Why ball bearings?

That's right, why? Why so many people recommend to replace plastic or metal bearings included in kits with ball bearings? If they were so important, how come they are not in every kit box? Some manufacturers include them, others don't or not for all their models. Here like so often, the main reason is cost-related: not that a ball bearing set is that expensive, but it saves a few euros on the final kit price. On the other hand, 15 to 30 years ago for the first models, the price was just prohibitive.

Tamiya only sells a few kits fully ball raced, generally hopped-up or race-oriented kits. For all the others, plastic or metal bearings are provided.

Those plastic bearings feature everything you want to avoid:
    high friction resistance
    prone worn leading to play

Metal bearings don't wear (or very few), but they share the same friction resistance with plastic bearings.

Friction resistance is a major flaw since it puts a strain on the model performance: on a buggy like the Baja King, the difference is about 5 km/h. Same thing on an on-road chassis like le TT-01: 5 km/h it's not much. Now, say it differently: we're talking about a top speed enhanced by 20% in both examples. Acceleration is about 5 to 7% faster, and the time needed to get from 0 to 20 km/h is reduced by 33%. I recommend you read this article (French only, sorry, but you'll understand the tables and graphs): TT Performance Analyser.

This friction resistance leads to another problem: shorter running times. The whole transmission is not free so the motor effort needs to be greater to overcome the friction resistance of the moving elements: thus it draws much more current, exactly like a car hauling a caravan.

With time, the plastic bearings have an impact on the overall model reliability because they tend to wear. The pinions which are designed to precisely fit tend to become looser: they suffer from play which leads to wear them much sooner.

Conclusion is obvious: plastic and metal bearings are evil! Ball bearings are the best and they will save our poor planet Earth! Well, sorry  The one and only must-have option for any model is a full ball bearing set.

     

Now that you now why you need ball bearings, let's see which ones your model needs.

Ball bearings references and sizes

In their manuals, Tamiya use references for their plastic and metal bearings: their ball bearings share the same reference. If most of the LHS know how to convert Tamiya references in standard measures, it's always better to check twice. Even more since Tamiya use the outer  / inner diameter convention to name their ball bearings when the industry uses the reverse. The following table will help: all meassures are in millimeters.

Reference	Inner Diameter	Outer Diameter	Thickness
620	2	6	2,5
630	3	6	2,5
730	3	7	3
830	3	8	2,5
840	4	8	3
850	5	8	2,5
950	5	9	3
1050	5	10	4
1060	6	10	3
1150	5	11	4
1160	6	11	4
1260	6	12	4
1280	8	12	3,5
1510	10	15	4
1680	8	16	5
2415	15	24	5
2617	17,5	26	5

Table based on the work of Savage-91 from Vintage-RC

Which ball bearings for my model?

First thing to know is the exact chassis of your model. Here are 3 ways to check this:
    The box: generally, it's written on it.
    The manual: it's generally mentioned somewhere.
    The best way to be sure is to get the information on this website's model listings.

These listings will help you to find a model by its reference (that you'll find on the box and the manual):
    For the 58000 series
    For the 58100 series
    For the 58200 series
    For the 58300 series
    For the 58400 series
    For the XB Xpert Built series

Be careful: Tamiya often provide the same bodyshell on different chassis. Be sure to check twice that the reference exactly matches your model.
For XB Xpert Built models, the corresponding kit reference you'll get into the list is the best possible match (it will always be the same chassis though). Then you'll have to find the corresponding kit model in the list to get its exact chassis reference.

Now that you exactly know your model chassis, just find it the table below:

