Santa Cruz Bikes

Representing our first foray into carbon fiber, the Blur XC turned most preconceived notions about lightweight bikes upside down. Incredibly light, yet at the same time much stiffer and stronger than its aluminum predecesor, the carbon fiber Blur XC set a new benchmark for cross-country expectations. Combining our proprietary one piece carbon fiber layup process with the proven ride of VPP suspension resulted in a bike that offers superb suspension and razor sharp performance. Now freshly redesigned, the Blur XC ups the ante again; a tapered headtube increases front end strength and rigidity, while further optimization of our carbon process has allowed us to trim even more weight from the bike. Lighter and stronger? rejoice.

Frame Features

• Full Carbon frame with one piece lay-up
• 105mm rear wheel travel
• VPP multi pivot frame design
• Recommended/Compatible with fork sizes 100mm to 120mm (*Tapered)
• Recommended rear max tire size - 2.35"
• Disc brake specific design, rotors up to 185mm
• Frame weight with RP23 Air rear shock - Approx 4.1lbs

Tech Data

• Shock Setup (pdf)

Reviews

• Singletrack - Issue 53 (pdf)
• What Mountain Bike - Nov 09 (pdf)
• Mountain Bike Page 1 : Page 2

Geometry

Blur XC Carbon Geometry
Based on 471mm axle-to-crown, 11mm HS stack

Frame Size	Top Tube Length*	Seat Tube Length	Head Tube Angle	Seat Tube Angle	BB Height	Wheelbase	Head Tube Length	Chainstay Length	Standover Height	Reach	Stack
Small	21.8"	16.7"	69.5°	73.0°	12.8"	41.5"	4.2"	16.6"	28.2"	15.2"	21.4"
Medium	23.0"	17.7"	69.5°	73.0°	12.8"	42.8"	4.3"	16.6"	28.7"	16.3"	21.8"
Large	24.0"	19.0"	69.5°	73.0°	12.8"	43.8"	4.7"	16.6"	29.2"	17.2"	22.2"
X-Large	25.0"	21.0"	69.5°	73.0°	12.8"	44.8"	5.1"	16.6"	29.7"	18.1"	22.5"

* Effective top tube
** Seat Tube length measured from center of BB to top of seat tube

Size Guide

Can I use a chainguide on my Blur XC Carbon?

Yes, there are plenty of guides that will work great on the Blur XC. For a more XC setup, try a top-only guide like the MRP 1x or E13 XCX. We'd recommend the bb mount version for lightest weight.

For full chainguidance, we recommend the MRP Lopes, MRP Mini G Sl, or the E13 LG1 Tr.

What size headset does the Blur XC Carbon use?

The Blur XC uses a tapered headtube often called "mixed taper". This setup uses a standared 1.5" external lower cup (49mm bore) and an internal 1 1/8" upper cup (44mm bore). Almost all headset manufacturers make this product.

Why does the Blur XC use a standard thread-in bottom bracket, when many of your competitors use press-in style (BB30, Pressfit 30, BB90, BB92, BB86)

It is true that there are some slight weight savings available with the various pressfit bb designs (exact weight savings obviously vary depending on system, frame manufacturing techniques, and crank model), but we don't feel this small savings make up for the inconveniences. We are still able to make a frame that is lighter than most of our competitors (4.1 lbs), while still using a heavier bb system. There are a number of disadvantages that exist with press fit systems:

1) Special installation and removal tools are required for these parts, including a headset press. This is not convenient for most home mechanics, and they are quite expensive. Traditional external BB's can be installed or removed with a simple $10 hand tool.

2) "Permanently installed cups". Shimano doesn't recommend removing and re-installing their press in bb cups (as they may become damaged), so moving parts from bike to bike is no longer an option. Shimano Instructions

3) Creaking or shifting bb's can be common with these systems. Since the bearing is pressed into a cup, which is then pressed into the frame- it can be hard to get all of the press fits snug- without being too tight on the bearing or too loose in the frame.

4) Reasonable tube sizes. One of the most commonly claimed advantages of a larger bb shell is the larger diameter downtube that goes with it. This may be an advantage on road bikes, where tubes can be increadibly thin and large for optimal stiffness. On a mountain bike, this area of the frame sees a lot of abuse from rocks and crashing, and needs to have a certain amount of wall thickness to survive actual use. Using what we consider a "safe" wall thickness and carbon layup, and a fairly typical tube diameter, we get an exceedingly stiff, light, durable product. If we used a larger downtube, we would either have a heavier frame (same wall thickness but larger diameter), or a less durable product (thinner walls and larger diameter).

