Rupp Roadster 2 Seat pan off center after wheelie incident

GustoGuy

Active Member
#1
Let my wife's nephew ride a couple of weeks and despite telling him not to gun it and take off easy he wheelied my stage 3 Predator 212cc Resto-mod Rupp over. I used a block and tackle with a hand winch to bend down the pan into place now when I am trying to put it together the license plate bracket and fender position seems to be out of alignment at least a quarter of an inch. Really pisses me off and I am putting an 11 tooth Rupp jackshaft sprocket on the front inplace of the stock 10 tooth to try and soften the acceleration which will throw you if you crack the throttle too much on take off. There is about 6 and 1/2 inches after the shock mount cross bar and it appears in addition to bending it upward he also pushed it over towards the left. Ideas to fix are screw gun a big block of wood to the back of the seat pan and use my 4lb sledgehammer AKA persuader to tap it over just over a quarter inch. Any other ideas?
 

GustoGuy

Active Member
#3
B
Hows the wife's nephew?

Few abrasions to his right hand and a bruise on his leg. He said that he used to ride a 1999 Yamaha 125cc dirt bike so I mistakenly thought he could handle the bike. The last thing I told him was not to gun it and to take off easy because it has enough power to wheelie up. Evidently he didn't listen
 

Triley41395

Well-Known Member
#5
Let my wife's nephew ride a couple of weeks and despite telling him not to gun it and take off easy he wheelied my stage 3 Predator 212cc Resto-mod Rupp over. I used a block and tackle with a hand winch to bend down the pan into place now when I am trying to put it together the license plate bracket and fender position seems to be out of alignment at least a quarter of an inch. Really pisses me off and I am putting an 11 tooth Rupp jackshaft sprocket on the front inplace of the stock 10 tooth to try and soften the acceleration which will throw you if you crack the throttle too much on take off. There is about 6 and 1/2 inches after the shock mount cross bar and it appears in addition to bending it upward he also pushed it over towards the left. Ideas to fix are screw gun a big block of wood to the back of the seat pan and use my 4lb sledgehammer AKA persuader to tap it over just over a quarter inch. Any other ideas?
I tried to straighten an old BMX frame once. Came out LOOKING perfect. It was never right again. Maybe you'll have better luck. As much as I hate to say it, you might be better off with a different frame. If it were a 25mph bike I'd say bend it back and go for it but being a faster bike Maybe not so much. That was a killer looking bike and I hope you get it back to its pre-nephew days.
 

GustoGuy

Active Member
#6
I tried to straighten an old BMX frame once. Came out LOOKING perfect. It was never right again. Maybe you'll have better luck. As much as I hate to say it, you might be better off with a different frame. If it were a 25mph bike I'd say bend it back and go for it but being a faster bike Maybe not so much. That was a killer looking bike and I hope you get it back to its pre-nephew days.
The part that got bent is the sheet metal seat pan. The bike seems to track just fine when I rode it. I doubt it bent the tubular frame part. From the damages I could tell he hit more on the right side of the seat pan because it was bent more sharply in that area. I could drill out the license plate bracket holes bigger and just shift it more towards the right and it should line up.
 

GustoGuy

Active Member
#7
I been thinking how to shift the seat pan towards the right just over a quarter of an inch. I have a wood deck trailer which i used for my snowmobiles and mounting the winch on the wood deck with wood screws. Then placing the bike with the right hand side rear top anchoring bolt of the shock against the side of the trailer and securing it tightly with nylon straps and then mounting the metal bracket I used to pull down the seat pan and pulling it gently towards the right with the hand winch until the bracket lines up better. If done slowly and gently it should not mess up the tubular frame alignment. 20220710_015330.jpg

20220709_230010.jpg
 
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GustoGuy

Active Member
#8
I put my 11 tooth front sprocket on the jackshaft and it turns out it won't make any difference since there was already a worn out 11 tooth sprocket on the bike. The chain will no longer come together at the master link so being it's new sprocket it has a slightly larger diameter so it may add a bit of top speed but I doubt with the torque of a built up stage 3 Predator 212cc it will make any difference in softening up how hard it hits off the bottom. I think it will need a 12 tooth or 13 tooth jackshaft sprocket to soften up the acceleration. Anyone know of a 12 or 13 tooth jackshaft sprocket that will fit on a Rupp Roadster 2.
 

GustoGuy

Active Member
#9
I found and ordered a 12 tooth Azusa type C 40 41 jackshaft sprocket so hopefully that extra tooth will tame the bikes tendency to want pull up the front end. Plus I am going to be way more discerning about who can ride the bike. Right now it is my son and my stepdaughters fiance who are allowed to ride the bike. Every one else gets to ride the Arctic Cat which is by far my slowest bike. Even the stage 1 Predator 212cc powered Doodle beast DB30 can wheelie if you gun the throttle on dry cement or Asphalt and are leaning back and it has a 14 tooth clutch. Was worse when it had a 12 tooth clutch and before the addition of 12 pounds of steel down low in front of the engine and 8 pounds over the handlebars I could ride it but others kept wheeling it over. Body english is definitely required to keep the front wheel on the ground.
 

GustoGuy

Active Member
#10
Here is a picture showing how the seat pan was shifted towards the left when it was wheelied over. The indentations are from the visegrip when I was trying to bend the pan back into shape after pulling it down with the hand winch with the homemadeblock and tackle. The edge of the seat pan was bowed out after it was wheelied over. I guess that why Rupp never put a 10 to 12 horsepower engine in its Roadster 2 bikes. Too many people would have ate $hit and died if they did. Once I finally fix it right nobody's going to ride it but me and a select few 1661877090199_1661877088787_20220821_204438.jpg
 
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GustoGuy

Active Member
#11
Here is how I am going to pull the seat pan over to the right just over a quarter of an inch. I will do it slowly and may even heat the seat pan with my heat gun to make it bend easier. Being it is just thick sheet metal it will bend but I would like to prevent any kinking of the steel while I am pulling it straight 20220830_123708.jpg 20220830_123717.jpg

I added the heat from a hair dryer to ease the movement of the seat pan towards the right. I will go out and cut the lawn and then pull it tighter 1 click at a time until it is back to it's pre-wheellied over state. Remember my friends it you have a hot rod minibike don't ever let newbies ride it or they will most likely wipeout or wheelie it over. 20220830_130312.jpg
 
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