I just purchased an xbr/ex 13.5 combo. my question is this: do I have the small bearing or large, good rotor or bad? This setup is new and the only one around so I have nothing to compare it to. Thanks

I just purchased an xbr/ex 13.5 combo. my question is this: do I have the small bearing or large, good rotor or bad? This setup is new and the only one around so I have nothing to compare it to. Thanks
This page from the Novak website will probably tell you more than you want to know about the EX series motors:

Novak's Sport Motors are Extreme (
http://www.teamnovak.com/products/brushless/ex_motors/index.html)

The rotor is a perfectly "good" bonded rotor; however, Novak suggests using a sintered rotor for serious racing applications (if it is allowed by your race director.)

Thank you for the quick response. I am the first person to buy brushless at our local track and have yet to run it. One more question, novaktwo: would the 17.5 be a better choice to compete with stock 4-cell oval than 13.5? (small bullring oval track). One last thing, Thanks to Novak for everything they have done for us oval racers. We are very greatfull !

Thank you for the quick response. I am the first person to buy brushless at our local track and have yet to run it. One more question, novaktwo: would the 17.5 be a better choice to compete with stock 4-cell oval than 13.5? (small bullring oval track). One last thing, Thanks to Novak for everything they have done for us oval racers. We are very greatfull !
Thank you for the compliment. I can't answer your question about using the 17.5 motor, but there are quite a few old posts on this forum about the motor and how it performs.

You have the large bearing in front. In fact, I believe Novak exclusively uses the large bearing in all of their latest motors.

Novak's motor chart can be seen here. (http://www.teamnovak.com/products/brushless/motor_spec_chart.htm) Their motor chart is wrong on the size of the bearings. Their chart says the EX series has the small bearing, but that is wrong. Even their EX web page says (http://www.teamnovak.com/products/brushless/ex_motors/index.html), "Oversized front bearing for increased load handling and bearing life". The way to visibly see is to look for the lip. If it has the lip, it's a smaller bearing.

Here is an example of the old 4300 with the small bearing in front:

http://www.teamnovak.com/timeline/large_timeline_jpgs/ss4300_system_tllg.jpg

And here is a motor with the large front bearing:
http://www.rc-car.com/Media/News/Novak-systemWEB.jpg

To give you an idea of speed/power:

27T brushed generates around 130 Watts of power (at 7.2V) when tuned perfectly.
Novak 13.5 with a bonded rotor produces 165 Watts of power.
Novak 13.5 with a sintered rotor produces 195 Watts of power.
Novak 17.5 with a sintered rotor produces 130 Watts of power.

So yes, the 13.5 with a sintered rotor is certainly faster. Almost as fast as a 19T. A 17.5 is much closer to a 27T brushed motor. Some report the 17.5 is faster, other's report it's slower.

Thank you both for all of the info.

would the 17.5 be a better choice to compete with stock 4-cell oval than 13.5? (small bullring oval track).

With a 'bonded' rotor the 13.5 Ex series motor would probably be close to stock speeds, (Sintered would make it too fast to run with stock if it was set up right)

The 17.5 motor is only offered with the SINTERED Rotor, and with 4 cell, it competes great against stock. (With the LIPO it competes great against 10.5/4 cell)

James,

Thank you for posting the pics...

I too thought the EX Series had the BIG bearing, but I had been told otherwise.

EX SERIES - Bonded Rotor, Big Bearing, NON-Ribbed Can

Let me get this straight, my EX will accept a sintered rotor with no other modifications? Also, do I want the standard sintered rotor or the 13mm "tuning" rotor?
Thank you in advance for the help as I am completely new to brushless

Yes, all Novak rotors are interchangeable with all Novak motors. The 13mm rotor reduces RPM's, increases torque and brake. Reports are it's not desirable for oval. If you put a sintered rotor in your 13.5 EX, you have the same exact motor as the 13.5 Pro with the exception of the can ribbing and slight weight reduction. They milled out some of the excess aluminum on the inside front part of the 13.5 Pro can.

