T-Bar Bolt Torques

Yamaha FJR Motorcycle Forum

Help Support Yamaha FJR Motorcycle Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Bluesy, I couldn't spell torque.... I cut an pasted yer fellow 'left siders" response. Ya know how we are over this way...

But we have to do a ton more **** to impress the "hood" Ya wanna race ridin mowers perchance? :lol:

:jester:

 
Bust - you's smarter than I thoughts. Yer my hero. I would hav never thought that. :rolleyes:

Riden mowers? I don't even no how to start mine....??? :eek: :cowboy:

I went to the shed and tryd ridin it just now, and burned my leg on the exhaust. That smarts on the inner thigh. I think I damaged my linkage. I'll get the wife to get 'er back in shape. :hyper:

I best not listens to you no mo, I'ms getting in too much trouble. ouch. :bigeyedsmiley:

Sorry, I think this went way off topic.... I went away for a while... but now I'm back.

 
Last edited by a moderator:
Long ago, I used to be all anal about "torquing it to specs". I actually used to torque the wheel lugs nuts on my cars.But the older I got, the wiser came with it. I can count the number of times, on 1 finger, that I was riding in a car and a wheel fell off.
Welp, put me in the anal retentive torque wrench happy camp.

But since you raised the point, torquing the lug nutz on a wheel isn't so the wheel "stays on". It's so the pressure around the brake disc (rotor) is even and the heat transfer away from the disc will be uniform. Why? So the damn things don't warp so often (exspeshully on those yuropeen cars)

So you see, it may not be obvious exactly why there is a torque spec. But I will grant you, having a torque spec on the t-bar is probably overkill...

 
Having just had the T-bar off today for removing the OEM clutchline on my 2004...

...Looking at the cross member, the frame gusset holes receiving the T-bar cross member are slotted horizontally perpendicular to the front back direction of the bike. <---->

If this cross bar is to act as a tension member in the frame, the bolt cannot "travel" in the slotted direction when tension forces occur but must be held in place by the bolted connection.

My guess is that the high torque values in these bolts are to "clamp" the two pieces in the connection together by means of bolt tension compressing the members together. If there isn't clamping force...then this cross brace tension member holding the two side frames together is doing nothing but sliding in the slot.

Then of course this is MY guess as a structural engineer looking at what the purpose of this cross bar is. I may be all wet. Obviously, either the connection changed or the yamaha design engineers discarded the need for tension in this bar if the torque values have been reduced.

 
Last edited by a moderator:
Then of course this is MY guess as a structural engineer looking at what the purpose of this cross bar is. I may be all wet. Obviously, either the connection changed or the yamaha design engineers discarded the need for tension in this bar if the torque values have been reduced.
Actually, Yammi engineers were under orders to change a dozen things on the Gen II bikes. After the mech guys were done, and marketing had came up with the "FJR" logo on the side panels after a late night brainstorming session, they were outta ideas. Desperate, they grabbed Joe Torqueasaki from the closet he'd been sequestered in since the infamous "Sumo drain plug" incident. Under threat of being traded to Shanghai Automotive Industry Corp, he shocked them all by coming up with a reduced torque requirement for the t bar, and a legend was born! Really!

 
Last edited by a moderator:
Then of course this is MY guess as a structural engineer looking at what the purpose of this cross bar is. I may be all wet. Obviously, either the connection changed or the yamaha design engineers discarded the need for tension in this bar if the torque values have been reduced.
Actually, Yammi engineers were under orders to change a dozen things on the Gen II bikes. After the mech guys were done, and marketing had came up with the "FJR" logo on the side panels after a late night brainstorming session, they were outta ideas. Desperate, they grabbed Joe Torqueasaki from the closet he'd been sequestered in since the infamous "Sumo drain plug" incident. Under threat of being traded to Shanghai Automotive Industry Corp, he shocked them all by coming up with a reduced torque requirement for the t bar, and a legend was born! Really!
That Joe Torquesaki "gets around" doesn't he?

 
That Joe Torquesaki "gets around" doesn't he?
Is he related to a guy named "Ugh"? Ugh is used when tightening a bolt real tight (you know that sound you make when really wrenching on a bolt). I never use Ugh to help with my T bar torque and I never use a torque wrench. It's not rocket science!

Torque wrenches are nice to use on things like heads, cam bearing caps and wheels (to avoid that previously mentioned disk warping). But a T bar?

 
Last edited by a moderator:
That Joe Torquesaki "gets around" doesn't he?
Is he related to a guy named "Ugh"? Ugh is used when tightening a bolt real tight (you know that sound you make when really wrenching on a bolt). I never use Ugh to help with my T bar torque and I never use a torque wrench. It's not rocket science!

