Chain Tensioner

Mini Bike & Go-Kart Parts

#1
I am doing an 8” frame stretch on a DB30, being powered by an old school 1975, 5 hp Briggs and Stratton. In doing the stretch I will need to remove the original chain tensioner bracket. Since I’ll have to fabricate another tensioner bracket, should I stick with the slotted style tensioner, or should I go with a spring loaded style? I want to end up with something that is both clean looking and reliable.
 
#3
Interesting design of mounting the tensioner to the engine rather than the frame. Unfortunately the sump cover of the engine does not have the threaded bolt holes around the PTO. So I will also have to come up with a way to mount a clutch cover/chain guard, or else find another sump cover. What I really want to hear is has anyone had a bad experience with a spring loaded tensioner?
 
#4
No bad experience so far with a spring loaded chain tensioner. The Baja I just finished has about 8.5 hours on it with no problems. My oldest daughter has an identical Baja Viper that we put on a 212cc Predator about 4 years ago. She doesn’t have a tremendous amount of hours in it, but has had no problem either. Jay
 
#8
#9
My friend built something very similar to that for one of his bikes. It worked great. For the cost of materials and diesel to drive to his house, I couldn't have him build me one for less. I'm going to have to pick one up to try out.
Quoting myself here. I picked up one of the RCF ones and am very happy with it. Running it on my DB30 since the tensioner/roller mount on that frame was butchered when I got it. Works great so far.

It's close, but zero clearance issues.
 

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#12
I make the tensioner rollers out of urethane skate board wheels.
In doing so,, you want to cut a slot guide so the chain doesn't walk back & forth.
Cool thing about making them out of skate board wheels is,, you can cut the slot & edges down where you want them.
I chuck them up with a 5/16 bolt in a drill,, & use a hobby balsa saw, hack saw blade,, & file ect., to cut & finish them.
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Fourtogo

Active Member
#13
View attachment 277420 Nice clean design!
Did you fabricate this tensioner yourself, or is it commercially available?
I made this one , this unit is for the jackshaft assembly you see . No need for a grooved wheel , the distance is so short it’s unnecessary on this install . I Built a couple of these , for my mini bikes . In photo it’s actually not mounted yet , it sits 50/50 between clutch and jackshaft sprocket when mounted. Lowbrow Customs sell a complete unit bolt on or weld on it’s like $100 looks very similar . They use a High quality skate wheel , from Stacy Perralta skating fame
 

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#14
Quoting myself here. I picked up one of the RCF ones and am very happy with it. Running it on my DB30 since the tensioner/roller mount on that frame was butchered when I got it. Works great so far.

It's close, but zero clearance issues.
Wow, it even fits with a 3 disc race clutch, good to know.
 
#15
I made this one , this unit is for the jackshaft assembly you see . No need for a grooved wheel , the distance is so short it’s unnecessary on this install . I Built a couple of these , for my mini bikes . In photo it’s actually not mounted yet , it sits 50/50 between clutch and jackshaft sprocket when mounted. Lowbrow Customs sell a complete unit bolt on or weld on it’s like $100 looks very similar . They use a High quality skate wheel , from Stacy Perralta skating fame
Nice piece !
 

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