USE P1100202

Relic dropped into Taipei show with a 48 tooth conversion sprocket for Shimano 11-42t sprockets to take you up to higher ground… without having to push your bike, and a simple one piece 2-speed single speed conversion that could do the same.

Also, with so many standards flying around these days, it’s hard to know which part you need. Da Bomb makes it easier by offering one simple headset for all of your tapered needs…

USE P1100209

A sprocket big enough to eat off of, Relic’s 48t was mounted and working smoothly. The best part is that there are no adapters you need to add to the derailleur for it to work.

SFW P1100206

As you can see, the derailleur’s pully wheel is just far enough away from the 48 tooth cog so that it doesn’t hit. This is what caused many of the 42 tooth conversions on 10 speed systems (that were made to top out at 36 teeth) to not work unless you added an adapter or longer screw to the rear derailleur. This backs up the fact that Shimano’s new 11-46 cassette will work just fine with their existing 11 speed derailleur.

USE P1100210 USE P1100214

The $90 kit comes with 48 and 18 tooth cogs and all you have to do to convert it is remove the 17 & 19 cogs and slap the 48 and 18 on. The cogs are machined out of 7075 aluminum and are compatible with Shimano XT & XTR 11 speed systems.

USE P1100215

Relic also had this 2-speed single speed cog and spacer kit. The reason behind this is that many single speeders will swap cogs based on where they’re climbing riding. This system makes the process a little easier and even something you can do while out on a ride.

USE P1100220

The only size available (for now) is a 14/18 combo. Depending on what you ride, this may be a little tough unless you’re running a 30 tooth chainring (maybe). Using a tensioner, sliding dropouts or a EBB, you should have enough room to adjust the chain’s slack for each cog. The two cogs are a one-piece design making them plenty wide so to not dig into a soft aluminum cassette.

USE P1100224

Da Bomb had what I thought was a thoughtful product, especially for shops. With so many standards and sizes, it is often difficult for shops to stock everything each person needs.

USE P1100222 USE P1100226

Da Bomb’s “Bomb Loop” will eliminate some of this as it comes with all the goods to fill your tapered headset needs. It comes with both 30 & 39.8mm fork races, both ZS44 & 56 and IS42 & 52 frame cups making it pretty much compatible with most tapered frames and forks on the market. (Price is TBD).


  1. eric on

    That second cog is unique and innovative. All it needs is a small mechanism to move the chain between cogs while riding. It could even be operated by a cable from a lever on the bars.

  2. Veganpotter on

    10-50 twelve speed jumps are almost the same as 10-42 jumps. Personally, I like the idea E*Thirteen has… 9-44. Maybe a 12 speed 9-46 would kill it with smooth shifting and less weight. This has gotta be heavy, even in aluminium

  3. velocodger on

    The 14/18 cogs can be changed by just removing the wheel, if you mount double chainrings with a two tooth difference. You get a bigger gear jump too. Just replace the bash guard with an outer chainring. The chain tension isn’t perfect, but it beats fiddling with the eccentric or re-positioning sliding dropouts.

  4. carbonfodder on

    +1 for Eric – I like where he is going with that. Seems like more would be better in this case and he has nailed the big picture. Just need to work the details and what to call these devices. Well done, truly innovative thought.

  5. Mateusz on

    Dartmoor has been doing headset with to crown reces for like two years now.
    They may come from the same factory tho.

  6. Fan Boy on

    “compatible with most tapered frames and forks on the market”
    just not Santa Cruz, Yeti and Intense (ZS49/EC49 lowers) or any of the is41 standards.

    and not Scott’s ZS55, or ZS46, or Giants 47mm or any of the 1 3/8″ versions.

    so in effect, this headset fits *two* of the many headset standards out there…

  7. ascarlarkinyar on

    My 3×9 drive train is still more durable, cheaper and bigger range. So what if I have to shift with my left hand also.

    • Johan on

      I get more than 2x the durability from my 1×11 than i used to get from 3×9, both chains and casettes. Enough to make up for the silly prices.

    • ascarlarkinyar on

      Highly unlikely since you spend all your time in one chainring in front. The rear will likely see the same wear, but to replace a 11 speed all the time is $$$$$$$

      I ride endurance so I can go through a lot of drive trains. This has been a fix for a problem that never was. It only makes the manufacturers money.

  8. Bill on

    Kinda scratching my head on that double cog. I’ve basically seen two types of single speeders.. ones using a freehub body and a single cog with spacers, or ones using dedicated single speed hubs. For the former, if you wanted to be able to change gears, why not just put two individual cogs on next to each other?

    • pTymnWolfe on

      You’re correct. People have been putting two cogs on a freehub body with two chain rings for years. One gear for riding to the trail and one for riding the trail. Nbd.

      • Chase on

        Sorry 48T not 50T. That would be crazy, right?
        I remember when I used to get laughed at when I wanted a 30T cog on my Spec Allez back in the day.

  9. Chase on

    I run a 10-46 XTR/Oneup Cassette on my 1X now and getting the shift to the large cog isn’t typically the issue and I’m pretty sure you could make it happen. The issue becomes one of chain wrap on the smaller cogs. Which is why I run the the modified Oneup cage and WolfTooth link on my XTR 11spd derailleur. Until you have skipped a tooth under power while standing this issue will not be of concern. But once you do, all you will be obsessed about will be fixing it. I don’t think the Oneup cage is long enough (Med) to have sufficient range for this 50T cog either. You’d have to run a stock SGS until someone comes out with the tweaked pivot version like Oneup in a long cage version.

  10. Roub80 (@aguycalled80) on

    I’m certain that the next generation of builders will look at bikes now and say; “I wonder if there’s a way to reduce these huge cogs on the back of the bike? Wait! I could put a smaller gear at the crank! It would be like having a hi-range and low-range of gears. That way I can shrink everything at the back!”

    Then someone else will come along and add a third gear at the front. Eureka! Hi-range, low-range, and super low-range. And the cassette and derailleur gets smaller each time.

    It’ll be revolutionary.

    • Bill on

      AMEN!.. I’m racing a “outdated” 27.5 xc with a close ratio triple chainring (26-34-40t) and LOVE it! I’m an old guy in 55-59 class and many of the older guys are running 1×11 and a few 1×12 trying to convince themselves they have the strength to climb with it,and sacrifice top end speed along the way. My 3×10 shifts well because of the close ratios (only 8 tooth difference from 26 to 34t and 6 tooth difference from 34 to 40t.) I shift down on the hills with my setup and pass them using less energy, and on the flat I shift up to my 40t outer chain ring and pull ahead of them all the time. But advertisment hype and peer pressure is a strong psychological force and they won’t consider a setup like mine, so I’ll continue to take 1st, 2nd and 3rd place almost every race with a big smile on my face.

  11. Aris Consuegra on

    I’ve recently bought an 2×11 xt 11/40 cogs..planning to add a relic 46t ring…is it duable…since all u guys mentioned here are for 11/42t cogs.


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