Steve Saunders Goldwing Forums banner

1 - 20 of 33 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Good evening all, I have been a regular stalker around for some time and the help you guys give each other is invaluable, however I now have a request for those in the know. I recently purchased a 76LTD GL1000 to restore and all was going well until I discovered the previous owner had the cut the front hanger bolts off at both end due to not be able to remove it. (Not Ideal) Any way I have now removed what was left of the bolt but I need the dimensions of the bolt to source a new one. I am away from home with work at the moment and it looks like when I get home everything will be shut due to this rotten virus, so I would like to order a suitable bolt on line if possible.

Does anyone know the exact dimensions required? I think its a 12mm bolt but have no idea about the length.....ANY help greatly appreciated.
 

·
Registered
Joined
·
171 Posts
Not sure on that bolt but a lot of them have sizes on the parts pages and/or the part number gives it away.
Try cmsnl.com and pick your exact model. Be aware the part you are looking for is not always in the obvious place!!
 

·
Registered
Joined
·
171 Posts
Bored so just checked for you. Assuming its the lower front long one yes its 12mm but its also a chromed special as it has a unique GL part number but no reason you cant use stud bar
 

·
Premium Member
Joined
·
5,967 Posts
Send off a message and ask there people from UK. Make sure you buy the upper or lower so you end up with the right one.

Complete set of bolts from Dereham Norfolk, United Kingdom,10 Euros for the set. All models from 1976 to 1987 will work. GL1000, GL1100 GL 1200 all work.
Dereham Norfolk, United Kingdom












 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Thanks to all for your help, it is the front lower I'm looking for. Unfortunately the freight to Australia for most of these bolts on Ebay is excessive and makes the bolt cost about $80.00 Australian dollars. I have previously checked CMSL and they dont give dimensions.

Thanks for your input though😃
 

·
Administrator
Joined
·
25,027 Posts
Get a length of 12mm all tread rod and cut it to length.
 

·
Premium Member
Joined
·
5,967 Posts
Jethro,
If you measure the distance from outside to outside on the bike and add 25 mm or so that is the length. If the bolt is M12 (12mm) the thread pitch would be 1.75. (12mm coarse)

If you would measure and find the distance from outside to outside on the bike was 375mm. (I have no idea if that is even close) You would add 25 mm for the acorn nut to make it 400 mm long. Assume the diametr is 12mm. The thread pitch would be 1.75. you would describe it like this:
M12-400-1.75 Class 10.9 where 10,9 is the grade or quality of the bolt. Choice from 5.8, 8.8, 10.9 and 12.9.
 

·
Premium Member
Joined
·
5,967 Posts
Yeah, do as Dave suggested and finish it off with a chrome cap nut on each end. It should look pretty good.
Get a length of 12mm all tread rod and cut it to length.
I would never secure the engine in my bike with threaded rod. Respectfully I think it is just too weak and my experience through out my life has shown that to be true many times. A threaded rod does not even have the strenth of a grade 2 or Class 8.8 metric bolt. I Googled "is thread rod as strong as a grade 2 bolt and got this.
Because the minor diameter (valley) of the threads is significantly less than the full size diameter of the shank on a headed bolt, the rod with nut often breaks at a much lower strength than a headed bolt. More importantly, even if the rod with nut does develop enough strength to meet the specification, it will often break at the junction of the nut which is acting as the head of the bolt when wedge tested per ASTM F606. For this reason, technically a rod with nut in lieu of a headed bolt will frequently fail mechanical testing because the head (nut in this case) comes off before the bolt breaks in the body or threaded section of the fastener which constitutes an automatic failure.
If it was holding on my muffler maybe but would it hold my engine? What about a crash? FWIW just my opinion. :)
 

·
Registered
Joined
·
5 Posts
Discussion Starter #13
Thanks again everyone, I'm not real keen on the threaded rod path, and unfortunately cannot measure as I am away with work. I seemed to think someone would have one laying around they could measure obviously not that easy. But thanks again to everyone for your suggestions, they really are appreciated.
 

·
Registered
Joined
·
171 Posts
I was a marine engineerr and have been on Hondas for years.
A bolts weakest part is where the thread is and studded bar is no weaker than the threaded portion of the original bolt, especially if you use stainless which is stronger than mild steel by a lot.

I have found that that bolt corrodes into the engine casings comonly due to the close fit between plain shank and alloy casing, stud bar wont do that.
 

·
Administrator
Joined
·
25,027 Posts
I would never secure the engine in my bike with threaded rod. Respectfully I think it is just too weak and my experience through out my life has shown that to be true many times. A threaded rod does not even have the strenth of a grade 2 or Class 8.8 metric bolt. I Googled "is thread rod as strong as a grade 2 bolt and got this.
Because the minor diameter (valley) of the threads is significantly less than the full size diameter of the shank on a headed bolt, the rod with nut often breaks at a much lower strength than a headed bolt. More importantly, even if the rod with nut does develop enough strength to meet the specification, it will often break at the junction of the nut which is acting as the head of the bolt when wedge tested per ASTM F606. For this reason, technically a rod with nut in lieu of a headed bolt will frequently fail mechanical testing because the head (nut in this case) comes off before the bolt breaks in the body or threaded section of the fastener which constitutes an automatic failure.
If it was holding on my muffler maybe but would it hold my engine? What about a crash? FWIW just my opinion. :)
I agree mostly but it is a place with not much stress and I have seen several with a threaded rod there, none of them broken.
 

·
Premium Member
Joined
·
3,657 Posts
I have a bolt and the measurements are: 12mm x 274mm from the inside of the hex head to tip of the bolt.
 

·
Premium Member
Joined
·
5,967 Posts
A motorcycle has a monocoque design.chassis. From the steering neck there are 2 down tubes. That bolt acts as a third tube to form a triangle. It does much more than hold the engine in place. I just feel like I would want a high quality bolt in that position. I'm not saying a threaded rod won't work. Just that the integrity of the bike frame is not near as strong. :)
 

·
Premium Member
Joined
·
5,967 Posts

·
Registered
Joined
·
171 Posts
Some frames are triangulated but with the weight of the wing frame plus Honda have that frame rail that unbolts (try finding a none rotten one of those in UK!!!) I dont think that bottom bolt adds much, if any, strength
 

·
Premium Member
Joined
·
3,657 Posts
That is for #13 on the 76 diagram. Lower front.
 
1 - 20 of 33 Posts
Top