Ditchin the tensioner?

The only reason to use these is to clear the stay.

Put a little tensioner on the little chain if needed.

the chain tentioner serves 2 purposes.
it takes up anyn chain slack (of course) and it MAY be needed to guide the chain onto the bottom of the sprocket properly.
if the chai keep tryig to run off the sprcket use the tentioner moved in/out slightly to guide it on.
also..... do not try to keep the chain 'banjo tight'. the chain needs a little slack to find the teeth.
also the sprocket teeth actually have flat ends when stock. i use a hand grinder to round off the tips to a nice end taper.

stay dry

gubba

The main problem I have with chain tensioners is they are the weakest part of the drive train and they will fail. I have had three different ones from different suppliers(including a motorcycle one) and they all failed. Twice they wound up in the spokes and I had to rebuild the wheel.

I welded track bike ends on my bike and then a derailleur hanger on the pedal side. I did have to get a better quick release than the Shimano one that I had before but, I guess you can't expect much from those guys anyway.

So far its lasted over twenty hours and hasn't failed yet.

mike

I used to use the tensioner just to guide the chain onto the rear sprocket. I had alignment close, but I was always off by just a hair. When I upgraded to a #41 chain, it was a little wider and allowed me to ditch the tensioner completely. It seems to roll easier now, and I have no regrets about tossing the tensioner in the trash =)

the #41 chain is wider than the #41.5 (415)
on SOME motors the housing around the power sproket (where the arm is) is just a little smaller and the #41 hits the screw housings on the inside.
in these cases i have seen the masterlink chewed up, sieze up (kink). switched to #415 and problems gone.
you can see where the chain hits and scars the inside 'high' points. sometimes a small rotogrinder dressing the metal away at the scar points helps the #41 clear and behave.

when the customer demands a grubeee kit i make sure it is shipped with an #415 (i pay extra for it if i have to). every build with the grubee bicycle chain in the kit has come back for me to put on a #415 and throw the bike chain away.....lol

stay dry

gubba

The main problem I had with the replacement motor I got was that it shipped with a stock BMX chain. That lasted about five miles and then BANG! Zinnnggg! Lucky for me I still had a fully working pedal side. At the same time a few teeth on my drive cog got bent and when I tried to cold set them back they broke.

To make a long story short I did find a replacement cog that fit a 415 chain and with my new rear dropouts and a stronger quick release Im back in on the road.

I like the KMC 415 silver BMX chain It works grate and looks good ,but its a lot of cash compared to Tractor Supply.

As for the chain "stretch" I think that the chain will go slack mainly because of the wear to the cheep bolt on rear cog. For mine I went after it with a Dermel tool and evened out the teeth and my chain did not get loose after that. I did have the master link fail so I used my chain tool and a hammer to "bang" it back in place "old stile" Its held up better than me lately.

mike