TOP SWING DOWNPULL FRONT DERAILLEUR

Evening all, hope I find you well.

Yet again I must bow down to the knowledge on this forum and wonder if I could tap into it (again).

What's a "TOP SWING DOWNPULL FRONT DERAILLEUR" for "DOWN-PULL CABLE ONLY" ??

I don't understand the terminology or it's application. Any descriptions, manufacturers, history, period of use etc. would be read with interest.

Thanks...

Never heard that before, but it sounds like a typically american verbose description of a Campagnolo record type. Can you give us some context?

A traditional front mech is bottom swing bottom pull. Bottom swing means that the cage swings from the bottom of the parallelogram, and the frame clamp is the highest part of the mech. bottom pull means the mech is pulled from the bottom, by a cable that passes under the BB.

Top swing means that the cage is attached to the top of the parallelogram, so the clamp is a lot lower than normal. this type was invented (I think) to provide larger clearances on full suspension mtb frames.

Top pull means the mech is pulled from the top, by a cable that runs along the TT and then down the ST.

both bottom and top swing mechs can be bottom or top pull, and some of them are dual pull, meaning they can be used either bottom or top pull, depending on how the cable is clamped.

Back to front action front mech eg Suntour. Pull the cable to pull it down onto the small ring ?

Shayun

Definitely sounds like an Americanism! Thanks chaps for replying so quickly. Foz - makes perfect sense written as you have - still perplexed though. You say cable routes under the TT and down the ST yet the frame to which this type of front mech is required (so i'm told) has downtube band on levers?

I've asked the owner all the relevant questions and this has been the sticking point as i'm confused on this front mech set-up.

The history of the frame is unknown & has no markings - i'm interested as a project and it would hopefully get my son of his bmx and onto a road bike - however no point if I cant find components that do a proper job!

pic (hopefully) attached - your comments will be most welcome

thanks...

looks like you have an older frame there... I'm not old enough to know much about this one, but I think old (60's or maybe 70's) front mechs had an outer cable stop built in, and a piece of outer cable ran from the cable stop on the DT to the mech itself. this was before the cable was routed under the BB and no section of outer was needed (late 70's or early 80's onwards, I think).

So I'll pass on this one and hope someone with more knowledge than me can give you a decent answer!

sorry!

much appreciated input Foz, thanks. I'm glad i'm not the only one confused by this set-up - agreed, I think it's early 70's and I have little knowledge of bikes from this era in all honesty. 85' is about as far back as I go.

hence posting this thread as a frame I cant use properly is something I want to avoid. Thanks again.

Just fit any normal front mech and run the cable under the BB shell and between the chainstays. It won't go anywhere it shouldn't - it can't! If you're REALLY nervous then cover it in a short length of outer cable - but this will attract muck and moisture.

My Merciers got that set up. It came with a Simplex front mech. If I get chance tomorrow I'll take some pictures of it as I've still got the cables and mech on the frame.

You could always drill a hole in the bottom bracket shell and rivet a cable guide on.

simplicity itself when you describe it like that, I like your forthright way of thinking. I wouldn't say i'm really worried just dont want to end up with something I cant get onto the road in the fashion I intend. Frame has never been built up, i'm concious that my knowledge of stuff from this era is limited, but also appreciate that it really cant be that difficult, which it why this frame appeals, could be a nice tidy bike with a bit of luck.

cheers