Is my chain about to snap?
 

Dragged the bike out the garage to give it a good clean afters Sunday big run out. Got the bike up on the paddock stand and noticed the chain was very slack. Now I mean VERY slack as in so slack that I reckon I could unhook it from the rear sprocket without too much effort.

Bikes done about 11k miles and I have looked after the chain with regular cleanings with a toothbrush and Duck oil, have always kept it well lubed and until a few weeks ago I used PJ1. Last few weeks I have used the Wurth dry lube. I checked the chain a few days ago and tension seemed ok, I lubed it using the Wurth stuff on the Saturday night in preparation for Sundays run out.

Did just over 400 miles on Sunday the last 150 or so in very wet conditions.

Is my chain about to snap? I dont really just want to adjust it to the proper settings only to have it snap a few miles down the road. I have checked the swingarm pinch bolts and they are done up to the correct torque so its not as if they were left loose on its recent service.

Dont want to ride the bike as it is.

Thought anyone?

With 11,000 miles on the chain Id have thought it has seen better days . You could try and measure it across 16 links it shoud be less tha 256.6 mm that nearly 10 inches in old money. 4D

Thanks for the reply Fordie, am at a loss to why it has gone slack so quickly? When I lubed it night before the ride out on Sunday I noticed it was very slightly slacker than normal but not enough to worry bout adjusting as I always prefer to have them slightly slack than too tight. Bike was in Ducati Leeds about 500 miles previous to this weekend and chain checked ok.

One thing I did notice on the way up to Scotland on Sunday was a very faint on off whirring noise that I had never noticed before. Hard to explain but is was like Whirr (for half a second) then silence (for half a second) wondered at the time if it was chain related. Actually thought of Eon (overipe&keen) as I remember a year or so back him saying he had a similar noise on his Multi that he never got to the bottom of.

Got some of info from tinternet as well as Fordie on and the length of each link should be 15.875mm so 16 links = 254mm or 10 inch. Well I got the steel rule out and 16 links on mine is about 258 - 260 mm depending which section of chain I measured. Which over 104 links is 39mm or approx 2.5 extra links worth of chain. Which is knocking on for 2.5% stretch that I had read was the limit before it was time to replace the chain.

I suppose the 11000 miles have been pretty hard and the bike has been thrashed to Monaco and back and hammered round the dales on a regular basis so I suppose I cant complain. Was just alarmed at how suddenly it went so loose.

Never kept a bike long enough to need a chain before, Will I need chain and both sprockets? Have not seen front sprocket but rear looks fine, no hooking etc. Was thinking of dropping a tooth on the front anyway and may go with one of them TSBUKKAKE chains everyone raves about.

[Edited on 23-5-2006 by MARTIN H]

[Edited on 23-5-2006 by MARTIN H]

[Edited on 23-5-2006 by MARTIN H]

They do recomend replacing chain and sprocket, but if the sprockets look OK and have no "hooking" especialy the front one then fine. The Tsubakke Chains are very good I' ve put one on mine. nice gold one from B&C Express about £74 if I remember right . 4D

Hello MARTIN H

Just thought, as to why the chain got so slack so quick.
Not sure what bike you have, but if the two pinch bolts at the back of the swing arm,
have worked loose, maybe it's possible the concentric hub has moved.

As this is what you would use to adjust the chain tenshion.

Fordie's right though maybe a new chain is in order.

regards


TopiToo

when a chain has had enough and starts stretching they tend to go quicker than you would normally notice (from past experience) replace it as soon as possible - never had one snap on me, but sounds nasty!

My Multi's chain was finished at 8700 miles.
Recently fitted a new Tsubaki gold chain from B&C,..cost £84.

If you do replace the sprockets Martin go for a few extra teeth on the back sprocket rather than 1 less on the front, it's kinder to the chain as it doesn't have to go through such a tight radius on the 15 than a 14.
having said that I fitted a 14t front on my Multi (cos it's so much cheaper when you're not replacing the whole set) and although it's knocked quite a few mph off the top end (which you can't happily use on such a naked bike anyway) it's worth it for the improvement around town and the extra acceleration :devil:

KeefyB, did you need the special tool for the tsbukai chain or is there another way of fitting it?

Psychlist, already decided today to go 2 teeth up on rear sprocket. Pretty much for the reasons you mention. Also it would be not quite a severe lowering of the gearing. Would probably make it just right. I assume 2 extra teeth on rear would mean to get a chain with 2 extra links over standard?

Had a look at front sprocket and its started to hook but rear looks fine. But while I'm at it I may as well do the lot and sort the gearing out.


My little gearing chart

Front Rear Ratio

15 42 2.80 Standard
15 44 2.93
14 42 3.00

15/44 seems best bet. Not as severe a drop as 14/42 but should improve things.

[Edited on 24-5-2006 by MARTIN H]

3 teeih on rear is the equivelent of going down one on the front mate.


Age