5) Chain clearance. Take a look at some of our competitors frames with press in bb shells. The down tube comes so close to the chainrings that many frames have chainsuck guards on the downtube! In our mind, the chain should be able to fall off on a mountain bike and not get jammed between your crank and thin-walled carbon downtube.

6) Backwards compatibility: Many of our customers purchase a frame and build it up with their choice of parts, or parts from an old bike. By using a standard bb, we are compatible with everything without requiring confusing adaptors.

7) Chainguide compatibility: While it may seem strange to talk about putting chainguides on a short travel bike, it is becoming more common now with 10 speed drivetrains. Thread in bb's mean the frame is compatible with bb mount chainguides. We like versatility....

What is the torque spec for the front derailleur?

Tighten the front derailleur on the Blur XC Carbon to 45 in/lbs

Is the new Sram XX group compatible with the Blur XC carbon?

Yes, but you must use the standard Q-factor version of the cranks (166mm). There is chainring clearance with the 26/39 tooth and 28/42 tooth chainring sets, but the 30/45 will have interference issues. There is only 2-3mm (much less than we typically require) clearance for the 42t ring, so in general the 39t setup will be a safer bet. However, we haven't seen any actual issues with the 42 to date. click here to see a photo of the chainring clearances
click here to see a photo of the crank clearances

There was a packet of "friction paste" or "carbon assembly compound" included with my frame- what is this for?

Use this on your seatpost. Carbon frames have a pretty slippery inner surface that makes it difficult to get the seatpost held tight without massive tightening forces at the collar. Using the carbon assembly compound adds friction so you don't need to crank the heck out of the seat collar.

It looks like the lower link is off center in my frame- is everything ok?

Yes- this is correct. With our newer pivot system, the pivot axle draws the link over to one side in order to properly preload the bearings. This offset is accounted for in the frame design so everything ends up nice and straight in the end.

What size fork should I use on the Blur XC Carbon?

The Blur XC Carbon accepts 100-120mm forks.
We wanted the Blur XC Carbon to be confidence inspiring and race ready at the same time, so we designed it to have a 69.5 degree head angle with a 100mm (471mm axle-crown) fork. The bike can be ridden quite aggressively with this setup, with no weight compromises. This is probably the size fork you would want for xc racing.
We definitely wanted to be able to use a 120mm fork on this bike though, and made it accordingly strong. For riding or even racing in rockier terrain, a 120mm fork is pretty fun.
Please don't use a fork over 120mm of travel, as it does exert more force on the frame than it was designed to handle. This also voids your warranty. The geometry will get pretty funny with a longer fork, so you wouldn't really want to do it anyway.

What size shock is on the Blur XC Carbon?

All frame sizes use a 6.5" x 1.5" (165x38mm)shock.

Mounting hardware on both ends is 22mm wide (21.84mm to be exact), with an 8mm through hole.

What kind of front derailleur do I need?

The Blur XC Carbon requires a bottom swing (high clamp), top pull, 34.9mm front derailleur. Both SRAM and Shimano make models that work. Note that all of our other bikes use a different style derailleur (top swing), so this part will not transfer from another one of our bikes.

Can I use a quick release seat collar?

Absolutely. The frame takes a standard 34.9mm seat collar, so there are plenty of quick releases that will fit. Our favorite is ours, of course. You can purchase it on our online store for $24.

Are there water bottle mounts?

Yes. All frame sizes have two bottle mounting locations. One on top of the downtube, and another underneath for longer rides. Custom aluminum mounting bolts are included with the frame.

I would like to use a different shock on the Blur XC Carbon, can I do that?

Yes, the shock is a very common size, and there are plenty of other models on the market that will fit.

What size seatpost does it use?

Like all Blur models, the XC Carbon uses a 30.9mm post. Make sure it is always inserted a minimum of 100mm into the frame.

What is the largest tire that will fit?

We never like to make promises here, as tire dimensions vary so much, but pretty much any 2.35" or smaller tire will fit fine.

What is the largest rear brake rotor that I can use?

Most riders will want 160mm rotors, but a 185mm will fit as well.

I'm addicted to using a Gravity Dropper/Joplin adjustable seatpost- can I use one on this bike?

We are all huge fans of adjustable seatposts, and included cable routing under the top tube for this purpose.

What kind of cranks can I use?

We use a standard 73mm bb shell, so pretty much any cranks you want will fit on there. Just make sure your crankset has a 50mm chainline, and you are good to go.