What did you do today? Cobba's rebuild

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cobbadiggabuddyblooo
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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Wed Jan 31, 2018 12:56 pm

coxylaad wrote:What's the stock one weigh?

Are you finding the limitations over the stock swingarm now?
It's only when I really start to push things hard on the throttle exiting some corners. The stock swing arm does an excellent job but it's at its limit. The excellent grip and stiff carcass of the Dunlop GPRacers gives great feedback. I'd be pushing things to the limit ( and I ain't going there ) once this swing arm is fitted to find similar chassis flex.
Alan Cathcart had Over place in extra bracing on his Swing arm from the brace to the pivot but I ain't going to push things that hard on mine.. :lol: :lol:
The stiffened swing arm just drove and chassis flex up into the frame hence why the diagonal brace he had on the frame under the tank. But remember he was running a 6.25" in world class competition racing where the limit is where you sit constantly.
I feel a 90 HP TRX is still well and truly capable of running the std swing arm even with a 5.5" rim fitted in there.
I can see so many advantages in weight alone by fitting a later model lighter R6 5.5" rim into the stock swing arm compared to the YZF 750 rear end conversion.
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Tarwetijger
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Re: What did you do today? Cobba's rebuild

Post by Tarwetijger » Wed Jan 31, 2018 1:58 pm

cobbadiggabuddyblooo wrote:Note to self...

Over racing swing arm weight 5.2kg
Bearings and bushes in place .
Just no rear axle or swing arm pivot pin.
coxylaad wrote:What's the stock one weigh?

Are you finding the limitations over the stock swingarm now?
swingarm
TRX: 4,4kg
YZF: 5,5kg

source
Last edited by Tarwetijger on Wed Jan 31, 2018 3:49 pm, edited 1 time in total.

coxylaad
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Re: What did you do today? Cobba's rebuild

Post by coxylaad » Wed Jan 31, 2018 2:39 pm

i wonder what the aprilia one is ? :?

cobbadiggabuddyblooo
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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Sat Feb 03, 2018 2:51 pm

Over Racing Swing arm fitted today plus I finally sorted the rear suspension issue with interference fitting bushes on all 3 bearings of the relay arm / shock mount plus the swing arm dog bone mounts.
0.008" smaller than the sloppy new bushes I purchased from Yamaha when I started this rebuild.
Now you can grab the rear of the swing arm when the frame is suspended in the air and there is no play. Previous you could see about 5mm lift at the end of the swing arm due to the loose fit on the 4 bolts n bushes on the rear shock / relay arm / dogbone mounts.
I'll post a utube link shortly seeing as Photobucket is trying to rought money for photos.
I'll take another reading of the swing arm angle with the 170mm dog bones now in place.
I'm hoping I'll be in the 12+*. Definately needs a longer stand now...
Exhaust off today too and exhaust ports look a nice mix of light and darkish tan colours.
Last edited by cobbadiggabuddyblooo on Fri Feb 09, 2018 2:35 am, edited 1 time in total.
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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Sun Feb 04, 2018 1:36 pm

Tarwetijger wrote:
cobbadiggabuddyblooo wrote:Note to self...

Over racing swing arm weight 5.2kg
Bearings and bushes in place .
Just no rear axle or swing arm pivot pin.
coxylaad wrote:What's the stock one weigh?

Are you finding the limitations over the stock swingarm now?
swingarm
TRX: 4,4kg
YZF: 5,5kg

source

TRX 850 Swing arm pivot pin bush and linkage bush combined weight is 520g hence the 0.5kg extra weight difference on the TRX swing arm weight from Robert.

I weighed the TRX swingarm, bushes and bearings still in place and came in at 4.9kg.

