My Unintentional 1x11 Conversion

Dan Dialogue

New Member
My 1x11 conversion started last Christmas when my family bought me a 125mm Brand X dropper post for my 2016 Bulls E-Stream EVO FS3 27.5. I’ve got a Fox Transfer post on my Cannondale Trigger and it’s awesome. A dropper post is one of those items that you truly appreciate and cannot live without once you’ve ridden with one. At least, that’s the case with me.

I was really excited about it until I realized that there’s no room on the bars for the lever. With the shift lever for the front derailleur and the Brose controller, real estate is at a premium. Since I wanted my Bulls setup to be similar to my Cannondale, I wanted to keep the dropper post lever in the same position on the bars. I’ve seen some of the other dropper post installs here on the forum and I preferred a different cable route and lever placement. Since my dropper post is internally routed, I needed space to run the cable to keep things tidy. That meant the front derailleur, cable and shift lever had to go.

After removing the shift lever, cable and derailleur, the post install went fairly smooth. It wasn’t until I removed the crank arm that the fun, err, confusion started. The right crank arm comes off with a regular crank arm puller. Underneath is a large nut holding the spider on the spindle and requires a special tool that I don’t own so I gently used a screwdriver and a dead-blow hammer to remove the nut. As it turns out, it wasn’t on very tight and took little effort to remove.

Here's the nut:



Once removed, the spider has a large octagonal pattern that matches that of the spindle. Maybe I’m naive, but I’ve never seen that before. I let my fingers do the Googling and went that produced no results, I turned to FSA.




I was able to make contact with FSA about a new chain ring and/or spider that would be a direct bolt on and they were very responsive. However, after showing them a picture of what I had, they said they hadn’t seen that type of mount and they didn’t offer anything that would fit, sigh. They recommended contacting Bulls. In hindsight, I probably should have done that first, but I figured the spindle would be the same as regular bikes and since the cranks are made by FSA…well, there you go.

I reached out to Court and he got me in touch with Barney at Bulls. Barney was very responsive and after learning about want I wanted to do, he did some research for me. As it turns out, the 2x spider used on my bike is the same spider that Bulls uses for their other bikes that run a 1x setup.

Problem solved. Barney even went so far as to reach out to Brose and verify that the chain line would still be okay.

I removed both chain rings and replaced just the big ring with a 1x specific chain ring (narrow/wide teeth and 104BCD) from Amazon and theoretically I shouldn’t need a chain guide. Time will tell and even though it was a bit of a headache, my 1x11 conversion is done and ready to ride. Best of all, it looks like it was designed that way.

The finished product(s):

Dropper lever right next to my shiny new controller


Dropper post and cable routing



And of course, the 1x11.


I big shoutout to Court, Barney w/ Bulls and Brian at FSA for your help!

Now if Mother Nature would only cooperate…
 
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Blueflash

New Member
Very nice write up. I appreciate the pics. Let us know if you miss the extra gearing by going to a single front ring. I hope to add a dropper post this spring and have been pondering the same issues you've encountered.
 

Dan Dialogue

New Member
@Blueflash Thanks! I'll definitely post a ride report. It's been cold and snowy here in Utah and I probably won't be riding it anytime soon. I did a 1x conversion on my Cannondale and use a 30t chainring. It's been pretty good with just leg power. I opted for 32t on the Bulls since it's got a motor and it's right in the middle of the two original rings.
 

Dan Dialogue

New Member
HI Guys! Just a quick update. I've ridden a couple of times now and put on about 30-miles on technical, tight single track. So far, the gearing has been fine. 32T up front has worked well and the narrow/wide ring hasn't dropped a chain yet. We'll see how it goes as I get more mileage on it.
 

jaga

New Member
Thanks for the good write up, pushed me to do the same.
Do you have any issues with your boost spacing spider? I was told from Barney over at Bulls I should get a NON Boost spider to get the chain closer to the frame, but I do not even know where to source one with that octagon mounting hole.
 
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racer cletus

New Member
Great minds think alike on converting to a 1X11 but I took a different approach. Used the existing spider, removing the inner 28T chainring and replacing the 38T outer ring w a 32T. Agree that the 32T w motor is just the right gearing (I also think a 30T will not fit on the outer spider!). I took the lazy guys approach of using the front derailleur as the chain guide (adjusted stops so that it’s positioned just right). Looks decent too. Jeff at Voltaire Cylces here in NJ worked this set up out with me - they’re great!
 

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Blueflash

New Member
That looks great. Very professional. It looks like you also used a combo mount for the brake and shifter? Or is that how it came from the factory. My 2016 has separate mounts. I decided I like the range of the 2-speed front chain ring and ended up putting my dropper lever on the right side of the handlebar. I used the lever that came with the LEV Integra. It's very small, so takes up little room on the bar. I understand wanting to simplify and going to a single ring, however, I've had no trouble with my front derailleur. It shifts well and I've never dropped a chain. I like your Ergon grips too. How do you like them?
 

racer cletus

New Member
Beautiful build, puts mine to shame. :) Any suggestions on a chain guide? Still concerned about dropping my chain which has happened to me before. Any suggestions would be appreciated.
 

jaga

New Member
That looks great. Very professional. It looks like you also used a combo mount for the brake and shifter? Or is that how it came from the factory. My 2016 has separate mounts. I decided I like the range of the 2-speed front chain ring and ended up putting my dropper lever on the right side of the handlebar. I used the lever that came with the LEV Integra. It's very small, so takes up little room on the bar. I understand wanting to simplify and going to a single ring, however, I've had no trouble with my front derailleur. It shifts well and I've never dropped a chain. I like your Ergon grips too. How do you like them?
Thanks, the dropper lever and shifter both share the Magura brake clamps, shifter had to ditch the shift display then buy new shifter cover and then a Magura to Shimano spec 2 adapter. I love the Ergon with the flat ends to rest your palms, they are super comfy especially when your hands get tired.
 

jaga

New Member
Beautiful build, puts mine to shame. :) Any suggestions on a chain guide? Still concerned about dropping my chain which has happened to me before. Any suggestions would be appreciated.
Like you I used the stock spider since I couldn't source another with NON boost spacing and added a 32T chainring, so far I have not had my chain drop yet.
What's everyone's next mod? Mine will be going to a 203mm front rotor.
 

Blueflash

New Member
Like you I used the stock spider since I couldn't source another with NON boost spacing and added a 32T chainring, so far I have not had my chain drop yet.
What's everyone's next mod? Mine will be going to a 203mm front rotor.
I highly recommend the 203mm front rotor upgrade. My bike has Shimano brakes. The adaptor and rotor were easy to find and inexpensive. I had a local bike shop change the rotor because I didn't have the tool for the center lock rotor, but they did it on the spot for $7. I've done some seriously fast and long downhills since the upgrade and was glad to have the extra stopping power. My next mod will be some heavier duty tires in a wider width, and going tubless. Will likely go with Maxxis in a 2.5 inch width. Sadly, it's winter here so I'm unable to ride for a few months.
 

Fahkncute

New Member
Here's my 2017 Bully E-stream, pending dropper post I'm still deciding If I should go Internal or external I kinda wanna keep my 2x setup due to climbing and flat trail speed!! If I do change my chain ring tho you guys think 32T or 34T would be just right? Thanks in advanced
 

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