SunRace's New 1X Drivetrain is for the Groms - Taipei Cycle Show 2018

Nov 3, 2018
by Mike Levy  
Taipei Cycle Show


If you saw my '7 Little Bikes That Make Me Want to be a Kid Again' piece, you already know that youngsters can get their hands on way neater stuff than previous generations ever could have. There are more and more solid options when it comes to pint-sized mountain bikes, too, with brands like Spawn, Rocky Mountain, and others putting out some proper machines made for some proper riding. Some even have decent suspension forks, shocks, and disc brakes, but our little buddies are often left using a less than ideal drivetrain. Either they get an expensive custom setup, a hack job of parts intended for adults, or a super budget crankset with (gasp) multiple chainrings. At this point I can barely remember how to use a front derailleur, so I don't know how anyone could expect Fortnite-addled tweens to avoid cross-chaining.

A decent single ring drivetrain simply makes the riding experience better, especially if you're just starting out in this game, but a complete kid's drivetrain just isn't a thing. Wasn't a thing.

SunRace's new M9 Juvenile series is a complete 1 x 9 groupset designed for kids and that can be had with an 11-50, 11-46, or 11-40 cassette. Cranks will come in 140mm or 152mm lengths, with shorter options possibly in the cards down the road, and the 287-gram rear derailleur even has a clutch to keep the chain where it's supposed to be.

Not surprisingly, SunRace has original equipment in mind with the M9 Juvenile group, but they haven't ruled out aftermarket sales, either. No word on pricing, but we hope that this will help get decent 1x drivetrains onto more affordable kids' bikes.
Taipei Cycle Show



Taipei Cycle Show


And now here's something for grown ups. The new MZ group sits atop SunRace's drivetrain hierarchy, and you'll find touches like a carbon fiber cage, an adjustable clutch, and aluminum pulley wheels (ack, sounds noisy) with sealed bearings on the highest-end rear derailleur.

You can skip the alloy pulley wheels to save a bit of money and weight, with the standard model coming in at 267-grams and the fancy pants one weighing a measly 5-grams more.


Taipei Cycle Show
Taipei Cycle Show


There are two versions - one compatible with SRAM shifters and the other for Shimano - and SunRace says that they'll work with 10, 11, and 12-speed cassettes. They look pretty nice, too, especially with the ti-nitride gold chain. Want less bling? There are black and silver options as well.


Taipei Cycle Show
Taipei Cycle Show


The shifters appear to be less polished, but there are four different versions to choose from depending on how you want it to mount (clamp or a Shimano-compatible I-Spec setup) and whether you want a giant gear display to look at or not. The right answer is 'No,' of course. There are five different 12-speed cassettes to pick from as well, with aluminum used for the top four cogs on the nicer models.

Gearing range runs from either 10-50 or 11-50 teeth, and weights start at 462-grams before topping out at chunky 702-grams for the all-steel-cog version.


Taipei Cycle Show


Nearly lost in the slew of new bits is how SunRace is attaching their two 10-50 spread cassettes to SRAM XD-style freehubs, especially since the cassettes sport a Shimano-style splined interface. The answer is a freehub adapter of sorts looks like a stubby, tapered sleeve with Shimano-compatible splines along its length. That little guy slides over the XD body, and then SunRace's cassette slides onto that before a threaded lockring clamps it all down.

You're probably not alone if you're sitting there asking yourself why someone wouldn't just run a relatively inexpensive SRAM GX cassette, but the answer comes down to saving money. SunRace says that if you use their freehub adapter and cassette, you'll end up keeping around €50 retail in your pocket compared to a GX setup. Whether or not that's worth the added complication of a freehub adapter is yet to be seen.


103 Comments

  • + 43
 1x9 sounds great, with very decent range too.Eagle has 3 too many gears anyways!
  • + 29
 Still waiting for 9 speed 11-45
  • - 12
flag jzPV (Nov 3, 2018 at 5:54) (Below Threshold)
 @ibishreddin: I can't see that happening, especially for people doing longer rides. you'll never find the right gear. 1x10 with 11-36 on my commuter (sort of road bike) drives me nuts...
  • + 3
 U need sram EX
  • + 4
 @ibishreddin: to use with your existing 9spd derailleur that has no clutch mechanism?
  • + 13
 @lccomz: You can actually use shimano 10 speed clutch mechs with 9 speed sram shifters
  • + 7
 @Weedling: yes
Used a x9 nine spd shifter with a 10spd zee derailleur on a 990 seam cassette
  • + 10
 what the hell, where are all Eagle fanbois when it is not me bashing giant saucers filled with first world problems.

