Topic: Triple A Crash Bars on CB750K3

[34barab]

I'm installing Triple A crash bars that I purchased used on line a while ago.  In the 70's they were made by Triple A for Honda as an accessory for the CB750 (in this case a 1973 K3).  The brackets on the bar are each about 6 mm thick, or 12 mm side to side.  This additional width makes the standard front lower hanger bolt (part number 90152-300-010, item 5 in the attached drawing) too short.

Need some information. A part number or a source for the correct length bolt would be ideal.  The rod portion of the stock bolt measures 315 mm, so I would need one about 325 mm, and I think it has a 10 mm diameter.  Does anyone know the thread and can anyone shed some light on this issue?  Thanks 

[Sigop]

I have a bar on my 73 that I put on in 74.  No mods needed, but not sure what I have.  Do you have pic of yours?

[BenelliSEI]

I have a lovely set that we’re made in Montreal, Canada, in the 70’s. They had a large hole in one of the plates and came with a long tube nut that reached through and made up the extra length. Most of the others I’ve removed were held in with a length of 3/8” threaded rod! Cut to length, with some stainless washers and nylock nuts, this can be a very tidy solution........ and a 14mm wrench fits the 9/16” nuts. Good luck! John D.

[Don R]

 I think mine had 3/8" rod also. It wasn't impressive.

[MauiK3]

Yamiya750 makes long bolts for this purpose.

[34barab]

Before an update, let me start off with a couple of questions.  Should the exhaust pipes fit perfectly? What I mean is does the pipe at the sleeve need to slide all the way up to the engine in order to seal the exhaust or does the exhaust clamp help seal it?  Also, when bolted up, can the pipes take some tension created by forcing the header pipe up to the engine about 5 or 6 mm?

Update:  Using 3/8" all thread rod to length, installed both guard bars, put on the right exhausts and the left inside (#2).  Could not get t  he left outside (#1) exhaust to fit properly.  It would slide almost all the way on to the exhaust pipe flange but not far enough to seal the exhaust, short by about 5 or 6 mm.  The guard bar lower bracket (bolts to the bike's "A" hanger) contacted the bottom of the alternator cover preventing the exhaust header pipe from sliding up far enough up the exhaust flange.  Also kept the rear foot peg bolt misaligned.

Attached pic shows the lower bracket that contacts the bottom of the alternator cover.  If this bracket were about 5 mm narrower I think the interference would not be an issue.  Any comments or suggestions?

[Don R]

 Yes, the pipes will sometimes take some movement to slide them all of the way on and will be OK. If they are stock 4-4's install them completely before you tighten anything. I've used a bundle of rags and a rubber mallet to gently tap the pipes on. 
 I can't say what the solution to the clearance problem is. It should not touch the engine covers. Could you be missing a spacer? I was looking at the motor mount thread and saw spacers on his crash bar.