'Top Swing Front Derailleur?

[fastpedaller]

Has anyone here tried a front derailleur called a 'top swing'? How does it compare to a regular front mech?

[531colin]

The pivots rattle themselves loose in half the time.
Only use if the bottle boss interferes with a regular mech.

[Brucey]

I agree; whilst you can add biasing springs to stop the rattles it is better not to have to try.

cheers

[PT1029]

Also, if you don't change gear at the front very often (middle ring does fine around hear most of the time), and ride without mudguards, top swing mechs are far more prone to the pivots siezing up. Unsiezed countless top swings at work, failed to unsieze quite a few more. Very rarely had to unsieze a bottom swing.

[foxyrider]

mostly big and clumsy too - best avoided

[mercalia]

mostly big and clumsy too - best avoided

eh? they are usually more compact.

[Brucey]

actually there is another rather prosaic point; top swing front mechs are mostly designed for an MTB chainline. If you try and use one on a road triple, it very often won't work; the mech won't get close enough to the frame to drop it on the inner ring.

They also don't fit very well on bikes with short chainstays and full-sized wheels; I think this is where the big and clumsy comment comes from.

cheers

[foxyrider]

mostly big and clumsy too - best avoided

eh? they are usually more compact.

more compact than what? I've never seen one as neat as the 'traditional' style, very often they almost rub the tyres on atb's they are so big! I can't actually see any advantage to their use in most instances.

[mercalia]

mostly big and clumsy too - best avoided

eh? they are usually more compact.

more compact than what? I've never seen one as neat as the 'traditional' style, very often they almost rub the tyres on atb's they are so big! I can't actually see any advantage to their use in most instances.

bottom swing

top swing

I have both and the top swing one is very compact compared to the later bottom swing one. As Brucey said the top swing one has a smaller chain line than the bottom swing one.

In fact Dawes put a top swing one similar to the RSX one above on my 1999 Horizon Tour. Never had any problem with it at all and was nicely hidden away, no rattles or anything

[Brucey]

I have both and the top swing one is very compact compared to the later bottom swing one. As Brucey said the top swing one has a smaller chain line than the bottom swing one.

In fact Dawes put a top swing one similar to the RSX one above on my 1999 Horizon Tour. Never had any problem with it at all and was nicely hidden away, no rattles or anything

I think you may have your top swing and bottom swing mixed up there; the RSX is a bottom swing, and has the tighter chainline capability.

cheers

[mercalia]

I have both and the top swing one is very compact compared to the later bottom swing one. As Brucey said the top swing one has a smaller chain line than the bottom swing one.

In fact Dawes put a top swing one similar to the RSX one above on my 1999 Horizon Tour. Never had any problem with it at all and was nicely hidden away, no rattles or anything

I think you may have your top swing and bottom swing mixed up there; the RSX is a bottom swing, and has the tighter chainline capability.

cheers

They are both RSX the blue lettering an earlier version to the black lettering one. As I undersrtand it the bottom swing means the band is higher than the cage? I'm going on the wiki entry for this -

"bottom swing
The derailleur cage is mounted to the bottom of the four-bar linkage that carries it. This is the most common type of derailleur.

top swing
The derailleur cage is mounted to the top of the four-bar linkage that carries it. "

unless I dont get its meaning?

[Brucey]

sorry, I didn't read the RSX on the top swing one! In any event I'm surprised that you say the chainline can be tighter with a top swing than a bottom swing (this is what you meant isn't it? If so it is certainly not what I meant to say) because I have rejected many top swing mechs because they won't do a road chainline.

cheers

[mercalia]

sorry, I didn't read the RSX on the top swing one! In any event I'm surprised that you say the chainline can be tighter with a top swing than a bottom swing (this is what you meant isn't it? If so it is certainly not what I meant to say) because I have rejected many top swing mechs because they won't do a road chainline.

cheers

I meant the chain line for the blue RSX is less (43.5mm) than the Black one (45mm) according to the shimano specs.

And Dawes did put a similar model to the Blue RSX on the old dawes Horizon. Seemed to be ok as far as I can remember ( used down tube shifters)

[Brucey]

have you actually compared the minimum possible chainlines on each mech? Whenever I've done that, the top swing ones won't manage as narrow a chainline as the bottom swing one.

Remember that one of those mechs is probably meant for a road triple and the other is for a road double...

cheers

[mercalia]

have you actually compared the minimum possible chainlines on each mech? Whenever I've done that, the top swing ones won't manage as narrow a chainline as the bottom swing one.

Remember that one of those mechs is probably meant for a road triple and the other is for a road double...

cheers

No I not able to make such delicate measurements. It seems u may be right about the blue RSX and double but it looks as if Dawes used it any way on the triple of the Horizon. lol. The strange thing though is that as far as I know that was the correct derailleur to use with their RSX 46,36,26 triple chainset BUT when it came to the 1-Down, they used this chainset but with the later black lettered RSX bottom swing!! You make sense of that lol