Need advice loosening a front sprocket nut - why you should keep the chain tensioned

[motorbyclist]

went on a 60km trail ride the other week, and by the last few km, if the weight of the bike wasn't all on the rear wheel, giving the throttle a squirt just made lots of chain noise and not much forward motion

safe to say i neglected to check the chain tension before beginning the ride

could've done with some more lube too


anyway, i've been trying for an hour now to get the front sprocket off. i've got the right size socket, covered the nut with crc and i'm turning it the right way, but sofar all i've managed to do is turn the engine over and bend a screwdriver i used to try to lock the rear wheel (put shaft in hole in rear sprocket, jamming against swingarm)

tried tightening it to hopefully crack any corrosion, tried using a hammer (of course) for a similar reason...

any hints/tips/advice/solutions?

(the bike is a '98 yamaha yz400f - and yes i know it needs a clean)

[The Pastor]

use a bigger power bar

[Disco Dan]

ya tried putting the bike in gear?

[Subike]

have you got access to an air powered rattle gun
if not
An impact screwdriver with a 1/2 drive head and a brass hammer
and be sure its not a left hand thread

Failing the access to those tools, take it to a person who has,
trying to lock the crank from turning to force the nut free could result in damage you just dont want to know about.

The right tool for the right job will always get you there faster.
The wrong tool will always wear out the soles of your feet

[motorbyclist]

ya tried putting the bike in gear?

yes, that's what i meant by "sofar all i've managed to do is turn the engine over"

tried jamming it at the rear wheel with a scredriver, but still no luck, just a bent screwdriver:(


have you got access to an air powered rattle gun
if not
An impact screwdriver with a 1/2 drive head and a brass hammer
and be sure its not a left hand thread

Failing the access to those tools, take it to a person who has,
trying to lock the crank from turning to force the nut free could result in damage you just dont want to know about.

The right tool for the right job will always get you there faster.
The wrong tool will always wear out the soles of your feet

i was worried about that

i'm sure about the thread - i can see a bit of it, and a left hand thread would be "wrong" for this application

i've got an impact driver, but it's got a 1/4" head, and i believe it may be broken anyway:(

[FJRider]

have you got access to an air powered rattle gun
if not
An impact screwdriver with a 1/2 drive head and a brass hammer
and be sure its not a left hand thread

Failing the access to those tools, take it to a person who has,
trying to lock the crank from turning to force the nut free could result in damage you just dont want to know about.

The right tool for the right job will always get you there faster.
The wrong tool will always wear out the soles of your feet

what he said

[Buddha#81]

Put the bike in 1st and get someone to sit on the bike whith their foot on the rear brake put a bit of pipe over the handle of your power bar and swing on it......tention the chain fairly tight first or it will just jump over the front sprocket.

Also make sure it doesn't have a lock tab stopping the nut from turning.

Good luck.........

[boomer]

i think you've got the wrong bit of ya bike.. those pics aren't of a sprocket!!! far out... maintenance hasn't been high on the agenda huh!?



get a socket set then get a hollow metal bar and use teh bar as an extension to put the force on the sprocket... maybe a couple of taps on the extension with a rubber mallet will 'help'

alternatively take it to the shop and ask for a FULL service ya tight arse :msn-wink:

[Subike]

Put the bike in 1st and get someone to sit on the bike whith their foot on the rear brake put a bit of pipe over the handle of your power bar and swing on it......tention the chain fairly tight first or it will just jump over the front sprocket.

Also make sure it doesn't have a lock tab stopping the nut from turning.

Good luck.........

Have a good look at the pic,
Doing what you suggest would have no effect what so ever
there is no teeth left on the front sprocket to lock on to

[motorbyclist]

Put the bike in 1st and get someone to sit on the bike whith their foot on the rear brake put a bit of pipe over the handle of your power bar and swing on it......tention the chain fairly tight first or it will just jump over the front sprocket.

Also make sure it doesn't have a lock tab stopping the nut from turning.

Good luck.........


Have a good look at the pic,
Doing what you suggest would have no effect what so ever
there is no teeth left on the front sprocket to lock on to

that, and i've tried it already


but what is this lock tab of which you speak?

