Rear Sprocket Bottoming Out

rswiggart

rswiggart

Member
I was curious what my options are as I had a problem with my rear sprocket bottoming out at a rough track last weekend. I know the obvious of growing the tires, but I was curious what my other options are. I had bent my aluminum guard in the heat race and switched to a spare plastic guard, and of course I lost a chain in the feature running 3rd at a 1,000 to win.

Thanks for your help Ryan
 
mike97760 said:
What driver is on your clutch and what axle gear? Are treaded tires allowed?
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I was running an 11/68. So mini gears are not an option.
Yes treaded are aloud.
I was on slicks as was 3 out of 4 of the heat race winners and 1st and 3rd in the feature. I thought about running treads but decided not to.
 
Make your own gear guard .
3/16 aluminum .
Use a old wore out sprocket for a spacer if unable to fabricate spacers . Maybe a little heavier the the lite weight stuff but you will finish the race. Jig saw , hand drill and a mill file . sprocket for a pattern.
 
Treads are quite a bit taller than slicks, that would help. If I was going to keep racing there, I would get the 10 tooth driver so you could be on a 64 or 65 axle gear.
 
Actually if you go to a 10 tooth driver. you could run a 61 rear gear or a 62.

You have a 6.118 Ratio now
a 10 driver and 62 rear gear would give you a ration of 6.20
and a 10 tooth driver would give you a 6.10 ratio.
both real close to what you are running now.
 
Stretching the tires or going to treads will give you greater ground clearance, but will not help if you are trying to run the same rpm. The larger tire will change your rpm and mph on that given sprocket and to attain your previous rpm, you'll end up back on gear that rub the track surface.
10/61 would be the better answer and stay on your slicks.
There are conversion kits to run a 10T driver on a Bully inboard, or use the Bully conversion for 9 or 10T but you'll need to run the clutch outboard.
Other alternative is a jackshaft.
Give us a call if we can help with anything.


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rswiggart said:
I was running an 11/68. So mini gears are not an option.
Yes treaded are aloud.
I was on slicks as was 3 out of 4 of the heat race winners and 1st and 3rd in the feature. I thought about running treads but decided not to.
Click to expand...
What size track is it, and what motor are you running, what ever it is you must be turning a lot of RPM with that gear.
 
I have contemplated getting the 10 tooth driver for awhile now.
Has anyone modified their bully or tomar for the BA driver?
I haven't found much information on it.
 
Carbon fiber gear guards. We ran an 11/69 all last year with 8.5" guards, they get chewed up just a tad but last a long time. our oldest set is 6 years old. We're on the 10 tooth for that track this year, still the same guards.
 
rswiggart said:
I have contemplated getting the 10 tooth driver for awhile now.
Has anyone modified their bully or tomar for the BA driver?
I haven't found much information on it.
Click to expand...

I have two of the drivers but have only put them on Gator style clutches, not wanting to commit a Bully to them but I recently found out there is now a piece made that you can insert where the bearing race that was cut off, allowing you to run the normal Bully drivers
 
I'm an asphalt racer so maybe a dumb question but with a gear that low and slicks on dirt and a built Predator are you getting wheel spin off the turns?

I would try to make that 9t outboard gear work as a first choice.
 
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sundog said:
I'm an asphalt racer so maybe a dumb question but with a gear that low and slicks on dirt and a built Predator are you getting wheel spin off the turns?

I would try to make that 9t outboard gear work as a first choice.
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Yes I felt like I was getting wheel spin, but the track was so rough, it was hard to tell. lol
 
rswiggart said:
Very little track. I have no idea what size but I turn my motor 7400 built predator.
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it seems like with that low of gear, you would be way over 7400. We run small block open and SA, on indoor tracks like Batesville on 12 or 13 front and 64 to 66 rear and turn 8400 to 9000, just seems like a lot of gear, it must be a very small track.
 
kartboy63 said:
it seems like with that low of gear, you would be way over 7400. We run small block open and SA, on indoor tracks like Batesville on 12 or 13 front and 64 to 66 rear and turn 8400 to 9000, just seems like a lot of gear, it must be a very small track.
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I will admit my mychron wasn’t working last weekend. My buddy was on an Nka clone (jr 3) and was on a 11/66 and turned right at 7,000. I had to guess on my gear so I went up 2 teeth.
 
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