Numerozero

https://www.pinkbike.com/news/micros...es-and-up.html

The goal for Super Short was simple: make a real, fully featured mountain bike group for smaller people. It had to be easy to understand and operate, while providing better shifting response and durability than the stuff that normally comes on 20" bikes.

So, we took the DNA of our Advent 1x9 and Acolyte 1x8 groups and rengineered things to be smaller. The result is a drivetrain that delivers big performance for little proportions.

The shifting throw is also shorter than our competitors by over 40%. That doesn’t just help people with small hands – it helps anyone who wants a quicker, easier shift. Even the index-thumb style shifter configuration is a plus: it allows the levers to get closer to the bar and also makes it easier to remember which lever makes it harder and which lever makes it easier.

The rear derailleur is made to be as short as possible. The 100mm cage is about 50mm shorter than standard ADVENT, meaning it will fit on a 20" wheel with plenty of ground clearance for irresponsible cornering.

To play nicely with 20" wheels, we opted for a cassette range of 11-38T. Smaller wheels make gears feel easier; a 20" wheel with a 38T cog feels the same as a 27.5" wheel with a 52T cog. That gives the rider plenty of range to take on anything the rest of the family can climb.

Visit https://www.microshift.com/news/intr...g-super-short/ for more details.

Reddleman

I could’ve sworn I saw a dead link referring to 20” wheels on the Microshift website the other month but it disappeared when I tried finding it again more recently! Glad to see I wasn’t hallucinating.

If you can live with the 11-38T range and you prefer the clearance the super short derailleur has, this is really ideal for a folding bike. That it’s compatible with their entire Advent range of shifters - bar ends, thumbies, trigger shifters and brifters - is even better.

Now, what I could do with is a short derailleur to fill the gap between the 38T max SS and the 46T max M option for optimal range and increased clearance…

pinholecam

Would have been best if it catered a 10-35T or 10-34T with a 10-11-12 teeth for the highest 3 gears.
That will take care of the riders that want to ride faster.
It will need a hub to be compatible to the smaller 10T sprocket, but these are more common from Shimano and SRAM nowadays


That said, thumbs up to Microshift for this and I might just get one for my daughter's folding bike.

50PlusCycling

Looks nice and compact. I’m running an XTR 10 speed driveline with a GS derailleur on 20” wheels, and so far haven’t had any real-world ground clearance issues. The same setup with 18” wheels didn’t work so well, the derailleur was constantly getting bashed. I love the XTR kit, it works very well, on the other hand, the entire Microshift group set costs less than an XTR derailleur.

Jipe

I fully agree with this: starting at 10t or even 9t would have been better for small wheel bikes and give a wider gear inch range.

I have a Shimano Ultegra RD-R6800GS and RD-R-8000GS medium cage on my two Birdy with 50x355 wheels and never had any ground clearance issue. The RD-R8000 goes till 34t but according to 3T website accept 36t (I use 9-32t and 9-34t cassettes with them).

tcs

The Microshift Acolyte short-cage wide-range derailleur certainly looks promising. I'm wondering about combining it with SunRace neo-Capreo hubs and cassettes:

https://www.sunrace.com/en/products/small-wheel




BTW: drivetrain efficiency - but curiously, only with hub gears - comes up from time to time. Efficiency drops with relatively smaller derailleur cogs, too, due to increased chain speed x increased articulation angle. This has been documented in numerous tests; here's one:

https://www.cyclingabout.com/drivetr...between-1x-2x/

pinholecam

I have had no issues with 18" and Shimano Saint (DH groupset). It has a short cage.
Similar experience with the XTR w/ 406 and 451 20" wheels, no issues.

Jipe

The answer is in your link: yes 1x is less efficient than 2x but the difference is small 0.5-0.6% while with a big gearbox like the Pinion the loss of efficiency is much bigger 2.6-2.9%. Note the godd performances of the Rohloff: 0.7-0.9% very close to the 1x.

The 2x is also more efficient only if the user uses optimally its 2 chainrings to reduce chain flex, i.e. if he doesn't use the biggest cogs on the big chainring and doesn't use the smallest cogs with the small chainring.

tcs

??? Not sure how 1x vs 2x even enters into the relatively poor efficiency of the small tooth number cogs used to get higher gears on derailleur equipped small wheel bikes, but, you know, whatever.

Jipe

Its also in the report:
In The Highest Gear:
The 10t smallest cog is 0.3% slower than the usual 11t smallest cog.

joey buzzard

Agreed.

