Shimano Ultegra R8100 Di2 Bike

Regular price $8,480

The all new Ultegra R8100 series is highest performing and most elegant version of the group to date.  Ultegra R8100 is only available as a Di2 option which mates perfectly with the ECHO.  Shimano greatly simplified their Di2 transmission by going wireless from the shifters and then keeping a wired transmission from the battery to the front derailleur and rear derailleur.  This eliminates one of our biggest pain points with the previous Di2 which is routing e-wires through handlebars and fitment of clunky junction boxes into the frame.  Our standard configuration comes paired with Industry Nine’s very lightweight UL250 CX wheels and the all-new WTB Vulpine ultra-fast rolling tubeless gravel tire in 700x40, but you can select the exact wheel and tire combo to build your beast as you please.

At the heart of the ECHO’s genetic code is pure unadulterated speed - the ability to transform from a road race thoroughbred to a versatile, agile gravel bike with a simple switch of flip chips at the front and rear dropouts. These eccentric chips and corresponding dropout design allow the rider to easily change the bike geometry, effectively changing the chainstay length and fork length by 1 cm. The difference transforms the bike from a road machine with 415mm chainstay length, 368mm fork length, 73-degree headtube angle, and tire clearance for up to 30mm, to a gravel bike with 425mm chainstay length, 378mm fork length, 72.5mm headtube angle, and 40mm tire clearance - all within a 10-minute switch of dropout chips. Pure road performance one day, gravel race-ready the next. One bike. No compromise.

The ECHO Stem is a fully integrated system designed in tandem with the fork. It conceals the cables while using a standard headset allowing the rider to easily swap stem lengths, and it works with a growing list of handlebars designed with integrated cables in mind. The ECHO stem system is the simplest and most user-friendly on the market today. The cables run through a channel on the top of the stem and are concealed by a faceplate, top cap, and the steerer tube. Headset adjustment is moved from the traditional position at the top of the stem to a threaded portion on the bottom of the stem, effectively increasing the steerer clamp length to provide headset preload, much like a threaded headset. The Echo stem is available in 6 sizes at 10mm increments (80-130mm) and is a -6 degree drop. Like all things designed by Allied, the ECHO stem is made in our Bentonville factory.

*Due to the wire routing on the Shimano front derailleur, Shimano Echo builds have a 38mm rear tire clearance. 

Key Features

Flip Chips change geometry between road and gravel.
ECHO Stem hides the brake cables, provides incredible stiffness and is painted to match.
The ECHO is compatible with all current electric road and gravel 1x and 2x drivetrain options from Shimano and SRAM.
2x downtube, and 1x seat tube
700x30mm in road mode, and 700x40mm, or 650x50mm in gravel mode.

Build Kit

Shimano Ultegra SM-BBR60
Shimano Ultegra BR-R9170
Shimano Ultegra CS-R8100 11-34
Shimano XT CN-M8100
Shimano Ultegra FC-R8100 50/34
Shimano Ultegra FD-R8150 Di2
FSA Energy Compact
Arundel Gecko
Shimano Ultegra RD-R8150 Di2
Selle Italia Model X Superflow
FSA SL-K Carbon Seatpost
Shimano Ultegra ST-R8170 Di2
Vittoria Corsa N.EXT TLR 700x28
Zipp 303 S Tubeless Disc-Brake

Sizing Guide

Crankset 170mm 170mm 172.5mm 172.5mm 175mm 175mm
Handlebar 40cm 40cm 40cm 42cm 42cm 44cm
Stem 90mm 90mm 100mm 110mm 110mm 120mm
Seatpost 0mm 0mm 0mm 25mm 25mm 25mm

Frame Geometry

G. Stack 515 530 550 570 595 620
H. Reach 372 381 387 394 402 409
E. ST Length 460 510 530 550 570 600
A. HT Angle 72 72 73 73 73 73
B. ST Angle 74.5 74.5 73.5 73.5 73.5 73.5
I. BB Drop 77.5 77.5 77.5 77.5 77.5 77.5
F. CS Length 415 415 415 415 415 415
Fork Length 368 368 368 368 368 368
D. Effective Top Tube 515 528 550 564 579 594
C. HT Length 107 123 140 161 188 214
J. Wheelbase 971 985 988 1001 1017 1032
K. Standover 722 736 769 804 825 846
L. Fork Rake 47 47 47 47 47 47
Front Center 562 576 580 593 609 624
G. Stack 520 535 555 575 600 625
H. Reach 367 376 382 389 397 404
E. ST Length 460 510 530 550 570 600
A. HT Angle 71.5 71.5 72.5 72.5 72.5 72.5
B. ST Angle 74 74 73 73 73 73
I. BB Drop 75 75 75 75 75 75
F. CS Length 425 425 425 425 425 425
Fork Length 378 378 378 378 378 378
D. Effective Top Tube 515 528 550 563 579 593
C. HT Length 107 123 140 161 188 214
J. Wheelbase 985 999 1002 1015 1031 1046
K. Standover 722 736 769 804 825 846
L. Fork Rake 48 48 48 48 48 48
Front Center 566 580 584 597 613 628
Have a Question?