[FROSTY]

Dude--the sprockets ferked right?--if yer gonna replace chain and sprockets why not tighten the chain till its bar tight -Then jam something into the sprocket/chain.
Wouldnt normally suggest it

[motorbyclist]

get a socket set then get a hollow metal bar and use teh bar as an extension to put the force on the sprocket... maybe a couple of taps on the extension with a rubber mallet will 'help'

alternatively take it to the shop and ask for a FULL service ya tight arse :msn-wink:

done the first bit, and that bike has never seen a mechanic since i bought it a few years ago:D

if i ever scrounge enough money together for a rebuild, i'll be doing myself anyway:bleh:

good ol' YZFs just dont die;)

[motorbyclist]

Dude--the sprockets ferked right?--if yer gonna replace chain and sprockets why not tighten the chain till its bar tight -Then jam something into the sprocket/chain.
Wouldnt normally suggest it

how exactly do you mean? already jammed everything at the rear wheel....

and the rear sprocket is surprisingly intact, but i'll be replacing it anyway - along with the plastic bit on the swingarm... chain has made it's own grooves in the metal:laugh:

[Ixion]

They tighten the damn thing ultra tight and then put high strength loctite on as well.

What Mr Frosty means , is tighten the chain as tight as it will go, then shove something like a tommy bar in between the chain and the sprocket just at the bit that the chain goes onto the sprocket (the front one ). So that when you turn the sheel, the tommy bar will be drawn into the sprocket so it ends up (or tries ot end up) jammed between the sprocket and the chain . Since the chain is tight, theres no room for the tommy bar, and it will lock the sproket.

It'll likely bugger the sprocket and the chain , but as Mr Frosty says, in your case, so what.

That'll lock it for certain. Only way the thing will turn then is to break the chain.

[motorbyclist]

They tighten the damn thing ultra tight and then put high strength loctite on as well.

What Mr Frosty means , is tighten the chain as tight as it will go, then shove something like a tommy bar in between the chain and the sprocket just at the bit that the chain goes onto the sprocket (the front one ). So that when you turn the sheel, the tommy bar will be drawn into the sprocket so it ends up (or tries ot end up) jammed between the sprocket and the chain . Since the chain is tight, theres no room for the tommy bar, and it will lock the sproket.

It'll likely bugger the sprocket and the chain , but as Mr Frosty says, in your case, so what.

That'll lock it for certain. Only way the thing will turn then is to break the chain.

right, i see both why it's do damn tight and how you mean to jam it

i'll give it a go tomorrow after work and get back to you


do you reckon it would've tightened at all during use? i can't tell if there's a spline on the shaft or not from where i'm sitting - all my past bikes had splines and a locker thing bolted on to the sprocket so it was pretty obvious

[FROSTY]

yea wot he said--give the thread a good soaking with CRC to help
Sorry Im tired -It wont bugger the rear sprocket but a pry bar jammed into the front sprockets gonna bugger it if it aint already

[Squiggles]

I have a 1/2" drive impact driver you could use, but knowing your success with tools i doubt its survival chances.... :lol:

[motorbyclist]

yea wot he said--give the thread a good soaking with CRC to help


did that


I have a 1/2" drive impact driver you could use, but knowing your success with tools i doubt its survival chances.... :lol:

well if i didn't insist on buying the cheap ones... and actually checked the bike toolkit before welding tools together... and who said i couldn't use my ratchet as a hammer when the real thing it out of my immediate reach?

:innocent:

[FROSTY]

bring the farkin thing over here--Ill get the sprocket off for ya

[motorbyclist]

you're in massey? local enough to take you up on that if i can't manage

[Ixion]

Jam the front sprocket, it's buggered anyway. Power bar on the socket (helps to have another person to push the socket onto the nut with his foot), and a length of water pipe on the power bar. And stand on it. It'll move. They don't tighten in use, but the torque setting can be as high a s 100 ft lb. That's tight.

I have a 3/4 inch drive socket set for these jobs, but a good 1/2 inch will be fine.

I doubt that a normal impact driver will work, they are just too tight.

[Max Preload]

Wasteful bugger... there's plenty more life left in that sprocket. :oi-grr:

[Animal]

Fuck me! That's the most shagged sprocket I've ever seen!

