Primary chain question

[Dellortoman]

I think I may have said this before, but calling that slipper doohickey a tensioner is somewhat misleading. It shouldn't put any tension on the chain at all. V-belts need tension to work properly, chains don't. All the 'tensioner' does is take up slack so the chain doesn't flap about. There should be a small running clearance between the components. Wind the screw in until you can feel the tension come on the chain, then back it off. How much you back it off seems to be a matter of conjecture. It depends who you ask. I've heard recommendations from ? a turn to 2? turns. I'd suggest somewhere between 1 and 2 turns.

BTW, if your chain's side plates have worn grooves in the black rubbery shoe of the tensioner, don't panic. It's normal. The side plates will wear the grooves in pretty quickly, making the chain looser, but only until the chain rollers contact the slipper surface and take the tensioner load. So if you install a new slipper. You'll need to re-check the adjustment regularly until that wear-in phase settles down.

 

[Schurminater]

So how close does a new slipper run to a new chain with the tensioner backed right off?

Adjusting mine again last night and not tightening it too much,when backing it off 1 1/2 turns you can feel the adjuster bolt come off the tensioner in the last 1/2 a turn?..........Would that feel right?

 

[mauricejota7604]

tension the chain by feel as discussed below then listen to it running its quite easy to detect too tight by the whine and too loose by rattle, its an aquired skill .

 

[Jo]

Agree, you feel when it is about right. For a beginner, you can approach the sweet spot in an iterative way, by backing it off 1/2 turn from feeling tight and then go 1/4 turn in again to see how that feels and so on. With a new set of cush rubbers and Merc Duplex not much of chain slack to be expected anyway. I added a freshly lined chain slider to that combo on my 3C, and finally needed to resort to plenty of spare copper washers under the domed counter nut to get it fully seated, with the adjusting bolt lifting the chain slider just about 1 mm to get the slack out of the chain.

Regards,
Stefan

Thank you Stefan, that's exactly how it is with mine after changing from old triplex to new duplex. Unfortunately I can't do the "whining test",
because the engine is not yet complete (still waiting for pistons) ...

 

[Rob]

when backing it off 1 1/2 turns you can feel the adjuster bolt come off the tensioner in the last 1/2 a turn?..........Would that feel right?

Not in my experience - but then I back off by 3/4 of a turn... 

 

[Schurminater]

Agree, you feel when it is about right. For a beginner, you can approach the sweet spot in an iterative way, by backing it off 1/2 turn from feeling tight and then go 1/4 turn in again to see how that feels and so on. With a new set of cush rubbers and Merc Duplex not much of chain slack to be expected anyway. I added a freshly lined chain slider to that combo on my 3C, and finally needed to resort to plenty of spare copper washers under the domed counter nut to get it fully seated, with the adjusting bolt lifting the chain slider just about 1 mm to get the slack out of the chain.

Regards,
Stefan

Hello to all.....and a little update........after reading all the helpful comments and advice given and going from Stefans reassuring post (that's like mine) to Andy's concerned post (did i really assemble it right!) i have come to the conclusion that there is nothing wrong with it........which takes us back to Laverdas post and maybe something ringing in my ear!

Agreed i did re-adjust it after the first ride and maybe that's it but after taking a 45 mile ride out yesterday i have come to the conclusion that it's perfectly fine.

I still find the adjustment method a little temperamental and i do feel that there is a sweet spot to be had between too tight, just right,and too loose as i'm sure you can feel it in the transmission? .....or maybe i'm just imagining it....... however, practice is the art of perfecting and the more i do it the easier it will become.

many thanks to all,safe riding

Schurmy  8)

 

[natm]

I fitted a new duplex chain on my SF3 last month and it a lot much tighter than the old chain. In fact when I screwed the adjuster bolt in tight, then backed off 1.5 turns, there was so much of the bolt protruding that the dome nut wouldn't meet the copper washer and I had to make a shorter bolt.

 

[Rob]

It's normal to use multiple copper washers rather than shorten the adjuster bolt!

 

[laverdas]

I fitted a new duplex chain on my SF3 last month and it a lot much tighter than the old chain. In fact when I screwed the adjuster bolt in tight, then backed off 1.5 turns, there was so much of the bolt protruding that the dome nut wouldn't meet the copper washer and I had to make a shorter bolt.

you just add more copper washers  (hello)

 

[sfcpiet]

It's normal to use multiple copper washers rather than shorten the adjuster bolt!

He's going to make a longer bolt when it gets too short... :

piet

 

[Paul Marx]

He's going to make a longer bolt when it gets too short... :

piet

Stupid.
You just take washers off.

Paul

 

[Ian D]

For what it's worth, I pt a dab of oil on my fingers and hold the screwdriver by it's shaft. fingers slip as soon as the slack is taken up.

Slippery little bugga there  Teez.

 

[Legs]

G'day Ian, how's it hanging?
Been doing that way for over thirty years; when the fingers slip, back off half a turn.

 

[sfcpiet]

Stupid.
You just take washers off.

Paul

My point, exactly.

piet

 

[Paul Marx]

My point, exactly.

piet

Aha.
Now I get it.
If you take too many washers off, you can always saw a bit off the adjuster.

Paul

 

[Ian D]

G'day Ian, how's it hanging?
Been doing that way for over thirty years; when the fingers slip, back off half a turn.

Swingin' in the breeze Terry.
Haven't ridden the Jota since Curdee Vale. Had 2 rides on the Hailwood but. 

When that slacker gets back from swanning around the globe must organize a ride if not before.

New house plans should get to the council in 7 or 8 weeks. :

 

[Laverda SF]

Primary Chain Adjustment. Basically you originally adjust it rather tight and she will whine when you fire up the engine  - Then you back off the adjustment until she doesn't whine.

May take a few more adjustments before you got the chain settled.

WARNING - Never run a Bike for any length of time with a whining primary chain as you will destroy your crank shaft bearings.

 

[Legs]

Glad to hear things are progressing Ian. Haven't ridden the Yellow Peril since Curdie Vale either. Been out and about on the Wee Monster; the more I ride it the more I like it.
Haven't heard from 'Our Man In Mali' for a while, apart from a settling comment about disparaging remarks made regarding hipsters

 

[AndyW]

Glad to hear things are progressing Ian. Haven't ridden the Yellow Peril since Curdie Vale either. Been out and about on the Wee Monster; the more I ride it the more I like it.
Haven't heard from 'Our Man In Mali' for a while, apart from a settling comment about disparaging remarks made regarding hipsters

Settle...

 

[Legs]

Ah! Glad you are among the living, things okay over there?