Locating an original Raleigh Sports chaincase proved to be difficult and costly. I was able to find a repo version online at the Yellow Jersey.
I was skeptical about using a repo because of potential fitment problems. I will continue my quest of finding an original but for now I need to make this repo work. The original case still had the rear bracket and riveted on front bracket support behind the chainwheel. I removed the rivets from the front bracket.
I then tried both brackets on the repo. The back bracket aligned perfectly with the drillings in the repo. The front bracket was close but I had to enlarged the center hole, which is the hole the small bolt passes through into the chainstay braze-on for the chaincase.
I then mounted the front bolt behind the chainwheel, chainwheel, and chain to check for initial fit. Threading the chain through the chaincase is difficult.
I slowly turned the chainwheel checking for rubbing and interference with the case. The chainwheel was rubbing on the front bracket, the chain was also rubbing the front portion of the case. The rear of the case was interfering with the rear sprocket. I marked on the chaincase were I thought additional bending would be need to add clearance. I made some adjustments to the case.
|Extra filing need on the radius|
|I had to deepen and extend the relief for the seat stay|
|This is the back of the case, I removed the inside front bracket and deepen the relief from the inside to make more clearance for the bolt.|
I remounted the case and tried again, this time much of the initial rubbing had been eliminated, but there was still some chain rubbing. See separate Post on adjusting the chain line. I then installed the rear cover and "pie plate".
This is the finished product. I think the repo might work, but I have concerns that the "pie plate" might become a problem because its just a press fit into the chaincase and does not seem very secure. Only actual riding will determine this. I do think that once the bike is farther along and ready for its first ride I will fill the rear tube with "Slime" to discourage any flats. I do not want to experience removing the rear wheel and fixing a flat in the field with the enclosed chaincase.
Please share your thoughts and experiences.