Spring Loaded Chain Tensioner,2 Stroke Motorized Bicycle Chain Guide | Adjustable guide wheel in black. Fits 49cc, 66cc, 80cc 2-stroke engines for motorized push bikes

Do yourself a favor and a favor for your loved ones. Change out the stock tensioner asap!Ask what happens when a stock tensioner fails and you'll understand.Great product and have used 1 on every build

Must have, way more reliable than tensioner provided w / kit

Excellent quality and fit, has kept my chain on for many miles. Only issue is bolt and nut that hold arm on loosens up. Needs a longer bolt so a lock washer can be installed. Do not overtighten the chain guide, it will not move and will cause issues with the bearings. Definitely worth the buy and far better quality than the closet door looking hardware that comes standard with the bike engines

This is a great tensioner.I would have liked instructions with the unit but the advertisement shows pictures of proper installation.I recommend to add lock nuts and luberican to the tensioner wheel to keep it able to move freely and also on the pivot bolt and nut with washer and lock washer to give it ability to move as needed.

Spring broke second week I had it on the bike so I made a new spring and working well now

Does exactly what it's supposed to do easy install

I never leave reviews. This is well deserved, bolts shown are Allen head, nuts shown are nylon lock nuts, what came is junk hex heads with regular nuts, the bolt that holds the wheel doesn’t even fit in the holes on the bracket. Spend the extra few dollars and a better brand

Works as it should excellent would buy again

Packaged very good looks to be good quality

everything fits good. my only problem is the cheap hardware. 1 bolt the threads all stripped off, and also the heads catch on my pedals. so i have to go to the hardware store and look for a couple better bolts. not a big issue. also the plastic roller wheel seems rather cheap, not sure how long its gonna hold up. for the price i guess it was worth it.

I struggled with many chain tensioners thinking ok i got it this time...? Dont kid yourself.. spring-loaded tensioners are the best solution for sure! The one thing I needed to do.. I grinded the bolt heads down about half.. so crank peddle can pass freely.. Use double nuts on the bolt harnessing flex part, to lock tight but still loose enough for tensioner to flex..Thats it.. Works great!

Love the idea, hate that I can't make it work.

Not a good setup, when trying to start the bike the torque on the chain is opposite of tension side causing the chain to slack and bind up solid in housing. I had to remove this and go with standard tensioner that came with the kit. So this is useless to me not.