Front mech...conventional or top swing?

[gazcoign]

Hi there, going to give my Scott Yacora(circa'05) an overhaul, replace drive train and front/rear mech. As i don't know jack(in general!) i have no idea whether i need to buy a conventional or top swing front mech...any help?
Also, i would like to add that this probably wont be the last question i ask on this subject!!

Thanks for any help

Gaz

 

[Paulus]

Are you going to replace like for like, or upgrade? As long as the cable routing is the same it is up to you. It depends on what groupset you choose.

 

[gazcoign]

Hi mate, slight upgrade, but only because shimano have moved on over the years! It's deore stuff i'm looking at...got some crackin prices over on ribble cycles. Not changing the routing of cables, so if i can fit either it begs the question...what's the difference?

Confused.com

Gaz

 

[Paulus]

I believe, and don't take this too literally, some older mtb's had the cable coming down to the front mech from the top. The normal routing is from the bottom. Deore is a good all round groupset that many MTB's, hybreds and some touring bikes use. Make sure you get the right one, I presume you have a triple chainset and not a double.

 

[gazcoign]

Hi Paulus, it's a triple chainset and yes, the cable does come down to the front mech. Ordered the stuff this morning and went for a top swing, so fingers crossed my guesswork pays off!

Cheers

Gaz

 

[John the Monkey]

You're thinking of "Top Pull" vs "Bottom Pull" paulus.

Top swing refers to where the derailleur pivot is in relation to its mounting, I think.

Wiki has a decent explanation;
http://en.wikipedia.org/wiki/Derailleur_gears

 

[gazcoign]

Hi again..another question!
With the chainset there are a few options, 170mm or 175mm and splined or square tapered..i take it this all depends on the bottom bracket fitted? And how do i tell which one i need?
Starting to wish i just gave my bike to my huffy LBS and bit the(financial)bullet.

Gaz

P.s. Interesting read John

 

[John the Monkey]

Does the whole crankset/bb assemply NEED replacing? You could just swap out the chainrings. I really like FSAs replacement chainrings, personally.

Splined & square taper both refer to the type of BB fitted to the bike, and it's interface with the cranks. 170/175 is crank length, and personally I'd stick with the length you have unless you're unhappy with it for some reason.

according to Bikepedia, your bike came with a shimano UN-25 bottom bracket, which would be square taper. (Cranks will have an 8mm (usually) bolt in the centre, unscrew that and you'll see that they fit onto a square spindle that tapers down towards the end. Splined interfaces are things like the "Octalink" standard, where the cranks have grooves fitting a series of splines on the bb spindle.

 

[threefingerjoe]

Be sure you get the right front mech. There are variables besides top pull or bottom pull. You also need to check the tube diameter. You need to check the maximum chainring size. Also, the capacity. Best bet is to talk to a mechanic, and find out what is available for your situation, before deciding on brand or model.

 

[gazcoign]

Cheers Joe, i've checked those points out mate. The front mech i've ordered is a fits all model and the 48 chainring is within its limits.

Ta

Gaz