Fork pinch bolt torque setting | GTAMotorcycle.com

Fork pinch bolt torque setting

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stangn99

Well-known member
In an effort to reduce the handlebar vibrations, and in turn mirrors that are blurry at rpms above 6k rpm, I thought it might be a good idea to retorque all the bolts according to the manual. I even loosened the engine frame bolts and let it "rest" overnight.

All was fine until I got to the fork pinch bolts (upper and lower). The manual calls for 19Nm for both upper and lower, tightened 3x each in alternating pattern for the lower ones.

I set my wrench to 12Nm as a test and noted the bolts turned a solid 1.5-2 turns before clicking... on both sides. Odd.

I tried setting my wrench to the required 19Nm setting but was really uncomfortable with how "tight" it was getting. The little gap in the clamp was closing up and, I believe , it's not really supposed to touch?

Anyway, I managed it torque it to 17Nm (where I felt comfortable) and left it at that but wondering if there's something wrong here?

Have I done something wrong here? After all that my mirrors are still useless above 6k RPM :(

This is on a '18 S1KR - completely stock.

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I thought blurry mirror came standard on most bikes.
 
Perhaps I was spoiled with my previous bikes? My previous 4 cyl bikes did have slightly buzzy handlebars but mirrors were fine.
My Street Triple was crystal clear throughout the entire rev range.

The vibrations on the S1K are caused from the engine speed, not travel speed. I can make the mirrors go blurry by just revving to 6k in neutral. It's really annoying.
 
stangn99 said:
In an effort to reduce the handlebar vibrations, and in turn mirrors that are blurry at rpms above 6k rpm, I thought it might be a good idea to retorque all the bolts according to the manual. I even loosened the engine frame bolts and let it "rest" overnight.

All was fine until I got to the fork pinch bolts (upper and lower). The manual calls for 19Nm for both upper and lower, tightened 3x each in alternating pattern for the lower ones.

I set my wrench to 12Nm as a test and noted the bolts turned a solid 1.5-2 turns before clicking... on both sides. Odd.

I tried setting my wrench to the required 19Nm setting but was really uncomfortable with how "tight" it was getting. The little gap in the clamp was closing up and, I believe , it's not really supposed to touch?

Anyway, I managed it torque it to 17Nm (where I felt comfortable) and left it at that but wondering if there's something wrong here?

Have I done something wrong here? After all that my mirrors are still useless above 6k RPM :(

This is on a '18 S1KR - completely stock.

View attachment 70210
Click to expand...
Are you sure your torque wrench is properly calibrated? Out of cal torque wrench is worse than no torque wrench. Easy enough to check for free at home with a weight, tape measure and piece of rope.
 
GreyGhost said:
Are you sure your torque wrench is properly calibrated? Out of cal torque wrench is worse than no torque wrench. Easy enough to check for free at home with a weight, tape measure and piece of rope.
Click to expand...
It's possible, though I did also try it with one of those digital torque adapters.

I used a dummy bolt set to 12Nm with my torque wrench until it clicked. I then set the digital torque adapter to 12Nm and tried tightening the same bolt - got the beep at just over 12Nm. I assumed that meant it was pretty accurate.
 
stangn99 said:
It's possible, though I did also try it with one of those digital torque adapters.

I used a dummy bolt set to 12Nm with my torque wrench until it clicked. I then set the digital torque adapter to 12Nm and tried tightening the same bolt - got the beep at just over 12Nm. I assumed that meant it was pretty accurate.
Click to expand...
Static vs dynamic friction can be a small change that that definitely gets you in the ballpark and is a fast and easy sanity check. Surprised the bike bolts were so loose.
 
How old is the front tire?
Any cupping?
Is it / was it balanced properly?
 
Gary said:
How old is the front tire?
Any cupping?
Is it / was it balanced properly?
Click to expand...
Tires were replaced in June - no cupping and balanced properly. I confirmed balance with my static balancer.

The vibrations are not based on travel speed. It's 100% engine vibration. I can reproduce buzzy/blurry mirrors in neutral.
 
They added rubber spacers in the handlebar clamps and heavier bar weights in the 17 XR, did they do the same for the R? I added heavier than oem R&G bar end weights to my 18 XR and did not notice excess vibration on the bike at all. Maybe that is a good option for you.
 
Hardwrkr13 said:
They added rubber spacers in the handlebar clamps and heavier bar weights in the 17 XR, did they do the same for the R? I added heavier than oem R&G bar end weights to my 18 XR and did not notice excess vibration on the bike at all. Maybe that is a good option for you.
Click to expand...

@Hardwrkr13 are you referring to the spacers in the image below? If so, yes. My '18 model comes with it.

I did consider HVMP/Rhinomoto bar ends but figured I already had enough weight at the ends of the bars.

The stock bar end (with the bolt) comes to 250grams each side.
The aftermarket bar end mirror with end cap and bolt weighs 235gram each side.

I initially mounted the mirrors with the supplied end cap, bolt and adapter. I noticed more buzzing in the handlebars and, again, lots of vibrations above 6,000rpm.

I've managed to mount the bar end mirror with the stock bar end weight, giving me a total of just under 500grams on each side (I'm using a longer M12 bolt which weighs more than the stock bolt). While this setup is better than just the bar end with supplied end cap, it's still pretty much useless above 6,000rpms.

Interestingly, my hands don't go numb or anything. I rode through Haliburton for 6 hours (stopping for fuel and lunch) with no tingling/numbness or any sort of discomfort. It's just the mirrors are useless (stock and several amazon aftermarkets).



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