SGS backing cage-plate for an M739 rear der.

Hi all.

It seems I've been relegated to search for the secondary/backing cage-plate off a long-cage jockey wheel unit from an XT M739 rear mech. I'm in need of the plate that does not have the pivot pin part in it, and has both jockey wheel holes threaded ... so if anyone has a completely trashed rear mech with a still good cage-plate ?

If so, please let me know, and thank you in advance!!

Re:

You may be in luck , I'm not 100% but seem to recall this was originally pared to a 739, the jockey wheel bolt centres are 85/86mm , send me a message if it's what your after

Damn - no, that's not quite it. I already have one of those on hand, but the arm is aligned differently than the main-plate (off an M951)that I want to use (I am extending the cage on an M900). The one that I'm looking for doesn't have that little 'notch' cut out of the top right hand corner (middle photo), and has a slightly different angled arm from top to bottom.

But thank you anyway. Back to the drawing board (to figure out what model der. the right configuration came off of) ...

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I do have a few more spare rear plates, I'll have a dig around for you later today after work

awesome, thank you! I've looked on-line, and the shape of what I need is exactly like the back plate for an M750 rear ... except that both jockey wheel axle holes must be threaded female holes (unlike the picture M750, which has one male/one female hole). I found the one I have on-hand in a used parts box in a local shop, and until i had the old powder-coating stripped off was stoked that I'd found what I needed. After the bare metal was exposed, I found that one of the arms has a crack right across the pulley spindle hole.

Sadly, I am not sure what exact model of rear mech it came off of, as it was sitting at the bottom of the box, unattached to its parent derailleur.

:?: :?: :?: :facepalm:

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I understand , it's a shame that you removed the powder coat :facepalm:

How about another possible way round

I can't recall from memory how the derailleur front plate attaches to the main derailleur body on the 739. But was it not attached using an Allen key'ed bolt, , like the M730/2/5's that if you unscrewed would then enable you to remove that plate away completely ? ,

I just thought , in the spares I've a couple of lower end Shimano mechs with long cages, also iirc somewhere in their is a long caged m730 ,,they are only in the spares as cosmetically logo speaking , their not in great shape , but depending on how the front plate is fixed, how about looking at replacing the whole assembly ? , then you'd remove the issue of trying to match up and carry on , just swap it all out

Do you understand, hard to explain and I'm not at home so can't send you pics of what I mean :facepalm:

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730's have an external screw to the side on the plate and solid bushing/roatating bit thingy.

900/950 series have a hollow budhing.rotating bit thingy and a bolt that goes through it and screw into the main body.

737/739 etc use a small grub screw into the side of the body to keep a solid whatsymathing in to place.

can you put a picture of the unknown cracked parts box, I can have a rumage through my bits and bobs too.

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memory serves, you have an m900 mech, you have taken the front plate off
and altered the top jockey hole to allow the screw to go the other way around.

Re: Re:

FluffyChicken":244zkgc2 said:

memory serves, you have an m900 mech, you have taken the front plate off

and altered the top jockey hole to allow the screw to go the other way around.

Click to expand...

That is correct ^^ I have the front plate off the M951 as pictured above, which plate I altered so that the jockey wheel screws both go in from the front side. I altered it like that because the back plate that I had already found, was configured for both screws to place in that way (back plate has both screw holes as threaded female). :idea: Unfortunately, that back plate proved to have a tiny crack in it across the tip (over one of the screw holes), so I am not going to use it. Had I not altered that front plate to fit the cracked back plate, I would already have found another back plate to mate with it (there's tons out there with the standard opposing jockey wheel screw configuration).

:facepalm:

Life. Never dull, for very long.

And, to mix it up even more ... the finished cage mechanism will be attached to an M900 mech.

I may have to get creative and make one from scratch.

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Here's what Ive pulled out the spares bin, but don't think any of these would be of use to you ?