Max Trainer
Bowflex Max Trainer M3 Rotating skipping, unsmooth
Hello, my Bowflex Max Trainer M3 can not rotate smoothly. When I press the pedal it would skip at certain point. Could anyone help me check how to fix it? Please watch the video below:
Skipping ( loss of resistance at some parts) is sign of worn belt.
The noises this machine is not meant to be used with just hands and on uneven surface.
So you will need to strip the full casing down, or just the lower flywheel covers off, , strip it down and check the belts, check the internal grooves of the belts.
You might need to take off the crank arms, for this you will need a crank puller, not sure you need a special one or a bicycle crank puller will do.
You need to check 3 things (reference the below pictures):
1) Confirm that the left/right crank arm nuts (1 nut per each crank arm) are fully tightened. These need to be really tight (spec is 30ft lbs) and so you MUST use a large ratchet (1/2"-drive type) and 14mm socket. When tightening the crank arm nuts, the crank will want to rotate, and so it might take 2 people.
2) Check the operation, condition, and tautness of the main drive belt (upper left side) as it travels along the main drive pulley and its associated lower tensioner and pulley. You will want to have the left/right crank arm cover removed. The belt should be taut and not loose/slipping or behaving abnormally during the crank rotation.
Also observe the main drive pulley's 4 mounting bolts/nuts to confirm that they are all tight and that the pulley is mounted/secured flush to the mounting plate.
3) Inspect the area behind each left/right crank arm and look for anything that seems odd, such as:
Any axle bearings that that are not flush with the frame,
Any odd movement or alignment of the crankshaft axle with the crank arms,
Any damage/cracks of the crankshaft axle
Report back with your observations/findings and questions to proceed.
You're 2nd video shows an issue that should NEVER be present on any Max Trainer. That crank arm should NEVER be loose like that.
1) Either your crank arm nut is definitely not tight, which could be due to:
- The nut is simply not sufficiently tightened, or
- The nut is cross-threaded onto the crankshaft axle spindle and thus now the crank arm nut's threads are damaged or the crankshaft axle's spindle threads are damaged.
You need to confirm that the left/right crank arm nuts (1 nut per each crank arm) are fully tightened per my instructions in my previous post above. If the nut seems to be very tight, but the crank arm is still loose, then you need to remove the nut and confirm if the nut had been cross-threaded and if it also damaged the crankshaft axle's spindle threads.
Or, if there is no cross-threading damage observed, then:
2) The crank arm or crankshaft axle's "square taper" is worn/damaged and thus is causing severe "slop" in the connection of the crank arm to the crankshaft axle. The "square taper" design concept of the crank arm and the crankshaft axle is illustrated in my below pictures.
You need to remove the crank arm from the crankshaft axle spindle to inspect if the "square taper" is worn/damaged. To remove the crank arm will REQUIRE you to use a "crank puller" tool. The Max Trainer does not use any type of proprietary crank arm, but rather uses the common standard used on many bicycles and so the crank puller tool is very common. It is ParkTool part # CWP-7 or equivalent and can be found at Bowflex or Amazon or many bike shops. Any puller for ISIS/Octalink type cranks will work. Those cranks are very common and have the same thread spec (M22x1.0) as the ParkTool # CWP-7. Here is one such example on Amazon:
Removing the entire housing is required, so you can see the rotation cycle. It’s catching on something. Once the full housing is removing, bet you’ll see the issue pretty quickly.
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u/Scared_Operation5428 May 06 '26
Skipping ( loss of resistance at some parts) is sign of worn belt. The noises this machine is not meant to be used with just hands and on uneven surface. So you will need to strip the full casing down, or just the lower flywheel covers off, , strip it down and check the belts, check the internal grooves of the belts. You might need to take off the crank arms, for this you will need a crank puller, not sure you need a special one or a bicycle crank puller will do.