RadCity 5+  For me, front wheel wobble was greatly reduced by installing 2.3" knobbies.  Maybe the wider tire added enough friction to act as a steering stabilizer.  Even without a pannier load the bike now feels steadier.   Just speculation here; could there be an inherent geometry issue with this model bike??  In general, installing 2.3" knobbies sure enhanced handling on dirt & gravel pathways encountered here in the Phoenix, AZ area.   (no I didn't want a RadRover with 4" fat tires)

Runningliner13, I like it!  What is the white material?  It formed nicely around the throttle.

This might work for someone.  Materials: 1" x 1" aluminum angle 1" wide, 2 quality plastic zips.  1) drill and file two rectangular holes for the zips. 2) carefully curve one side of the aluminum to match the shape of the twist throttle. 3) Attach zips as shown, position aluminum tab where it feels right before final tightening of the zips. 4) run some CA glue between the zips and aluminum to prevent the new throttle from twisting sideways.  There is NO gluing to the original throttle.   I've enjoyed this thumb throttle mod for 400 miles now without issue!

I installed Continental eRuban Plus tires, from REI.  You'll have to decide if they are appropriate for your bike.  I've over 100 miles on them and I'm very happy with them.  As per my posting, mounting these tires require clearance modifications.  I've attached 3 pictures.  One shows the Rad multi-terrain tire on the previous RadCity. One shows my eRuban.  Those outermost knobs cause the clearance issue.  The last pic shows the primary clearance modification I did.  I used a cut-off grinding disk to cut the fender bracket, then spliced-in an annealed brass tube for 3 inches of width.  Note the bends along the length of the wire to bring the attachment ends back in, so there is no stress at the splice.  You can solder or loctite the splice.  Finding a tire without those large outside knobs would simplify your tire swap!  If you have more specific questions please click the "Personal Message" icon below my name.   Happy Trails!

The previous version of RadCity came with 2.30" "multi-terrain" tires.  The center knobs on my eRubans are not much larger than the knobs on those tires.  They are closely spaced so the tire is quiet and smooth running.  The outer two rings of knobs are progressively larger, giving much better grip in soft conditions, especially when cornering.  There has to be some loss of battery range, but I think that is irrelevant as my rides are usually 24-40 miles.  Still plenty of reserve.

My experience:
For my riding on the Phoenix East Valley pathways and roads, the RadCity 5Plus standard 2.0" smooth tread tires, are inadequate.  The 2.30" knobbies I installed (58-584) made a great  improvement in handling and tracking.  Per Rad Customer Service, 2.30" is the largest tire that can be mounted on the rims.  If you're considering knobby tires, beware of tires that have large knobs on the outer edges (like eRubans).  These cornering knobs interfere with the fenders and fender support brackets.  With modifications though, such tires can be made to work.  Hope someone finds this knowledge useful.  ((No, I didn't want a fat-tire bike))

Another possibility: check the accuracy of your tire pressure gauge to ensure that your tire is not getting overinflated, causing a failure.

When riding on a dusty dirt pathway, my RadCity 5+ rear brake does start squealing.  My solution: at home, mark the top of each pad, remove the cotter-pin, pull the pad & spring/bracket assembly, remove each pad, brush off loose dust, place a sheet of 320-400 grit emery paper on a flat surface, and sand off the glazing.  If the pad surface was not glazed (shiny), sand maybe 4-6 strokes, re-assemble with the pads on the same side as they came off of.  Test ride.  Hope this works for you.