BMW K1600 Forum banner
  • Hey Everyone! Enter your bike HERE to be a part of this months Bike of the Month Challenge!
1 - 18 of 18 Posts

·
Registered
Joined
·
541 Posts
Discussion Starter · #1 ·
Was checking things over on the B before my trip and never noticed this. The bolt that goes through the drag link on the rear suspension does not go all the way through where it mounts to the bike. One would think it would go all the way through with a nut ??
Automotive lighting Automotive tire Bumper Gas Automotive wheel system
 
  • Wow
Reactions: CaliCruiser

·
Premium Member
Joined
·
548 Posts
If yours is wrong so is mine (2018 GT), which leads me to believe that’s just the way it is.





Sent from my iPhone using Tapatalk
 
  • Like
Reactions: WOTYSGTB

·
Premium Member
Joined
·
8,083 Posts
2022 MI/KM:
11,951
My bolt (2016 GTL) is even shorter than yours. o_O I thought maybe it backed out but I can't tighten it. Tomorrow I'm going to remove it and check things out. I'll definitely be purchasing a longer one somewhere.

Automotive tire Wood Plant Tints and shades Rim
 

·
Premium Member
Joined
·
548 Posts
Maybe there is more to this than 1 bolt?? This is a picture for the 2016 GTL. 17,18,20 and 21.




Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
992 Posts
When I was working in the water and wastewater treatment plant sales office, engineer's specifications always called for bolts that were secured with nuts to have a minimum of three thread pitches showing after everything was tightened. The items being put together were flanged pipe and fittings with through bolt holes, no threads. Not really the same, but it would stand to reason that the bolts going into a threaded hole would need to go all the way through. Much less likely to strip than when left short.
 

·
Registered
2013 GTL
Joined
·
1,852 Posts
The bolt is just past half the thickness of the aluminum and I believe thats enough, although it would be better if it went flush with the outer surface of the aluminum.

In this case if the threads protruded, the exposed threads could get fouled or corroded, and tear up the thread when the bolt is extracted,

Eye Automotive tire Eyelash Jaw Flash photography

Jaw Automotive design Gas Auto part Automotive exterior
 

·
Registered
Joined
·
992 Posts
While the bolts and nuts to hold flanges together are not subject to traveling down the road, it would seem a slightly longer bolt would not be a bad thing. At least one that got a few more threads turned than some pics above.

I just had the rear suspension link recall done on Tuesday. I don't know what parts that involved. Probably wouldn't be the worst idea to crawl around and look up in there.
 

·
Premium Member
Joined
·
548 Posts
The specs on the screw (#21) on the 2016 GTL show it shorter than the 2018 GT spec. It appears that way in these bike photos so I looked it up.

What year is your bike @1004ron??


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
878 Posts
My bolt (2016 GTL) is even shorter than yours. o_O I thought maybe it backed out but I can't tighten it. Tomorrow I'm going to remove it and check things out. I'll definitely be purchasing a longer one somewhere.

View attachment 168301
I have heard from others that you had a short bolt.🤣
 

·
Registered
Joined
·
541 Posts
Discussion Starter · #11 ·
The bolt is just past half the thickness of the aluminum and I believe thats enough, although it would be better if it went flush with the outer surface of the aluminum.

In this case if the threads protruded, the exposed threads could get fouled or corroded, and tear up the thread when the bolt is extracted,

View attachment 168303
View attachment 168305
Yours makes mine look long, lol. One would think the engineers have this all figured out and the bolts are long enough to do the job. Being an old aircraft mechanic, I like overkill. I think I would be getting a longer bolt just for peace of mind though.
 

·
Premium Member
Joined
·
8,083 Posts
2022 MI/KM:
11,951
We need to make sure the replacement bolt is of the same strength or grade as the original. I don't know if Torx socket head bolts have a grade number stamped anywhere like hex head bolts do?
 

·
Premium Member
Joined
·
8,083 Posts
2022 MI/KM:
11,951
The specs on the screw (#21) on the 2016 GTL show it shorter than the 2018 GT spec. It appears that way in these bike photos so I looked it up.

What year is your bike @1004ron??


Sent from my iPhone using Tapatalk
The bolts in both the GT and GTL 2011-2016 are 20mm (.787") shorter than the GT, GTL 2017 and up. I might buy one of the 2017 and up bolt to replace mine.
I wonder if it comes with shift assist? :p

edit: I ordered the longer 2017 and up bolt. $13.68 plus $14.60 shipping, ouch!!
 

·
Premium Member
Joined
·
548 Posts
The bolts in both the GT and GTL 2011-2016 are 20mm (.787") shorter than the GT, GTL 2017 and up. I might buy one of the 2017 and up bolt to replace mine.
I wonder if it comes with shift assist? :p

edit: I ordered the longer 2017 and up bolt. $13.68 plus $14.60 shipping, ouch!!
Sounds like your fix is in Jim. I’m sure that was overnight shipping……not.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
541 Posts
Discussion Starter · #15 ·
After looking at the drag link hinge points, it looks like there would be minimal stress so I wouldn't think the shear strength and tensile strength would have to be extremely high.
 

·
Registered
Joined
·
107 Posts
2022 MI/KM:
4351 mi
On my 2016 that bolt is short as well.... Maybe half the thread in.
Will order the 2017 one as well. I wish I could un-see it,, now it will bother me all the time.... :rolleyes:
 
  • Like
Reactions: Arizona Jim

·
Registered
Joined
·
1,057 Posts
As a rule of thumb, the maximum clamping force for a bolt in a tapped hole is when thread engagement reaches 1 x Nominal Thread Diameter for a thread in steel, and 2 x Nominal Thread Diameter for a thread in aluminium. Any more than that and you’re wasting bolt length.

In the instant case, if the bolt can reach the specified tightening torque without the thread stripping in the tapped hole, the bolt is long enough - whether it looks short or not.
 

·
Premium Member
Joined
·
8,083 Posts
2022 MI/KM:
11,951
As a rule of thumb, the maximum clamping force for a bolt in a tapped hole is when thread engagement reaches 1 x Nominal Thread Diameter for a thread in steel, and 2 x Nominal Thread Diameter for a thread in aluminium. Any more than that and you’re wasting bolt length.

In the instant case, if the bolt can reach the specified tightening torque without the thread stripping in the tapped hole, the bolt is long enough - whether it looks short or not.
True. An example is the steering head nut is fairly thin and yet the torque spec is 90 nm. That connection is steel and steel. I over torqued mine by using an electric socket gun and the steering head spindle distorted and then finally the threads started to strip. It is not heat treated where as the nut is. I have a new spindle that I need to install.
 
1 - 18 of 18 Posts
Top