I'm about to build a big block minibike for 1/8 mile fun. I see some of the drag bikes are running tensioners and some are not. The bike should have a good bit of power from 3000-7500 on alcohol and I'll be running a 4 disk clutch and #35 gold on gold chain for now (hopefully it'll make some passes). I've looked at a high-end tension that looks like it'll work well or I might make my own if needed. I'd just like to know from experienced minibike racers what's worked best for them even if it's no tension. Thanks
Chain tension on drag mini?
- Thread starter durandbagwell86
- Start date
https://www.oldminibikes.com/forum/...hain-tensioner.html?highlight=chain+tensioner
Check out the link above and find post# 13 by Stargazer7467. I like his tensioner. I am going to attempt one change to his design and that is to use a spring for tension, his appears to be fixed adjustment. I like the clean appearance and think it would work well on a fast motor.
Check out the link above and find post# 13 by Stargazer7467. I like his tensioner. I am going to attempt one change to his design and that is to use a spring for tension, his appears to be fixed adjustment. I like the clean appearance and think it would work well on a fast motor.
I only have only raced the 100ft in it but it is set up for 1/8mi
Turned 38mph in the 100ft and there is more in the bike
Bike makes around 25hp at the tire it is a small block Briggs on methanol
I use Polar junior OD clutch with jackshaft the chain is not super super tight but there isn’t lots of play.
What kills my setup is using mini bike sized wheels and tires. I am running a 6” wheel with 10.5 or 11in Burris slick
The small tire helps on launch which a 100ft bike needs but you are running 15” tall tire which is way better suited to the 1/8 than my little tires. Check out pics of the bike in the my rides section there is more descriptions of the bike there but I can answer questions too
Turned 38mph in the 100ft and there is more in the bike
Bike makes around 25hp at the tire it is a small block Briggs on methanol
I use Polar junior OD clutch with jackshaft the chain is not super super tight but there isn’t lots of play.
What kills my setup is using mini bike sized wheels and tires. I am running a 6” wheel with 10.5 or 11in Burris slick
The small tire helps on launch which a 100ft bike needs but you are running 15” tall tire which is way better suited to the 1/8 than my little tires. Check out pics of the bike in the my rides section there is more descriptions of the bike there but I can answer questions too
Thanks man. My rear slick will be 12". I'm not sure the power it'll put down but on Russell's Dyno (nr) it made 27.xx and 37 ft/lbs of torque with a stock head, 35# springs, mild cam, and stock carb on gas. Now it has a parsons ported big valve head (40/33mm valves) cut .080 with 65# springs, bigger cam, 1.2 ratio gage roller rockers, 34mm Mike Clements alky carb. I hope I can keep the chain from breaking, if not I'll switch to 428. I'm really not sure if a tension will help the chain from snapping or not. How often do y'all run 100' drags?
https://youtu.be/dsKNfW6gueI
This is it, it's a little faster now but that's it. I don't think I have any saved pics. I'll take some when the weather clears up.
This is it, it's a little faster now but that's it. I don't think I have any saved pics. I'll take some when the weather clears up.
It's a 460cc big block with billet rod and flywheel, 40/33mm valves ported by Jeremy Parsons and cut .080 with 65# valve springs ( he runs well over 100 with same head at Daytona), Clements 34mm flatslide alky carb, the cam lift with the 1.2 ratio gage roller rockers is .368 and duration is 260° @50. The motor on the my motovox is just a mild 212 that I normally turn 8-8500 rpms.