AMP Research research

[Gerard]

Without the back story to these pics you dont really know what it went through to get it to fail. Certainly that one is a big rear landing, so is it a case of the owner over estimating its strenght ?

True, must have been a hell of a whack. Needless to say (from memory ...I've read so much over the last week or so) he insisted this was the second or third issue with AMPs.

I guess I just need to make a decision. Aluminium is not without it's issues.

 

[danson67]

Personally I'd be suspicious of the views of someone who has apparently managed to bust 3 AMPs...

I own, and have ridden, the B4 bonded carbon, bonded aluminium and older welded versions...they all work fine for me.
but then I'm 72kg, and ride my bikes smoothly, treat them like a rigid, try not to get too much air and never forget that they are 20+yr old, 22Lbs full suspension aluminium thoroughbreds.

It's always really difficult to sequence a failure like this without it on your hand. Maybe a failure of the RH chainstay tube?. ..and of course he was probably 'just riding along' when it happened.

-The seatstay to dropout joints look good.
-Seatstay bridge is still in place.
-RH chainstay to BB is unclear.
-LH chainstay to BB is good
-RH chainstay to dropout is in place.
-LH chainstay to dropout has de-bonded.
-The shaft on the rear end of the Risse shock seems to have sheared.

I have also seen a report of one failure of these bonded B4s at the hole in the chainstay horseshoe yoke cut for the Mercedes carbon fibre kickstand.

They'd made the bonded forks for years, but maybe AMP were not too familiar with the risks of carbon/aluminium bonds when they upgraded their bonded Alu rear end to carbon for Mercedes?

Plenty more reported failures of Manitou, Marin, Pace, Klein, Cannondale and Nishiki frames out there, and people are still riding those.

All the best,

 

[Gerard]

Re:

I found this and thought it might be of interest/help. Dan has given some very helpful measurements. This is dated later.

 

[danson67]

Wow, Gerard :shock: Gold dust
You must have been doing some serious digging...never seen that sheet before.

All the best,

 

[rva]

whatever was KTM making were they all AMP licensed or a simple knockoff?
this is some weird stuff here: http://tufotki.pl/umT7k#p10842773

also, is this a B3?

 

[danson67]

Looks like a badged early B3 with the flat oval downtube.
Some later ones ran a normal round downtube like the B4.

Not sure about the KTM mixte frame thing, though.
F2 fork OK, but the rear end looks locally made.
What's the little piston thing below the rear shock?

All the best,

 

[Gerard]

Re:

Question re brakes:
The rear triangle, some appear to have welded brake mountings which I assume don't have disc mounts. Disc specific rears don't have v brake mountings, but can you get a bolt-on mount?
It seems the top frame in this photo has bolt-on mounts, if I'm not mistaken. If available, are they like hen's teeth?

 

[danson67]

Hi Gerard,

All the B4s have disc mounts.
The AMP specific mount is the two 6mm holes built into the LH dropout.

As you say, some early ones also have the welded on canti mounts, later bonded ones have clamp on canti mounts.
Same goes for the forks. F3 and F4 have the disc mount built into the dropout, some have welded, bonded or clamp on canti mounts.

Availability? I've seen a few fork clamp sets go past, but never any rear mounts. Could be fabricated fairly easily, though.

All the best,

 

[Gerard]

^^^^^^^^^
Thanks Dan. I'm not sure I have the ability to fabricate, so I might be in touch. I could probably make an adapter plate for ISO disc though.
I think I have sorted a frame , so just forks to work out! Another bike to smuggle in. :facepalm:

 

[danson67]

Hi Gerard,

B3 here on the forum was making ISO adapters for front and back for a while.
He's been pretty quiet lately, though. There's a thread somewhere with details.

A rear adapter needs a dogleg in it, to keep the inward face in line with the inward face of the dropout.
Front adapters are a whole lot easier. I made mine from a 4mm (?) aluminium plate with strategically placed holes.

All the best,