Chain tension

[Blue Beastie]

After a successful evening working on my monster, keeping in mind that I am a mechanical novice, something still bothers me. Everytime I adjust the drive chain tension to what I think is the correct tension, roll the bike backwards and forwards, the chain just goes back to the same as it was before. It's not an old chain and everything is tight (nut and bolt wise). It's quite loose but not worryingly so. Just wondered if there is an obvious reason that I am missing.

Other than that, I managed to replace the neutral switch, service the rear brake caliper and change the pads, and remove/re-fit the back wheel for a tryre change. The drive chain thing happened before I touched the rear wheel!!

[nik_the_brief]

After a successful evening working on my monster, keeping in mind that I am a mechanical novice, something still bothers me. Everytime I adjust the drive chain tension to what I think is the correct tension, roll the bike backwards and forwards, the chain just goes back to the same as it was before. It's not an old chain and everything is tight (nut and bolt wise). It's quite loose but not worryingly so. Just wondered if there is an obvious reason that I am missing.

Other than that, I managed to replace the neutral switch, service the rear brake caliper and change the pads, and remove/re-fit the back wheel for a tryre change. The drive chain thing happened before I touched the rear wheel!!

You should have about 25mm of play (that'a an inch to those of us born before the 70s) at the tightest point of the chain if properly adjusted.

I assume that you pushed your bike back and forth til you got to the tightest point and then did your adjustments? If so then there's nowt to worry about although you may want to keep an eye on the chain and consider replacing the whole thing (as well as the sprockets) if it does go slack with ever increasing regularity.

[slob]

Almost all chains have tight spots. You need to find the tightest point and adjust the chain there. It should be adjusted so you have the correct free-play with your weight on the bike.

[steviej]

Do you use a paddock stand when adjusting the chain???


If I remember correctly, the adjustment should be done with the bike on the sidestand.

It's all about physics, mechanics and fulcroms

[steviej]

............. at the tightest point of the chain...................
..........You need to find the tightest point...............

Now then, don't you mean the 'slackest'..........

i.e. at the centre of the length of chain..........

[slob]

At the centre where there is most play, yes but where the chain itself is tightest.
Check out how your chain goes loose-tight-loose-tight as the wheel rotates, next time you pop the bike on a paddock stand Stevie.

[nik_the_brief]

Now then, don't you mean the 'slackest'..........

i.e. at the centre of the length of chain..........

Definitely at the tightest!

If you adjust the chain at a slack point it will do it no good at all when the sprockets rotate and put too much strain on it.

[steviej]

Well, you've both agreed and contradicted...........and took the bait. :D :D :D

The chain goes "loose-tight-loose-tight", 'cos of uneven wear due to the doppler/sine wave effect. So it would make sense to adjust the chain when it's at its tightest point.....................

.....................but check it at its slackest part!!! :confused: :eek: ;) :rolleyes: :cool:



Confused? You will be........... :p




God!!! I love this place...!!!! :D

[slob]

Neil, I hope this helped. Stevie, clearly you need an oscilloscope to check your chain.

[Unit 18]

Oh, and don't forget to retighten the adjuster bolts after you finish, or it can all get a bit messy.

[gary tompkins]

Oh, and don't forget to retighten the adjuster bolts after you finish, or it can all get a bit messy.

Oh yes - if the adjuster bolts loosen off the end plates will drop out, spin and catch in the rear disc/sprocket and get mangled!

Almost saw this happen to a monster at Mallory in June :eek:

[Scotty]

http://www.ukmonster.co.uk/monster/attachment.php?attachmentid=6947&stc=1

i some times wonder why im keeping broken bits

[gary tompkins]

Ahh yes, I see that in true 'Blue Peter' stylee, danger-man Scotty has as been kind enough to knacker one for us in advance :lol:

[nambduke]

Chain must be adjusted on the tight spot otherwise you risk either snapping your chain - it can and does happen!! - or destroying sprockets and/or output shaft bearings.

[cgreen]

Oh yes - if the adjuster bolts loosen off the end plates will drop out, spin and catch in the rear disc/sprocket and get mangled!

Almost saw this happen to a monster at Mallory in June :eek:

yup happened to me, pottering along fine, BANG! DING! heard metal going down the road, bike felt odd and off centre.
Sure enough adjuster bolt had sheared right through and gold end plate gone (looked for it too no sign of it) worst thing was it ripped the end of the swingarm right out and it was split too so not just a heat up and bend back job.
Lucky for me Stuart had an M900 swingarm kicking around so I bought that god knows how much a new one is...

[nik_the_brief]

A stupid question perhaps but more or less on topic...

