Engine mount bolt torque value

[ryanschillinger_imp]

Yup! Haha that's about it.

[2017EX_imp]

I am new to this party, and had the same concerns as previous posts. I am a big believer in "case saver" bars from past experience, and installed Motech bars on my 2017 CB1100 EX. I will try to explain what I discovered. The included long bolts are metric grade 8.8 ( roughly equal to SAE grade 5 ) whereas the stock long bolts are roughly the metric equivalent to SAE grade 8. This partially explains the difference in torque value of 38 N.m ( 28 Ft. Lbs. ) for the long bolts supplied by Motech, to the 44 Ft. Lb. torque for the stock bolts ( 44 Ft. Lbs might over torque the threads on a metric grade 8.8 ). Here is what I believe is the second part of the situation: In stock form, the long engine bolt is only supported by the stock hanger, inboard of the mounting ear of the engine. So, in order to be certain that bolt stays horizontal with no flex, a stronger bolt using a higher torque value is used. The Motech bars actually add an additional hanger, outboard of the engine mounting ear. So, the engine ear is now supported between inboard and outboard hangers, preventing downward bolt flex, and requiring only the torque necessary to keep the bolt tight ( plus I use blue thread locker ). Although as others have said, the stock bolts will work by the thickness of the nut, I prefer to use the slightly longer Motech bolts for better purchase on the nuts. Bottom line, if stock bolts are used, torque to factory spec of 44 Ft. Lbs., but if Motech bolts are used torque to 38 N.m which is 28 Ft. Lbs. The shorter stock bolts on the frame down tubes use the factory spec of 36 Ft. Lbs. I have emailed Motech with this question, and if the response is different than what I have speculated here, I will update.

[Cormanus]

G'day, 2017EX. Welcome to the forum and thanks for the information. Drop into the new member's section sometime and introduce yourself.

[2017EX_imp]

I received an answer from Twistedthottle, the U.S. distributor and representative for SW-Motech. I had originally sent the inquiry directly to Motech. It would appear that I was partially correct in my speculation, but the response adds critical information that I had not considered. Use the longs bolts and torque spec supplied by Motech! Below here is the entire email response from Twistedthrottle.

Hello Bill,

SW-MOTECH of Germany forwarded us your inquiry regarding their products. As SW-MOTECH's North American distributor, Twisted Throttle takes the lead in handling all product inquiries as we speak the language, can ship quickly from our warehouses in Rhode Island and Ontario, and have a local call center for installation tech support.

The bolts you are talking about will be more exposed with the crashbars.
So you want those bolts softer than the engine or frame. If a force is exerted to the crash bars the energy has to go somewhere. It's better if the fail point is the bolt instead of the head of the motor.
In case of crash it's cheaper and easier to change the bolt than the frame or engine part.

Because the grade of the bolt is softer, the torque will be lower too.

I hope this information is helpful.

If you have any other questions, please don't hesitate to contact me.


How'd I do today?
Super Great! Not Bad Hmmm


___________________________________
Antony
Customer Service Rep - Je parle Français

Twisted Throttle LLC
570 Nooseneck Hill Rd
Exeter, RI 02822
401-284-4200 (phone)
401-223-6954 (fax)
info@twistedthrottle.com
http://www.twistedthrottle.com

[Cormanus]

Thanks 2017EX. Makes sense.

[TCinNC_imp]

So the correct torque value for the Motech bolt is 28 ft/lbs, not 44 as the manual calls for?

[2017EX_imp]

So the correct torque value for the Motech bolt is 28 ft/lbs, not 44 as the manual calls for?

Yes. The 2 supplied long Motech bolts are metric GRADE 8.8, roughly equal to an SAE GRADE 5, and are slightly longer than the 2 stock long Honda bolts. The STOCK Honda long bolts are roughly the equivalent of an SAE GRADE 8. So, the softer Motech bolts take a lower torque value of 38 N.m ( Newton Meters ) which is equal to 28 Ft. Lbs. The manual calls for 44 Ft. Lbs. FOR THE HARDER STOCK LONG BOLTS. If the softer Motech bolt were torqued to 44 Ft. Lbs. it might strip the bolt threads. The Motech bars use the STOCK Honda bolts on the frame down tubes, so those bolts use the Honda torque spec of 36 Ft. Lbs. as called for in the manual.

