Shimano 100gs

[alans27]

Ello all, I've just won myself an old raleigh on eBay. Not got it yet, just arranging a courier ATM. Anyway, this bike has a shimano 100 GS groupset which we all know is a budget groupset and chances are I'll have to change a few bits. My question is this... On the rear mech where it bolts to the frame there doesn't appear to be a bolt there. Just a smooth surface. Is this just a cap covering the bolt head up or does the 100gs rear mech fix to a frame in some crazy way? Cheers

 

[SeeingisBelievingGTMuseum]

The 100GS rear derailleur was available two ways in the old days. Either hanger mount or direct mount. From what you have explained it sounds as though any rear derailleur you use will need to be mounted to a hanger because it doesn't sound as though your frame has a rear dropout with a threaded hanger to direct accept a standard thread in rear derailleur.

Most of the bikes spec'd with 100GS back in the day tended to be base starter model bikes that were a mixture of hi-tensile steel with a chromoly seat tube.

 

[alans27]

Ah no it is a direct mount type. Not the hanger type, it's on a Raleigh Amazon and it's defo the direct to frame mount. Not hanger. Just that the bolt the holds it on appears to be hidden

 

[Chopper the ex Copper]

Is there a plastic cap that prises off to reveal the bolt, like the old Altus mechs?

 

[legrandefromage]

It might actually be a nut on the inside of the frame that bolts the mech to the frame rather than threaded into the frame.

The frame will still have threads for a standard mech

Its the really naff pressed steel mechs that have this bolt I'm thinking of.

70GS bolts to the frame not into the mech hanger:

Chopper is referring to old Huret mechs with a plastic cap on the bolt. Can't think of any Shimano mechs that covered stuff up.

See how this Simplex rear mech 'bolts' to the hanger and doesnt use the hanger threads? Same should go for your 100GS:

 

[alans27]

Ahh yes it's that top photo mate, the 100gs one I'm referring too. That's what's on this raleigh I'm getting. See what I mean, there's no Allen key bolt to undo there so was wondering if that's a cap you take off in there.

 

[legrandefromage]

no, its a bolt on the other side - read the text, dont just look at the pictures I spent ages googling for!

 

[alans27]

Re:

Ha ha fair enough sorry matey. Right then a bolt on the frame it is. Bit daft mind, I mean why didn't they just bolt the thing into the frame like god intended? Seem to be just making pointless changes for the sake of it.

 

[legrandefromage]

flaps

 

[legrandefromage]

Booomshankaaaaa!

Heres a pic or two:

plastic cover hides awful monkey metal