Good luck removing the bastard. If all else fails, find a bloody long piece of 50mm x 10mm flatbar, make a hole on it that the socket will fit through and weld it to the sprocket - which is fucked anyway. Park one of the wheels of you car on the end of the flatbar, and have another go with the socket and power bar.

[Squiggles]

Fuck me! That's the most shagged sprocket I've ever seen!

Good luck removing the bastard. If all else fails, find a bloody long piece of 50mm x 10mm flatbar, make a hole on it that the socket will fit through and weld it to the sprocket - which is fucked anyway. Park one of the wheels of you car on the end of the flatbar, and have another go with the socket and power bar.

He'll get carried away and weld it to his car too... :laugh:

[Max Preload]

BTW it shouldn't be anywhere near that tight. There's a lock washer behind the nut that hasn't been used properly.

[Skunk]

Last resort: Cold chisel the nut with an off centre path; turning the nut anticlockwise (assuming right hand thread).
I don't think the lock washer has been used at all.

[homer]

Last resort: Cold chisel the nut with an off centre path; turning the nut anticlockwise (assuming right hand thread).
I don't think the lock washer has been used at all.

do you think it needed a lock washer

[Max Preload]

Last resort: Cold chisel the nut with an off centre path; turning the nut anticlockwise (assuming right hand thread).

Not a good idea to strike the nut with a hammer & cold chisel as there's a couple of bearings on the final drive shaft that are sensitive to that sort of thing.

[Max Preload]

do you think it needed a lock washer

Do you think if they'd used the lock-washer provided, they'd not have needed to crank 3 colours of shit out of the nut causing the current problem? (Although, admittedly, the sprocket should have been changed long ago when it actually still gripped the chain thus assisting the nut's removal...)

[Ixion]

It'll come off. Just sprag the sprocket, and put a long pipe on the power bar. I keep a six foot length of water pipe just for such nuts.

If it's really obdurate and you have access to a gas torch , heating the nut good and hot will break the loctite . But it's a fine line between getting the nut hot enough and cooking the seal behind the sprocket.

[homer]

Do you think if they'd used the lock-washer provided, they'd not have needed to crank 3 colours of shit out of the nut causing the current problem? (Although, admittedly, the sprocket should have been changed long ago when it actually still gripped the chain thus assisting the nut's removal...)

yeah i guess ,still laughing

At least the lock washer wont need replacing

More lube ....lol

[motorbyclist]

Fuck me! That's the most shagged sprocket I've ever seen!

Good luck removing the bastard. If all else fails, find a bloody long piece of 50mm x 10mm flatbar, make a hole on it that the socket will fit through and weld it to the sprocket - which is fucked anyway. Park one of the wheels of you car on the end of the flatbar, and have another go with the socket and power bar.

400cc of RAW POWER and a young hoon tend to do that:D

i wouldn't dare touch it with a welder though - the seals etc on the gearbox would be rooted (though in the past on another bike when i somehow sheared the spline off the shaft i welded the sprocket to the shaft :sweatdrop)


(Although, admittedly, the sprocket should have been changed long ago when it actually still gripped the chain thus assisting the nut's removal...)

it was fine before the ride!

just neglected to check the chain:Oops:



was knackered today after work, will have a try tomorrow. failing that i'll clean the bike and seek help/tools

[Animal]

400cc of RAW POWER and a young hoon tend to do that:D

Yep, been there... !

So, we're all waiting with baited breath... did you get the bastard off?

Several guys have raised a truly valid point about controlling how much heat you apply due the seal melting. So, would it be worth borrowing a Dremel, or similar high-speed grinding/cutting tool and cutting the nut in half?

[homer]

next question i have is .....Has anyone actually got the damn sprocket off yet

lol

[FROSTY]

no phone call from him so i guess hes fixed it

[motorbyclist]

sorry guys, didn't get home frm work till 8:45pm

both my employers seem to want me at the same time

[homer]

but have you got the damn sprocket off yet
Thats the question burning a hole in my brain

[speedpro]

I'm almost hoping he doesn't get it off. Just so the poor bike can have a respite from the abuse.

[TimeOut]

Boiling water is sometimes enough to free the loctite

[homer]

Its a bit like a competion

whos going to win ....the bike ...or the sprocket

Im backing the sprocket

[motorbyclist]

had a go today.... bent the screwdriver a bit more once it was properly jamming the chain/front sprocket.....

i think i'll take it to frosty....

