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2023 SRX helix?

Thanks! Never thought Yamaha had a 37 degree helix. Was that 37 degree offred to the public? Or they were all cut to 35-39?
In 2017 & 2018 the Sidewinder came with a 8KC50 (35 degree straight cut helix). They offered a 37 & 39 as well (8KC70 & 8KC90). From 2019 on the 129, 137, 141 units all come with a 35-39 helix, it is either marked 8KC70 (I believe this was in 2019 & 2020) and now marked 8MA10 I believe for 2021 and further.


  • Sidewinder Helixes.jpg
    Sidewinder Helixes.jpg
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I don't use them. I don't think they need it. There isn't enough turbo lag in my opinion to warrant a helix like that.
They delay the upshift, which if you are trying to go fast is not what you want.
Are there some riding styles and area's of trail/mountains that MAY justify using it? Maybe?, but not for me.

This is all just my opinion of course, others may have found what they consider success with them.
I dont usually use them but I dont hate them either. Ones like 33/35 are useless imo but 35/39 is a great cruiser when spending alot of time at 60+ mph. They cruise at low rpms and pull good at speed and you dont give up anything down low vs a straight 35. With that said I dont find the backshift great and if you are having problems holding the belt at high speed this will only make it worse all other things equal. Also they work even better with a magnetic style weight or something you can place weight in an exact spot. Set screw style weights allow you to put weight where you want it but not fully. Adding a 4 gram setscrew in the heel of a weight spreads 4 grams across a 1” section of the weight, adding 4 magnets in the heel of a weight adds 4+ grams to the area the size of the magnet. Both styles will work but if you get larger spreads in helix angles wether normal or reverse it is easier to “fine tune” or be precise with certain styles over others. Reverse cuts arent for everybodys style for sure but they can be perfect for some.
what's the thoughts on the reverse helix once tuned

Depends on the tune and clutch arms. I've only found them to slow a sled down substantially for ET's if thats what you are looking for. Not sure why Yamaha is using them on the stock sleds. The straight 35 is better suited for it.