Aussie Ray Gen 4 / CRF450R 06

Building Tips, Suspension Set Ups, Conversion Parts .... Build to your Heart's Content!
Flatbiller
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Joined: January 22nd, 2011, 1:10 am
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Post by Flatbiller »

Did you break them right in the bend? Where the tube gets smaller?
Those new rails are straight gnar kill !!!!!
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racein01
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Location: Central Qld Australia mate.

Post by racein01 »

Any pic's of the breaks Ray?
speedway501
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Post by speedway501 »

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AlisoBob
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Post by AlisoBob »

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Gee, no doubler.....
speedway501
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Post by speedway501 »

I realise the engine mounts should have been a lot wider where they meet the frame rail. Rails stood up to 58hp engine for a good few months. They failed when we upped the HP.
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coley13
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Post by coley13 »

are you sure it's not the headstay? i think i read another 450 broke in similar fashion not long ago. Everyone seemed to think it was the headstay?
13 isnt unlucky i just keep falling off
Flatbiller
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Post by Flatbiller »

I agree with bob. Those motor mounts are rather small. Kinda concentrates the load instead of spreading out load. On that note those billet ones should be bomb proof!!!!
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2strokeforever
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Post by 2strokeforever »

my completly unprofessional opinion
i think its mostly the headstay, (motor mounts could use help too) while it is built nicely, it dosent provide enough front to back stiffness.... it works on a 450 cause the headstays go straight down, on the billet ones they go in then down on a 90, not the way any other headstay works on anything....
just by looking at it you can see its gonna flex forwards to back real easy, even being billet

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now look how honda does it, straight down, not in 4 inches then a 90
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the 450 will have less power and will be harder to start, and will be heavier, but to make up for it it will require more maintenance.
4stroke=dead fish
100hp honda
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Post by 100hp honda »

seems to me that using the doubler has a few benefits. obviously it spreads the load wider but also your not putting all the weld heat directly onto the frame rail. hell i could be wrong though
speedway501
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Post by speedway501 »

The motor was only braced sideways when the first rails broke. We thought maybe headstays came loose. Which caused stay to brake and load frame rails with too much force. Rails held up fine for 6 months running standard engine. They broke on first outing with 80+hp engine.

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When we rebuilt the the frame rails we braced it sideways and added an extra brace back to shocky tower. All bolts and nuts were installed with Lock Tight and closely monitored for loosening. The rails broke on second outing. The bike is used for beach racing only. It has not been jumped at all.
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100hp honda
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Post by 100hp honda »

aparently you have too much power :cool:
speedway501
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Post by speedway501 »

Ha Ha 100hp, not enough we recon.
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Gravel Scratcher
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Post by Gravel Scratcher »

Where do you guys beach race ?
if there's one thing dad likes more than serenity… it's a two stroke engine on full throttle!
speedway501
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Post by speedway501 »

Grasstree near Sarina
KE 336
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Post by KE 336 »

I'm not saying it is the cause but I can't help but wonder if bending the tube in T6 condition played a part in the breaks. I do think the mounts should have been wider as you already said. Props to you for showing the busted rails and those billets look bad ass! May have a break some where else but it ain't going to be on the rails. :lol:
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AlisoBob
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Post by AlisoBob »

KE 336 wrote:Props to you for showing the busted rails...
Yup.... We cant make things better without knowing what isnt working.
AMA714
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Post by AMA714 »

Speed... not sure if I missed it somewhere in this post, but who made the pipe?
speedway501
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Post by speedway501 »

First Pipe was CPI.

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Second pipe.

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nmdesertrider
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Post by nmdesertrider »

I think the abrupt shoulder on those mounts focus the torque in a small area. It seems as though the designs that match OEM work out the best-i have never seen anything like that with bikes that reused the stock bottom mounts.
03 CRF450/85 500
speedway501
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Post by speedway501 »

nmdesertrider, Yeh I think you are right. The original mounts were pretty much a copy of Shanmans, from his PDF file. His mounts have been use on a lot of bikes with out issue.
speedway501
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Post by speedway501 »

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speedway501
Posts: 62
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Post by speedway501 »

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speedway501
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Post by speedway501 »

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Gmbond
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Post by Gmbond »

Wow, I bet the raw piece of billet alone needed to make those rails cost a pretty penny!

Looks good though!

Sure hope you don't find the next weak point now!
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AlisoBob
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Post by AlisoBob »

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Why the mismatch?
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