Derailleur suggestion and tale of woe

[simonov]

Almost two years ago my TSDZ2 converted e-bike was stolen and a couple months later I replaced it with a Giant Cypress 3, which I have been using ever since to commute to and from work.

I love my Cypress 3, mostly because it fits me so well and with me that’s the main thing; but it is a low end bike and one of the places where Giant saved money was with the derailleur, apparently. The brand of the derailleur and shifter is Advent, which I have never heard of, so I don’t know whether it is a down-market brand or Giant’s in-house brand. In any case, within a year I began having problems finding a particular gear when shifting up. I don’t know whether that’s the manufacturer or simply the modern age when nothing is expected to work correctly or to last (my previous bike went nearly 20 years without a problem).

So I was about to fix this issue when I decided to convert the Cypress after all. A Bafang BBSHD motor and one of the better Chinese batteries have been sitting in a box on a shelf in my workshop for about a year or so. This will be my third conversion. But if the Advent system is sub-par, it will be destroyed by all those Bafang watts.

So I decided to replace my derailleur, and came here looking for advice on what to get, how to do the work (never done this before, but I am a tinkerer), and whether I should replace the cassette while I’m at it. I like the little paddle shifters I have now, but I liked even better the grip shifter my 2004 Giant Sedona DX had.

 

[neptronix]

Are any of the drivetrain parts shimano compatible? ( probably the casette will have a marking on it )
If so.. a shimano derailleur would be a fine replacement.

 

[Chalo]

Microshift Advent 9 is its own compatibility standard, with some intercompatibility among other Microshift Advent and Acolyte parts, but not with other brands. It works excellently well, so probably you have an issue with derailleur hanger alignment, bent or worn sprockets, damaged or draggy cable housing, or something related that isn't the derailleur (unless the derailleur itself is bent).

If you want to keep 9 speed but switch away from Microshift, Sunrace makes a derailleur called M9 that works with any 9 speed Shimano pattern shifter and will cooperate with sprockets up to 51 teeth.

 

[simonov]

Thank you for your reply. So are you suggesting that if I repair the Advent (probably an adjustment somewhere), it should be a satisfactory set-up for a BBSHD conversion? Obviously that would be the preferred approach.

 

[neptronix]

I mean if you haven't adjusted it yet, you should.

Derailer Adjustment

 

[simonov]

I understand. But the fact it started giving me problems after less than a year of riding made me wonder whether it was a quality part in the first place. Chalo suggests it is. It's just 2025, right? You can't expect things to last 20 years like they used to.

I'll see how I can fix this thing.

 

[neptronix]

Derailleurs can detune themselves over time, or if you drop the bike, they can get bent, etc.
Things like wheel alignment can affect derailleurs too.

I wouldn't replace it without trying an adjustment first.

 

[Chalo]

Thank you for your reply. So are you suggesting that if I repair the Advent (probably an adjustment somewhere), it should be a satisfactory set-up for a BBSHD conversion? Obviously that would be the preferred approach.

Advent 9 is as good a choice for wide range "one-by" gearing with BBSHD as any 9 speed system. My experience suggests that you'll get 7 good gear ratios and two rough noisy ones at the low end. If starting from a clean slate, I'd use Acolyte 8 for a little more durability and fault tolerance than a 9, 10, or more speed system. But Advent 9 is fine.

 

[amberwolf]

Derailleurs can detune themselves over time, or if you drop the bike, they can get bent, etc.
Things like wheel alignment can affect derailleurs too.

And if there are plastic parts (bushings, etc) involved in any of the moving bits besides the jockey wheels, including inside the shifter, they wear over time, and deform from temperature chagnes and pressure, which also affects alignments.

 

[offGridDownUnder]

and came here looking for advice on what to get

Check on how much your chain has worn. If you don't have a wear checking tool, get one.

It may be that your chain went beyond the safe limit and began machining your sprockets - this will affect shifting and replacing the sprockets and chain will cost more than replacing the chain. The effect will be more pronounced, if anything, with a powered crank set.

 

[2old]

Chalo nailed it, as I've had excellent service from Microshift. Every time there's been a problem with shifting on my bike or my wife's, it's been rectified by straightening (or once replacing) the hanger.