What happens when my chain has been adjusted (tightened) so much that the adjustors are at the end of their travel and I can tighten no further? Is it time for a new chain/sprocket combo? :confused:

[slob]

It's probably stretched beyond its servicable limit by then Nik. If not you could maybe take a pair of links out but hardly worth the bother.

[Fosse Foxfight]

sorry dudes but the rest of ya are out of step, Stevie J is the only one who knows where to check his chain tension.

ta ra

[steviej]

A stupid question perhaps but more or less on topic...

What happens when my chain has been adjusted (tightened) so much that the adjustors are at the end of their travel and I can tighten no further? Is it time for a new chain/sprocket combo? :confused:

It's probably stretched beyond its servicable limit by then Nik. If not you could maybe take a pair of links out but hardly worth the bother.


As Slob/Rob says "It's probably stretched beyond its servicable limit".

I wouldn't attempt to take any links out, just change it...........
.......(I ain't measured it but I reckon you'd not get the chain on again if you did!!) :eek:

[steviej]

sorry dudes but the rest of ya are out of step, Stevie J is the only one who knows where to check his chain tension.

ta ra

Why thank you young man :p

[Fosse Foxfight]

Why thank you young man :p
For calling me young man, theers a blow job for ya next time you're round Bath.....or maybe just a glass of elderflower cordial and a cucumber sandwich?

ta ra

[Phoenix]

theers a blow job for ya next time you're round Bath

............... :eek: ................

[Fosse Foxfight]

............... :eek: ................
what? :( :o

[gary tompkins]

A stupid question perhaps but more or less on topic...

What happens when my chain has been adjusted (tightened) so much that the adjustors are at the end of their travel and I can tighten no further? Is it time for a new chain/sprocket combo? :confused:


How many miles has it done Nick? I've known fairly new chains (mainly cheapo ones) to stretch a lot in the past, and if they were a touch long to start with you can run out of adjustment way before time. If this is the case you might get away with splitting it and re joining it minus a few links.

A good quality o-ring chain should be only about £80-100, and if you fit a scottoiler you may even get close on 20K miles out of one like me :D

[slob]

'servicable limit'

Nik, if you don't know what to look for: max. 256.5 mm between 16 pin centres with the chain stretched out on a flat surface, according to my book of words.

[steviej]

For calling me young man, theers a blow job for ya next time you're round Bath.....or maybe just a glass of elderflower cordial and a cucumber sandwich?

ta ra

Well you are 2 years YOUNGER than me, as for the 'BJ', I'll stick with the Elderflower and Cucumber me thinks :D :D

[nik_the_brief]

Cheers Gary and Rob, much appreciated. I'll have a look this weekend then.

Thinking about it it's probably overdue replacement anyway, tried to do a search on here to see my old threads about the problems I had at the time but that was before the 'great thread loss' of 2004!!

Any idea of who's doing a decent deal on new chain and sprockets at the moment? - I quite fancy one of those nice red 'uns! :twisted: (Don't worry Busters came up with a good deal - £82.50 including postage for a new chain and shiny red rear sprocket.)

[MilesB]

(Don't worry Busters came up with a good deal - £82.50 including postage for a new chain and shiny red rear sprocket.)
Dont forget the front sproket too Nik :eek:

Have you got a link to Busters - as I'll be in the market for a new chain soon too :(

Miles

[nik_the_brief]

Dont forget the front sproket too Nik :eek:

Have you got a link to Busters - as I'll be in the market for a new chain soon too :(

Miles

Yep, you remember my front sprocket problems eh!!

T'was the whole set, front and rear sprockets + an o ring chain. For an extra £20 I couldn've had an X ring and could go up from there but since tis only an ickle 600 I thought the standard O would be more than sufficient!

Linky - - > http://www.busters-accessories.co.uk/faq.asp

[Will]

Get a shaft drive and all these problems disappear :D :D :D :D :D

[gary tompkins]

Not ready for the pipe & tartan carpet slippers operation just yet :rolleyes:

[Capo]

At the centre where there is most play, yes but where the chain itself is tightest.
Check out how your chain goes loose-tight-loose-tight as the wheel rotates, next time you pop the bike on a paddock stand Stevie.

Why is this?
Does it imply that the sprocket teeth are not concentric with the bore?

[steviej]

Why is this?
Does it imply that the sprocket teeth are not concentric with the bore?

I reckon you'll find it's all due to the power surges from the engine causing a sinusodal wave in the chain. This results in slight uneven wear in the chain length (on top of accumulative minute errors in manufacture) thus you end up with tight/slack spots within the length, i.e. the distance between the links and NOT tight as in movement................. :confused:

[Capo]

That makes sense