Anyone know the brand of this swing arm or how I go about fixing this?

[Joshmc628]

Chain snapped and knocked the adjuster screw loose. Bought a new chain and jb welded the adjuster screw back into the orange plate the axle goes into. It immediately snapped when I tried pulling off hard and the back wheel moved so much that my axle was crooked (hence the chain being loose in the photo). I have no clue who made this swing arm to buy a replacement part. I’d hate to have to get a new swing arm over such a small piece. Any insight on how I go about fixing this is greatly appreciated.

 

[Joshmc628]

More pics of the arm. I just painted it black and put it on my bike. All I know is that it’s from a gen 1 busa

 

[Dancallun]

Am I retarded or are the bolts on the wrong side of the axle?

 

[Joshmc628]

Am I retarded or are the bolts on the wrong side of the axle?

Haha yea the bolts on this swing arm are on the opposite side. Never seen this swingarm on any other busa ever so I’m at a lost on how to get replacement parts

 

[RedBull]

When is "stretched" to much? | General Bike Related Topics

Just curious what you guys like in terms of streeeeeetching your Ride :whistle:

www.hayabusa.org

 

[Joshmc628]

When is "stretched" to much? | General Bike Related Topics

Just curious what you guys like in terms of streeeeeetching your Ride :whistle:

www.hayabusa.org

That’s pretty insane haha. I’ve actually mastered that same trick with this swing arm I got now. I’d never stretch it that long haha

 

[ItsDooomz]

That's a stock arm with weld on extensions, I'd seriously recommend an upgrade.

 

[Joshmc628]

That's a stock arm with weld on extensions, I'd seriously recommend an upgrade.

I always had a suspicion it might of been welded, looks way too similar to the stock gen 1 arms! An upgrade is definitely on the list but not convenient for me at the moment. Really hoping to be able to fix this, but if I can’t I may have no choice.

 

[c10]

Is the adjuster steel ? Magnet stick to the broken orange part the axle goes into?

 

[Notenoughtoys]

If this happened to me on my bike I would most likely do the following - remove everything and have someone drill out and rethread BOTH orange yokes up to the next size. Clear the access hole in the back to swingarm and fab up a pair of larger threaded studs to redo the assembly. I definitely would not use hardware grade plated stuff - maybe order a foot of grade 5 threaded rod from McMaster Carr ?? Put jamb nuts at the contact surfaces to control all fore and aft movement...... I would definitely like to see that stud assembly loaded in compression but given the length of the slot in the swing arm it’s impractical at best. May cost you a little bit to get this fabbed up better, but per your earlier trial, a failure in this component will have dire consequences. Ideally I think the design is very poor to begin with but as you said bucks are tight - at least this won’t cost too much and the safety factor will increase but I still would not be sleeping too well at night !!

 

[rubbersidedown]

I know nothing about them. Its not my recomedation,but the price seems right,for a budget.
Evil Arms
Rubb.

 

[ItsDooomz]

I won't use a swing arm with the adjusters on the back, when they fail the axle moves forward, chain comes off and kablooey...

 

[Berlin Germany]

sorry in advance for my very harsh words
but as an engineer i only have one main question - what damn stupid built this crap?

1. such a thin screw, looks like 5/16 (M8) or 3/8 (M10) is supposed to hold this great tensile force?
total stupidity - it is not for nothing that the original screw was designed so that it is subject to pressure.
and even with statically balanced arms, the clamping block / tensioner-block is much longer to keep the adjusting screw as short as the original
2. such a super long gap (for axle adjustment? ha ha ha) is supposed to hold the big torque? what a self-despicable construction - i guess some more 100 or 200 miles (on road) and it will break.

for show (moving the bike by hand) the construction may look nice,
but for daily use with full throttle it might be deathifying.

@Joshmc628
hammer a large nail into your workshop´s wall and hang the arm there as a permanent example of technical crap .

edit
@Joshmc628
what do you think why they offer that " Adjuster Blocks for 6 inch adjuster slot" ?
i guess for stabilazing.
but the heck - who would build such a long adjuster gap?

