Hi - I have a ~3 year old Rad Wagon 4 - it's a GREAT bike - but one recent issue is the pedal/gear slips when I'm in the top gear (7) - this doesn't happen in any of the lower gears (1-6). I recently had the chain replaced hoping this would fix the issue, but alas it still slips. Any advice or guidance on next steps? Thanks!
Quote from: ztglare on November 02, 2023, 03:34:53 PM
Hi - I have a ~3 year old Rad Wagon 4 - it's a GREAT bike - but one recent issue is the pedal/gear slips when I'm in the top gear (7) - this doesn't happen in any of the lower gears (1-6). I recently had the chain replaced hoping this would fix the issue, but alas it still slips. Any advice or guidance on next steps? Thanks!
I owned a derailleur bike just long enough to know it was important to turn it upside down to be sure the derailleur was adjusted to line up the chain just right in all gears, and that everything was clean and lubed. I think it's something else, though.
I once had a bike that started slipping in high. I'd worn down the rear sprocket teeth climbing a 10% grade a quarter mile long in high gear. (It didn't happen to normal people because normal people shifted to low.) If that's the cause of your problem, it makes sense that it would be the sprocket with the fewest teeth (high gear). It may take a careful inspection to see that teeth are misshapen.
ztglare, I don't have any advice but during the first season (2021) on my RW4 the chain came off the front sprocket two or three times. It only happened when I was in 7th gear. I have no idea why but it hasn't happened for the last two seasons although I suspect it is because the chain is soooo long and the derailleur may not be able to keep it tight enough all the time.
I'm going to keep an eye on this thread as someone with more knowledge may have a solution for you.
Sounds to me the most likely suspect would be the maladjustment of one of the derailleur limit screws, specifically the higher limit screw.
(https://support.radpowerbikes.com/@api/deki/files/1659/Derailleur_limit_screws_labeled.jpg?revision=2)
Try turning it clockwise. Prop the rear wheel up or turn the bike upside down (with suitable padding to avoid marking up the seat and damaging the handlebar furniture), and crank the pedals manually while operating the shifter to test the adjustment.
:-[ Oops. I just read the first post more carefully, and finally noticed that it's popping off the front sprocket.
Maybe it's the chain tensioner.
I don't have one in front of me at the moment, but in this image note the helical spring around the bolt that passes through the chainstay of the frame:
(https://files.mtstatic.com/site_14425/1671/0?Expires=1702894255&Signature=pEMUINahVbjx3j1f22~b92KetQ6-3gTRNly0z6quJRh704A-iwbTOSMbLhV8vgm6s6pUPzkpacBRBxCPalGsH02KcmAs2DzySnNy3oOyCQr11MDNcoil2pkdGzPM0ToBKNAIthNGred3tAmFAHLQcj8M6Ql8BQ9F65ragu6jJCk_&Key-Pair-Id=APKAJ5Y6AV4GI7A555NA)
See if one end of the spring or the other has a hook or a bend on it that may have slipped out of place, resulting in less torque.
:-[ :-[ Oops again. I just went and looked at the derailleurs on out RadMini ST2 and RadExpand 5, both with different Microshift derailleurs, and they look nothing like that diagram, *facepalm* which appears to be for a single-speed model, so it's not an actual derailleur. The spring (on mine) is concealed inside a black ... thing. But it does the same job.
[later]
Ah. Maybe it looks more like this drawing for a RadRunner.
(https://files.mtstatic.com/site_14425/1560/0?Expires=1702799699&Signature=tO-VMUx9a-8KDFCKPx4pFKAw2AE23xbvyFtgmKuIbNHjeZU9Y71~z9m~Gbkzq7N7Oo10BUIfNV9XUlrWrVIfaR74FePRwftPpxkn5R8Q91TCBh93BA0MvTvUuit743W-eFBUKmhV2qL0fS9-5nKMb4izaGbbfhkNXkSfnW6kxwY_&Key-Pair-Id=APKAJ5Y6AV4GI7A555NA)
The big orange arrow is pointing right at where the spring should be, that the two idler gears pivot around.
I found those on the RAD page https://support.radpowerbikes.com/Maintenance_and_troubleshooting/Shifting_and_drivetrain . Since they give a procedure for replacing them, presumably you can buy the replacement parts. (If that is problem to begin with.)
Another thought - do both of the idler wheels on the chain tensioner appear to be intact?