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Post Info TOPIC: Final drive chain tensioner.


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Final drive chain tensioner.
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image.jpg

I dont see chain tensioners on bikes anymore.  My 1979    Yamaha TY 175 had one from the factory. 

Wondering why they have done away with them, is it because they have chain guides  instead. 

Or maybe bikes these days have so much suspension travel that they wouldnt work and cause problems. 



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Funny you should bring that subject up Mark! I was used to having a chain tensioner on my old dirtbikes and I think it helped prevent chain slap etc.

I have bought a generic chain tensioner (with a slide rather than roller as I don't think a roller would last long underneath the swing arm) and it's on the bench as a future project!

I would be more than happy for you to crack a fitment first wink

Brian



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Really annoying chain slap on Slider
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I wonder if the great collective can help with this please as its wearing me down a bit now !

Have a blue 2004 TTR and running the standard 14/44 sprocket setup with a new Renthal R3 chain. 

Finding I'm getting a really annoying chain slap on the upper swing arm chain slider (long green thing). 

Adjusted the chain so it is at the tight end of the spec at 35mm mid length with the rear sprocket centre/swing arm/front sprocket in line but it still does it really bad.

So yesterday I put a 50t sprocket on the back and it still does it badly.

It doesn’t do it on the overrun, just with slight throttle, not heavy throttle. 

It’s almost like it goes into a mad resonance slapping against the chain slider – I can actually see it doing it when I look down.

Any advice to improve this situation folks ?   Would a tighter chain help and how tight can I go before I run the risk of bearing damage ?  I did wonder if it was because the chain was new and bit less flexible ? 

Thanks all



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If your mixing a new chain with old sprockets they wont mesh well .
This slap is normal when a chain or sprocket getting a bit old .
Dont overtighten chain it will snap .


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I find with my lowering link the chain hits the top roller rather than the slider (14/49 sprockets) - at exactly the same rev range, ie cruising high ish revs but low load. It's worse with luggage on if I forget to alter the spring preload. Once I was happy it was not the engine about to detonate, I managed to put up with it. Can't say whether it's better or worse with a new or old chain, but definitely DO NOT overtighten the chain - rapid countershaft bearing wear will result. Sorry I can't really offer a solution except maybe lace in a cush hub to your wheel?

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Final drive chain tensioner.
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Back in the day, enduro bikes often used to have simple sprung chain tensioners fitted with polyurethane slippers or rollers.

I bought one about 10 or so years ago to test fit it to a TTR250 to see if it reduced chain slap. Maybe I need to dig it out and try it wink

However, having just Googled motorcycle chain tensioners there seems to be more user-fitting-friendly types available for very little money - see here for an example.  Anyone tried one of these on a TTR?

Brian



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Really annoying chain slap on Slider
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Thanks all, it does sound then like this is a common thing.

The other night I put the bike on the stand and ran it in 1st and watched the chain bouncing around, it appeared like it was sticking and this was perhaps helping the slap even though the back sprocket is new. Thinking the new chain grease may be the cause I completely degreased it. No real change. I did also tighten the chain to 25mm at maximum arc but no improvement.
I will try removing another link on the chain to bring the tyre in closer as I do have the room but if this doesn’t help I’ll just have to live with it.
Perhaps it will ease when the chain wears in and loosens up.

I have not changed the front sprocket though. So as comeragh said above I will also do this.

Thanks all

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Super Guru

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Anyone bought and fitted or made a chain tensioner for the TTR?
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It would be nice to reduce the chain slap a bit. Anyone tried fitting a tensioner?

Brian



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RE: Final drive chain tensioner.
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Hi Neil

I broke my own rule by just putting up a post without doing a search on the topic first disbelief

I have merged all 3 threads I found and hope it isn't too confusing wink

Let's see if we get any more responses smile



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So here is the pic of my experiment into this subject, the one Brian recommended above, more testing required but I think it did help reduce the chain slap a bit. Im Figuring that if I can crack this it will not only improve the riding experience but also reduce component wear



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Super Guru

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I think it will help with general chain noise, but the harmonic wave form in the upper chain will be difficult to remove - that bit of the chain is already under tension because it's the bit doing the driving.
A 14 tooth front cog will lift the chain off the swingarm slider better than a 13, but gearing down with a bigger rear sprocket puts it closer to the upper roller, which already gets a good pasting if the suspension has been lowered. I have come to accept that these are dirtbikes rather than road cruisers, and as long as there's no metal on metal contact, the plastic sliders and rollers are just wearing parts.

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Looks a good idea .Only thing with it on bottom it could get bent and catch chain.Would it mount on top off swingarm.

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I think the pulley has to go on the bottom of the chain but you are right this setup is vulnerable but I couldn’t find an easy way of fixing it otherwise to try the idea. A welded bracket to the swing arm would be better I guess.
I see this as a possible option for using the bike on very long trips rather than shorter off road forays.
I’m not giving up on the idea yet as there is an improvement ! Neil

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