We’re off to the reigning champion Faggio Vajina-Sandatta: I need smooth intermediate steps for optimal cadence in all conditions. Because I’m worth it
  • + 14
 I would buy the following:
- 1 x 9
- 12 speed cassette spacing (small lateral distance between cassette cogs) for use with a narrower 12 speed chain.
- Cassette with decent range, but not eagle range (11-45?)
- Quality rear hub that would use the extra space from the three eliminated cogs for better spoke angles (Think the advantages of superboost on boost hubs). Maybe they could integrate hub flanges with disc brake bolt mounts to save space on both sides.

If they could make a system like that shift smoothly ( which might be tough with such big jumps between gears), it would probably be lighter, simpler, and build a stronger wheel. Regular racers probably wouldn't like the big jumps. I find myself shifting 2-3 clicks at a time on my current 32 x 1 x 11-46. A 9-speed cassette would mean fewer shifts to get to the gear I want. People who don't like to get out of the saddle wouldn't like it (Until they learn that they'd be faster and more powerful if they stand and mash sometimes) The old 9-speed stuff was bomber. Build it, someone! Box needs something different.
  • + 5
 @toadlywilde: Hell yes! I was just talking about this in a different post. Although I want to bring it down to only like 6 gears. Less gears to click through and wider flange spacing on the same axle size. Too much logic and benefits for mtb industry to implement it though. They'll keep selling yuppies on more gears and new axle sizes.
  • + 5
 @WAKIdesigns: All of us are worth is. I'd rather have a high level of durability with nine or ten gears than 30 subtle choices with complications.
  • + 1
 @ibishreddin: The closest I've seen is a 11-42T for the 9 speed.
  • + 3
 @boxxerace: i know why they are not here. Owner of golden Eagle would never open article with Sunrace in the title Big Grin Big Grin Big Grin
  • + 1
 @scottrcameron1: mee too. 9spd sram + 10 speed shimano = 9 speed shimano XD
  • + 5
 @toadlywilde: why do you want to use a narrow 12 speed chain? That's where most of the durability issues with modern drivetrains come from IMO. Old 8 speed chains used to shift forever, didn't matter how many miles you put on them, as there was so much more tolerance with the bigger dimensions.
  • + 0
 @not-finbar: I think it has to do both with the chain width and the width of the cassette spread. Narrow chain working in extreme ranges. I can’t imagine 12sp chain having issues with 6-7cog cluster and well set chainring.
  • + 1
 Used their 11-40 8 speed til the bike it was on got stolen. Super cheap but 60 grams heavier than adding a ten speed expander to a shimano 8 speed.
  • + 1
 @jzPV: I have Rival 1 on my gravel bike that I use everywhere, so 11spd 10-42. Bigger jump on the high end (10-12) but other than that the same as your cassette, just an extra cog.
It's perfectly fine for me. I'm not racing anyone, so I can find the right cadence because I don't care that much about my speed. Smile
  • + 1
 @Weedling: a 9spd Sram shifter with a 10spd Shimano shifter, huh? That honestly sounds horrible.
  • + 2
 @not-finbar: You're right, the old 8 and 9 speed chains did seem to last longer. I would want to use the 12 speed chain simply because it allows for the most efficient use of axle space. With a 12 speed chain/spacing, you could make a significantly narrower cassette, leaving more space for better spoke angles. I rarely break chains (maybe I'm not as powerful of a rider as you). I don't feel that chains are a deal breaker because I don't break them often and because they're really not very expensive compared to the overall cost of the rest of the drivetrain, I don't mind replacing them a little early in order to reduce the wear on my cassettes/rings. Then again (I just checked the price on a 12 speed chain which I have never bought before), 12 speed chains are significantly more expensive so your argument/question is definitely valid. Ok, so why not do both (options are good): 9-speed cassette with 12-speed spacing AND/OR 7-speed cassette with a wider chain. Take your pick between chain durability and tighter shift ratios. Just buy the right shifter.
  • + 2
