Rear Axle bolt dangerously too short - 2005 Bulldog

[PAUL NOBBS]

So I torqued up the bolt and it sprung back out like it had stripped thread in the axle. It is a 9/16 UNF Thread of only 1/12 inches in my Bulldog. I assume an original standard item? There must be loads of bikes out there with same item in. The frame and oval spacer washer right side] takes nearly an inch of bolt before it enters the axle leaving barely 1/2 inch of thread to do all the work. This is under lots of load and tension and keeps your back wheel on. Looking inside the axle there is at least another inch of thread unused. So I am binning the stock item and cutting [with a die] a longer threaded bolt to solve further issues of back wheel coming loose!!! Suggest you guys out there check your Big DOG too!
#bigdogaxlebolt #bigdogloosewheel #bigdogwobble

 

[Mr. Wright]

Interesting. I will have to look into that.

 

[PAUL NOBBS]

fyi - The longest fully threaded bolt that is available off the shelf for us in UK is 1 1/2 '' [same as bike was built with] and next length is 4 1/2'' but with a too longer flange that i am cutting into with die to extend threads. Then cutting down to size to use all threads in axle

 

[Mr. Wright]

fyi - The longest fully threaded bolt that is available off the shelf for us in UK is 1 1/2 '' [same as bike was built with] and next length is 4 1/2'' but with a too longer flange that i am cutting into with die to extend threads. Then cutting down to size to use all threads in axle

Use anti-sieze when you install that bolt.

 

[francoblay1]

 

[PAUL NOBBS]

One doesn't need a picture of a 1 1/2'' inch UNF hex bolt sir. Deduct the inch that the frame takes up and it leaves barely 1/2'' thread that pokes inside the axle. If your bolt is a longer one then you are a lucky fellow. Take yours out and have a look, only takes 10 minutes!

 

[francoblay1]

One doesn't need a picture of a 1 1/2'' inch UNF hex bolt sir. Deduct the inch that the frame takes up and it leaves barely 1/2'' thread that pokes inside the axle. If your bolt is a longer one then you are a lucky fellow. Take yours out and have a look, only takes 10 minutes!

Yeah..... like I carry the bike with me all over the fucking Desert so I can have a look at it every time I read something here.....

 

[BWG56]

Yeah..... like I carry the bike with me all over the fucking Desert so I can have a look at it every time I read something here.....

How do you really feel? I saw your pics mountain riding, are you saying your Dog won't go in the sand?

 

[PAUL NOBBS]

Yeah..... like I carry the bike with me all over the fucking Desert so I can have a look at it every time I read something here.....

I am sad you had a bad day at the office dude

 

[BWG56]

I am sad you had a bad day at the office dude

Franco's ok, sometimes he gets too much sand in his undies

 

[HMAN]

I am sad you had a bad day at the office dude

His "office" can be a nasty place at times....

 

[kickstart]

Maybe the way the size was written may have caused some confusion, OD-Pitch X Length (9/16-18 X 11/4" Grade 8) is the size listed in the manual.
If your bolt is too short at your stated length (1 1/2") maybe there is another issue.

 

[PAUL NOBBS]

You have confirmed the bolt is 1 1/2 '' - that is exactly the size of my failing stock bolt. I was merely saying that 1'' of this bolt is taken up inside the swing arm and bushing before it starts to enter the axle thread. Then there is 4mm gap between the swing arm and the last axle spacer. [I cant believe my bike is the only one like it] So when I torque up the bolt to the specified amount it first has to squeeze up both sides of the swing arm to compress the wheel and all the spacers. That is already an awful lot of tension for this one bolt to soak up before you even start to tighten up with torque wrench. So the 1/2'' of bolt that is doing all this work in the axle does not seem man enough for the job. Bearing in mind it is a stock Bulldog using a stock bolt it seems crazy that just 1/2'' is taking all this load [hence mine decided to strip itself. Probably done by previous owner or workshop. There is 1'' of extra thread inside the axle unused! My fix was to add 4mm of shim washer to fill the gap [to avoid extra tension on bolt] then re-cut, with a die a fresh/longer bolt from a 4'' flanged version [cut back to 2 1/2 ''] . It then utilizes more internal thread = much more secure and torques up nicely!!!! I think it is a build quality issue that could have been sorted!