I have just changed my chain and noticed one strange thing. New chain is 6.6mm in width, but the old one is 6.1mm. Old one is SRAM PC89R HollowPin and the new one is PC89R (non HP model). Is it possible that chain shrinked 0.5mm due to wear in 4700km that it has done? It sounds too much to me. Also note thet it is not near 1/16" mark. I have mesured it with that odd tool and it said 1/2 of max allowed elongation. New one doesn't skip in any gear. The reson I noticed it is that chain rubs on big chainring while in 39/12 and 39/13. With the old one it did that only at 39/12 and it was a minor issue. Now it grabs alot. As I would really like to have those two gears available I thought I could do something about it. In my toolbox I have found a piece of shim that plummers use (dont know exact eng. word for it) and it fits great. It is about 1-2mm in width. Now everything works great but I'm afraid it might damage my frame because I have basicly extended the axle. Is that 1-2 mm extra dangerous? I really wouldn't like to ruin my Alu DeRosa 🙂) I saw some guys with MTB hubs (5mm longer axle) on their road bike but I'm still worried....I guess I wouldn't be with steel frame 🙂))
I have just changed my chain and noticed one strange thing. New chain is 6.6mm in width, but the old one is 6.1mm. Old one is SRAM PC89R HollowPin and the new one is PC89R (non HP model). Is it possible that chain shrinked 0.5mm due to wear in 4700km that it has done? It sounds too much to me. Also note thet it is not near 1/16" mark. I have mesured it with that odd tool and it said 1/2 of max allowed elongation. New one doesn't skip in any gear. The reson I noticed it is that chain rubs on big chainring while in 39/12 and 39/13. With the old one it did that only at 39/12 and it was a minor issue. Now it grabs alot. As I would really like to have those two gears available I thought I could do something about it. In my toolbox I have found a piece of shim that plummers use (dont know exact eng. word for it) and it fits great. It is about 1-2mm in width. Now everything works great but I'm afraid it might damage my frame because I have basicly extended the axle. Is that 1-2 mm extra dangerous? I really wouldn't like to ruin my Alu DeRosa 🙂) I saw some guys with MTB hubs (5mm longer axle) on their road bike but I'm still worried....I guess I wouldn't be with steel frame 🙂))
I forgot to say... Imprtant parts are: Shimano 105 39/53 crankset (FC-5500) Shimano Ultegra BB 109.5mm (BB-6500) Shimano 105 12-25 cassete (CS-5500) SRAM PC89R chain Mavic Cosmos '03 rear wheel