 @casman86 In the mourning of SRAM 7 speed DH specific drive train ATOMLAB already made a brilliant effort ( m.pinkbike.com/news/atomlab-releases-dhr-7spd-hub-2015.html ). It Could be a great exercise to match a 157mm super boost hub with a shrinked down 12 to 7 speed wide range cassette
  • + 1
 @om1wan: That's pretty cool. A wide range version of that with 12x148 axle is what I imagined. A special cassette with chain ramps made for the big jumps would be ideal.
  • + 29
 GX cassettes are most definitely not relatively inexpensive. They're expensive.
  • + 4
 yea that shiz is wayyy too damn pricey
  • + 23
 They are only inexpensive compared to the most outrageously priced MTB product ever - the Sram Eagle cassette.
  • + 8
 @IluvRIDING @pinhead907 hence the "relative" part of "relatively inexpensive". Smile
  • - 2
 @brianpark: great job on pushing it down our throats
  • + 23
 Hell with the kids, there's lots of adults would be very happy with the grom-spec 1x9 11-50! And the teeny tiny cranks would be perfect for all the silly low bottom brackets we keep being told we must have.
  • + 19
 sunrace is like the mvp of cheaper drivetrains, they used to do ridiculously cheap stuff that wasn't nice but slowly they pop up interesting designs, cheaper alternatives, etc.
  • - 16
flag mnorris122 (Nov 3, 2018 at 5:38) (Below Threshold)
 I dunno, Sunrace still isn't very good...all these derailleurs look flimsy and cheap, and the shifters doubly so. My experience with a Sunrace wide rande 10 speed cassette was a bad one, shifting wasn't very good and I snapped two chains on that cassette in situations where I wouldn't expect to break one. Now that Shimano makes an 11-42 10 speed cassette I see 0 reason for anyone to buy Sunrace.
  • + 25
 @mnorris122: 0 issue with my 10 speed 11-40 Sunrace cassette. You can't generalize only on your personnal experience.
  • + 4
 @mnorris122: But It's really cheap,you don't know how much some people want to use 12s with little monet that can't afford shimano or sram
  • + 2
 @mnorris122: agreed. I have both Sunrace and Shimano 11-42. The Shimano shifts better and is a similar price (if not a bit cheaper).
  • + 4
 @mnorris122: zero issues with a 11-50 sunrace cassette here - chainline needs to be spot on and then it shitfs on par with a shimano or sram
  • + 11
 @mnorris122: I heard this wise words somewhere I can't remember: "There is no such thing as snapping chains, just chains installed incorrectly." Smile
  • + 1
 @mnorris122: really they should have never made anything beyond 11-42 for 10 speed conversions. A good shop tech would have talked you into a smaller chain ring and a 40 not 42. They work well and are quite nice in the 40 variety. But yeah 42 is too much for the 10s derailleurs. I guess some blame goes to Sundance for offering it, but really the quality is good.
  • + 3
 @takeiteasyridehard: 42 even works with a Zee FR derailleur, a XT works even better. I can't see the problem with going 42t.
  • - 5
flag mnorris122 (Nov 3, 2018 at 8:28) (Below Threshold)
 @takeiteasyridehard: Seeing as I am a shop tech I think I'm OK thanks...My Zee derailleur with a RADr cage works absolutely brilliantly with the 11-42 CS-HG500.

I stand by my previous point. The highest end Sunrace 10 speed 11-42 is only 30 grams lighter than the HG-500, is $30 more expensive at MSRP and shifts nowhere near as well.
  • + 0
 @ugez: Nah, there's also shifting under a bit too much load on a shitty cassette.
  • + 5
 @mnorris122: The Sunrace MX3 is 387g, the HG-500 is 435g.
  • + 0
 @flunkymonkey: OK, I'm off by less than 20 grams Rolleyes My own HG-500 weighed in at 427g on the scale. Not light by any means, but I guarantee you won't notice the difference in weight between the Shimano and Sunrace versions. What you will notice is the difference in price, where Shimano wins, and shift quality, where Shimano wins again.
  • + 1
 @alaric0108: Likewise, and in the muddy PNW. Everything else is breaking down, but my 11-40 Sunrace (the better of the two) has held up way longer than expected.
  • + 2
 @mnorris122: It's your fault then. Shitty chain can destroy a good cassette. You can't blame the casette if you improperly installed a chain, and/or used a worn one.
  • + 3
 @mnorris122: "Seeing as I am a shop tech I think I'm OK thanks..."