There is no difference with electronics with the 13.5 EX and the 13.5 Pro. Charlie from Novak says they dyno the same when they are tested with the same rotors.

Thank you! I will be ordering my sintered rotor.

i also have a EX 13.5 it looks like it comes w/ a small bearing and gray rotor
i to need to get the sintered w/ a bearing. its $43.00 on lefthanders who going to allens 14 &15 brl race.

Exceedingly unlikely that an EX13.5 would come with a small front bearing. Novak made that "mistake" on the original 13.5s but I doubt they would do that in current production. Before you spend money on a new endbell, take the motor apart (you have to take it apart anyway) and see if a regular 1/8" shaft is tight in the bearing or has 1/16" of slop. You probably only need to buy the sintered rotor. My EX13.5 came ith a large front bearing.

i am new to brushless i may have make the missake but if you look at the picture james put on the posting if EX motor you see the taper shaft on the pinon side i think :confused: that the big bearing. my EX motor has no taper shaft the bearing is 1/8 when i open the motor it has a brass sleeve over the 1/8 inch shaft to retand the rotor. this is what i saw. it is just like the
ss4300 motor i have. please let me know i get screwed it brand new from al's
i would like to know so i get replace or what by 14-15 brl race
thanks Dave :freak:

From what you described it sounds like you got the small bearing. If your rotor is black you have a big bearing, if your rotor is gray you have a small bearing. That will tell you 100%.

This is the upgrade kit that you need to upgrade an EX motor to a SS Pro (sintered) equivalent:

Novak Electronics EX & SS4300/5800 Sintered Upgrade Kit (http://www.shopatron.com/product/part_number=5923/135.0.15995.17447.0.0.0)

...I would have sworn that the EX motor was listed as having the small bearing, but it wouldn't suprise me if that's been upgraded.

I think the Ex series of motors was a way to sell the older motors by relabeling them and dropping the price...instead of being stuck with the old tech motors sitting dead on a shelf. (GOOD Marketing)

I would bet at some point the EX series will get the RIBBED can if enough of them are sold...cause I really doubt NOVAK is having the Non-Ribbed cans made any longer...

As far as getting screwed, the Ex series of motors is designed to be a more affordable choice for a B/L motor..and although easy to upgrade, if you know/knew you were going to want a SINTERED ROTOR version of the motor...it's actually cheaper to buy the PRO version up front.

You can run the motor the way it is...in fact depending on your driving level you may like the feel of the bonded rotor better...because it's got a little less power.

We've got a couple guys running the Ex Series 10.5's that have been very competitive w/o upgrading the rotor...as they slowly get into the Brushless motor game.

Thanks, Joe...

I couldn't have explained it better.

Since I have to return my setup to novak, would I be further ahead to get an xbr with a 17.5 motor? How much difference is there really with a 13.5 and 17.5? the only track I will be on is a small oval carpet track that averages 80-82 laps in 4-cell stock.

The 17.5 motor isn't offered in the EX series.

As far as speeds, the 17.5Pro motor runs very close to STOCK 4 cell speeds.

Out where I am we don't and never really did run 13.5's (We started B/L later then the East/Mid West area) and saw the 13.5's were quicker than STOCK quickly...and were already working on the 17.5, so we never went the route of 13.5.

I know it is not offered, but I could still buy a 17.5 ss ! Thanks for the info, by the way, it is much appreciated!

so i order the upgrade w/ bell end and rotor for EX & 10.5 i have. $40.00ea.
i don.t think what to bad for new. the package $169.00 for the XBR 13.5EX
and 40.00 for upgrade $210.00 the cheapest GTB package 249.00
swtour i haven't raced 7 year the feel will be full troddle

there are two differnt motors first one is the13.5 xbr the other one is the ss pro 13.5 first one has small rotor the ss pro has the larger rotor and larger bearings. The xbr 13.5 comes in the kit form and is not recomended for hard racing hope this helps

I believe that is xbr's have the bonded rotor and small bearing and the ss have the sintered rotor and big bearing. both of the rotors are the smae size just made from different material.