Metra will run special Saturday Bike trains on six Saturdays from September 9th thru October 14th on the Heritage Corridor, the normally weekday-only commuter line to Joliet. A bike train consists of a Metra train with two special cars with bike holders behind the engine.
All trains will make all regular intermediate stops. Full schedules and a map are available at URL below.

https://metra.com/sites/default/files/inline-files/SeatDrop8.5x11_H...

I live downtown. I enjoy the LFT, but use Metra and CTA to expand my recreational trips. Most of the time starting from downtown the Centennial / Michigan and Illinois Canal Trail involves miles of congested street riding or poor public transportation connections. At least one Saturday this fall I will be boarding the 10:30 Heritage Corridor bike train from Union Station to Willow Springs. I will bike the trail with a leisurely lunch side trip and return on a non-bike Metra from Joliet.

Boarding a Metra with a bike means you have to carry the bike up the train steps, something to plan on if you are thinking e-bike. I have not been on this trip for a few years, but last time this had abnormally rough tracks with lots of bangs, bumps, and jerks. Leave your bike helmet on if you walk to the onboard restroom.