No double spring on the Gan Sport rear derailleur. I did modify it though. For riding the longer courses in Eroica and avoiding walking, I found that I need a low gear using a 27t rear and a 36t front. I can get this to work with a late version Super Record rear derailleur if the high gear cogs are 14t and 47t. This bike has a Gran Sport rear from the early 1950's, and will not handle this range of gear stock. I modified a SR pully cage to fit on the GS. I had to use a Record spring stop, and I had to modify the upper pivot limit stop. The derailleur angles forward instead of being almost vertical. I also included a pair of my modified Enduro pulleys. The result is it shifts all the gears nicely. The front derailleur is a Cyclo Benlux rod shifter. It was used, I made new parts to reduce all the slop. This works very well also. The stem is a period correct GB Kromo, it's excellent. Bars are aluminum GB. The seat post is period correct, an aluminum Titan. The pedals are period correct Holdworth Allez, very rare. They were hardly used. The clip headset is also a Holdworth Allez item, it came with the frame. The original bearing design, Chater Lea intigrated races, really doesn't work very well. I modifed the lugs to accecpt modern sealed drop in 1" bearings. I remade all the headset parts, they look just like the original but work much better. The crank arms are Chater Lea, with double chainrings made by me with Holdworth Allez design. The saddle is a 1950's B17 that has been modifed for use by a pro racer back in the day. The hubs are Airlite, made by me. The QR's are original Airlite period correct. Brakes are Ballila side pull, Holdworth used brakes from this Italian company starting before WWII. I made amost all the hardware for them. This frame was originally made for use with tubular wheels! I used a pair of 1950's Weinmann rims.Jim