Kent to the Mill Creek Metroparks Bikeway - Access to Niles, Canfield, Washingtonville, Letonia and Lisbon
The map below shows two routes from Kent to the east side of the West Branch State Park (Michael Kirwan Reservoir) and Cable Line Rd (magenta vs gold markers). From Cable Line Rd, the best road connection to the north end of the bikeway in Niles is shown. Other routes are possible, but those roads are less ideal.
Both routes from Kent to Cable Line Rd avoid most traffic and are relatively flat over much of their distance. However, due to glacial end moraines in the Kent area and north of West Branch, some rollers will be encountered. The northern route takes you to the east side of Ravenna on the Portage Hike and Bike Trail, then through a very hilly 4.75-mile section on Newton Falls Rd. Going eastbound there are two large hills among a series of smaller climbs. The second one is around a third of a mile of 8-9% (see elevation profile below). Westbound is probably a bit more challenging. About a mile of travel on Rt 5 is required (a fast main road) unless you do a little exploring where the remains of an old railroad crossing for Newton Falls Rd exists on the south side of Rt 5. There is a narrow shoulder on 5, but the traffic is very fast (60-70 mph). The southern route encounters some hills in Kent, and on Tallmadge and Alliance Rds, but remains mostly on quiet back roads. None of these hills are as extreme as Newton Falls Rd.
Once you reach Niles and the Mill Creek Metroparks Bikeway, you can continue south until the trail ends south of Canfield. From there ( at West Western Reserve Rd), you can continue south on Washingtonville Rd (6.1 miles), which will connect to the Little Beaver Creek Greenway Trail. This trail ends near Rt 11 east of Lisbon. An easy road route from that location to the Ohio River does not currently exist.
The Mill Creek Metroparks Bikeway is essentially a southern extension of the Western Reserve Greenway. The WRG can be accessed via city streets through the northern part of Niles and Warren. The Connecting to the Western Reserve Greenway page shows a more direct route from Kent to the WRG via back roads. That is a better route for folks heading towards Lake Erie and beyond. Those really adverse to hills, but wanting to travel south to the MCMB can connect to the WRG and then head south, traversing city streets in Warren. That's a much longer route.
Hills you may want to avoid: Newton Falls Rd Elevation Profile from Garrett Rd (left side of graph) to Rt 5.