Tech Question Re: Mechs on Proflex Beast.....

[Grisley Paul]

Evening Guys,

Can someone give me a bit of advice on the following;

I have a 96 Proflex Beast
A Deore XT FD 761 A front mech
A new Deore RD M591 rear mech
Truvative Firex GXP chainset
SRAM PG980 9 speed cassette
SLX M660 front and rear shifters....

Now... can I get the whoel ot to work properly can I heck....

Sadly my knowledge on fixing and adjusting bikes is limited but my father is a life long cyclist but even here on retrobike his knowledge is outdated :cry:

We cannot get the front mech to change cleanly and it's also not an ideal fit / cage shape for the frame....

I think the reality is our combined knowledge is either not there or outdated, but my question really is are they're proflex owners out there running this setup without issues ?

If so then it's clearly just an adjustment issue etc but if not then we may be pi@@ing in the wind....

I say this as from some searching it seems the modern front mechs state whether they are 9 or 10 speed etc..... this older XT was I'm assuming NOT designed for 9 speed rear cassette's but I also though this was only an issue if riding with a poor chain line ?

Anyway, any help appreciated, I just want my bike back on the road with all 27 gears working smoothly..... my father is too proud to take it to the LBS and admit defeat......

Cheers
Paul

 

[jimo746]

I "think" that front mech should be ok with a triple ring chainset, but I know that on some Proflex with the alloy swingarm you need to use a certain type of front mech or they can foul on the swingarm... bottom pull, top swing rings a bell...

Is it for your Black Proflex? does the cable come down to the front mech from the top?

Do a Search on here and you should find a few useful threads, I remember the question being asked before.

A Beast with alloy swingarm and front mech...

same swingarm design as yours?

 

[Grisley Paul]

Not the same arm on my black flex no, mine pivots behind the seat tube, thanks for the info, like you say think there must be a small selection of front mechs that work but maybe not this particular xt.... Will see what I can sort.....

 

[hamtaro145]

i used a common old normal lx bottom pull on my 95 proflex....interesting to note that the subtly changed the angle of the seat tube on the '96 ones for better Fd operation/compatibility

 

[softride tragic]

Hi, you might have to adjust the high/low screws on your front derailleur,they adjust for large and small chain ring selection. most High clamp bottom/dual pull front mechs will work with your Beast. I have a 96 656,which I think is similar to yours. I'm running Sram 9 gear on it .Cheers,Rob.

 

[Jussa]

One STX-RC front mech, £10 NOS from evilbay, High mount, bottom pull, works a treat, mind you i have full STX-RC on my 856 but i also have a Beast and similar set-up / geometry. Can be a bit fiddly, top tip, replace the cable clamp with a Hex bolt saves the hassle of removing the rear wheel and inserting a long Hex/Allen key through the hole on the swing arm to tighten and slacken the cable.

 

[cornholio's RC200]

Alternatively use an M739 mech and have the benefit of the allen bolt on the top

 

[Grisley Paul]

Thanks for all the replies guys

Think we've finally got it sorted after a fair bit of fiddling....

Had a few short test rides and a chain off but after a few tweeks on the stops all seems to be good thus far....

''An'' issue was that due to the frame being freshly powercoated it comes in at 32.3 mm on the seat tube as opposed to the original 31.8 so some fabrication was necessary to get the mech clamped securely without any movement but got there in the end.....

Thanks again, great to be part of such a friendly helpful site

 

[WD Pro]

Some of the swing arms were relieved a bit (from the factory) to help front mech cage clearance :

WD

 

[Grisley Paul]

Well just to update this and calling all proflex owners.....

Despite more tinkering and even taking it to the LBS we can still not get it to work properly without fouling the front mech cage at some point......

It appears the mosy important factor here is the external style bottom bracket pushing the chainset further out and with this setup it looks doubtful that any front mech would work....

So it looks like a swap back to a square taper BB that the frame was designed for and a suitable chainset is the only way.....

UNLESS...... any Proflex owners out there are running external BB's and still getting their front mech to work properly ?