Building the bike nobody wanted. 1991 RidgeRunner.

[mk one]

First little hurdle, I had a 31.9 M900 front derailleur lying about from a Zaskar frame I sold.
Not sure who invented this kind of system but I'm lost to why, maybe it has some physics properties that actually improve shifting but I highly doubt it.
Since the original piece was not on the bike I used one I got of a Concorde Kudu, it's plastic, hasn't got bearings so I might ditch it altogether but I need it for mock up. I tried to look for a similar part with bearings (bushings?) in metal but only came across one here from a post made in '13.

But this isn't going to work well, the way it's set up now. But it'll have to do until I can sort something else.
First two is from the interwebz and that's what the original looks like.
The third is mine.

Most front mechs were bottom pull so top routed cables needed the pulley to convert the pull direction.

Also @racer x used to have spare pulley wheels in stock, may be worth sending a pm over.

 

[Elev12k]

SJS stocks them too: https://www.sjscycles.co.uk/gear-spares/problem-solvers-cable-pulley-black-fs0917/?geoc=NL

 

[Elev12k]

In reply on post #18:
The mech is a regular downpull mech. The unique bit is the tiny bit on top where the outer cable hits. The inner cable connects to where the pulley would be. Would also work with XTR downpull mech.

 

[Spankyfart]

Ahh gotcha.
So the end of the cable is clamped where the pully should be.
I might look into that.

 

[Spankyfart]

Well reversing the pulley action won't work as there is just not enough room and it will otherwise has to make a really awkward run down the otherside of the tube.
I did however order nice pully with bearings which should DIY nicely into a proper working FD.

On another note, this came in today.
It needs some form of canti bosses but I have no clue which ones and what length, I'll do some research on that and can appreciate any info regarding. I don't have any on hand to mock.
Got these NOS M733 (which were originally specced), hoping to mount them soon.

Still don't have a fork, that's most likely becoming a huge chore as my pockets aren't that deep but deep enough to buy something nice and period acceptable.

 

[Tootyred]

Your missing a bit! You will need some u brake mounts.....fyi, they are different from cantilever mounts......

Im also not sure why your bosses have holes in them? U brakes don't use a spring like a cantilever, its essentially the gripping force of the rear of the brass insert, against the boss that stops the internal spring rotating.....sure they weren't originally roller cam brakes?

I will see if i can get you a measurement and photo...

 

[Tootyred]

U brake bosses.....

I cant find the measurement, but, if you get desperate, i can always take one off, but im sure somebody has a frame bare they can measure.

 

[Tootyred]

Ubrake instructions here

https://www.retrobike.co.uk/gallery2/main.php?g2_itemId=73341&g2_imageViewsIndex=3

 

[Spankyfart]

Im also not sure why your bosses have holes in them? U brakes don't use a spring like a cantilever, its essentially the gripping force of the rear of the brass insert, against the boss that stops the internal spring rotating.....sure they weren't originally roller cam brakes?

These are originally specced.


Now I don't have the booster which I assume is optional?
And to why this frame has holes in the frame where the bosses go in, I have no idea.
This frame has been the world over it seems and no one ever finished it once after atleast '03.

So I'm looking for more stuff yay.
I'll download the setup pdf, cheers.

 

[Tootyred]

Instructions here for m733

https://manualzz.com/doc/53871436/shimano-br-m733-brake--u-brake--service-instructions
The only real difference is the bits that hold the plate / tension the bolt and the bolt is slightly longer to accommodate the plate and missing the step in it.

What bits came with your u brake? As i can't see the silver bits?