450 frame bracing

[Teckhardt]

I am considering getting another frame that I can "cafe" over time (like I need another project ).

Is the bracing on the 450 frame really necessary for the 450 motor? That bracing is one of the problem areas I ran into with my current frame. Is it possible to add rigidity to the frame w/o the big flat pcs on the stock 450 frame?

[DewCatTea-Bob]

" Is the bracing on the 450 frame really necessary for the 450 motor? "

____ I guess some of it is...
I had a friend who wanted to race his 450 (disguised as a 350), and after a season of circuit racing, both of the frame's side down-tubes (which connect near the side-plates -[for the upper-rear motor-mount bolt]), developed cracks completely through the pipe-tubing ! _ After the first cracked-tube was welded-up, then the other tube later cracked-though, and after it too was also welded-up, then the first tube later cracked through (again), just above it's weld-up job. - (More on this problem down-below.)
__ On my own 450, I cut-off only the added plate-bracing work just above the carb-top, and no problems ever developed from dong that.

" Is it possible to add rigidity to the frame w/o the big flat pcs on the stock 450 frame? "

____ Now once again, back to my friend's tube-cracking problems...
Both original/stock tubing-sections were eventually replaced with SOLID steel-tubes (with expert welding,, after both messed-up side pipe-tubing & all previous [non-expert] weld-up work, was first completely removed).
__ Hopefully, somebody else will have more info (& advice) which I'm unaware of !


DUKE-Cheers,
-Bob

[Teckhardt]

Was afraid you were going to say that.....

Don't see many 450 frames come up on Fleabay. May have to get a 250/350 and add the bracing on.

Old Racing Spares sells a Cr-Mo frame. Don't have to guess that it is way out of my budget of next to nothing.

[Teckhardt]

I was looking at this one, but if you need it more than me, you should bid on it. Specially since I don't have the time to start on my first project yet!!

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=190390898241&viewitem=&sspagename=STRK%3AMEWAX%3AIT

Saw that. Do I need another project???

[JimF]

I can't tell for sure, but to me it looks like a Mototrans frame. Not that there is anything wrong with that.

The bracing on a ducati 450 frame that occurs where the main tube terminates into the subframe just ahead of the seat mount turns down and goes along the subframe in the downward direction along both sides, gradually shrinking as it nears the battery box.

I can't see that on this frame. Also the frame bracing starts earlier on the main tube than I can see in this photo.

The frame loop over the rear tire on the eBay frame is flat metal bent into a loop, and on every Ducati frame I have ever seen (both wide and narrow case) the loop above the tire was tubing as opposed to flat stock.

Flat steel was only used on the Ducati street models as a cross brace when there was no "loop" over the tire needed to provide extra suspension travel as is the case with street scramblers. The flat steel would serve as a place to hold the regulator on the narrowcase street models.

To this end I have a Mototrans frame, I think this exact same style as the eBay frame being offered, hanging from the rafters of my garage. It has the little bit of frame bracing, but not having seen a Mototrans 250 or 350 I can't say for sure if the frame is a 450 frame or not. I bought it off of eBay years ago and it was advertised as a Ducati 450 frame. The pictures were grainy and I took the chance that it was but it wasn't.

If you or anyone else on this lists wants it, you can have it for the cost of shipping.

By the way, I think Phil at Road and Race in Australia sells the bracing that can be welded on to 250 or 350 frames.