TRX 4.9kg
Over 5.2kg
YZF 6.0kg

Swing arm angle came in at 11.8* with the 170mm dogbones. Forks flush with top tree.
Yzf750 dogbones came in at 11.5* (172mm)
Std dogbones came in at 9.8* (182mm)

Ballpark figure approx0.1666' degrees of swingarm angle for every 1 mm of dogbones length....
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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Sat Feb 10, 2018 6:59 am

No more updated photos from photobucket pics so it's video thanks to Utube now.
Should have put the carbon fibre front guard back on... #-o
No need for the carbon rear hugger any more as the swingarm bracing gets in the way.


https://www.youtube.com/watch?v=QXZ5BMB ... e=youtu.be
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Rod.s
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Re: What did you do today? Cobba's rebuild

Post by Rod.s » Sat Feb 10, 2018 12:43 pm

Looks like you're missing the inner left exhaust clamp spring :D

But it's looking bloody nice =D> =D>
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Re: What did you do today? Cobba's rebuild

Post by coxylaad » Sun Feb 11, 2018 12:08 am

have you rotated your fairing backwards?

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dicky
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Re: What did you do today? Cobba's rebuild

Post by dicky » Sun Feb 11, 2018 1:57 am

Looks like he has.
At 1:22 and 1:38 you can see the brackets to move the rear fairing stay mounts down and forward.

Cobba, did you bend the front headlight bracket to get this angle, and how well does the headlight work at that angle?

Also, for Photobucket hosted images there are fixes available to enable viewing the images.
You need to install an add-on to your browser of choice, just search for photobucket embed fix, tick the boxes, and all the images become available again.
A bit to late for those who ditched PB in disgust, and it has to be installed by the viewer, each and every one of them, but it does help to resurrect otherwise lost pics.
dicky
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cobbadiggabuddyblooo
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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Sun Feb 11, 2018 5:29 am

No mods to the fairing sub frame as such just the mounting.
Top frame/subframe mounting bolt is in the original position but I have just rotated the fairing using this bolt as a pivot. The bottom frame bolt I have placed a small bracket either side which extends the sub frame mounting point forward. This subframe bolt now sits just in front of the headstock/frame mount it bolts to.
I used a simple flat bracket on the radiator/fairing mount bracket to hold things in place there.

The double bubble screen on the race fairing sorts the air flow. Not worried about the road fairing as it's just a to and from the track fitting now.
As for headlight position Dicky, it's good for spotting possums on overhead wires... :lol:
I've got 2 small 3" LED's and flat LED indicators I plan to fit into 1 of the spare race glass I have plus I'm sorting my fresh cool air feed that will sit front and centre in the fairing where the std trx headlight usually sits.

Maybe I'll find time over the next few months to complete this now I have a little more time up my sleeve.
I'll rig up a different sub frame from a mangled 1 I have that chops out the headlight mount section to loose further weight.
Spring is in place Rod, just hidden due to the black rubber outer sheath.

Photobucket sorted on my laptop, but not on the iphone and just hate being bombarded by adds and blocks when I download further photos.
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Re: What did you do today? Cobba's rebuild

Post by coxylaad » Sun Feb 11, 2018 11:17 pm

Isn't that funny, I was messing about with rotating my fairing backward the other week!

I decided to just leave it where it is me being stiff mofo I need all the wing protection I can get :lol:

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Racer-unk
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Re: What did you do today? Cobba's rebuild

Post by Racer-unk » Tue Feb 13, 2018 6:48 am

nice....just a question.....do you leave your garage door locked or unlocked?....... =P~

cobbadiggabuddyblooo
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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Tue Feb 13, 2018 9:56 am

Locked and shotgun loaded... :lol: :lol:
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Racer-unk
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Re: What did you do today? Cobba's rebuild

Post by Racer-unk » Tue Feb 13, 2018 11:29 am

cobbadiggabuddyblooo wrote:Locked and shotgun loaded... :lol: :lol:

You safe.....i'd have a problem taking it as hand luggage on the plane.

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Re: What did you do today? Cobba's rebuild

Post by cobbadiggabuddyblooo » Tue Feb 13, 2018 2:04 pm

https://www.musclecardiy.com/performanc ... e-engines/

Thirst for knowledge and comprehensive understanding on the impacts of exhaust pulse.
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