Subframe rebuild Aluminum or Carbon fibre?

[satanzhand]

Hi,

I am just looking at lightening and lifting the butt on my VTR.

I was thinking of doing a carbon fibre rear subframe, but the lack of information available about the strength etc. puts me off the idea now, even though I think I would be super cool.

So I'm looking at constructing a subframe out of old faithful Aluminum...anyone have any thoughts or Knowledge about the subject?

[warby221]

Strength for weight ally and steel are about the same IE for a given strength of steel box section you would need a thicker wall section of aluminium for the same strength that’s why ducati use a steel truss frame. Carbon fibre is lighter and stronger than steel but can shatter that’s why they banned CF tanks from racing
If your only looking for the bling factor why not rap the original steel sub frame in carbon fibre

[satanzhand]

I have order some solid aluminum bar stock now which I'm going to fashion a new subframe with...and then I'm planning on just drilling out the unwanted weight. I'm hoping to bend the lower sub-bar so its almost not visible...but ill have to see how the Al handles the bend.

The main purpose of the subframe change has really become changing the look of the rear with out changing the tail dressing e.g. lifting the butt. I've gone this route because I didnt want to change the rear shock with a lift as it screws up the suspension ride.

[sirch345]

Be careful what you are doing

The early Hayabusa had problems with the rear sub-frame cracking or breaking. They replaced the alloy one with a new steel version. Iirc it was owners who carried a pillion and/or panniers full of luggage that this weakness showed up

Chris.

[Zakalwe]

Be careful what you are doing

The early Hayabusa had problems with the rear sub-frame cracking or breaking. They replaced the alloy one with a new steel version. Iirc it was owners who carried a pillion and/or panniers full of luggage that this weakness showed up

Chris.

IIRC ithe subframe on busas cracked where owners had changed the exhaust cans. The end cans on the early busas were a structural member supporting the rear subframe

[sirch345]

Be careful what you are doing

The early Hayabusa had problems with the rear sub-frame cracking or breaking. They replaced the alloy one with a new steel version. Iirc it was owners who carried a pillion and/or panniers full of luggage that this weakness showed up

Chris.

IIRC ithe subframe on busas cracked where owners had changed the exhaust cans. The end cans on the early busas were a structural member supporting the rear subframe

You could well be right on that Zakalwe, it certainly sounds feasible.

Chris.

[Zakalwe]

IIRC ithe subframe on busas cracked where owners had changed the exhaust cans. The end cans on the early busas were a structural member supporting the rear subframe

You could well be right on that Zakalwe, it certainly sounds feasible.

Chris.

Suzuki seem to have a history with their bikes breaking up.....you heard about the recall on the K5s?

[sirch345]

Suzuki seem to have a history with their bikes breaking up.....you heard about the recall on the K5s?

No I can't say that I have. What was that all about

Chris.

[Zakalwe]

Suzuki seem to have a history with their bikes breaking up.....you heard about the recall on the K5s?

No I can't say that I have. What was that all about

Chris.

Suzuki GB have issued a full recall (via VOSA) to have all K5 1000s returned to have a frame brace glued on. There have been a couple of cases where the frames have cracked at the headstock (when I say cracked, I mean the front has fallen off)...allegedly after an accident or wheelies.....
Details here


( A K5 after a 30MPH collision)



And another one:

[firestorm996]

Jeez, the K5 pics are scary

Regarding the subframe...if you're gonna go the ally route, you might be best keeping it as a single seater. The only ally subframes I've seen have been built for racing. They were made from hollow section ally and welded with a bit of cross bracing.

[sirch345]

Suzuki seem to have a history with their bikes breaking up.....you heard about the recall on the K5s?

No I can't say that I have. What was that all about

Chris.

Suzuki GB have issued a full recall (via VOSA) to have all K5 1000s returned to have a frame brace glued on. There have been a couple of cases where the frames have cracked at the headstock (when I say cracked, I mean the front has fallen off)...allegedly after an accident or wheelies.....
Details here


( A K5 after a 30MPH collision)



And another one:

That is scary

Chris.

[tony.mon]

[quote="satanzhand"]Hi,

I am just looking at lightening and lifting the butt on my VTR.

quote]

K5 pix scary, right enough, but at least in the first one the butt's lifted

[LotusSevenMan]

Best to lighten ones own butt I'd have thought! Safer eh?

[satanzhand]

I will be keeping the bike as single seater. Its a pretty basic job.. doesn't even need much bending just a little tig'ing.