Jim

[DewCatTea-Bob]

____ Concerning the wide-case DUKE-frame in question here, (as seen by following that link to eBay), I hadn't intended to bother stating anything about it before,, but now that Jim has brought-up a few points of considerable interest, I now wish to add my own DUKE-expert comments on this ! ...
__ Now being as knowledgeable as I am on all DUKEs -(OHC-singles), I feel I must declare that that particular frame must be a late-1969 to early-1971 Italian-type 250/350 Scrambler-frame ! ...
While I can only be as sure as the picture allows me to be, I've determined what that frame is, by the unique-points which that particular frame appears to have...
__ First, it doesn't have any of the unique 450-frame's added flat-bracing. - (Another-thing to note is that 450-type swing-arms include the added flat-bracing, there as well !)
Next, (starting at the rear-end), that frame's tail-loop has the added nipple-mount, (intended for the SCR-type taillight-bracket's forward-upper attachment-point), plus, it also has the added flat-steel bracket -(located directly above the rear-wheel area), which is mainly intended for support of the (lifted rear of the) SCR-type seat, (as well as rear-fender) ! _ BOTH of those two add-ons are NOT found on any of the non-SCRambler models !
Next, that frame includes the added fork-lock, which I'm pretty sure did not exist before late 1969.
And the visible nipple-mount (just above the fork-lock), is intended for attaching the fuel-tank's left-front mounting-ear... That point plus the rear taillight-bracket nipple-mount, both indicate that the frame is not a Mototrans type frame !


DUKE-Cheers,
DCT-Bob

[Teckhardt]

Besides what Bob mentions that are unique to the SCR frame, to my knowledge the scrambler is the only frame that the tail-loop tilts up. That is the way I have been able to tell the difference in frames at a glance. I also thought I read somewhere that the upper shock mounts on a SCR frame where in a different spot. Is that true?

If I am going to "cafe" a frame, is there any reason to choose one frame over another? Spanish vs Italian? If the Spanish one does not have the front tank mount, it sounds to me like I want an Italian one. I suppose I could always add that too...

Jim, I will take you up on the frame if you don't need it. Figure I will have to add the bracing to anything I get.

[JimF]

Okay, the frame is yours.

PM me your address.

I am going to ping the seller on the ebay auction and see if he'll reveal the shipping company on his $75 flat rate shipping.

Hopefully this will be something I can put a tag on and get it shipped to you for the same cost of $75.

Now I am not trying to keep my frame, but did you see the RT frame on eBay:

http://cgi.ebay.com/ebaymotors/Ducati-D ... 335c32acc2

I mention it because it is almost certainly lighter than the street and scrambler 450 frames we have been discussing.

Arguably I don't know how your tank would accomodate the main tube, and you would likely need to weld on some metal to hold rear sets and a battery tray at the least.

OK, even more now - I see that the one seller says his $75 shipping fee is UPS ground, and the RT frame just mentioned has about a $38 fee for UPS ground. So I am guessing the frame I have will cost you somewhere inbetween the two to ship to you.

Jim

[DewCatTea-Bob]

By: 'Teckhardt'...
" to my knowledge the scrambler is the only frame that the tail-loop tilts up. "

____ That's correct ! _ That's indeed one of the more obvious differences between the Scrambler and the other wide-case models !


" I also thought I read somewhere that the upper shock mounts on a SCR frame where in a different spot. "

____ That's also quite true as well ! _ As the upper-mount locations are both forward & lower than on the non-SCR frames.


" If I am going to "cafe" a frame, is there any reason to choose one frame over another? Spanish vs Italian? If the Spanish one does not have the front tank mount, "

____ That's the main difference between them,, as the Mototrans-version has it's pair of receptors (for the Mototrans-type fuel-tank's pair of pegs), located UNDERNEATH the tank (instead of in front).
__ Otherwise, those two road-type w-c frames -(Italian & Spanish), are more alike than either is to any Scrambler-type frame. _ So a SCR-frame ought to be the last-choice for conversion to 'cafe' .


DUKE-Cheers,
DCT-Bob

[Teckhardt]

I am reviving this thread rather than starting another...

I am working on my cafe frame project and wondering what would be the best option for bracing.

I could use the factory 450 type:

http://www.discovolantemoto.co.uk/ducat ... d_975.html

I could follow Eldert's lead and put in a few pcs of tube:



Or I could just go without and wait to see if it ever cracks.

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