What the heck just happened?!

So I was doing my regular commute to school. Like any other day and when powering up a hill at around 18MPH, I feel some lag and then I hear a crunching/grinding sound and my board slows down to a stop. I do a quick check and realize that 90% of the teeth on my belt have just grinded off! I run the belt at a medium tightness and I have an idler, any help as to what could have caused this issue would be greatly appreciated! Just to note, the belt and motor pulley was quite hot to touch, almost too hot to touch when the belt broke. Here are some pictures of the belt.

Happened to me once. I let me dare devil friend ride my esk8 and he went full throttle up a 15% hill. Almost shat his pants when the belt teeth got grinded off and he had to abandon ship :smiling_imp: :passenger_ship:

What belt width is that? Do you run single or dual drive?

It can happen for a few reasons like the belt being incorrectly aligned and things like that but the most common is just not enough torque transfer. What size belt is it?

It is a 9mm belt running in a 14/36 gear ratio and I’m running a single drive (TB 6374). Will be upgrading to a 12mm belt later this week.

Edit: It is 280mm long if that helps.

I would recommend at least 15mm. Chain drive is preferable however. Never had any issues with my street board on a chain drive.

Yeah have seen this happen to 9mm belts too on a single drive agree 12mm or 15mm belt it’s far less likely to happen only issue with upgrading is making sure the pulley is big enough and everything still lines up and fits well.

Alright, so 15mm belt it is! Also, hows the torque difference with a 16/40 ratio and a 16/36 one?

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That’s insane. You just made me really glad I won’t compromise and use anything less than 15mm width. At least it’s not in vain

Once the first tooth chips the rest will follow quite quickly. Had the same thing happen, belt was pretty worn out tho and eaten som rocks that got wedged between belt and pulley so was somewhat expected. Proper alignment is key for lifetime of belt.

wow wow wow. that never happened

Could be belt too tight, alignment wrong, middle set screws ate the belt, belt too loose.

If your running up steeper hills 12/15mm or dual motors provide more traction.

The age of your belt could also be a consideration, and degradation as a result of UV light.