Mountain Biking - Front mech....

Ok, ive searched the forums for this already, and I cant find anything, i have a Specialized Hardrock Sport Disc 04, It looks like this

Hardrock (http://www.specialized.com/SBCBkModel.jsp?spid=5931&JServSessionIdroot=luotq1oh8d.j27001)

i know it says that the front mech on it is a botom pull, but what is the difference between top swing, bottom pull, top pull and bottom swing and stuff like that, it has me very confused, i'd like to put an LX mech onto my bike, aswell as an Lx mech on the back.

these 2 front mechs are what im looking at, but i seriously have no idea what im looking for, because i dont understand the difference lol, If it helps at all, the gear cables go under neath the bottom of the tube that says specialized, have no idea what that one is called, and then it comes up underneath the bb and connects onto the mech from underneath. Can somebody point me in the right direction, thx

Cornish_Rdr

im an idiot, I forgot to put the 2 mechs on LOLOL

Shimano LX F-Mech Conventional 8sp (http://www.chainreactioncycles.com/viewproduct.asp?category=Gear+Mechs+Front&ModelID=1710)


Shimano LX F-Mech Top Swing 8sp (http://www.chainreactioncycles.com/viewproduct.asp?category=Gear+Mechs+Front&ModelID=1257)

Also does anyone have any idea what they mean by conventional?

You have a bottom pull derailleur setup.

This derailleur is probably what you need. (http://www.chainreactioncycles.com/viewproduct.asp?category=Gear+Mechs+Front&ModelID=446) But call and talk with them about your particular bike. This unit clamps to the seat tube and it looks as if the bottom pull you posted somehow requires a lug on theb seat tube and wraps around the bottom bracket shell as well.

so im better off staing with bottom pull? and is bottom pull the same as top swing?

Your frame is more likely not equipped with cable lugs to accomodate a top pull. And yes a top swing is probably the same as bottom pull, if you look on the web page item description it has an abbreviation of BP which means Bottom Pull.

one more thing, Im on an 8 spd set up, will those mechs acommodate this as it says it is to be used with a 9 spd?

Front derailers will work on both.

Cornish geezer. Be a bit careful if you decide to ever swap the fron mech for something else. You need to match the new one to the post diameter I recall. Guess you knew that anyway?

If in doubt buy a Deore front, they'll fit just about any seat-tube and can be pulled up or down.

my seat tube is 31.8 i think.... Which the LX will fit

Bottom pull, top pull and bottom swing and top swing are different.

You can have a bottom pull with a top swing or a top pull with a bottom swing.

"Pull" refers to which direction the cable attaches to the derailer. A top pull will come down the seat post and pull from the top where as a bottom pull will be routed under the bottom bracket and pull from the bottom.

"Swing" refers to where the pivot is related to the cage. A top swing will have the pivot below the cage and the bottom swing will have the pivot above the cage.

For the most part, if you have a top pull you will not be able to use a bottom pull and if you have a top swing you should stay with a top swing.

You can get away with changing the swing if you change out the chain rings.

:beer:

my seat tube is 31.8 i think.... Which the LX will fit

LX, XTR, XT and so forth all come in different sizes to fit just about any bike.
If you take the derailer off, look at the inside of the clamp, Shimano stamps the size there.

:beer:

Front deraillieurs? What are those?;) Sounds like it all has been taken care of.

I found out for sure that it is 31.8, i saw it on the specialized site. Thx for all your help :) Ill have a look around and look for some mechs, Ill get back to you when i find one :)

It would be easier to forget about the front derailleur, a lx isnt going to perform any better than whatever you have.

Acera....

Acera....

Yep. If its not broken dont fix it, or replace it.....

Why, isnt there much difference between shimano mechs?

OK, so i finally finished paying back my bike today and i got abit of money, i bought this mech, the measurments are right, and its bottom pull, its 8 speed compatable so i take it it will fit mine well cos my bike is 8 speed and not 9.... I wasnt sure about top and bottom swing still... so i bought a top swing, because i didnt see any bottom swings..

This is what i bought

http://www.chainreactioncycles.com/viewproduct.asp?category=Gear+Mechs+Front&ModelID=1257

You know the one you bought is made to be held on by a Shimano E-type bottom bracket?

It does not clamp on the seat tube. It is held on by the bb. I believe your bike does not use that type. Did you post the right link?
:beer:

The derailer I would suggest would be this one

Front Mech (http://www.chainreactioncycles.com/viewproduct.asp?category=Gear+Mechs+Front&ModelID=825)

Either this one or the one SirSpinsalot posted.

:beer:

yeh that link i posted was the right one, thx for the input dbd..... Ill try and cancel the order if i can...

dont wanna question ur unlimited knowledge dbd :) But are u sure that its a bb mounted one, because ive been looking at the XTR bb mounted. and it actually says on the name its bb mounted, and the pic looks completely different, Also the LX has measurments for the seat tube, 31.8... Surely if the mech is mounted on the BB then measurments wont be needed for the seat post? And the XTR bb mounted mech doesnt say anything about seat tube measurments.....

Just making sure :)

Thx

And here is the link to that XTR bb...

http://www.chainreactioncycles.com/viewproduct.asp?category=Gear+Mechs+Front&ModelID=1840

ive also just read that the bb mount is an option on the XTR.... Do u think it will be the same with the LX?

dont wanna question ur unlimited knowledge dbd :) But are u sure that its a bb mounted one, because ive been looking at the XTR bb mounted. and it actually says on the name its bb mounted, and the pic looks completely different, Also the LX has measurments for the seat tube, 31.8... Surely if the mech is mounted on the BB then measurments wont be needed for the seat post? And the XTR bb mounted mech doesnt say anything about seat tube measurments.....

Just making sure :)

Thx

i think it might be the case that that site has it's pictures mixed up... the link to the derailleur you said you ordered looks like the bb mounted one... and the link to the bb mounted derailleur you gave looks like a seat tube mounted derailleur.

here's a picture of the xt m750-e bb mounted derrailleur:
http://www.jensonusa.com/store/product.aspx?i=FD707A04

you might want to check out the "jenson tech library" link on the page i gave the link for. it's got some good info on how to choose the right front derailleur.

So the LX mech that i chose will definatly not fit my bike?

As Rasheed said, the pic is of a bb mount type. It can work but you would have to get a different bb. Also as he stated the site might have the pics messed up.

If they will let you either cancel the order or call them and find out if it is the correct one they sent you.

:beer:

Thx alot guys.... I will try and cancel it....

Thx alot guys.... I will try and cancel it....try contacting them first to ask them if you ordered the right derailleur. from the options on the site, i think you did order the right one, i just think they got the pictures for the derailleurs mixed up...

hmmm
Ill do that lol.... this is a long thread for such a stupid thing lol