​​​​​The problem isn't generally a lack of low gears on 20" or 16" bikes but rather gaining more gear inches. If I could run s 9t or 10t on my cassette as my highest gears on my 20" bike I could use a 53 or 54 up front and a 36t would be perfectly great for tackling any mountain roads. In fact I'm currently riding 53t. 11t-36t and I'm climbing the steepest roads in Spain's highest mountains every day with ease. Never understood people wanting a front derailleur on this type of bike. Microshift would do well to make something like micro-spline in 9 or 10 speed for small wheel bikes imo.

CliffordK

Capreo seems to be dying quickly.

The derailleurs made for 11T are usually just fine with 9T or 10T.

While this setup may be picked up by folding bike riders, the ad appears to indicate kid's bikes. And, a kid riding 20" wheels likely doesn't need a 9T cassette (although there is a 9T BMX sprocket).

So far my only issue with size and rear derailleurs is a 20x4.25 small FAT wheel that the derailleur overlaps with the rim slightly, and thus risks getting caught on the rim.

My Bike Friday with 451 wheels seems to be fine with older generation long cage Ultegra.

I'm not sure 1x gearing will work for my needs, although 1x works fine with a Dual Drive rear hub (which is also dying out).

tcs

The Capreo-pattern is alive and well @ SunRace (post 6 upthread) and Chosen.

Hybrid internal gear hub/derailleur gearing is alive and well at Sturmey-Archer (who's offered it since the early 1930s).

Jipe

Shimano Capreo is dead, its almost impossible to find spare parts anymore.

Indeed, the Sunrace solution for small wheels is derived from Capreo but is not Capreo, its better with 10s and 11s cassettes. The 9-36 11s cassette is really nicely spaced and provide a wide range of gear inches (spacing is better than the one of the Ethirteen 9-34 cassette with a slightly wider overal gear inch)..

The problem I see now is that the parts seems also difficult to find, the few online shops I knew who were selling the hub and the cassettes do not have them anymore ???

And its fully proprietary to Sunrace, if Sunrace stop producing the cassettes and/or hub, it won't be possible to replace it by anything from another manufacturer.

2_i 

Interestingly, 53-36T on 20" gives about the same lowest gear, 1.08m of development, as I have on my Brompton, 1.03m, albeit with the hub getting involved. In my case, that lowest gear is needed for the steepest inclines in Rwanda. The gear is hardly usable, though, in a continuous manner, rather just in surges like within a turn. For a continuous use, some sort of ratchet mechanism would be needed, to prevent the bike from rolling back when the torque from feet is reduced within the turn of the pedals.

Wiel

Years ago I made an Excel-file for calculating the development of all kinds of BB-gearboxes , deraileur combinations and hub gears.
It is on the downloadpage of my website.
Gearchart metric

Greetz, Wiel

jfouellette

Hi, anybody has a review or tested this drivetrain?

Reddleman

I’ve had Microshift Advent with the medium derailleur installed on two Terns with 406 wheels for a year or two now, using both bar end and rapid fire style shifters. The installation was straightforward and the documentation and videos are pretty good. Shifting feels clean and it keeps its indexing well. Once installed it hasn’t needed any further attention. The kit itself feels quite sturdy and tough. Would definitely recommend it for a commuter, touring or general bike about town.

tcs

Microshift Super Short company video:

vaultbrad

I’ve now installed two Super Short groups on bikes for two of my kids. The quality of the parts is “fine”. As good as I would expect for the price, and more than good enough for 8sp and kids’ bikes.

Both rear wheels have freewheels, but since spacing is the same for 6,7,8 all works swimmingly, just one or two clicks less.

The clutch is not as powerful as on a nicer MTB derailleur, but again, more than good enough for my kids’ bikes and we haven’t had any dropped chains, despite ramps in the street and trips to the skatepark.

Shifting is easy and the shifter sits closer to the bars to accommodate small hands better, but my monkey hands have no trouble hitting the shifter paddles.

Having some experience with this stuff now, I’m very much tempted to put the 9sp Super Short group on my Bike Friday Pocket Llama. I’d up the chainring, just a bit, and rebuild the wheel without the SRAM Dual Drive, just to simplify the drive train.

badspeling

I'm now using Advent Super Short (9-speed) on a 20" mini velo, with the "Trail Trigger Pro" shifter instead of the short reach shifter. Installation was straightforward, it comes with a plastic doodad to help adjust the b-gap.

Functionally, it seems fine. The chain marks that I used to see on the chainstay protector are gone. Shimano shifts smoother, I think, but there have not been any reliability issues so far. My only wish is that the 11-38t cassette also came in silver.