BOTW: Mosaic RT-1

We've shown other Mosaic RT-1 builds before, but if you are new to our site this is the Boulder, CO companies top of the range road frame.  The RT-1 (Road, Titanium, top of the range) frame features custom selected tubing in various diameters, custom butted main triangle, custom geometry, 44mm machined head tube and a few finish options done in house or full paint from Spectrum Powderworks (for an up charge).  There are other add-on options like internal rear brake routing, integrated seat post, and smaller things like fender/rack mounts or chain hanger.

Since the frame is custom and especially since it is custom butted on selected tube sets, the ride is really based on what you want it to be.  As most of you may know, titanium is well known for it's damping qualities and every RT-1 we've ridden has been incredibly smooth.  But that does not mean it's soft, depending on the tubes selected and the butting Mosaic can build frames for any type of rider in any type of event or race.  Mosaic founder Aaron Barcheck is getting a name for some of the cleanest welds out there.

We've been using Fizik bar tape, saddles and seat posts for quite a while now and we're extremely happy with the Italian companies new range of bars and stem.  Very clean with a simple design with minimal graphics is a nice contrast to the majority of what is on offer from other companies right now.  In short, they make 3 models of handle bar with three levels in each model, starting at $99.00 and going up to $400 for the dupe light 00 version.  The stem is available in one model with two different rises, a pretty standard seven degree rise and a negative twenty degree which I am really not sure why they bothered with.  A negative seventeen looks better as it pretty much matches most horizontal top tubed frames and is not too aggressive and we feel would have been a better choice.  The seat post has been around for a while but was re-finished this year to match the new stem and bars.  It is available in an aluminum R3 model and the carbon R1 model.  There is a lighter 00 model coming out in the future as well.  The posts are only available with 25mm of setback but have long platforms to hold the saddle rails and there is ample room for adjustment.  The Fizik seat posts are also very easy to adjust and look great, especially when used in conjunction with the rest of the Fizik cockpit.

Another look at the Fizik R1 carbon handlebar with the sweet Bar Fly made by our former shop manager and made exclusively for the Fizik stem.  This is only one great reason to go with the Fizik set-up.

The clean lines of the internal rear brake routing.  It's run all the way through the top tube, so you will use a full cable housing which keeps the rear brake cable clean and good for many miles before needing to be replaced.

The Shimano Dura-Ace Di2 rear derailleur.  Still prefer the mechanical version ourselves, but if you have to go with a battery, this setup is hard to beat.  We made it even better with the addition of Ceramicspeed rear derailleur pulley's.

The front Dura-Ace Di2 derailleur is a bit bigger and not as sculpted as the mechanical version, but it is pretty spectacular in operation.  A think of true beauty though is the front derailleur braze-on with Aaron's standard setting welds.

Hooded dropouts, non tapered stays, proper Shimano Dura-Ace quick release skewers and White Industry T-11 hubs all add up to a great rear end…

This is the first place you look to check out the welding talents of any titanium frame builder.  We'd say Aaron knows his stuff.  Ceramicspeed bottom bracket enhances the Dura-Ace drivetrain.  Also, check out the machined bottom bracket shell, one examples of the little things that add up to such a great finished bicycle.

We hope you enjoyed the tour of this Mosaic RT-1!  Thanks for reading and don't hesitate to contact us with any questions or comments!