[TCinNC_imp]

So the correct torque value for the Motech bolt is 28 ft/lbs, not 44 as the manual calls for?

Yes. The 2 supplied long Motech bolts are metric GRADE 8.8, roughly equal to an SAE GRADE 5, and are slightly longer than the 2 stock long Honda bolts. The STOCK Honda long bolts are roughly the equivalent of an SAE GRADE 8. So, the softer Motech bolts take a lower torque value of 38 N.m ( Newton Meters ) which is equal to 28 Ft. Lbs. The manual calls for 44 Ft. Lbs. FOR THE HARDER STOCK LONG BOLTS. If the softer Motech bolt were torqued to 44 Ft. Lbs. it might strip the bolt threads. The Motech bars use the STOCK Honda bolts on the frame down tubes, so those bolts use the Honda torque spec of 36 Ft. Lbs. as called for in the manual.

Yes. The 2 supplied long Motech bolts are metric GRADE 8.8, roughly equal to an SAE GRADE 5, and are slightly longer than the 2 stock long Honda bolts. The STOCK Honda long bolts are roughly the equivalent of an SAE GRADE 8. So, the softer Motech bolts take a lower torque value of 38 N.m ( Newton Meters ) which is equal to 28 Ft. Lbs. The manual calls for 44 Ft. Lbs. FOR THE HARDER STOCK LONG BOLTS. If the softer Motech bolt were torqued to 44 Ft. Lbs. it might strip the bolt threads. The Motech bars use the STOCK Honda bolts on the frame down tubes, so those bolts use the Honda torque spec of 36 Ft. Lbs. as called for in the manual. Thank you.

[2017EX_imp]

So the correct torque value for the Motech bolt is 28 ft/lbs, not 44 as the manual calls for?

Yes. The 2 supplied long Motech bolts are metric GRADE 8.8, roughly equal to an SAE GRADE 5, and are slightly longer than the 2 stock long Honda bolts. The STOCK Honda long bolts are roughly the equivalent of an SAE GRADE 8. So, the softer Motech bolts take a lower torque value of 38 N.m ( Newton Meters ) which is equal to 28 Ft. Lbs. The manual calls for 44 Ft. Lbs. FOR THE HARDER STOCK LONG BOLTS. If the softer Motech bolt were torqued to 44 Ft. Lbs. it might strip the bolt threads. The Motech bars use the STOCK Honda bolts on the frame down tubes, so those bolts use the Honda torque spec of 36 Ft. Lbs. as called for in the manual.

Yes. The 2 supplied long Motech bolts are metric GRADE 8.8, roughly equal to an SAE GRADE 5, and are slightly longer than the 2 stock long Honda bolts. The STOCK Honda long bolts are roughly the equivalent of an SAE GRADE 8. So, the softer Motech bolts take a lower torque value of 38 N.m ( Newton Meters ) which is equal to 28 Ft. Lbs. The manual calls for 44 Ft. Lbs. FOR THE HARDER STOCK LONG BOLTS. If the softer Motech bolt were torqued to 44 Ft. Lbs. it might strip the bolt threads. The Motech bars use the STOCK Honda bolts on the frame down tubes, so those bolts use the Honda torque spec of 36 Ft. Lbs. as called for in the manual. Thank you.

Yes. The 2 supplied long Motech bolts are metric GRADE 8.8, roughly equal to an SAE GRADE 5, and are slightly longer than the 2 stock long Honda bolts. The STOCK Honda long bolts are roughly the equivalent of an SAE GRADE 8. So, the softer Motech bolts take a lower torque value of 38 N.m ( Newton Meters ) which is equal to 28 Ft. Lbs. The manual calls for 44 Ft. Lbs. FOR THE HARDER STOCK LONG BOLTS. If the softer Motech bolt were torqued to 44 Ft. Lbs. it might strip the bolt threads. The Motech bars use the STOCK Honda bolts on the frame down tubes, so those bolts use the Honda torque spec of 36 Ft. Lbs. as called for in the manual. Thank you.
You are welcome, and glad I could lend a hand. I have the Motech bars on my bike, and from my research on everything available out there, my personal opinion is that they are the best option in terms of design and quality for the CB1100.

[easy_imp]

thanks a lot for all above guys, just about to install SW-M crash bars, all went fine and without doubts :-)
Cheers!