Ultima spur gear choice

[Boons]

Hi all,

A I correct in thinking my Mk1 Ultima has no (standard gearbox) spur gear choices in terms of teeth or strength? I'm talking about 32dp as I understand it's stronger and or more reliable than the 48dp.

And my spur has a large bush in there, can I replace with 4 bearings of some sort?

Finally (for now!) My car has uj driveshafts and bearings in the hubs however the wheel has a fair amount of play in it. Were the bearings for the uj's the same as for the standard shafts?

Cheers all!

Ryan

[gomachv]

As far as stock, there were no 32p choices- just the standard cluster used on all optima and ultima. A few people on rc10talk have used the traxxas hawk/sledgehammer cluster gear 1884 (comes with a new shaft also, takes 5x11 bearings) as an inexpensive replacement and it offers a different ratio than stock. Here is a quote from rc10talk about it....

... It is a 44t main gear/20t secondary. This changes your ratio with the stock counter gear to 2.73. The gear comes with a tapped 5mm shaft, you just have to drill your motor plate a new hole ~.75 (maybe an extra .0625 or so mine meshed to tight.) from the center of the top shaft.

And a link.... http://www.rc10talk.com/viewtopic.ph...33609&p=364761

[Boons]

That's a good read, thank you for posting!

[terry.sc]

Thorp and Robinson Racing made Underdrive and Overdrive gear sets to alter the gear ratios, and they had 48dp spur gears.

As for the bushing, replace it with two flanged bearings.

[gomachv]

Yes, for aftermarket there were a couple manufacturers, nice thing was they were standard 48p not metric like the hop up kyosho part.

The cool way to go if you can find it is the traxxas adapter to run regular spurs as shown in the thread I linked above.

Btw...makes you wonder what Kyosho was thinking using non flanged bushings and bearings when it was clearly meant to be

[Boons]

Can I use this with the Traxxas mod?

http://bit.ly/1cwWzb6

And I take it the same flanged bearings can be used on the Traxxas spur?

Cheers

[gomachv]

The kyosho upgrade gear you linked to is the same pitch, so no problem. The traxxas gear uses larger 5x11 bearings without flanges. Don't forget it requires re drilling a new hole in the motor plate and probably will effect the gear cover as well. It is a modification based more on the cost of the part vs original.

[Boons]

But more teeth though?

[gomachv]

Yes, more teeth. It changes the ratio

[Boons]

Any idea on what pinion to run on that with 13.5t brushless? If I used the standard spur a 17t pinion has been mentioned.

Cheers