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Post by RyanWiltshire on Sept 5, 2023 17:13:41 GMT -5
is there a thread or well written blog post about shimming and when should you shim and not shim? I understand you shim to make the boss longer, but when should you shim.
let's say the belt is at the top of the rear pulley all the way up the top, what most would call "good fitment" but then we have the front belt what sits more on the rightside on the boss, making 0 contact on the left drive face?
what would you do to allow the front drive face touch the belt?
my belt doesn't seem to touch the face when moving the belt forwards and backwards, but fits really nice in the back?
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Post by oldgeek on Sept 5, 2023 19:43:22 GMT -5
CVT setup is quite the balancing act. If the belt does not touch both sides up front then you have too many shims or the boss is simply too long. IMHO You want the belt to just barely grab in the front, enough to turn the motor over just a bit as you pull the belt forward. If there is too much space then you have wasted travel of the front pulley that could easily translate to lower top speed. If the belt is too tight in the front pulley the CVT may start shifting before the scooter is even moving which could hurt your takeoff, so then you would add a shim. I have spent many hours tuning a CVT for that perfect balance of takeoff and top speed. The weights and contra spring also come into play as you tune, even the carb tune has a role in the CVT setup.
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Post by oldgeek on Sept 5, 2023 19:52:44 GMT -5
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Post by Lucass2T on Sept 6, 2023 0:21:05 GMT -5
OG described it well.
You don't want belt slip on launch. You'll notice soon enough when that really happens.
And don't go overboard on the stiffnes of contra spring to counter any slip.
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Post by RyanWiltshire on Sept 6, 2023 1:39:50 GMT -5
CVT setup is quite the balancing act. If the belt does not touch both sides up front then you have too many shims or the boss is simply too long. IMHO You want the belt to just barely grab in the front, enough to turn the motor over just a bit as you pull the belt forward. If there is too much space then you have wasted travel of the front pulley that could easily translate to lower top speed. If the belt is too tight in the front pulley the CVT may start shifting before the scooter is even moving which could hurt your takeoff, so then you would add a shim. I have spent many hours tuning a CVT for that perfect balance of takeoff and top speed. The weights and contra spring also come into play as you tune, even the carb tune has a role in the CVT setup. this is the kit I am using, it come with the bushing, shims, spring, etc etc I am using one shim as the front pulley will not sit tight unless 1 shim is in the bike already. only thing that is different, I am using the orange contra. Stage6 do a Pink one xtra soft and soft which is orange. I have noticed I get this burrrrrr and all of a sudden all the power just appears, like there is dead power, no power and all of sudden it goes from being a bog type "burrrrrrrrrr....brappppppppppp, like everything comes just explodes giving it fall beans clutch is set tight as well, I am just confused on how I can obtain that low end, fast biteing of the CVT, instead of that bog, then everything kicks in.  |
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Post by RyanWiltshire on Sept 6, 2023 1:42:36 GMT -5
would you guys like me to take a photo of my belt fitment so you guys can offer some suggestions?
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Post by Lucass2T on Sept 6, 2023 3:45:23 GMT -5
The bike should do burrrrrr's and "burrrrrrrrrr....brappppppppppp's...It's a two stroke😁
As long as you have installed the cvt parts as should no pictures are needed.
Shim the variator like OG said. There are plenty of how-to's to do that.
FIRST, put in standard clutch springs, way too heavy rollers and the softest contra spring.
It doesnt matter the bike runs crap because otherwise it's very hard to tune it. It's very hard to notice belt slip or rollers that are too light.
Do a testride. If you have belt slip change the contra spring to a stiffer one.
Do another tesride and tune the rollers to the desired rpm. It will still take off like crap but with too stiff clutch springs it's hard notice if the roller are too light.
Do another testride and change the clutch springs to the desired take-off rpm.
If you do it in another order you're just chasing your own tail or having a poorly tuned bike.
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Post by RyanWiltshire on Sept 6, 2023 4:05:51 GMT -5
The bike should do burrrrrr's and "burrrrrrrrrr....brappppppppppp's...It's a two stroke😁 As long as you have installed the cvt parts as should no pictures are needed. Shim the variator like OG said. There are plenty of how-to's to do that. FIRST, put in standard clutch springs, way too heavy rollers and the softest contra spring. It doesnt matter the bike runs crap because otherwise it's very hard to tune it. It's very hard to notice belt slip or rollers that are too light. Do a testride. If you have belt slip change the contra spring to a stiffer one. Do another tesride and tune the rollers to the desired rpm. It will still take off like crap but with too stiff clutch springs it's hard notice if the roller are too light. Do another testride and change the clutch springs to the desired take-off rpm. If you do it in another order you're just chasing your own tail or having a poorly tuned bike. No, what I mean is when I go to take off and then stop again and immediately try to take off again, there will be a dead point where it just bogs/burrrrrr and then everything seems to shift. It’s very hard to describe. I pull the throttle and there is no movement until it decides to kick in, some sort of delay. Stage6 clutch has hardest springs you can get and their adjusted pretty tight Rollers for my set up seem fine, 4.5, if I go lower the bike isn’t fully shifting on the variator, I can feel the lack of power. 4.5 seems fine in rollers, I might try going heavier, 5gs? Here is my belt fitment, on both sides      |
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Post by oldgeek on Sept 6, 2023 5:57:56 GMT -5
Belt looks like the width may be wore, measure it. Back up and take another picture of the whole CVT, belt looks like it may be a bit long?
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Post by RyanWiltshire on Sept 6, 2023 6:12:55 GMT -5
Belt looks like the width may be wore, measure it. Back up and take another picture of the whole CVT, belt looks like it may be a bit long? it's the only belt you can get for the stage6 overrange kit. only thing that fits is the Stage6 R/T Oversized Belt. I haven't even put 100 miles on the bike xD |
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Post by Zino on Sept 6, 2023 7:56:08 GMT -5
When I shim the variator ,I am trying to get rock bottom on the variator by the drive boss and also get as much travel on the outside of the variator This is actually too much shim for this set up . I want the end of the drive boss plus shims to be even with the inner edge of the belt The drive boss by itself is almost long enough this shim makes it too long The stage 6 variator fan from your picture has an indent for the drive boss to fit into so it in effect shortens the drive boss . You may need less shimming or no shimming to get the best take off 
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Post by Zino on Sept 6, 2023 8:07:55 GMT -5
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