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42t spur with 12t clutch?

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gears

gears

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Location
Ohio
RC Driving Style
  1. Bashing
Anyone out there running the HOT Racing 42t spur gear?

They also have a 12t clutch that takes smaller bearings.

Anyone have any experience with these parts?

This is for bashing (someone just sent me some really sweet huge tires so I've got to modify the gearing to compensate).
 
I would seriously like to know how huge a tire you are getting that you think you need to go so outrageously in your gearing. Unless you are gonna use it for a crawler.
 
the new tires are 6.5" tall and I'm bashing in the woods - even with that huge gear change I think my new top speed (with these monster tires) will be darn close to stock.
 
Sounds like wheelie central as well! pretty sweet. If you go for it let me know how it is, I found a sweet place around here that involves very steep rock studded hills and might get a backup set of gears
 
I had a set of proline 40 series mashers i blieve they were 6"s or maybe 6.5"s can't remember on mine with stock clutch bell and 40t spur and it seemed alright but a 42 and 12 might be to low. That is a drastic change. but hey its worth a shot let us know
 
Come to think of it up to now I haven't even heard of a clutchbell with less than 14 teeth on it. Could be a little exxesive but hell its not like they cost a lot and you only live once!
 
Traxxas offers a 13t clutch and a 40t spur

HOT racing says smaller bearings are required with the 12t clutch.

My only real concern is tooth contact with 12 & 42 that will barely be one tooth of the clutch engaging the spur

If I run the 13t clutch there will be more tooth contact area (engagement) with the spur.
 
gears said:
My only real concern is tooth contact with 12 & 42 that will barely be one tooth of the clutch engaging the spur
Click to expand...

That would concern me also. I would say use the 13t clutch bell and try a 40t spur. Since spurs are only 3 bucks it would be cheaper to replace if gearing isnt low enough. I don't think you will notice a terribly big difference in the 12t and 13t anyway.
 
ok, here's the math:

Revo stock gearing 14 / 38 is a ratio of 2.71:1

Increasing my tire diameter from stock 5.75" to 7" (I re-measured last night) is an increase of 1.22%

Therefore, to maintain stock overall gearing (acceleration & top speed) I would need to increase my clutch/spur ratio to 3.3:1

12/42 is a 3.5:1 ratio - killer acceleration / lower top speed.

13/42 - 3.23:1 closest to stock performance, slightly lower acceleration but higher WOT speed.

13/40 (traxxas's shortest gearing) - 3.08:1

Ideally I'd like to go with a 43 or 44t spur and a 13t clutch pinion but no-one makes such a monster.
 
He should be alright I had a 40t spur mated to a stock clutch bell. So a 42t should work with a 13T.
 

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