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Discussion Starter · #1 · (Edited)
Hi All,
Im new to this forum... been a lurker for a while and like most of you have been seriously irritated with the throttle on my duke. The action is so long you can almost swing on it.

Since Im a mountain biker I was looking through my spares doing a cleanup and found one of my headset spacers, looked at it and thought I think I can use this for my throttle on the Duke.

I took the spacer, cut a section out to match the throttle and then carefully grooved it with a hack saw.
The spacer is smaller than the part of the throttle that it had to go over so I had to pop it on using a bit of leverage!

The whole mod took me about an hour and a half and now I have a throttle which is nice and quick like my old MX bike and scooter.

Ive attached some pics so that you can see and get an idea on the size piece of aluminium spacer I used.

It fits very snug and theres no chance of it moving, if you feel necessary you can glue it.

I hope this helps :)
 

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Nice mod Sean, welcome to the forum.

Duke its a ratio thing, the circumference has been increased which means the cable covers more area with less input......thats probably a crappy explanation!
 

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Discussion Starter · #5 ·
Nice mod Sean, welcome to the forum.

Duke its a ratio thing, the circumference has been increased which means the cable covers more area with less input......thats probably a crappy explanation!
This is probably the exact same way as I would have explained it :D

You increase the diameter of the cam where the throttle cable sits, therefore reducing the amount of twist needed.

Standard twist from closed to full throttle is 105 degrees, mine is now about 75-80 degrees of twist to get full throttle.
 

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Do you find it to touchy now though? It seems to be a pretty big change in sensitivity. I'd be afraid that I would adjust the sensitivity too much...
 

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Do you find it to touchy now though? It seems to be a pretty big change in sensitivity. I'd be afraid that I would adjust the sensitivity too much...
I guess if you have a stand you can always keep adjusting it while getting a real feel for the response without the risk of being on the road
 

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Do you find it to touchy now though? It seems to be a pretty big change in sensitivity. I'd be afraid that I would adjust the sensitivity too much...
if you're uncomfortable don't do it. Someone mentioned in a thread a few weeks back that the 105 degrees of throttle twist was necessary to accommodate the majority of new riders who take the Duke otherwise take off would of been too snappy.

thanks for the post @SeanN, welcome to the boards!
 

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Someone mentioned in a thread a few weeks back that the 105 degrees of throttle twist was necessary to accommodate the majority of new riders who take the Duke otherwise take off would of been too snappy.
Yeah its been dumbed down incase new riders grab a fist full by accident, its a very forgiving bike down low but completely different story past 6000. If you pop 2nd or 3rd at around 7000 the front becomes nice and light ;)
This is without doubt one of the best bikes for a new rider to buy, its crazy stable at low speeds the brakes wont bite your head for getting it wrong, the clutch is user friendly although heavy. Personally I reckon it needs some changes but thats because its far from my first bike......still havent heard back from Race Dynamics about the PowerTRONIC being available so maybe Power Commander get my money instead.
 

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Discussion Starter · #10 ·
Do you find it to touchy now though? It seems to be a pretty big change in sensitivity. I'd be afraid that I would adjust the sensitivity too much...
Personally I dont find it snappy at all, I was annoyed beyond belief with the way it came out of the factory so the mod for me is fantastic.
I suppose for a new rider the factory throttle is fine but if you are a bit experienced and know how to control your throttle, i'd definitely do the mod.

The bike feels like its awake now and no, it wont bite your head off :)

The beauty about this mod is that if you dont like the feel of it, pull it off.
 

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It sounds like a good mod. I hate having to double grab the throttle, particularly as I often ride with all controls going most of the time or in contact with my hands and feet; both brakes, clutch lever, gear lever, throttle, horn button, headlight flasher and now I have to double wind the throttle?
 

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Discussion Starter · #12 ·
It sounds like a good mod. I hate having to double grab the throttle, particularly as I often ride with all controls going most of the time or in contact with my hands and feet; both brakes, clutch lever, gear lever, throttle, horn button, headlight flasher and now I have to double wind the throttle?
I would do the mod then if I were you... if you want to know exactly what I used it was a headset spacer for a Giant Overdrive 2 headset.

If you have a bicycle store that stocks Giant Bicycles go in and ask if you can get a 5mm headset spacer for a Giant Overdrive 2 headset.
The 5mm is the correct width, dont get a fatter one.

Cut a small section of it out so it fits on the throttle and then groove it neatly with a hacksaw or a very thin file for the cable to slot into.

You may need to take it on and off a few times and file it down as it did catch a little bit and was sticky.
 

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Beginners probably shouldn't be playing with the throttle like this, but I think that whatever the throttle response is, people will get use to it. No point in doing something to the throttle unless you felt there was a problem in the first place.

If it ain't broke, don't fix it.
 

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Beginners probably shouldn't be playing with the throttle like this, but I think that whatever the throttle response is, people will get use to it. No point in doing something to the throttle unless you felt there was a problem in the first place.

If it ain't broke, don't fix it.
it's always best to ease into the power level ranges, some newbs dont get that and eventually end up getting hurt. it's unfortunate, tough way to learn
 

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Beginners probably shouldn't be playing with the throttle like this, but I think that whatever the throttle response is, people will get use to it. No point in doing something to the throttle unless you felt there was a problem in the first place.

If it ain't broke, don't fix it.
but it is broke. double twisting the throttle isn't just an inconvenience it could also be a touch dangerous, its an extra movement that doesnt need to be there as a distraction
 

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Discussion Starter · #17 ·
but it is broke. double twisting the throttle isn't just an inconvenience it could also be a touch dangerous, its an extra movement that doesnt need to be there as a distraction
One of the main reasons for me doing it was because I had to double grab the throttle to get the rest of it open.
Shortly after, I then had to brake so when you think you've closed the throttle to brake quickly, its not closed.

I almost soiled my pants :eek:
 

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One thing to remember with this mod is that you can do it as much or as little as you'd like. I think most people don't want to have to double grab in order to get full power out of the throttle. You can always adjust to be tighter than stock without it being really touchy. There is a middle ground.
 

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One of the main reasons for me doing it was because I had to double grab the throttle to get the rest of it open.
Shortly after, I then had to brake so when you think you've closed the throttle to brake quickly, its not closed.

I almost soiled my pants :eek:
Exact same thing happens to me occasionally when I ride the twisties.
I will have to try your Mod.

Thanks for the tip...been trying to look for an aftermarket company that makes one for the 390...a simple bolt on affair....I will go try yours first.
 

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Personally I dont find it snappy at all, I was annoyed beyond belief with the way it came out of the factory so the mod for me is fantastic.
I suppose for a new rider the factory throttle is fine but if you are a bit experienced and know how to control your throttle, i'd definitely do the mod.

The bike feels like its awake now and no, it wont bite your head off :)

The beauty about this mod is that if you dont like the feel of it, pull it off.
Sean, question...do you really have to put a groove on that headset spacer? I ride Mtbikes too and that spacer you're talking about it the spacer that seats on or on top of the handlebar stem right? Anyways, good idea there!!!

By not putting a groove on it...it will make the cable sit higher onto the spacer, thus, creating a better throttle action with less twisting degree.

Just wondering if i can just cut and simply put the spacer on without having to groove it with a hacksaw or file?
 
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