f*@# me check this

[motoluver]

Riding to work tonight on the rx fanging around a corner at 80kmph i feel the rear end twist and fish tail. Felt like i had a flat tyre. I got to work and the head on the swingarm bolt had snapped clean off. Never seen anything like it before.... Was a very slow ride home.

 

[wogtaz ryder]

WOWW lucky you ! could of been dangerous ...
that is very weird to....

 

[user 12599]

wow, lucky you got outa that one easy... could have been messy

 

[DvDRip]

I've seen that happen to engine mounts but not swingas, is that a stock bolt or hi-tensil?

 

[pbk]

i have done that on my bike thought my mate was riding it at the time just going over some stutters and i saw the swingarm drop down on one side and chain go super tight

you are bloody lucky that your whole swingarm didnt drop out

if i were you i would be buying some HD one....maybe even upgrade your engine mounts while your at it you dont want that droping out at 80km/h

 

[motoluver]

Yehhhhh just the stock motovert swinga axle.... crayzeeee

 

[sean01]

yeah seen em bend but not snap...your really lucky mate....this story could of been a sht load worse..

 

[no_crf50_here]

I've had a few snap back when i used to ride dirt, but never at 80km.. that's scary stuff. I'm going to replace my motard one now

 

[motoluver]

yehhhh pretty bizzare. Why would it snap at the head???

 

[prox666]

!.

it could have been to tight or just shit bolts i snaped the head of my top motor mount on my old prox 14o got a new good bolt from fastner shop and snaped that to

 

[Cactus Jack]

A sharp edge in the corners between the shank and the bolt head acts as a stress riser ... similar to a hack saw nick or a score mark on a tile ... They should really run a chromoly bolt with rolled threads and a radiused fillet at the head ...

You could take the bolt to a bike shop to see what genuine Jap Bike bolt will fit ... I've never liked the idea of a 10 mm bolt for the swinger ... it simply doesn't make sense ... The fact that these bikes require up to a 1200lb shock spring should give you an idea of the stress placed on the bolts by the forward mounted shock setup ... The original XR/CRF50 design puts waaaayyy less stress on the swinger pivot ...

Tightening the crap out of any bolt pre-loads it so that it will break at a lower load than it would if it was just nipped up ... A nyloc nut lightly tensioned would get the job done safer with the stock china swinger bolt ... DHZ used to sell monster frames that took a 12 mm pivot bolt ... but it's hard to find bearings to suit ...

 

[no_crf50_here]

mine always used to snap sprocket side. I just figured it was stress from the chain pulling combined with my fat ass..hahah

 

[Cactus Jack]

Bolt threads also form stress risers ... that's why rolled threads are stronger than die cut threads ...

 

[1fifty1wheel]

the 1200lb spring cactus mentioned brings up a point to note.
Without having a swinger to measure. If the shock mount is 25% of the distance from the swinger bolt to axle, then with a 300lb force getting applied at the wheel (just as an example) gives 1200lb at the shock and the swinger axle would have 900lb of shear load. This is taking the shock as the fulcrum (pivot point).
900lb (409kg's) is alot for a poor quality 10mm bolt!

Just food for thought.
And a ramble.

Feel free to correct me, this isn't taking any angle shifts into account and assumes a horizontal swinger.

 

[short.y]

shitt mate got outta that one lucky!

ive only ever really seen 1 rx riding regoed in newy wonder if it was you?

 

[motoluver]

yehhhh its in newcastle 5 days a week. my plates are [wtf 50]

 

[davedonzella]

yeah i did that on my old bike, i thought it was a flat tire at first. I was half way round a very long loop track and had to hold the bolt in with my heel the rest of the way back.

 

[short.y]

yehhhh its in newcastle 5 days a week. my plates are [wtf 50]

ahh mate thats gold!

Howd you get em through?haha well done..Will keep an eye out.