Debate of the Day: Experimental Chain Tensioner

**Stevo** · 28 September 2018

I agree... I don't believe Aluminum is the right material to use for the sprocket or the carrier.

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**Richard230** · 29 September 2018

Originally Posted by Stevo

I agree... I don't believe Aluminum is the right material to use for the sprocket or the carrier.

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I agree. Instant wear. Anyone recall the days of the nylon rear wheel sprocket and oil-less, non-O ring, no maintenance chains? The motorcycle magazines were touting those clean and light chain drive systems for a few years about 20-30 (?) years ago.

Then everything went silent - because the nylon sprockets wore out very rapidly or stripped their teeth, followed quickly by the self-lubricating "sintered" chains.

Another bright idea and start-up industry down the drain.

**Stevo** · 29 September 2018

I do remember those too. That was basically an idea straight into production without any real world testing and R&D. It questionably may have worked on a bicycle, but I doubt it. Ya I was dumb and was suckered into buying into the test group

...tried one on my 1st bike hawk.jpg circa 1980
It didn't last a week LOL I returned it for refund.
I thought Teflon may have worked, but probably ultimately not tough enough. Maybe graphene infused teflon??

**Stevo** · 05 October 2018

It looks like this is the best I can do with controlling the chain slack. It appears to be working pretty good... I'll see how long these ceramic bearings last.

**Ted Dillard** · 06 October 2018

That's kind of brilliant... in a sick and twisted way, of course!

Good job - it will be interesting to see what, if anything, fails. Looks pretty beefy to me, though.

**Richard230** · 06 October 2018

That is a neat solution to accommodating chain slack as the suspension moves. However, I will make one observation: All of the street/dual purpose motorcycles that I have seen don't use an active chain tensioner but instead use a replaceable plastic rubbing rail along a portion of the upper swing arm to keep it from being damaged as the chain rubs against it. Now that is either an indication that you don't need an active tensioning device to control chain slap - or that the manufacturers selected the cheapest method of dealing with the issue and that they don't think chain slap is a safety problem and just want to protect the swing arm from damage.

**Stevo** · 06 October 2018

I agree with you Richard... and on the prior video with inactive top tensioner, it appears to be ok to be run without it. This company went bankrupt in 2003-4 and getting consumable parts is near impossible now. Brake pads is not an issue as Husqvarna and KTM uses the same, but the swingarm slider is unique. The bottom rear chain guide will be an issue when it wears out. I may have to fab one up out of teflon, or modify something from a different make/model. It's really hard to find fork seals for it...last time I only found 'em in Europe and had to have 'em shipped. All said, it's one of the main reasons I converted it to ev. I'm also a glutton for punishment

**Richard230** · 06 October 2018

Stick with it, Stevo and good luck keeping your bike on the road.

**Michael Moore** · 07 October 2018

Stevo, teflon "cold flows" under pressure. A strip of UHMW-PE would probably be a better choice and it is easy to find.

Extremely tough abrasion resistant, low cost plastic, used for a wide range of wear applications. UHMW (ultra high molecular weight polyethylene) is an extremely tough plastic with high abrasion and wear resistance.

cheers,
Michael

**Stevo** · 10 October 2018

Thanks Michael, for your expert opinions and suggestions. I wasn't sure if "pressure" and "friction" are the same. I thought for chain guides, friction was the main abuser. I have a small, 4"x6" 1/8" thick piece of teflon in the garage somewhere that I was going to try a test with when the time comes, but I like your suggestion better. Thanks