Tamiya TT02 High Speed Gear Set Query

[Bodi007 3]

Hi all,

I've bought some hopups for my Plasma Edge 2 (drive shaft, propeller joints, high speed gear set, motor mount etc). I didn't do much research before buying the high speed gear set as I just thought, what the heck, I'll add it the the order as it's pretty cheap. I've since read some of the discussions on here regarding the high speed gear set and wanted to ask. Whilst I'm replacing the drive shaft, and propeller joints, is it worth installing the high speed gear set just with the stock pinion gear? I'm not that interested in increasing the top speed if it's going to lower the Torque, but I may well buy a brushless motor in the near future as that sounds like a better option.

Apologies if it's a bit of a dumb question but I don't really have much experience with gearing. I understand the theory behind it though. Just wondered if it's worth installing it whilst I'm doing the other hop ups?

I read that if I do install it and use the stock pinion gear, I would have to change the position of the motor on the mount? Dumb question number 2 - What does changing the mount position of the motor actually do?

Thanks

[Aerobert 2125]

59 minutes ago, Bodi007 said:

Dumb question number 2 - What does changing the mount position of the motor actually do?

Can't answer your first question, but you have to change the mount position of the motor as the high speed gear spur has only 68T in contrast to 70T of the kit spur. 

[Elbowloh 1127]

The mount position needs to change depending on the size of pinion/spur gear you use to ensure the correct gear meshing. 

You can get an aftermarket Yeah Racing motor mount that is adjustable (like a sliding scale rather than a number of different holes).

[alvinlwh 5891]

According to the instructions, to use the stock 22T pinion, you will need to use hole E not G, giving you a FDR of 8.04 instead of the standard 8.27, meaning more top speed.

The reason for the change in the mounting hole compared to stock is the speed gear is smaller, so the pinion needs to be closer to engage with it.

[OoALEJOoO 3127]

Welcome to the forum @Bodi007 .

A bit of background on TT-02 gearing. Stock gearing (from TT-02 manual):

High speed gear set:

TT-02 touring cars:

• Kit comes standard with 22T pinion + 70T spur, for a gear ratio (or Final Drive Ratio, FDR) of 8.27
• Tire size affects the effective FDR. Touring cars generally use 65mm OD tires.
• Touring cars are generally run with FDRs in the 5.5 to 7.5 range (the kit standard 8.27 is too short).
• The standard kit 70T spur allows FDR down to 7.28 only, which is not great. This triggers the need of the high-speed gear set to push it further down.

TT-02B Buggies (Plasma Edge II):

• Kit comes standard with 17T pinion + 70T spur, for an FDR of 10.71.
• Buggies have larger tires, thus requiring higher (shorter) FDR to achieve the same speed. The Plasma Edge II comes with ~88mm tires.
• Buggies are generally run with FDRs in the 7.5 to 10.5 range (the kit standard 10.71 is a bit too short).
• The standard kit 70T spur, with FDRs that can go all the way down to 7.28, is already great for a buggy.

Back to the question of whether the high-speed gear set is needed for the Plasma Edge II. These are my thoughts:

• FDR-wise, you don't need it. The 70T spur can give you plenty of gearing options for the buggy-size tires.
• The kit comes with a 17T pinion. If you do install the 68T spur that comes with the high-speed gear set, you won't be able to use the 17T pinion since the smallest pinion that can be paired to the 68T spur is a 18T pinion.
• Regardless of the spur gear, the kit standard pinion is made of very soft aluminum that will wear quickly and chew-up the spur once it does (EDIT: The TT-02B kit comes with a 17T steel pinion and not soft aluminum). It is recommended to use a steel pinion, or at least hardened aluminum.
• The only real benefits I can see of installing the high-speed gear set on a TT-02B buggy is that the aluminum spur mount will make the gear spin with a bit less wobble (better fit), which is not a must-have improvement for a mild-power basher. It would also allow to fit gears of other tooth size (module, say 0.8mod instead of the provided 0.6mod) but this would require an aftermarket fully-adjustable motor mount and again for a basher not really needed.

The TT-02B is a fantastic basher. Assuming you plan to use the car as a basher using the stock motor, my recommendation is to stick with the standard 70T spur, get a steel 18T pinion (motor mounted on position C) and save the high-speed gear set for a TT-02 touring car.

EDIT: Since the TT-02B kit comes with a steel 17T pinion, a good option could be just to keep it (motor mounted on position B).

[Bodi007 3]

Thank you all so much for the advice and taking the time to write all that information. That certainly answers all my questions and I now understand gearing! :-) . I think I will stick with the 70T spur and get an 18T pinion as suggested by OoALEJOoO.

