Doodle Bug Sprocket Adapters For Sale

#81
I just tried to install the adapter today on my DB30R (new style frame) and am struggling to get the parts to fit right. It's a beautifully machined item, and fits the sprockets and hub perfectly, but am struggling with bolt clearances.

The adapter is thicker than the stock 70 tooth sprocket, so the bolts to the hub now stick out just far enough that they hit the frame, and I need to put a washer on the axle as a spacer to get clearance. Does this not happen on the old style frame? or am I supposed to not use the stock lock washers with these bolts to make clearance?

but I also apparently don't have the right types of bolts to hold the split sprocket to the adapter, the bolt heads and nuts stick out too far and hit the chain guard bracket. What nuts and bolts are you guys using that have a very shallow head to avoid any interference? where are you getting them from?

thanks!
 
#82
I just tried to install the adapter today on my DB30R (new style frame) and am struggling to get the parts to fit right. It's a beautifully machined item, and fits the sprockets and hub perfectly, but am struggling with bolt clearances.

The adapter is thicker than the stock 70 tooth sprocket, so the bolts to the hub now stick out just far enough that they hit the frame, and I need to put a washer on the axle as a spacer to get clearance. Does this not happen on the old style frame? or am I supposed to not use the stock lock washers with these bolts to make clearance?

but I also apparently don't have the right types of bolts to hold the split sprocket to the adapter, the bolt heads and nuts stick out too far and hit the chain guard bracket. What nuts and bolts are you guys using that have a very shallow head to avoid any interference? where are you getting them from?

thanks!
I had the same problem! I used button head socket cap screws! Try Fastenal or OSH or Ace Hardware!
 
#83
I just tried to install the adapter today on my DB30R (new style frame) and am struggling to get the parts to fit right. It's a beautifully machined item, and fits the sprockets and hub perfectly, but am struggling with bolt clearances.

The adapter is thicker than the stock 70 tooth sprocket, so the bolts to the hub now stick out just far enough that they hit the frame, and I need to put a washer on the axle as a spacer to get clearance. Does this not happen on the old style frame? or am I supposed to not use the stock lock washers with these bolts to make clearance?

but I also apparently don't have the right types of bolts to hold the split sprocket to the adapter, the bolt heads and nuts stick out too far and hit the chain guard bracket. What nuts and bolts are you guys using that have a very shallow head to avoid any interference? where are you getting them from?

thanks!
Grant, please post some photos of the clearance issues.
 
#84
Grant, please post some photos of the clearance issues.
Hopefully the image works.

Never mind that I have the sprocket on the outside instead of the inside (this is just a test fitting), but you can see how the hub bolts down near the center are actually now taller than the spacer and are contacting the frame, due to the thickness of the adapter. Also you can see the tapered head bolts I got from Tractor Supply (with the taper they center the sprocket halves really nicely), but the heads are too tall and are contacting the rear chain guard tab.

Flipping the sprocket to the inside instead of the outside will still have bolt clearance issues. But using flatter head bolts for both locations (perhaps button heads) may possibly just clear the frame.

What I had been thinking of is if I knew anything about how to machine (which I know absolutely nothing) I'd love to see the adapter have the middle section shaved to half thickness in about a 2.5" diameter bore, to fit over the hub's mounting surface. This would offset the adapter away from the frame by the thickness of the gear teeth and I'd get all the clearance I need. Plus you could keep the sprocket on the outside then, to maintain correct alignment, and the adapter and sprocket look a lot better mounted on the outside (that's important, right? :) ) But unfortunately I have no idea if this idea is even doable, or how to do it.

I may need to go bolt shopping in the meantime.

 
#86
I was trying to see if I could directly link the jpg out of my google drive. I can see the image, but I guess others can't? Anyway, here's a link to the google drive shared page, if you click on it you can see the image. adapter clearance photo

I know the sprocket should be inside, but whether it's inside or outside won't make those bolts clear the frame any different. I guess I'm just a little surprised no one else seems to have mentioned this issue when I search through hte forums, and that OldMiniBikes doesn't sell a set of bolts to go along with the sprocket, it seems to me that everyone else knows something I don't about bolting these things up that I'm too new to the scene to know :)
 
#90
I solved my fitment problems by cutting off all the tabs for the chain guard, which lets the outer bolts and chain clear everything cleanly. Then I used some flat head hex bolts for the hub instead of the taller allen key bolts that came stock.
 
#91
I am wanting to purchase one of these sprocket adapters for my DB project. But I would prefer to have one that is not bead blasted. But I like the look of the raw machined sprocket adapter like what is pictured in post #1. I prefer the machined look where you can slightly see the tool path. Are these still available For me to purchase?
 
#94
Confused :confused:

I have a Newer style DB30. What do these sprockets do? Increase speed/torque? I read through the 9 pages, and didn't really find anything explaining these sprockets. For newbie's like me lol.

I am looking into getting a jackshaft for the DB30. Would this replace it? I doubt it. Just wondering on what these new sprockets do compared to the stock that it came with.
 
#95
Confused :confused:

I have a Newer style DB30. What do these sprockets do? Increase speed/torque? I read through the 9 pages, and didn't really find anything explaining these sprockets. For newbie's like me lol.

I am looking into getting a jackshaft for the DB30. Would this replace it? I doubt it. Just wondering on what these new sprockets do compared to the stock that it came with.
These adapters allow you to easily change the gearing by using the very common split style "Go Kart" sprockets. Lots of used gears available so you can decide what ratio you like fairly cheaply.
 
#96
Is this similar to what you have?..this is a PMR jackshaft.the clutch sprocket goes to the larger one then the adjacent smaller one goes to rear sprocket ..really just adds teeth to rear final sprocket is easy way to visualize this. IMG_20160819_182309.jpg
 

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#97
These adapters allow you to easily change the gearing by using the very common split style "Go Kart" sprockets. Lots of used gears available so you can decide what ratio you like fairly cheaply.
I have the newer style Doodlebug. It's automatic just pull the throttle and go. What would changing the gears entitle me? And what is the difference between the ratio's? My bike is all stock right now. What would changing the sprocket do? Or is that something you only change if you upgrade the engine?

I'm so lost :confused:
 
#98
I have the newer style Doodlebug. It's automatic just pull the throttle and go. What would changing the gears entitle me? And what is the difference between the ratio's? My bike is all stock right now. What would changing the sprocket do? Or is that something you only change if you upgrade the engine?

I'm so lost :confused:
An engine can only put out so much horse power and rpm's unless you modify it! If you have a small 2.5 engine on yours and its struggling to pull you you can change the gearing for more torque or if you have the 6.5 and it can handle it you can gear high for a higher top speed with a slower take off! Gear ratios means 6-1 equals 6 revolutions at one end to get one revolution at the other end!
 
#99
An engine can only put out so much horse power and rpm's unless you modify it! If you have a small 2.5 engine on yours and its struggling to pull you you can change the gearing for more torque or if you have the 6.5 and it can handle it you can gear high for a higher top speed with a slower take off! Gear ratios means 6-1 equals 6 revolutions at one end to get one revolution at the other end!
I have the stock engine right now. So by changing the sprocket i can get more torque? I thought thats what the PMR jackshaft was for. Or can a different sprocket replace the jackshaft?
 
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