Eccentric chips in the ECHO’s dropouts transition it from a tight, reactive road-racing machine to gravel versatility with a kicked-out wheelbase and raked-out fork.


Built in-house and painted to match, our ECHO Stem reduces clamping forces, conceals cables and hoses, and accommodates a growing list of internally routed handlebars. We like our cockpits coated in gravel dust but free of clutter.

2x, 1x, your choice

The ECHO is compatible with all current electric road and gravel drivetrain options from Shimano and SRAM.

Customer Reviews

Based on 3 reviews
Amazing Bike with an Amazing Feel

Our shop has had a couple Echos and Ables in for a year now and after riding them and other gravel rigs, I finally decided to order an Echo Ultegra Di2 12 speed build. I ride in NJ where it is mostly road but not far away are a few parks packed with excellent single track. I will also ride this at my pad in Vermont where as the otters review mentioned you get 100 ft / mile of elevation and you can easily find 50% or more gravel to road, but still plenty of road.

With that "any road is my road mentality" I picked the Echo over the Able. I didn't want to build a rigid MTB, rather wanted a non stoppable road bike. The. Echo is it and after just a few rides I'm impressed. My last ride I cruised a dozen miles with my road team then broke off and did a few miles of single track solo. The bike did both well and the handling on the road or single track is fantastic. The bike handles very well. Sharp turning but not to steep and twitchy, the bike strike a perfect balance for its mission.

My only reservation and reason for the 4 star rating is I did not know the Ultegra set up will only fit 38mm tires. I'm running Spesh Pathfinder 38s and they are excellent. It was news to me and our shop that the Shimano builds only have room for 38mm and I'm a bit bummed I cannot run the vulpine 40s that I test rode on the Echo (SRAM) in our shop. I rode the Vulpines at the VT Monster a few weeks back (bout 80miles 9K climbing) and I loved them.

That said, I'm not looking back, I still absolutely LOVE this bike. This machine is my non-stoppable go anywhere road bike and not intended to cross into MTB territory. There are plenty of great tires including the pathfinders at 38mm. Cole has helped me lots and has supported our LBS, where we are all into this American Built company.

Get One!

Bryan Haas
Incredible bike - If there is a one quiver bike - this is it.

Recently purchased from LBS - Echo Frame. Given the parts shortage I cobbled together an Ultegra Di2 11spd parts kit. Enve cockpit with flaired out h-bars for gravel riding. I have been on compact frames for some time now. Jumping on the size medium (I typically ride a 54cm. I am 5'10", 32 inch inseam) it felt big, different than my compact frames. To be clear, the frame size is correct, for me, but it is a bit different and I prior to logging a ride I was curious to see how it would work out. It worked out great.

I have logged about 30 hours of gravel riding on rough New England roads where we get 1000 feet of elevation for every 10 miles of riding. The descents are often steep and strewn with loose rocks. The first thing I noticed about this bike is that it is incredibly stable on the descents. Like - wow! I am running Conti speedmax 700x36 tires. I could run bigger and I bet it would be better still. The bike is about 17.5lbs with SPD pedals. For a gravel bike! Come on man, that is great. Frame is stiff and comfortable. I have ridden lots of nice high end bikes over the past couple decades of playing bikes and giving an assessment of a gravel frame is tough. The tires are big and comfy which probably has a bigger impact on ride then the actual frame and the gravel roads bounce you around, all making it difficult to really assess the frame.

My solution - flip the chips (this was pretty easy with one exception) and ride it on the road. When I changed up the geometry my chain length was too long. I think this is an easy fix. I should be able to shorten the chain and still get full range of gears on both set up. I am running a 50/34 front and a 34 cassette in the rear. I road 4 hours on the tarmac on the bike. Yup, this frame is pretty incredible. Light. Stiff. I put some I9 wheels on it, which brought the weight down to 17lbs. I may swap the gravel bars out for aero road bars and see if I can really make this the true one quiver bike. Currently, my road bike is a full on aero race bike. Its going to be tough to compare the two rides. It is really apple and oranges, but if you are looking for one solution, this has gotta be it.

Okay - why 4 stars and not 5 starts. My guess is that the folks at Allied are always innovating and upgrading - maybe the next version is 5 stars. Bottom line - my four stars is really five stars. I like to allow for one star of new innovation.

Final comment- I am so proud of the "Made Here" sticker. The fact that this bike was made in America is just wonderful.

Nicholas Lysne
Best sales and expertise

I recently purchased my Echo and I can say that working with Cole and Will regarding the sale, build and compatibility of my bike has been outstanding. The team at Allied is undoubtedly the most professional I have ever worked with. The processes from start to finish are top notch. I am glad to spend my time and money with Allied thanks to these two gentlemen and the build team behind the scenes. Delay no longer people, get yours today..