Thanks again!

 

[OoALEJOoO 3127]

@Bodi007, I just realized that the 17T pinion that comes in the TT-02B Plasma Edge II kit is actually steel (black colored), and not soft aluminum (silver colored). A perfectly fine option is to use it. My earlier recommendation of 18T steel was made since it's recommended getting a steel pinion anyway, best get one with a bit taller FDR and one that could eventually be used with the 68T spur in the future, thus 18T.

If edited my earlier post to reflect this.

[Bodi007 3]

Ah ok, that’s good to know as I wondered if the stock pinion was Aluminium or not. I do have a Tamiya branded 18 and 19T pinions, but they are silver coloured so assuming they are Aluminium. Are they ok to use when not racing? I don’t run the car flat out for long periods, or should I just bin them and buy steel pinions? Strange that they would manufacture pinions that are no good.

Thanks

[alvinlwh 5891]

4 hours ago, Bodi007 said:

Ah ok, that’s good to know as I wondered if the stock pinion was Aluminium or not. I do have a Tamiya branded 18 and 19T pinions, but they are silver coloured so assuming they are Aluminium. Are they ok to use when not racing? I don’t run the car flat out for long periods, or should I just bin them and buy steel pinions? Strange that they would manufacture pinions that are no good.

Thanks

I don't think I ever used the standard aluminium pinions, ever. It is a Tamiya thing, same as bearings not included when almost everyone else does. Supposingly to keep the cost down but they are not that cheap compared to equivalent from other brands.

[Bodi007 3]

Regarding the steel pinions. Is this suitable for the Plasma Edge 2? I'm assuming so, but wanted to double check.

https://www.rwracing.co.uk/product/cnc-tamiya-0-6-module-pinion

Cheers!

 

[gkatz 49]

hi guys;

lots of info here but I am still stragling a bit with gearing.

I already am building my TT02B and already installed some hop ups like the adjustable motor mount.
I am trying to undertsand the gearing changes I can do.
assuming I get a gear mount like so:  https://www.ebay.co.uk/itm/High-Speed-Gear-Mount-Plate-Tamiya-TT-02-TT-02B-TT-02D-XV-01-RC-On-Road-Car-/155318999642 

a few questions come to mind:

1. this mount plate has 4 screw design, so I need only gears with these 4 holes in the correct place. this already reduces the amount of things I can buy and also its hard to know if a spur gear will fit (buying from AE - I usually dont get the tamiya branded ones)

2. should I care about the spur diameter? I already have an adjustable motor mount so I assume no problem putting a smaller diameter spur but is the diameter an issue here?

3. there are talks about 0.6 / 0.8 other - I have no idea what these numbers are and how they apply here

4. what is a good spur teeth/pinion teeth combination to increase speed in a buggy like neoscorcher / plasma edge

thanks a lot for the help!

[BuggyDad 4411]

2 hours ago, gkatz said:

hi guys;

lots of info here but I am still stragling a bit with gearing.

I already am building my TT02B and already installed some hop ups like the adjustable motor mount.
I am trying to undertsand the gearing changes I can do.
assuming I get a gear mount like so:  https://www.ebay.co.uk/itm/High-Speed-Gear-Mount-Plate-Tamiya-TT-02-TT-02B-TT-02D-XV-01-RC-On-Road-Car-/155318999642 

a few questions come to mind:

1. this mount plate has 4 screw design, so I need only gears with these 4 holes in the correct place. this already reduces the amount of things I can buy and also its hard to know if a spur gear will fit (buying from AE - I usually dont get the tamiya branded ones)

2. should I care about the spur diameter? I already have an adjustable motor mount so I assume no problem putting a smaller diameter spur but is the diameter an issue here?

3. there are talks about 0.6 / 0.8 other - I have no idea what these numbers are and how they apply here

4. what is a good spur teeth/pinion teeth combination to increase speed in a buggy like neoscorcher / plasma edge

thanks a lot for the help!

I read this then went looking for a recent post to share. Then I found it, on this very thread! 😜

On 1/25/2023 at 1:14 AM, OoALEJOoO said:

Welcome to the forum @Bodi007 .

A bit of background on TT-02 gearing. Stock gearing (from TT-02 manual):

High speed gear set:

TT-02 touring cars:

• Kit comes standard with 22T pinion + 70T spur, for a gear ratio (or Final Drive Ratio, FDR) of 8.27
• Tire size affects the effective FDR. Touring cars generally use 65mm OD tires.
• Touring cars are generally run with FDRs in the 5.5 to 7.5 range (the kit standard 8.27 is too short).
• The standard kit 70T spur allows FDR down to 7.28 only, which is not great. This triggers the need of the high-speed gear set to push it further down.

