That last hill/climb--km 115 to 130--I think most groups would skip that. Instead, at 113.7 or 114.2 turn right to go into Fukumitsu and then take route 27 over to 金大 (kanzawa uni). (Some smaller turnoffs on route 27 allow you to bypass tunnels.)
An alternate/better way into town and the station-- at 134.2 bear left and take the long/fast downhill to route 22. Go left on that, very quickly thru a long tunnel, but... While route 22 is big/busy, a bypass, but you can stay on the wide sidewalk there, and it's only a short distance. Actually there's an upper (shorter) and lower (longer) tunnels there, and the upper may be better, since the goal with going this way is to get to, and then follow into town along Saigawa.
With the upper tunnel, you'd turn right before the river, and follow it down along that side. With the lower tunnel, you 'get off' at the Yamada denki, and then head into town, but with this latter, at the park (okuwa guru guru koen) cross back over to the north(ish) side of the river since the road along that side is a little better for biking. Getting thru the tunnels on 22 right at this point is how I commuted for years and years... (I'll try to PM you some garmin links, but quick/immediate, here's yesterday--by that park both ways--shows the easy-to-follow routing from there down the river if you zoom in. Go full screen and you'll see route 22 just up river.)
The tactic from there is to follow/along down the river till you come to where the train tracks cross the river (actually to the road/bridge for cars just before that, route 146) then it's a relatively short jag over to the station (big busy roads, but there is a possible quiet way). To visit/see the non-eki part of downtown, route 157 (which you'd cross going this way) is ground zero for that (Katamachi, main food entertainment area).
edit: coming in that way, right about where you'd hit route 22, there's a bike shop right there (tho expensive, and a little snooty--not really service-oriented).