12.7 lbs Gravel (versatile road), disc brakes, electronic shifting X-Shifter

[andreszucs]

I'm building up a cyclocross bike. Can I get your thoughts on your seatpost choice, as a gravel bike takes a similar amount of punishment to that of a CX bike. What post did you go with and why?

I'm a huge proponent of a 'cross bike' idea with full suspension, like my second bike here: //uploads.tapatalk-cdn.com/202012 ... 8e322c.jpg

Otherwise I like to just call it 'versatile road bike' if it's fully rigid. No seatpost can give you a proper replacement for a rear suspension if you are pushing the limits on technical trails. In this case here, I'll be using this bike on the road most of the time, with some fire roads time to time, so a simple carbon post is just enough. Got mine from china for about $15, and some modification to make it lighter, all I need.

[tgoods]

What post did you put on your cross bike w/suspension?

[andreszucs]

What post did you put on your cross bike w/suspension?

Same cheap carbon post, homemade actually. I got a carbon tube at the right diameter for my frame, and made the cuts and holes to install the attachments.

[andreszucs]

Well, a collarbone injury on December 31st took me away from biking for 3 months, but I'm finally back at it and had a chance to take some pictures of the finished assembly.

12.7lbs as pictured, you might say that's not enought gear range to call it Gravel, but It clears all my routes that I typically do. it's a 9-32 3T cassette with 38T Ring up front.


Magura latest Mt8 levers, combined with Brake Force One H20 hose (the lightest ever, also alloying me to use heat to create that curvature next to the lever), and X-Tube Heat Shrink Wrap (put on ebay) creating a very nice finish with the handlebar.


Security titanium bolt M4 replacing the compression starnut assembly


Internal view


First, I repositioned the Derailleur Hanger, with a forward bolting placement, SRAM Red short cage RD with a small bridge to offset the top pulley similar to 'Type 2.0'. I also turned the spring inside the RD to increase the chain tension


Since it's electronic, I don't need the barrel adjuster


X-shifter placed on the bottom of the frame (I know, not an ideal position with mud, but I'm deciding to give it a try, worst case I'll move it to the side of the frame next to the crank)


Elsa and Anna band-Aid to hold the hose in place (I have two daugthers)


Reliable seatpost clamp with M6 Titanium Bolt and Hex Nut (upgrade from original)


SRAM Force Brake Calipers with Upgraded hollow Titanium bolt (I wanted Red to match with the RD, but they have both the same weight...eventually I'll find a set of Red's)


Cyclocross Rear tire giving me lots of traction for those steep gravelly hills


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[Klaster_1]

@andreszucs awesome build man, what really make it stand out are, IMO, unusual solutions likes X-Shifter, MT-8 on a drop bar, modified chainring and now a security bolt. Makes me want to design drop bar adapters for my R1r's and be able to convert XC FS bike to a monster FS gravel bike on a whim.

[andreszucs]

@andreszucs awesome build man, what really make it stand out are, IMO, unusual solutions likes X-Shifter, MT-8 on a drop bar, modified chainring and now a security bolt. Makes me want to design drop bar adapters for my R1r's and be able to convert XC FS bike to a monster FS gravel bike on a whim.

Thanks!
Yes I’ve been playing around with each individual idea on separate times, so this build is a culmination of lots trial and errors, to this point where everything works perfectly.

The security pin works, and I also find it super safe.
X-shifter is actually a few grams lighter than etap, highly customizable...can even work with 13sp, and I also like that I can use any RD and they cost $80-$100 range, instead of having a $600 Etap hanging and exposed.

MT8’s are powerful! The tiny X-shifter remote is a good marriage with this solution.

Very happy overall.


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[kilo]

feedback of the x-shifter?

[bobrayner]

Security titanium bolt M4 replacing the compression starnut assembly

That feels instinctively wrong to me - a plain nut tightened against the curved inner surface of a CFRP tube? But if it works for you, and if nothing has cracked, then maybe it's not wrong.

How much weight does that save?

[andreszucs]

feedback of the x-shifter?

Same precision shifting benefits like etap and Di2, but waaay cheaper. Easy to fine tune each individual gear, can be paired with several numbers of gears, up to 13sp, it’s light.

Still checking the battery range, but I’m happy so far, about 70 miles in a single charge so far and I’m still at 70%.


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[andreszucs]

Security titanium bolt M4 replacing the compression starnut assembly

That feels instinctively wrong to me - a plain nut tightened against the curved inner surface of a CFRP tube? But if it works for you, and if nothing has cracked, then maybe it's not wrong.

How much weight does that save?

1- I tapered the nut
2- doesn’t need too much torque because what is effective is the head of the bolt sitting on the stem in the outside. It works.

Really depends on the combo to tell the weight saving, about 30-40g I’d say


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[fourfa]

Curious - why not use an expander plug, set the stem, then remove the plug? Then don't even need the small nut and bolt

[andreszucs]

Curious - why not use an expander plug, set the stem, then remove the plug? Then don't even need the small nut and bolt

That only works with lefty forks (old model) because the upper lefty clamp holds the steerer tightly, and the stem is not the element compressing it (I've done it before). It doesnt work with traditional system, overtime it will decompress.

[bobrayner]

1- I tapered the nut
2- doesn’t need too much torque because what is effective is the head of the bolt sitting on the stem in the outside. It works.

Really depends on the combo to tell the weight saving, about 30-40g I’d say

Good work!

Are those Xpedo R-force pedals? They look cool. I really wanted a pair, hoping they would have the same spindle as the Xpedo M-Force (allowing lightweight DIY power-metering), but it looks like the spindle geometry is different - they have a different width between inner and outer bearings.

[andreszucs]

1- I tapered the nut
2- doesn’t need too much torque because what is effective is the head of the bolt sitting on the stem in the outside. It works.

Really depends on the combo to tell the weight saving, about 30-40g I’d say

Good work!

Are those Xpedo R-force pedals? They look cool. I really wanted a pair, hoping they would have the same spindle as the Xpedo M-Force (allowing lightweight DIY power-metering), but it looks like the spindle geometry is different - they have a different width between inner and outer bearings.

I was fortunate to find those at a good price on eBay long time ago. I also have the M-force, and yes, spindles are different


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[Klaster_1]

feedback of the x-shifter?

Non-existent customer support. Sleeps after ~15-20 minutes without shifts, so you miss miss a shift ocassionaly, like a on wireless keyboard; this was supposed to be addressed by firmware update long time ago. Expensive replacement batteries for what they are if you manage to get your hands on any, making your own fixing the existing one is much easier. It does what it claims to do, though, and potentially is hackable with appropriate skills.