Chassis	Bearings		Chassis	Bearings		Chassis	Bearings		Chassis	Bearings
58001*	1x850		58003	None		58004	4x1150 2x850		58005	4x1150
58010	6x1150 (4x1150 for CS)		58013	6x1150		58015 (SRB)	12x1150		58017	4x1150
58021*	4x1150 5x850 (?) 2x6mm ?		58023	8x1150		58025	6x1150		58028 (3 SPEED)	7x1150 (apart from gearbox)
58032	6x1150		58035*	6x1150 4x850		58036*	10x1150 2x850		58038	12x1150
58042	6x1150 1x850 1x730		58043	9x1150 1x850		58044	9x1150 1x850		58046	9x1150 1x850
58047	17x1150 5x850		58051	10x1150 2x850		58053	2x1150 5x850 1x730		58055	17x1150 5x850
58056	11x1150 1x850		58059	16x850 6x620		58061	11x1150 1x850		58065	20x1260 4x850
58067	17x1150 4x850		58068	1x1150 5x850 1x730		58072	4x1680 10x1150 4x850 2x830 2x620		58076	4x1680 10x1150 4x850 2x830 2x620
58079	4x1680 10x1150 12x850 2x830 2x620		58080	2x1680 10x1150 8x850 36x730		58081	2x1680 10x1150 2x850		58082	2x1680 10x1150 2x850
58084	3x1280 2x1260 2x1150 4x850		58085	4x1680 10x1150 12x850 2x830 2x620		58087 (DF-01)	16x1150 6x850 (+ 4x850 58100 / 58107)		58088 (Group C)	3x1280 2x1260 6x1150
58093	12x1150		58096 (TA-01)	16x1150 6x850		58097	2x1680 9x1150 7x850 16x730		58101	12x1150
58104 (F-102)	3x1280 2x1260 2x1150 4x850		58116	3x1280 1x1260 8x1150 8x850 1x830		58121 (FF-01)	2x1510 2x1260 7x1150 3x850		58126 (F-103)	3x1280 2x1260 4x850
58128 (TA-02)	2x1510 2x1260 12x1150 6x850		58132 (XC / CC-01)	2x1510 2x1260 11x1150 8x850 1x830		58134 (F-103L)	3x1280 2x1260 4x850		58136 (TA-01/TA-02)	16x1150 6x850
58144 (TA-02W)	2x1510 2x1260 12x1150 6x850		58149 (M-01)	11x1150 3x850		58156 (F-103RS)	3x1280 2x1260 4x850		58157 (TA-02RS)	16x1150 6x850
58158 (M-02)	11x1150 3x850		58172 (TA-02SW)	2x1510 2x1260 12x1150 6x850		58173 (M-02L)	11x1150 3x850		58177 (TA-03F)	4x1510 4x1260 8x1150 2x850 2x730
58180 (M-02M)	11x1150 3x850		58184 (DT-01)	9x1150 1x850		58191 (TL-01)	24x1150		58192	12x1150
58193 (TA-03RS)	4x1510 4x1260 8x1150 4x850 2x730		58194 (F-103RX)	3x1280 2x1260 4x850		58196 (M-01M)	11x1150 3x850		58203 (TA-03R)	4x1510 4x1260 8x1150 4x850 2x730
58211 (M-03)	12x1150 2x850		58218 (TA-03FS)	4x1510 4x1260 8x1150 2x850 2x730		58221 (TL-01B)	24x1150		58224 (FF-02)	12x1150 2x850
58231 (WR-01)	24x1150 (4x4) 16x1150 (4x2)		58232 (Juggernaut)	16x1260 14x1150 2x850		58236 (M-04L)	12x1150 2x850		58242 (WR-02)	16x1150
58247 (F-103LM)	3x1280 2x1260 4x850		58256 (Juggernaut 2)	16x1260 14x1150 2x850		58257 (TB-01)	4x1280 1x1260 10x1150		58261 (TA-04)	4x1510 8x1150 8x850 2x840 3x730 2x620
58265 (M-03L)	12x1150 2x850		58267 (TB-Evo)	5x1280 9x1260 2x1150 2x850		58272 (TA-04S)	4x1510 8x1150 4x850 2x840 3x730		58276 (TA-04R)	4x1510 8x1150 8x850 3x840 4x730 2x620
58280 (TXT-1)	16x1260 6x1160 10x1150 12x850		58284 (TB Evo II)	5x1280 2x1150 6x850		58288 (F-201)	8x1510 2x1280 4x1260 3x1150 2x1050 7x850 2x620		58290 (TA-04SS)	4x1510 8x1150 4x850 2x840 3x730
58293 (TL-01LA)	24x1150		58299 (TB Evo III)	4x1510 2x1280 1x1260 8x1150 2x850 2x630		58302 (TT-01)	4x1280 12x1150		58307 (M-04M)	12x1150 2x850
58310 (TB-02)	4x1510 2x1280 8x1150 1x1060 8x850		58320 (TRF415)	4x1510 8x1150 2x850 2x840 2x630		58328 (DF-02)	4x1280 12x1150		58331 (TB Evo IV)	4x1510 1x1260 3x1060 8x950 2x850 2x630
58340 (DT-02)	14x1150		58345 (TA-05)	4x1510 8x1150 8x850 2x840		58348 (TT-01R)	4x1280 12x1150		58349 (TT-01D)	4x1280 12x1150
58367 (F-103GT)	3x1280 1x1150 2x1060 4x850		58368 (M-03M)	4x1150 8x1050 2x850		58370 (DF-03)	4x1510 8x1150 4x1050 3x950 8x850 1x830 1x630		58371 (TB Evo V)	4x1510 1x1150 2x1060 2x1050 8x950 2x850
58372 (3SPD 2006)	4x1260 35x1150 1x1050 2x850		58389 (TA-05 IFS)	4x1510 8x950 12x850 2x840		58395 (DB-01)	4x1510 8x1050 8x850 2x840 2x730		58402 (TT-01E)	4x1280 12x1150 4x850
58405 (CR-01)	2x2415 1x1510 8x1280 22x1050 7x850		58409 (TB-03)	4x1510 2x1060 11x1050 12x850		58417 (DF-03Ra)	4x1510 8x1150 4x1050 3x950 8x850 1x830 1x630		58420 (TB-03D)	4x1510 2x1060 11x1050 8x850
58431 (F-104)	2x1280 1x1150 2x1060 4x1050		58435 (TA-05 v.II)	?		58438 (M-05)	12x1150 6x850		58443 (M-05 Pro)	8x1150 4x1050 6x850
58454 (M-05M)	12x1150 6x850		58453 (M-05L)	12x1150 6x850		58463 (FF-03)	?		58464 (M-05Ra)	?

        The * sign next to a chassis name means I'm not sure about the ball bearings references

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First publication: january 12, 2010 Last modified: july 10, 2010

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