Does anyone have a good line on sub 100mm dropper posts?

I can locate a few high end ones meant for gravel bikes but haven’t found anything sub 100mm on AliExpress yet.

Anyone built one or have good ideas for sourcing frames, wheels and forks?

Couldn't find much information around here so figured a specific thread would be applicable.

Here's some frames/wheels I've come across recently;

DIY Carbon Bikes has 24/26" carbon rims, Hardtails and Full Suspension carbon frames;
https://www.diycarbonbikes.com/collections/junior-kids-mtb-parts


BXT on AliExpress has a 24" carbon hardtail;
https://www.aliexpress.us/item/3256805599651247.html


There are a few cranksets available on AliExpress,

CRUZbike makes a crankset that looks promising, 127-140-150mm lengths and 25t-38t GXP chainring options to choose from.
https://www.aliexpress.us/item/3256805875386865.html

Interesting. What derailleur/shifter combo are you using? I've been riding exactly the same cassette but with Sroad branding since 2022 and both of my SLX and Deore derailleurs paired with GX shifter seems to "overshoot" on lowest gears. Whis causes chain rub on second gear and exceptionally bad downshifting from first gear. The derailleur hanger was trued and I also tried 2 new hangers with the same result.

I'm using the WheelTop EDS mtb system.

Do you have a link to the model you picked ?

Looks like the ones I ordered are longer available.  Shame, I really liked the zippers on the leg cuffs and just above the front chamois. (why isn't that a bigger thing?)
http://www.aliexpress.us/item/3256804849170372.html

I wound up with some thermal bibs from YKYW that are nice, but not as comfy as my DeMarchi summer bibs.  The smallest size is still a tiny bit too big in the chamois/waist area.
http://www.aliexpress.us/item/3256803116373954.html

Spotted this new frameset on their social media,  no more information yet.









https://www.facebook.com/Seraphfactory/

I had a KS dropper on my stumpy, bought the bike in 2018 it was on it.  Was still on it and working fine with zero maintenance when I sold the bike 2 months ago.

Figured it must be pretty good, so I got another one off AliExpress for my current MTB.

I worked in a motocross suspension shop for years so this is my take.

Suspension Servicing Schedules are wildly variable.  How many hours have been ridden?  What kind of conditions?  How fast or big is the person riding? etc etc.   And just like any mechanical thing,  Cheap oil and grease that is clean is better than expensive oil/grease that is dirty from 100 hours of use.

Anecdotal information; When I worked in the shop, I played with pure nitrogen vs pumping up suspension bladders with "regular" air on my personal bikes (a fun luxury of being "in the biz", I could fiddle with things A LOT more than the average person, for free!)  I couldn't tell a difference on the shock dynos or in regular riding.  Maybe a pro could? Maybe with an MTB being so light, and completely dependent on the air spring it would be noticeable.

"Regular" air is about 78% nitrogen so its theoretically 22% less heat stabile than nitrogen I guess?  I would assume the difference would be most noticeable once the suspension starts to get *HOT* and the normal air is expanding more than nitrogen would.  (Dirtbike suspension, especially the shock, gets REALLY HOT compared to *most* mtb stuff.   

I never tested air vs nitrogen for long term for seal life because suspension service life is wildly variable and the outside world we use our bicycles and motorcycles isn't a lab environment.