Proflex 752 hack build

Thias

Klein Fan
Hey there!
As it seems, I didn't have enough open project lurking around in the corners of my basement. So it's time to start another one. n+1 at its best.

I got that Proflex 752 karma'd to me a little over a year ago. Now I found it while trying to do some cleanup. I don't like cleaning up. But I like building bikes. ...

So if I use some parts and that frame that are laying around, clean them, put them together and hang them on the wall in a tidy manner - that counts as cleaning up. Right?

Perfect reasoning.

... commence procrastination!

So this is how I got the frame. Minus the drill ;)
@joglo sent it my way. I think it was a a parts carrier for one of his builds, if I remember correctly. So some parts might be missing, or be a mismatch to this particular frame. But I don't really care. The elastomer is long gone, of course.


First order of business: Puzzle it together somehow. Use whatever is laying around the cave. No buying parts. It's the cleanup, remember?
I don't have elastomeres that size. But I do have many steel springs. That'll be the route to go for now, I think.


Notice the crack in the seat clamp area? Yea. That was me bending the tube back from years of using a too small diameter seat post. I think the metal was already fatigued. An it really didn't like me prying.
Let's just pretend we didn't see it. :rolleyes:

The steel spring fits nicely though. It might not be stiff enough for my a$$. But I hope it will do for a first test. Or I stop eating for a month or so.
... That might actually be a good Idea. o_O

The original seat post size is 28mm I think. Hard to say with that bent and cracked tube.
Don't have that odd kind of size. But I do have a 27.2 and a nice little tin box with a bear... And a hammer.


Perfect!

Nobody will be seeing the bear like that. Sadly. But the seat post fits "perfectly".

Maybe I should make a headbadge out of the second bear? :LOL:
 
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Time to decide on a fork.
The frame was sold around `92/`93, I think? And they were sold with a rigid fork+flexstem iirc. Or a Mag20something. I don't have a flexstem (yet) and I have too many bikes with a Mag so that's a no to those two options.

My first try:
RST Mozo pro. It's red. It's thick. Like the frame. Might work? I haven't used one of these yet. I'd like to ride one of these once.


But the red is off, it bothers me. Not good. Keep trying.
 
Next try:
AMP. It's thin appearance and black legs might go well with the rear, I thought. And I have yet to ride one of those, too. They work great but do flex alot, I hear. But let's mock them up first. See how they look.



Oh! I like. I really do.

Let's find a headset then. Found a decent enough Ritchey somethingtherather in the "unasorted used headset drawer". Slightly mismatched top and bottom. Who cares? It'll work.

That's when I realized.

1 1/4" steerer tube.

:eek:
 
1 1/4" problem solved. "Quickly" peeled some bushings on the lathe for a 1 1/8" headset to fit.


Normally, I'd use my trusty old oak hammer (as seen laying on the workbench in the last post) to (sensibly) knock in the headset coups. And usually I'd get a lot of flames for that over at the German mtb forums. 😇
But not this time I didn't.
Used some leftovers to cobble together my very own headset squeezer. Even whipped out the angle gage to fake engineering prowess.



Did it go in smoothly? Yes it did.
Would I still rather use the hammer? Absolutely. It's just faster...
But it sure was fun to try some different route.

Ok. So the fork is fitted. Let's throw on some wheels and have a look.





Looks kind of agressive. I think I like it.

Next up: The brakes.
I think I'd like to use a pair of black XT BR-M732 - You know. The little wingy things.
The problem: I'm missing the little lever that originally came with the frame right there:


So this will be the next part for me to make.

This is what the original looks like:
 
I had a 550 back in the day - which was pretty much the same frame.

The rear brake rockers are an absolute pain to set up and used to drive me absolutely insane. I ended up putting a magura on the rear as it was annoying me so much. Might be worth just putting a V brake on there for a hack build

Don't expect much from the rear suspension :)

AMP forks look awesome.
 
I don't mind a little hassle here and there. In this case, it's about the looks. And about cleaning the basement. Which isn't always easy anyhow... 😇

About my expectations from the suspension: My other currently somewhat unfinished project is this:

What do you think? Is it better or worse? :D

I have a knack for those early rear suspension frames. I'm trying to compare them. Find the pro's and con's. Have a little laugh here and there about the "quirks and features". Like the Mantras and Szasbos trying to lever your ass over the bars whenever you brake. Or the RTS being all around weird. Then I usually try to understand what went wrong and sometimes find ways to correct those flaws. EG the Mantra needs a very long, more modern fork plus a platform shock in the rear to make it ok going downhill while still beeing excelent going uphill.
 
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That's quite a rare sight. Think I've only seen one before.

I'd imagine they ride quite similarly given the rear setups - both likely to suffer under pedal load.

Good luck with the rear rocker!
 
I have a nice original 752 with a Vector :)

In terms of the rear brake thingy...

proflex.JPG

I started to draw up this not so long ago. It's not far off what the original is. I think I left room for some brass bushings to be pressed in for the main pivot. Can fire you the drawing if it's any help?
 
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