 

[Joshmc628]

sorry in advance for my very harsh words
but as an engineer i only have one main question - what damn stupid built this crap?

1. such a thin screw, looks like 5/16 (M8) or 3/8 (M10) is supposed to hold this great tensile force?
total stupidity - it is not for nothing that the original screw was designed so that it is subject to pressure.
and even with statically balanced arms, the clamping block / tensioner-block is much longer to keep the adjusting screw as short as the original
2. such a super long gap (for axle adjustment? ha ha ha) is supposed to hold the big torque? what a self-despicable construction - i guess some more 100 or 200 miles (on road) and it will break.

for show (moving the bike by hand) the construction may look nice,
but for daily use with full throttle it might be deathifying.

@Joshmc628
hammer a large nail into your workshop´s wall and hang the arm there as a permanent example of technical crap .

edit
@Joshmc628
what do you think why they offer that " Adjuster Blocks for 6 inch adjuster slot" ?
i guess for stabilazing.
but the heck - who would build such a long adjuster gap?

Your right, I’d hate for it to fail again. If I was going faster that could of been much worse. Might just be time to replace this arm instead of repairing an already bad design.

 

[rubbersidedown]

Your right, I’d hate for it to fail again. If I was going faster that could of been much worse. Might just be time to replace this arm instead of repairing an already bad design.

Did you look at the 525 dolla Evil arms?
I like Roaring Toyz myself. I trust my arm.Seems bullet proof,so far. Running an RCC Ultra 550 HP turbo turning an' RC Components Stocker 330 tire. 4" stretch.
Rubb.

 

[xc700]

I thought the axle after its torqued took the load not the adjusters. I would buy a new swingarm stay away from extensions .

 

[rubbersidedown]

That’s pretty insane haha. I’ve actually mastered that same trick with this swing arm I got now. I’d never stretch it that long haha

That arm looks like a nice "back yard build" cobbed on with bolts,prolly a jackshaft too. Funny stuff.

Long arms can be handy thou...like for road trips...or moving.

I wonder how many links are in those chains? 250?

I thought the axle after its torqued took the load not the adjusters. I would buy a new swingarm stay away from extensions .

Yer right. The adjustment blocks can help a bit thou. The one's that have blocks adjusted from the back say...can do a push/pull thing as torque is applied and the axle wants to twist.Kind of the like the rear end in a car that twists when you stand on it.
Rubb.

 

[Dennis]

Every chromoly arm I've seen adjusts from the back. The Evil arms have 7/16" threaded rod. Most aluminum arms adjust from the front. If you axle is torqued properly I don't see an issue either way. I've seen front adjusters bend when the axle isn't tight but I haven't seen rear adjusters fail in tension.

For me, I'm done with chromoly arms. My last one had an issue with tossing the chain whenever I had a 60' in the 1.22 range. I think it was flexing, and I think I bent it a little. I currently have an older MacIntosh aluminum arm that is nice (but I wouldn't buy a new one) and my other bike has a DME aluminum arm that I think is the best arm out there now. It isn't the lightest, but it is very well built. They aren't cheap, but it won't twist like the chromoly arm I had before. I would look around for a used arm that is the length you need if funds are tight.

 

[c10]

Unrelated , but Chromoly , vs Alum in the mountain bike industry . Many riders like Chromoloy for its flex in cross country racing where Alum was very stiff . Same in BMX . The Alum would let you get power down wit no flex in the chain stays , but chromoly would flex . At the end of the day chromoly was easier on the body .

 

[fallenarch]

What if he welded aluminum plates to either side of that huge adjustment hole, welded a block of aluminum in there and converted the tensioner to a compression type rather than a tension type. Would that not make this doable? if you know a welder that wouldn't be too expensive. Obviously a swingarm costs $1000 give or take and a funeral costs $3-8K.