I hate this argument. Anyone can work as a bike mechanic. My first job ever was working as a bike mechanic...
I started tinkering with my own bikes in the first place because of my bad experiences with shops and stupid "mechanics".
  • + 8
 SunRace has some impressive pieces! It’s good to see them and Box available, considering the market has been dominated by Sram and Shimano for many years!!!
  • + 1
 That and TRP is coming up too and if their transmission is as good as their brakes i will not hesitate 1sec to pick a TRP spec bike for 2020.
  • + 4
 eagle sucks in my eyes. does anyone else have the issue of never quite being in the correct gear on the trail? I'm constantly changing gear? I'm not talking on the climbs just in and out of turns etc. never had that problem with 11 spd, just always seemed to find that right gear all the time but struggle with eagle. Don't get me started on eagle jocky wheels ripping off and the very tight adjustment tolerances.... this product is refreshing along with the box stuff I saw yesterday...
  • + 2
 Man, my X01 eagle is fantastic. I've had zero issue with it. You just need to find that shifting rhythm that works. There may be an extra click you need but that's it, I'm never searching for a gear. Setup wise, I built my whole bike so I know it's done right and I can tweak it quickly as the cable stretches. It could be a chain line spacer missed or the wrong size put on etc too. The B screw thing is funny but the tool really makes it dead simple. The only tricky part is that it's a 2 person job. The b screw needs to be set under sag, using the red tool. I don't think everyone is doing that. Maybe it's not a big deal but mine is exceptional. The new XTR being able to shift under full load does sound cool tho if it works.
  • + 4
 @toop182 That sounds strange especially if you run SRAM 11 speed before. The Eagle has the same size sprockets with the 50t added as 12th speed. I have GX Eagle on one of my bikes and with 27,5 wheels the cage catches on everything and it bends very easily. Flimsy, cheaply made stuff.
  • + 1
 @bikeinbih: possible to do with my 29 wheels? I had 27.5 on when I ran 11spd?
  • + 1
 @toop182: Yes, that's possible. The jumps between the gears are still the same but the with the different wheel size you might be a half gear off compared to the 27,5. You can check and compare the gear inches for both wheel size in some online bike gear calculator. www.bikecalc.com/gear_inches
  • + 4
 The OEM cranks are the big deal here. I'm seeing companies spec 165mm cranks on a kiddie 24in grom bike. Their knees are nearly at their chin when they pedal. 140mm is ideal.
  • + 1
 This. In bmx we have tons of 5mm increments for little legs. But the larger market mtb has two options for shorter cranks really.
  • + 1
 @fruitsd79: yeah only spawn and trail craft sell nice 140mm direct mount cranks but they aren't OEM. For anyone else.
  • + 2
 Hold on here. They are using an adaptor to put a 10-50 cassette onto an XD driver because their cassettes use a Shimano spline interface. Are you suggesting that they are making a 10-50 cassette that will fit onto a Shimano splined driver? I thought this wasn't possible, hence the new driver standards...
  • + 3
 Yea, we need more info on this front. Saves me $100 if I decide to go 12s in the spring. Full steel cassette too, ultimate cost effective bikepacking drivetrain?
  • + 7
 @thatwaspontus: Ultimate cost effective bike backing drivetrain definitely doesn't need 12 speeds. It needs a front derailleur.
  • + 1
 @alreadyupsidedown: And in my case that would require a new frame.... so not that cost effective. How about cost effective 1x drivetrain?
  • + 1
 @thatwaspontus: the adapter is needed with xd driver because it looks like there are no normal shimano hg splines on the 10t. No way to make 10t work on a hg splines. I've often wondered why sunrace don't make a 10-46 xd cassette... Must be Sram patents I'm guessing but e13 is willing to license