[homer]

dont let it beat ya
what about a huge set of vise grips grab the sprocket and tie the handles to the swingarm

[FROSTY]

Nahh dude bring it over --I have --Le "fuck off big prybar" to jam in the sprocket and le "bllody big water pipe" for extra leverage

[motorbyclist]

Nahh dude bring it over --I have --Le "fuck off big prybar" to jam in the sprocket and le "bllody big water pipe" for extra leverage

yeah ok, but i really cant be fucked cleaning it at the moment, so excuse the shocking state of cleanliness

i assure you it's what's on the inside that counts, and that afaik the insides are clean... clean enough....

[Animal]

Damn! I was looking forward to hearing tales of innovation and improvisation. Bugger... !

[motorbyclist]

Damn! I was looking forward to hearing tales of innovation and improvisation. Bugger... !

well, if it was my old xr200 there would be such tales, but i cant afford to break the yzf... and i'm sick of bending screwdrivers


oh the tales i have from the mighty xr200.... including the galv trampoline leg i used for an exhaust pipe, and once the welds broke, my trip around engineering workshops, stealing steel from the bins and building my own, tuneable, square, stainless steel and aluminium muffler which, once tuned properly, gave more power :D and more noise :D (and it was a better sound too:D)

and the time i needed to remove the sparkplugs from my nc30: after hours of furious searching of the shed for the/a suitable tool and fiddling around with other ones, i got a 1/2" socket, drilled the back of it out, welded that into another spark plug tool that fit down the hole and used that. about 15minutes later i found the genuine honda tool - in the bike toolkit, under pillion seat:Oops:


does anyone else find that ring-spanners are very good for looping over the handles of ratchets/allen keys to gain more leverage? and the good ol' vice grips on the screwdriver trick?

[homer]

Damn! I was looking forward to hearing tales of innovation and improvisation. Bugger... !

yeah me was too ,can someone post the details of whats happening
:niceone:

[motorbyclist]

yeah me was too ,can someone post the details of whats happening
:niceone:

waiting for frosty to PM me back....

the guys from the uni club might have a crack at it tonight when/if they come round

[homer]

well, if it was my old xr200 there would be such tales, but i cant afford to break the yzf... and i'm sick of bending screwdrivers


oh the tales i have from the mighty xr200.... including the galv trampoline leg i used for an exhaust pipe, and once the welds broke, my trip around engineering workshops, stealing steel from the bins and building my own, tuneable, square, stainless steel and aluminium muffler which, once tuned properly, gave more power :D and more noise :D (and it was a better sound too:D)

and the time i needed to remove the sparkplugs from my nc30: after hours of furious searching of the shed for the/a suitable tool and fiddling around with other ones, i got a 1/2" socket, drilled the back of it out, welded that into another spark plug tool that fit down the hole and used that. about 15minutes later i found the genuine honda tool - in the bike toolkit, under pillion seat:Oops:


does anyone else find that ring-spanners are very good for looping over the handles of ratchets/allen keys to gain more leverage? and the good ol' vice grips on the screwdriver trick?

I actually find a ring open ender with the ring end of another spanner on the open end provides sufficient leverage

[FROSTY]

waiting for frosty to PM me back....

the guys from the uni club might have a crack at it tonight when/if they come round
sorry dude--missed that one--call me 0210354615

[homer]

whats happening with the sprocket has been removed?
is it still stuck fast

we need to know
has there been so form of kiwi enginuity we have been told of?
:2thumbsup

[Ange09]

I had the same problem. Some guy came with a puller and pulled it off.

[homer]

oh wow thats really stuck

[Pixie]

1. make this
2. use it

[homer]

1. make this
2. use it

Dont they usually have another black thing on the other end as well
:bash:

[JMemonic]

Not needed that is enough to get you arrested in certain places.

Handy tool to have but I doubt in this case it would work to well.