TT-02B Buggies (Plasma Edge II):

• Kit comes standard with 17T pinion + 70T spur, for an FDR of 10.71.
• Buggies have larger tires, thus requiring higher (shorter) FDR to achieve the same speed. The Plasma Edge II comes with ~88mm tires.
• Buggies are generally run with FDRs in the 7.5 to 10.5 range (the kit standard 10.71 is a bit too short).
• The standard kit 70T spur, with FDRs that can go all the way down to 7.28, is already great for a buggy.

Back to the question of whether the high-speed gear set is needed for the Plasma Edge II. These are my thoughts:

• FDR-wise, you don't need it. The 70T spur can give you plenty of gearing options for the buggy-size tires.
• The kit comes with a 17T pinion. If you do install the 68T spur that comes with the high-speed gear set, you won't be able to use the 17T pinion since the smallest pinion that can be paired to the 68T spur is a 18T pinion.
• Regardless of the spur gear, the kit standard pinion is made of very soft aluminum that will wear quickly and chew-up the spur once it does (EDIT: The TT-02B kit comes with a 17T steel pinion and not soft aluminum). It is recommended to use a steel pinion, or at least hardened aluminum.
• The only real benefits I can see of installing the high-speed gear set on a TT-02B buggy is that the aluminum spur mount will make the gear spin with a bit less wobble (better fit), which is not a must-have improvement for a mild-power basher. It would also allow to fit gears of other tooth size (module, say 0.8mod instead of the provided 0.6mod) but this would require an aftermarket fully-adjustable motor mount and again for a basher not really needed.

The TT-02B is a fantastic basher. Assuming you plan to use the car as a basher using the stock motor, my recommendation is to stick with the standard 70T spur, get a steel 18T pinion (motor mounted on position C) and save the high-speed gear set for a TT-02 touring car.

EDIT: Since the TT-02B kit comes with a steel 17T pinion, a good option could be just to keep it (motor mounted on position B).

This is the most helpful concise piece I've seen on TT-02 gearing. So I was going to say - check that and spec spur and pinion to suit whatever final drive ratio (FDR) you want. Lower FDR is like a higher gear in your car - higher top speed, less acceleration, harder on the motor (which will overheat at too low a FDR). But because its a touring car chassis there's a lot of extra speed available with just pinion changes on the TT-02 before you need to worry about the spur. If I had a TT-02B I'd start stock and then if I want a bit more speed just try a bigger pinion, say a 19 or 20, and see how I get on with that. For my TT-02SR I've gone for the high speed gear set because on road and small wheels. 

0.6 and 0.8 are referring to tooth pitch, essentially the size of the teeth. You need the spur and pinion to match. Some people change the TT-02 to a finer pitch/smaller teeth for quieter running, but I'd guess unusual in a TT-02B. 

[gkatz 49]

54 minutes ago, BuggyDad said:

I read this then went looking for a recent post to share. Then I found it, on this very thread! 😜

This is the most helpful concise piece I've seen on TT-02 gearing. So I was going to say - check that and spec spur and pinion to suit whatever final drive ratio (FDR) you want. Lower FDR is like a higher gear in your car - higher top speed, less acceleration, harder on the motor (which will overheat at too low a FDR). But because its a touring car chassis there's a lot of extra speed available with just pinion changes on the TT-02 before you need to worry about the spur. If I had a TT-02B I'd start stock and then if I want a bit more speed just try a bigger pinion, say a 19 or 20, and see how I get on with that. For my TT-02SR I've gone for the high speed gear set because on road and small wheels. 

0.6 and 0.8 are referring to tooth pitch, essentially the size of the teeth. You need the spur and pinion to match. Some people change the TT-02 to a finer pitch/smaller teeth for quieter running, but I'd guess unusual in a TT-02B. 

thanks;

of course I have read this thread and looked at the drawings. but I was still confused. also, like I said I have a motor mount with adjustability so I dod not think I was bound to the restrictions of that drawing... this is why I posted my questions... (besides the fact I know nothing about gearing). I guess that in order to be on the safe side and not start adventures I would stick to tamiya's reccomendations

[gkatz 49]

4 hours ago, gkatz said:

thanks;

of course I have read this thread and looked at the drawings. but I was still confused. also, like I said I have a motor mount with adjustability so I dod not think I was bound to the restrictions of that drawing... this is why I posted my questions... (besides the fact I know nothing about gearing). I guess that in order to be on the safe side and not start adventures I would stick to tamiya's reccomendations

another example of what I dont understand. on the tamiya motor and gear drawing shown above, the 64T spur pinion list starts from 22T. is there a reason for that? why cant I use a 19T pinion with the 64T spur for example?
thanks for the help