Torque wrenches are nice to use on things like heads, cam bearing caps and wheels (to avoid that previously mentioned disk warping). But a T bar?
Theoretically, the T-bar is an integral structural member of the frame. That's the story behind the highly torqued bolts that I've heard anyway. And if it's not, WTF is it even there for? Throw it away.

 
Last edited by a moderator:
That Joe Torquesaki "gets around" doesn't he?
Is he related to a guy named "Ugh"? Ugh is used when tightening a bolt real tight (you know that sound you make when really wrenching on a bolt). I never use Ugh to help with my T bar torque and I never use a torque wrench. It's not rocket science!

Torque wrenches are nice to use on things like heads, cam bearing caps and wheels (to avoid that previously mentioned disk warping). But a T bar?
Theoretically, the T-bar is an integral structural member of the frame. That's the story behind the highly torqued bolts that I've heard anyway. And if it's not, WTF is it even there for? Throw it away.
Everyone is free to use or not use a torque wrench, but using one can't hurt. Not using one, can hurt.

People who have been wrenching for years do develop a feel for most bolts. Multiple mechanics have told me, they just know when it's about right.

I would love to see some sort of machine that could actually calculate the torque that someone applied. Thus we could test out all of the mechanics and wrenches who say, I don't need no stinking torque wrench. Maybe they would be spot on. Maybe they would be way off....

Either way, I don't trust my "feel" for a tight bolt, and thus I torque just about everything to spec.

*Edit* except the drain bolt!

 
Last edited by a moderator:
That Joe Torquesaki "gets around" doesn't he?
Is he related to a guy named "Ugh"? Ugh is used when tightening a bolt real tight (you know that sound you make when really wrenching on a bolt). I never use Ugh to help with my T bar torque and I never use a torque wrench. It's not rocket science!

Torque wrenches are nice to use on things like heads, cam bearing caps and wheels (to avoid that previously mentioned disk warping). But a T bar?
Theoretically, the T-bar is an integral structural member of the frame. That's the story behind the highly torqued bolts that I've heard anyway. And if it's not, WTF is it even there for? Throw it away.
Gunny. Period.

Though not convenient, it would nice to compare Gen 1 to Gen 2 side by side to see what if anything changed in the T-bar conn.

If nothing changed, then Joe Torquesaki performed a miracle and magically reduced the requirement. Isn't the T-bar there to keep the side frames from spreading?

If so, a slotted connection will not work unless a torqued bolt clamps the pieces together to maintain tension tie to hold the side frames in.

If the Gen 2 also has a slotted connection, then this high torque is nonsense and was never needed in the first place. However, if a revised connection using a round hole in the Gen 2 T-bar is present, then that would make sense for the torque to be lowered as no clamping force would be required in the connection.

 
I believe the reduced torque on the Gen-II T-bar bolts, is the cause of asymmetrical front tire wear.

There, I feel better now.

 
No torquey, no ticky.

610x.jpg


Honorable Engineering Dept.

 
Last edited by a moderator:
Gen I & Gen II 'cross over tubes' look identical. Both have round holes. Gen I: 5JW-21119-00-00    Gen II: 3P6-21119-00-00   The prefix is different, dunno what that means. Someplace in the Forum someone has given us a way to break down the P/Ns.

 
Gen I & Gen II 'cross over tubes' look identical. Both have round holes. Gen I: 5JW-21119-00-00    Gen II: 3P6-21119-00-00   The prefix is different, dunno what that means. Someplace in the Forum someone has given us a way to break down the P/Ns.
Yes, the tubes may be identical, but the slot I was mentioning was in the frame gusset receiving the T-bar.

If both Gens are identical, ahamaY has some explaining to do IMO. :huh:

 
I'm not disputing that this t-bar is a structural brace. I'm sure it is.

But 58 ft-lbs. in aluminum threads is just asking to rip the threads out.

I'm sure the Yamaha revision accounts for this.

 
The 3P6 prefix on the part numbers was introduced on the '06 model. That usually indicates the part was changed for the '06.

The T-bar bolt part numbers also changed but the washer part numbers are the same. So that likely means that the bolts are the same diameter but the length or thread pattern was changed.

 
I know I am resurrecting a two year old thread, but I have a question regarding vibration. Does the T-bar torque value make a difference in the vibration of the frame? The reason I started to wonder is that I sent my Snap on torque wrench to Snap on for repair and recalibration. After R/R the T-bar for maintenance I now feel more vibration in the seat, tank and handle bars. So assuming that the wrench is accurate and I was over torque bolts before, I wonder if I can dampen the vibration by increasing the torque on the T-bar mounting bolts. I was thinking of splitting the difference between 58 foot lbs and 27 foot lbs which would be 42 foot lbs and see if it makes a difference. Has anyone else noticed a change in vibration by increasing torque more than spec?

 
Top