Broken Neos...
 

I was warned.

Shortly after buying my 2007 Dahon Boardwalk last year I swapped the original 7-speed rear gears for a wider spread of 11-32 to allow for faster cruising and better climbing here in Colorado. It worked great...except...

...in the new 32 tooth 1st gear the Neos derailleur was extended completely forward and the chain "chattered" through the jockey wheels when back pedaling. Forward pedaling in first felt and sounded fine, if maybe a little "stiff".

Techs at two shops said the rear derailleur would break under these conditions. One gave it 4 months if ridden daily. I'm a daily commuter, but I don't ride it daily, but maybe about a third of the time. For the last few rides the rear derailleur has been making bad noises under heavy load in any gear.

So yesterday I inspected it and discovered the lower jockey wheel was missing some teeth and the flange by the bearing race was chipped enough to allow the wheel to deflect and dislodge the chain onto a ridge on the cage. Also, the shifter cable has sawed a slot in the barrel of the hollow adjustment bolt that sits in the final ferrule, due the the exagerated angle demanded by the wider gears.

I like the gears so I am getting a Neos adapter and will then put an appropriate rear derailleur on it. I saw no-name brand Neos adapters for $19.99 on Ali Express, but I have had some quality issues with some (but not all) of the components I have bought through them. Instead I bought the adapter for $30 from Tern, which puts its logo right on the part, so I hope this means they are confident in it. The local bike co-op has scads of used rear derailleurs in all sorts of sizes and shapes averaging $15, and in all sorts of conditions including like-new.

I guess the advantage of the Neos compact derailleur is that it tucks under the chain stay and out of harms way when the bike is folded and possibly put on its side because leaning or sitting a bike, folded or unfolded on the drive side can bend the derailleur hanger, as I have done on a couple of my non-folding bikes over the years.

However, I look forward to a more conventional derailleur if it means smoother operation with the wide range of gears I want and need in hilly Colorado Springs.

(Here's the bike in first gear with the Neos)

https://cimg0.ibsrv.net/gimg/bikefor...0eef32fb0d.jpg

I am not sure I understand the cog 11 being earlier referred to as first gear, early in the post, and the derailleur being then extended completely forward. One would expect the derailleur then being completely tucked in, with one jockey wheel getting close to the cog and the other busy absorbing the chain slack. The photo shows cog 33 in operation, with reference again to the first gear, and then the derailleur extending the tensioner arm forward.

In any case, it sounds like the capacity of the derailleur got exceeded, and that became the source of the problem, and not the derailleur being of unconventional type. Is that right?

Lol, no idea why my brain keeps thinking that was "broken nose" even after looking three times.

Yes, you are correct. I exceeded the range of the derailleur. And I have fixed my post to refer to 1st gear as the 32-tooth ring.

Fingers crossed that the "Tern" derailleur hanger fits.

Derailleur hangers are far from universal.

https://cimg5.ibsrv.net/gimg/bikefor...b574a1f4a1.jpg

The one I know works for Dahon steel frames (like the Boardwalk) is the LitePro KC072:

https://cimg1.ibsrv.net/gimg/bikefor...bfa4274d65.png

Oh, I'm so interested in this. My speed P8 needs a derailleur hanger. The Neos one died, and I wanted to do a 3-speed conversion (8 speed is DOA now that Thor has retired, even though I keep in contact with him), but it would still need a chain tensioner. I could use the tensioner if this works for you.

Earlier today I received an email from Tern saying the order was canceled due to product availability. So I found a 'comparable' product on Ali Express for $13.95 with free shipping. It estimates it will be here in 6 weeks. I'm hoping it is of decent quality.