i have old sugino cranks with a built in chainguard and a 52t chainring that is unremovable. i haven't been able to find anything online about these cranks and would love to know some history and if they're worth anything. hopefully, someone on this forum knows.

It seems strange that i would be unable to remove the chainring and chaingurad. the chainring bolt holes seems awfully small as well.

i have pictures of the crankset here.

thanks for your help,
bryan

Kinda looks like the crank I pulled off a 80's something Schwinn World Sport. I've still got the crank, it didn't appear to be made very well. Compared with the Sugino Idol crank I used to replace it, from a 80's something Maruishi.

You have a successor to Sugino's low-end Maxy line, which first appeared ca. 1972, with a permanently mounted 52T outer ring (boo, hiss), a swaged spider (boo, hiss), and a solid spindle which took nuts, rather than bolts, at each end (boo, hiss).

I suppose I am not a fan ...

thanks john,
you're right, im not so excited about these, but i wanted to find some info before selling them. you dont happen to know the model number do you? also, how much do you think these cranks would go for? obviously not for much based on your original reaction to them.

The crankset is similar to the Sugino Aero 5, but not identical. Based on the numbers on the back of the spider, I would assume it to be an Aero 7. The Aero 5 was found on 1980s, entry level models, so the Aero 7 should be on comparable models. There is little value in these cranks.

The integral chainguard and permanently attached large chainring are cost reduction designs. A separate chainguard would require an extra, very expensive mould. It is also less expensive to design the large chainring mounting pins into the spider and peen them with one hit of a press than it is to buy five bolt sets and assemble them by hand. Since the large chainring is permanently attached, steel is used because it wears better and is less costly.

wow, thanks for the great info!