14/39 or 15/42

I ordered a 14t front sprocket only to find I cant put it on unless i cut the chain. There seems to be not enough room to slide out the front sprocket with the chain in place. Has anyone done this?


Option 2
I am thinking of getting a 42T rear sprocket but can i fit without braking the chain?

thanks
Billy

[slob]

You might be able to fit the 14T front sprcket if you move the wheel as far forward as it will go first.

I think you might need a longer chain (1 link/2 pins) to accommodate a 42T rear sprocket.

Technically 15/42 is probably a better solution, as the chain doesn't have to turn such a tight radius at the front and doesn't risk rubbing on the swingarm/slider. It is more expensive though and as I said before. I think you need a longer chain for it to fit, I did on my 1000 but I'm not sure about single sided swingarms.

[Mr Gazza]

I need to take the clutch slave off my 900 to get the sprocket off (with the chain on).
I imagine yours will be the same.
You won't need to cut the chain to change either sprockets

A 15 tooth front sprocket will be much kinder to your chain and also your swinging arm come to think of it.
The only advantage I can think of with a Z14 front is that it will give you a bit more space to fit a case saver, which I know is very tight on the 750/600 models. That said; more space without a case saver is not a good thing.

A case saver is just a band of metal that hugs the chain round the sprocket and stops the chain from smashing it's way into the cases should it break. This writes your engine off, so it's worth it for a few pence.
It simply keeps the chain on the sprocket and hopefully shoots it out below the bike.

http://www.ukmonster.co.uk/monster/s...ad.php?t=49399

I have removed the clutch slave but there is no way you can take the front sprocket off with the chain intact. there is no room to lift the chain off the teeth as the 15t fills the area and the swing arm stops it sliding off the output shaft so its option 2 new 42 rear :-)

Billy

[Luddite]

As slob says, you won't need to split the chain just to change the front sprocket, just rotate the eccentric chain adjuster completely forward to slacken the chain. Make sure you torque up the pinch bolts properly after you're done (to 31Nm in sequence 1-2-1 after using moly grease). Overtightening can damage the swinging arm.

Your 796 and my 1100 both run the same sprocket and chain set with 104 links. If you want to fit a 42 tooth rear, then you will need to go up two teeth to 106.

Pros and cons?

14/39
For - quick, cheap, easy, no special tools needed, easily returned to stock if required.
Against - tighter chain run gives chain and sprockets a harder time (in theory). Less clearance between top front chain run and swinging arm means the plastic swinging arm protector may wear quicker.

15/42
For - kinder to chain and sprockets. More clearance between chain and swinging arm means swinging arm protector will be untouched.
Against - expense (new chain needed), old chain needs splitting, chain riveter needed, more fitting time required.

I'd say, if your chain has worn out and needs replacing anyway, then go for the 15/42 combination. If your chain and sprockets are still in good condition, (or you're not sure whether lower gearing will suit you), go for 14/39.

For what it's worth, I've been running 14/39 for 10,000 miles with no problems and the chain has only been adjusted about five times, so wear hasn't been an issue.

[Luddite]

To slacken the chain, rotate the adjuster clockwise (viewed from the chain side). When retensioning the chain, don't overtighten it. When you check the play, you're not measuring the up and down movement as you would with a conventional swinging arm, instead you measure the distance from the underside of the swinging arm to the centre of one of the chain pins. It should be 62mm +/- 1mm at a point equidistant between the two sprockets with the bike on the sidestand.

Note that, while the suggested amount of play seems very loose compared with a conventional swinging arm, when you're sat on the bike, the chain tightens considerably so don't be tempted to over tighten it while it's on the stand. Get someone to sit on it and feel the difference between loaded and unloaded.

[Murray Mint]

Just a thought, have you taken the chain off the rear sprocket first before taking the front sprocket off?

[Luddite]

PS it's been a long time since I swapped my sprockets (over eight years) so I can't remember exactly, but you might need to remove the chain from the rear sprocket first (after fully slackening it off) to give you the clearance you need to slide the front one off.

[Luddite]

Originally Posted by Murray Mint

Just a thought, have you taken the chain off the rear sprocket first before taking the front sprocket off?

Great minds...

[Murray Mint]

Two hearts that beat as one. :-)

[Doggy]

Billy, I recently fitted a 14t front on my 796 and had no problem?. You do need to loosen off the rear hub to get the front sprocket off. The chain stayed on the rear sprocket. Only had two short rides and it seems livelier, not too sure if I 100% like it or not yet. A couple of more rides should be enough to tell.

this chain and sprocket set must be quite new as there is very little ply even with the hub all the slack. there is very little sideways movement at all so front change with chain intact is no way possible to pull sideways off the output shaft.


so lets just put the 42 on the rear when it comes.
Billy

[Luddite]

When I fitted my sprocket, the chain was less than 500 miles old and I had no trouble with the change over. Perhaps your eccentric adjuster is slightly seized?

The thing is, if you've not got enough slack now to remove the front sprocket, then you certainly won't be able to fit the larger rear anyway, which requires a longer 106 link chain.

If you genuinely can't remove the front sprocket after slackening the chain, I'd suggest you remove the rear sprocket carrier, since you'd have to do that anyway to fit the 42 sprocket. If you do it now, that will give you the clearance you need to fit the front sprocket and you'll save the cost of a rear sprocket (and new chain).

Is it the original chain do you know? I wonder if it's been replaced with a non-standard shorter one (the correct number of links is 104).

Also, while you have the rear wheel out, I'd recommend checking the eccentric chain adjuster moves smoothly - if the bike's been used in all weathers, then it may need stripping and cleaning if it's showing signs of being notchy or sticking.

[Ron1000]

I’ve recently done the 15/42 mod. Absolutely brilliant I’d say…maybe a little bit buzzy for some and puts a dent in your fuel economy. But for me and my riding I love it.

Also as an aside, I recently changed the track bike R6 15t sprocket to a 16t that was easy to swap out with no mods to the chain or cutting or such like.

Another aside if you buy a chain tool buy the pbr one with quadstake anvil. Tremendous bit of kit. If you need the exact part no let me know I’ll dig it out.

I think I have confused you re fron t sprocket removal.

when i say there is not enough play i meant sideways not length ways

I just saw this vid

https://youtu.be/p9lHBeVJuqI

This shows what I am saying. He removes the the big bracket holding the front and rear foot rest and gear shift, then, and then only there is room to move the sprocket and chain in one piece.



just like the vid. lol

I am not getting a new chain just to use the 43 rear.

Billy