TechMoto Chain Chum – KTM 790/890 & Husqvarna 901 Chain Slack Tool

The controversy is over!

With so many opinions on proper chain tension for the 790/890/901, we’ve created a tool based on a proven technique to quickly and accurately adjust and be on your way.

One of the main reasons proper tension is critical is for when the front and rear sprocket are at their maximum distance apart when loading the rear suspension – sufficient slack is required so the chain does not break.

At the other end, too much slack may cause the chain to come off its sprocket.

In order to determine the ideal tension, we lifted the rear wheel and statically compressed the suspension to get a straight line between the front sprocket, the swingarm bolt and the rear axel. This geometry is the maximum distance between front and rear sprocket.

Once the suspension was released, the amount of slack that resulted was how we determined how to design the block (height & length).

Simply place the Chain Chum where instructed and turn the adjusting screws accordingly to achieve optimum tension.

Instructions on using the chain tool:

1. Refer to your manual on how to prep the bike for chain adjustment.
2. Remove chain guard, clean chain, etc.
3. Ensure your chain guide is in good shape.
4. Once the rear is lifted, ensure there is enough slack to fit the Chain Chum on top of the chain guide and on the outside of the ridge.
5. Rest the Chain Chum as (shown in pics), ensuring two full links are resting across the top surface of the tool.
6. Turn the Adjusting Screws to create tension on the chain. If there is a few millimetres of chain slack on the underside of the swingarm, that’s okay.
7. Once you achieve the desired tension, continue with the instructions in the manual on how to complete the process.
8. Lube chain, replace chain guard, and ride on…!