion is as long as you mesh revs and speed propably you should be right on the gear up. you do this when you use the clutch anyway
as the guru said the gear down is a different story clutching is essential

like i say i could be full of shit to

my 2c

 

[Cactus Jack]

You should NEVER shift with the gears under load ! When you think of it - the auto engines (which are the same box minus the manual clutch) ARE shifting without using a clutch but you should really still blip the throttle on the shift to allow the dogs to fully seat in the slots of the next gear . The auto clutch has give in it to absorb shock on the dog lugs but a manual clutch has NO give once it's fully engaged .

To explain metal hardness - look at a drill bit - they're SUPER hard on the flutes but can be snapped easily or shattered like glass by a blow from a hardened and tempered hammer head . Some cheap boxes can also have soft gears that are just cheaply case hardened .

With Ford 9 inch diff gears - the stockers are hardened all the way through so they snap like twigs when shocked in a manual drag car which gets near 100 % traction . That's why a lot of drag racers run auto trannies - they're easier on the gears and axles .

Manual drag cars and higher powered cars need to run Nickel Pro gears - they're softer in the centre to handle shock without cracking - but have hardened tooth wear surfaces .