[homer]

Right oh

so is the fucken sprocket still on the bloody bike or is is removed

I havnt spent a week checking for progress not to know the answer, and can someone tell me how they got it off if they indeed have

:pinch:

[motorbyclist]

still on... need to find time to see frosty

uni started today, so i'm pretty busy

[homer]

still on... need to find time to see frosty

uni started today, so i'm pretty busy

Ok thats great
just keep us all imformed of progress

[motorbyclist]

Ok thats great
just keep us all imformed of progress

will do

my attention has turned back onto getting my nc30 back on the road for uni and a coro loop this weekend

though if i'm driving the ute to pick up my new NC30 parts, i might chuck the dirtbike on the trailer and take it to my uncle and borrow his rattle gun

of course him being on the far side of mt wellington, and my nc30 parts being in the city and barrys point rd, it's not likely i'll have time.. gotta be at uni by noon

[homer]

sounds cool ,think id just cancell the day and go ride a bike
:laugh:

[homer]

Whats doing with the sprocket

i would like to hear its been removed a nice shiny new put in its place
:2thumbsup

[FROSTY]

OHH FFS---166a central park drive Henderson--drop the thing in and Ill sort it for ya.

[FilthyLuka]

OHH FFS---166a central park drive Henderson--drop the thing in and Ill sort it for ya.

lol, i drive past you on my morning commute! should pop in and say hi at some point

as for the sprocket

King tony 1" drive power bar, works on all my bikes :) Jam something in the sprocket, skidmark works well for this, he is dense enough and doesn't bend under pressure of the power bar.... however his latest honda purchase may have altered his physical coefficients in reference to bending both ways, best just use a crow bar :mellow:

[FROSTY]

lol, i drive past you on my morning commute!
I know this -Im the bloke moving the cars out in the morning.
Mind you Im the guy makes the coffee, scrubs the loo. washes the cars (and bikes) Im the lowest paid employee :innocent:

[Max Preload]

Oh FFS! Just wire both sides of the chain together behind the front sprocket and turn the fucking nut!

[Ixion]

Um. One wee caution. getting that nut undone is going to involve a lot of force. And locking things one way or another. There's a small but real chance something might break (like the chain) , in which case bits may fly around at a fair speed. So please in such circumstances, always wear safety eye protection .

[homer]

Oh FFS! Just wire both sides of the chain together behind the front sprocket and turn the fucking nut!

Actually thats a really good idea
i didnt think of that

[Max Preload]

Um. One wee caution. getting that nut undone is going to involve a lot of force. And locking things one way or another. There's a small but real chance something might break (like the chain) , in which case bits may fly around at a fair speed. So please in such circumstances, always wear safety eye protection .

Whatchu talkin' 'bout, Willis? There's no elasticity in a roller chain, and no inertia (since it's not being undone while he's bolting down an enduro track at 80km/h) and the chain would have to be ultra fucked beyond being able to transmit any power to the wheel before you'd ever break it with the torque you could put on the sprocket nut through a socket (that is to say, it'd have already broken the chain through use to turn the rear wheel).

[Squiggles]

i reckon the socket and man bar will shatter, sending splinters deep into him.

[Buddha#81]

I reckon when the nut lets go he will drive his knuckles into the ashphalt and shatter them, he won't be able to ride his bike and be forced to sell it.:jerry:

[FilthyLuka]

I reckon when the nut lets go he will drive his knuckles into the ashphalt and shatter them, he won't be able to ride his bike and be forced to sell it.:jerry:

Thats why you use your boot and stand on the man bar...

As for it shattering, i used a king tony 1" drive 2 1/2 foot long T-bar and a wookie :-) 100 kilo westie standing on a 2 1/2 foot strong arm gets pretty much anything undone

[Buddha#81]

I'd pay more for to see my option.............

[homer]

i just want to know if the sprocket is off or still on

[motorbyclist]

I got it off :D

:banana:

see attached pictures


when the nut finally moved it felt like something was shearing off!

thanks for all the advice guys

[Ixion]

Yep. That's exactly the sort of pipe you need to get those nuts loose!

[PirateJafa]

Who'd you sucker into giving you a hand?

[motorbyclist]

did it all on my lonesome

little brother was there doing his bike too so he took the photos of me

[Max Preload]

did it all on my lonesome

little brother was there doing his bike too so he took the photos of me

Liar! I can see John Lennon holding the pipe in this (http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=89286&d=1205546174) photo!