Complete 9mm GT3 Belting Kits for sale

Hey guys, I’ve just launched a kit that contains everything you’ll need to upgrade your machine to 9mm GT3 belting. The complete kit is just $75 (compare at over $120).

Here is what’s included:
(6) Powder coated steel 9mm belt clips
(6) Smooth Idler Kit for 9mm belting
(3) Timing Pulley, 20 Tooth, GT3 belting, 1/4” bore
(3) 1.2 meter (48”) lengths of GT3 9mm belting

The kit is available now at


I might get a set tomorrow, thanks

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Interested in this 9mm upgrade, had problems with belts and pulley bearings in the past. What name brand are these and what kind of quality can I expect?

Hey Steve -

We buy these in bulk direct from the manufacturer, so there’s not really a name brand to assign to them. However, I can assure you that these are not ‘bottom of the barrel’ parts. Even after our bulk pricing, we still pay more than it would cost us to buy individual pulleys from the ‘bargain’ sources online.

Also, rather than just sending a bag of components, we assemble and test every piece before shipping. On our idlers, we press in the bearings and make sure the internal spacer is installed properly. On the sprockets, we ensure the bore is correct, preinstall the set screws, and check to make sure the sprocket spins true.

These aren’t Ferrari parts, but they’re definitely not Yugo parts either.

If for any reason you’re not satisfied with what you get, we stand behind our products 100% and will work together to make it right.



Hi Luke-

What do you recommend using for sleeve clips with your kit?

Also, to be clear, this is a 3GT3 kit, not a 2GT3 kit, correct?

That is correct, this is 9mm wide 3mm pitch belting with fiberglass reinforcing. I also have 2mm pitch kits available, the advantage being that they are compatible with the stock motor pulleys on newer machines, although the 2mm pitch belting is not as strong as the 3GT belting.

When fed through the belt clip, the teeth interlock and do most of the holding for you. For added insurance, you can throw a zip tie, a little bit of heat shrink, or even a wrap of electrical tape around the ends to prevent them coming loose.

A few new options have been added at You can now select “add spare belt” to include a full set of spare belting on both the 3GT3 and the 2GT2 kit. Also, I have added the option to replace the motor pulley set screws with socket head cap screws for extra insurance against slipping motor pulleys.

There is also a new FAQs section to check out!

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Anyone else making these kits now that TBD is no longer offering?

Hey David, Inventables will have these for sale soon - I am in Chicago now working with the team to finalize some details in prep for launch :slight_smile: