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07-10-06, 01:29 PM
My wife wanted me to turn her old motobecane mixte into a 5 speed, which I did, but because of the arrangement of the crankset I can't use just the smaller front chainring.
It's a Solida cottered steel crankset, 3 bolt type, with a 52 large and a 40 small. The large bolts to the spider, the small bolts to the large. The spider has threaded holes and has uneven, raised lips around the holes. The large ring has unthreaded holes that fit over the raised part of the spider, so bolts screw into the spider holding the large ring in place. The small ring has threaded holes and it's similar to the spider in that a bolt goes through the large ring (and a spacer) and screws into the small ring.
Now, I won't go into minute detail of why the bolts as they are won't work to just let me screw the small ring onto the spider, just trust me that there is no combination of the extant hardware to get the small ring onto the spider in any satisfactory way. What I need are new bolts.
I went to the hardware store and the closest thing they had was metric 7 bolts. These actually do not have quite the same thread and apart from that, they were too long. Was there ever some kind of weird old standard for bolts like this, or were they different from manufacturer to manufacturer? If there was, is there any resource for this kind of stuff? I've checked ebay, loose screws, harris, and I suspect there's just nothing out there, but any help would be appreciated.
It's a Solida cottered steel crankset, 3 bolt type, with a 52 large and a 40 small. The large bolts to the spider, the small bolts to the large. The spider has threaded holes and has uneven, raised lips around the holes. The large ring has unthreaded holes that fit over the raised part of the spider, so bolts screw into the spider holding the large ring in place. The small ring has threaded holes and it's similar to the spider in that a bolt goes through the large ring (and a spacer) and screws into the small ring.
Now, I won't go into minute detail of why the bolts as they are won't work to just let me screw the small ring onto the spider, just trust me that there is no combination of the extant hardware to get the small ring onto the spider in any satisfactory way. What I need are new bolts.
I went to the hardware store and the closest thing they had was metric 7 bolts. These actually do not have quite the same thread and apart from that, they were too long. Was there ever some kind of weird old standard for bolts like this, or were they different from manufacturer to manufacturer? If there was, is there any resource for this kind of stuff? I've checked ebay, loose screws, harris, and I suspect there's just nothing out there, but any help would be appreciated.