OneUp used to make a micro hg freehub to work with their 10t, but looks to have been discontinued.
  • + 1
 Doesn't look like it. It has shimano-like splines. But you see the splines don't go all the way out to the lockring. The adaptor steps down (twice), most likely to provide clearance for the smaller 10T cog.
  • + 1
 It's not a Shimano spline interface - hence the inclusion of the 10T sprocket. The adapter threads onto the XD thread (using a standard Shimano HG cassette lockring tool interface) and it has another captive threaded section at the other end onto which the cassette lockring threads and holds everything in place (also a standard Shimano HG lockring tool interface). It's smaller in overall diameter than a standard 11T lockring so gives the required room for a 10T sprocket. It's really neat in person!
  • + 1
 @alreadyupsidedown: Maybe. It's all about durability, ratio AND the chain not falling off. There are options either way and should be.
  • + 2
 I had Eagle, came from GX 11sp, and I couldn’t get rid of Eagle fast enough!

Talk about finicky and loss of function when dirty, I had to clean and lube my Eagle chain every twenty miles, once in the middle of a ride.

I’ll stick with GX 11sp, bomber and works when the going gets dirty.
  • + 3
 surely a 50t cassette paired with a 20" wheel would cause you to go literally nowhere, its like 1ft forward for each crank revolution **zero scientific evidence to support this figure**
  • + 2
 Yeah I wonder even on 24" the feasibility. Tho kids def need the climbing gears more so than adults...yet often they RIP harder than adults down and need the speed too. Grom programs these days are so strong. Glad we are seeing at least something else. These will really benefit the non-groms stuck on something like a crappy kids Spesh bike with a 11-28 7sp. Hopefully these replace that and make bikes better for the masses of kids.
  • + 1
 I love these how Sunrace is coming in and shaking things up forcing especially Shimano to start paying more attention to what the market wants instead of simply continuing to dictate what they think is right. Specifically their lack of wide range cassette options. Who cares when Shimano gets around to it these guys are helping Sram lead the market and they are going to start cutting into Shimano's OE market share. Its all good for us going forward. I can't imagine why kids should have all the fun with wide ratio 1x9. That's just what all us classic retro mod fans need. 11-50 9 spd cassettes been on Wish and Aliexpress from no names for awhile but pics of bent cogs weren't appealing. I've used a few SR cassettes and found them to be great. As for the MZ group now we know why its 7 months and counting late. When Sunrace originally announced it on BRAIN they said the derailleurs would do both Sram and Shimano making it sound like one RDR for both. All us mechanics were skeptical and waiting to get our hands on them to see for ourselves. Apparently they may have jumped the gun in April but Im glad to see its happening soon.
  • + 1
 It's great to see that Sunrace recognizes the need for more options on kids bikes. Like others have said here, the lack of smaller crank options is the biggest problem when building our kids bikes and not being able to easily change things out as the kids grow. BTW I put a Sunrace 11-46 11spd cassette on my bike and I am very satisfied with the quality.
  • + 1
 (Dons hard hat and pads...) I can see these finding their way onto lower end HT and full suss ebikes too. There really is no need for 12 or even 11 speeds on ebikes, but durability is a big issue that a decent 9 speed setup might help to solve.
  • + 1
 So, Sunrace can get a 11-50 cassette in the rear and apparently work with a derailleur cage short enough to be used with a kids rear wheel. Not sure what size kids wheels are supposed to be of course. The mtb my girls ride has 20", I (grown man) ride 26" so it must be something between those sizes. An Eagle mech probably wouldn't fit between the ground and the axle. Good to see someone create a mech that does.

As for the claim that this is the first kids drivetrain, I thought Zee was the first (though aimed at gravity riding too). Just like Nike 6.0 was targeted at kids (6.0 implying that it was good for six different sports as kids didn't need to choose at that age) but grown athletes were riding those (or at least sporting the logo). And yeah, I'm riding with Zee too.