[BuggyDad 4411]

3 hours ago, gkatz said:

thanks;

of course I have read this thread and looked at the drawings. but I was still confused. also, like I said I have a motor mount with adjustability so I dod not think I was bound to the restrictions of that drawing... this is why I posted my questions... (besides the fact I know nothing about gearing). I guess that in order to be on the safe side and not start adventures I would stick to tamiya's reccomendations

You're not bound to those options but even with the stock spur you have a lot of options is all I'm saying - range of FDRs from 11.38 to 7.28. If I take my Associated B64 towards the faster extreme of that with only a fairly hot motor, it overheats, hence my gut feel the stock spur would take you as far as you'd likely want to know. 

4 minutes ago, gkatz said:

another example of what I dont understand. on the tamiya motor and gear drawing shown above, the 64T spur pinion list starts from 22T. is there a reason for that? why cant I use the 19T for example?
thanks for the help

If the spur and pinion combined are smaller, their centres have to be closer together. With any mount, the motor can only be moved so far. Add the total number of teeth of pinion and spur together and the number needs to be above a certain minimum number for that reason. That looks like 16+70=86 (at 0.6 modulus) but maybe the sliding mount might go a little further - I don't know. 

[gkatz 49]

1 hour ago, BuggyDad said:

You're not bound to those options but even with the stock spur you have a lot of options is all I'm saying - range of FDRs from 11.38 to 7.28. If I take my Associated B64 towards the faster extreme of that with only a fairly hot motor, it overheats, hence my gut feel the stock spur would take you as far as you'd likely want to know. 

If the spur and pinion combined are smaller, their centres have to be closer together. With any mount, the motor can only be moved so far. Add the total number of teeth of pinion and spur together and the number needs to be above a certain minimum number for that reason. That looks like 16+70=86 (at 0.6 modulus) but maybe the sliding mount might go a little further - I don't know. 

got it

TBH, i am not sure how I feel about the adjustable mount, it feels like the first thing that will happen is that it will slowly slide away to the point where the pinion will not touch the spur - there's a lot of forces there

thanks

[BuggyDad 4411]

58 minutes ago, gkatz said:

got it

TBH, i am not sure how I feel about the adjustable mount, it feels like the first thing that will happen is that it will slowly slide away to the point where the pinion to not touch the spur - there's a lot of forces there

thanks

Sliding mounts are common and this one seems to come recommended so it should be OK. Also, it's more of a pivot than a slide so the top one has a bit of mechanical advantage. One thing I found is that the mesh tightened a little when I first fitted the gearbox cover, so I did reassemble it again, but it was the work of only a few minutes. 

[OoALEJOoO 3127]

Adding a little bit more into the mix, I've been sloooooowly working on a model to predict top-speed for different FDR's. This is what I have so far:

Notes:

• Using 65mm touring car tires. For other tire sizes, scale linearly.
• Spurs on table reflect Tamiya's available 06Mod parts (70T: 51215 or TT-02 stock: 51531, 68T: 51423, 66T: 51548, 64T: 51356, 63T: 51609). All can be fitted with the high-speed gear set on the TT-02.
• Tamiya makes 06Mod pinions up to 29T. Higher than this can be obtained from other manufacturers.
• You can't fit a 28T or 29T pinion with a 68T spur on the TT-02 with Tamiya's motor mount (mounting holes just allow up to 27T).
• I've run a TT-02 with a 32T Pinon (made by MST) + 63T spur and you need to trim the gear cover (part D3) from the inside a bit as this large pinion will rub. I suspect that a 31T pinion *might* be small enough to not need trimming.
• The above table applies to any car with a chassis ratio of 2.6. Beside the TT-02, other chassis with the same ratio include the FF-03, XV-01, XV-02 (which can use these spurs) and the TT-01.

About the numbers:

• Calculations are based on scaling and a bit of basic physics.
• No actual speed measurements have been taken (I don't have equipment) but info is somewhat matched to empirical data found in youtube (mainly cageman's videos).
• The listed values are top-speed, acceleration is another matter. Higher-powered motors will feel a lot more punchy throughout.
• The listed top-speed for the lower-powered motors when using very low FDR (high ratio) would need quite a long straight and therefore impractical.
• I'll continue working on this, progress is made at a lame snail's pace.

For more info and details on how I'm approaching this, you can check this thread (I haven't really worked on this for over a year ):

Theoretical Speed & Distance Curves - General discussions - Tamiyaclub.com