I picked this bike up off cl last year for $35. It was pretty rough, but the 25" frame size and length was perfect for me. I’ve been wanting to make my own restomod bike for some time, and this seemed like a good candidate. Never been able to figure out the year and model, but I suspect it’s a 1975 model 731 or 732. On the bottom of the frame it’s stamped “31 400”

Looks like a 1974 Takara 732.

How can you tell?

T-Mar is the god of bicycle recognition.

Forgive my blasphemous question, just want to be enlightened

Do the numbers mean anything?

Who's the man with the spooky bike-dar?
Can ID any bike from afar?
(That is, if it's classic
[but not quite Jurassic])
It's none other than our own [MENTION=20650]T-Mar[/MENTION].

Takara made it's debut for the 1974 model year, so it's no older than that. Most of the early Takara were manufactured by Kuwahara. The dropout style and pillbox cable stops are consistent with the boom era Kuwahara product. The exact composition of the Kuwahara serial number format during this period is unknown but it appears that the first number may represent the year. If so, it would be a 1974 model manufactured in late 1973. For further confirmation, please report the date codes on the crankarms, which appear to be OEM.

Thanks for sharing the wisdom! So the crank arms have this engraved... “FORGED 165 49.6” that last number might be 49.5, it has a layer of paint that makes it difficult to read.

Also the fact that the crank being a nicer three bolt helps date it since by the mid 70's they went to 5 bolts.

The crankars date to June of Showa year 49, which is 1974. So, it could still be a 1974 model but if those crankarms were in inventory for a few months at either Sugino or Kuwahara, it could be a 1975 model. It does seem strange that the crankarms appear to post date the frame by at least 6 months.

Here’s the bike mostly finished...
1974-75 Takara Model 732 restomod

unfortunately the original crank was bent to the point that it was too much trouble to keep on the bike.

The serial number is from manufacturer Kuwahara. This format was used before 1975. Kuwahara started to include year and month information with the serial number starting in late 1974.