So a new kids group is great news for us grown ups who couldn't care less about the latest "improved performance" claims and just need something affordable that works. Unless of course they didn't overbuild these kids components for a change (which seems to be the norm).
  • + 1
 the adult rear derailleurs have been available for a while in the UK. I wonder how many they actually sell as XT & XTR are only marginally more expensive. i've been using the sunrace cassettes for a few years with no issues. the shifting isnt as fast as shimano, but the wears a little better
  • + 4
 Great idea that adapter for xd/shimano cassette…
  • + 5
 would be great if they sold the adapter on it's own
  • + 1
 ah man I hope they aftermarket this ASAP. In the process of a custom rebuild on a Specialized Gromhit for my son -- shorter cranks are the final piece I need but wouldn't be opposed to adding a wide-range 9-speed.
  • + 2
 Dude just buy them from Spawn or Trailcraft. No need to wait.
  • + 1
 @Svinyard: ya I'm likely grabbing the spawn ones but the whole drivetrain is a tempting addition. Glad to see more options coming out for kids bikes and components.
  • + 2
 @Svinyard: sunrace make their zeron cranks in a 152mm size, $70 including 30t steel NW ring and bb. The trailcraft and spawn options are great, but hard to justify the $$$ when my own adult setup would cost less
  • + 2
 @Poziman: sorry, sr suntour not sunrace with the zeron cranks
  • + 2
 Suntour has 140mm/152mm Race Face Cinch direct mount cranks. $99 CAD with a ring and bottom bracket. Uses normal Shimano Hollowtech II BB.
  • + 1
 @ronufoh: Thanks! Still thinking going shorter than 152 would be worthwhile though. I like the idea of 140 or even less for the little legs.
  • + 1
 @neons97: whoa, that's a great deal. I need to talk to my shop and see if they can get those before I order Spawn.
  • + 2
 @ronufoh: The Trailcraft are a premium kids crankset for sure.. www.trailcraftcycles.com/product/trailcraft-direct-mount-cranks You pay extra for the substantial weight savings as it uses an aluminum spindle to save a bunch more weight. 26,28,30,32 tooth aluminum direct mount chainring options in 140mm, 152mm, and 165mm lengths. The 152mm Trailcraft Cycles Direct Mount are super light compared to a similar SRAM 155mm NX by well over 100 grams, that weight savings comes from the aluminum spindle and chainring. Great place to save weight on typically super heavy kids bikes.
  • + 1
 @TenderRoni: oh no doubt. I appreciate what they are doing, and also the fact that they are likely pretty low volume which affects the retail price. But I do die a little everytime I see what they are selling their bikes for, ie. $2500usd for a 26lb FS bike. I clearly don't love my kids enough.
  • + 1
 @ronufoh: Never look at the custom carbon kids bikes with Kashima, Spank, XTR, the works. They exist...

"I clearly don't love my kids enough" Salute tup Right there with ya. Save the high end for when they've grown well, higher. Wink they'll outgrow the bike within a year anyway. Razz
  • + 1
 I see they hit us with some new free body standards in there with out telling us, seems like gearing has gotten better, but havent resolved the real problem?
That gearing gets dirty, so why not put it in a box?
  • + 3
 Awesome to see options for building my kids bike, especially cranks!
  • + 1
 Suntour has 140/152mm kids cranks with a Race Face Cinch direct mount interface. Crank, 30T 1x ring and BB for $99 CAD I believe.
  • + 1
 @neons97: can you post a link of these cranks? The closest i could find are the Zeron and 152 is as short as they come
  • + 3
 I would try that stuff for sure
  • + 1
 Where is a picture of the kids 9 speed shifter? Indication is good for kids.
  • + 1
 And I'll add. Gripshift for kids is THE WORST. Their hands are too small and too weak to operate it reliably. I'd love a 9 speed trigger shifter with numbers for my kids.
  • + 1
 Derailleurs will die. It's a matter of time...Until then though, yes, make the derailleur great again...
  • + 1
 Wait a second... does that adapter mean I can use their 11-46 11 speed cassette with my gx 11 speed?
  • + 1
 Sounds like it. I have a sunrace 11-46 paired with an XX1 11 speed and am very happy with it
  • + 1
 Wide range 9spd....I'll buy one set for my son, and one for me! Hopefully it's designed to work with 9spd chains.
  • + 2
 Technical patent of Shimano and Sram?
  • + 2
 CHANGING THE GAME
  • + 0
 It's like Huawei or Great Wall Motors of bike industry Smile Not so serious products for not so seriously hooked people...
  • + 1
 Huawei is not serious? How?
  • + 2
 Designed for Randy Jr?
  • + 1
 1x9 11-50! I'm in
  • + 0
 I'm sure Box is glad they will finally be able to offer 12 speed!

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