By Rick Schultz
- Very Large surface area offers carbon steerer tube full support against over-compression from overtightening the stems’ pinch bolts.
- Easy / simple installation
- Low cost for the protection it offers
- None Identified
Price MSRP: $24.99
Source: Bike shops, Websites
Features: 6000series aluminum expansion wedges w/knurled sleeve
How Obtained: Manufacturers sample
Summary: One of the best full sized expansion plugs available
I’ve always been a huge supporter of Cane Creek products and use their headsets exclusively. When my 2014 Giant TCR Advanced carbon fork developed a hairline crack, it was time to quickly replace it. Luckily I had a spare Enve carbon fork laying around. The problem was that the Enve fork was a 2020 model and did not fit the 2014 Giant headset. A quick call to Cane Creek tech support supplied me with which headset I needed. In the meantime, waiting for the headset to arrive (unfortunately the Ancora didn’t exist back then), but fortunately, I had a spare Cervelo steel sleeve for carbon steerers (the one that gets epoxied into the steerer tube) that I started prepping the new fork with. With this solution, I could safely insert a star-nut.
Several days later the headset arrived and that’s where the second problem surfaced. As I tightened the center stem bolt, the headset bottomed out on the top of the head tube and the fork wouldn’t turn. A second call into Cane Creek quickly resolved that problem as well. Their solution was for me to install shim spacers that fit between the top of the upper bearing and the stem hat/cap. I bought a set and after they arrived, I finished the installation and I’m still riding the bike today!
Fast forward to several months ago where I described my build process for prepping a stem, selecting and installing the correct compression plug see – https://www.roadbikerider.com/bicycle-carbon-steerer-tubes-and-safety/.
There are severe and sometimes fatal consequences for skipping stem prep steps. Here is a graphic illustration. Carbon is strong but fails instantaneously. Ill-prepped stems, choosing an inadequate compression plug or the wrong compression plug, overtightening the stem’s pinch bolts – anyone of these can easily lead to a crack in your carbon steerer tube. And, to make a potentially catastrophic steerer issue even worse is the fact that not all steerers are created equally – see below.
The steerer tube on the left is from a Giant TCR advanced, the one on the right Orbea Orca. Notice 2 differences?
Wall thickness – Giant = 6mm, Orbea = 3mm
Center material – Giant = aluminum reinforced carbon, Orbea = carbon.
Which fork would you trust more?
The figure above shows several different ‘expansion or compression plugs’
- DO NOT USE ON CARBON
- NOT GREAT since the stem needs to clamp over the expansion part towards the bottom of the plug
- Carbon steerer tube with crack
- BEST OPTION allowing the stem the most adjustability and to clamp where there is SUPPORT
Extremely simple, easy and foolproof installation. Just slide the ANCORA into the steerer tube and tighten with a 6mm hex wrench. Add top cap and you are done!
If you would like one for yourself, check out: https://canecreek.com/product/ancora/
6000 series machined aluminum expansion wedges paired with a knurled sleeve to ensure a secure preload.
Note: Top cap sold separately.
Coach Rick Schultz is an avid cyclist who trains, races and coaches in Southern California. Rick is an engineer by trade, and in addition to being a coach, he’s a bike fitter and prolific product reviewer. He’s the author of Stretching & Core Strengthening for the Cyclist in the RBR eBookstore. Check his product reviews website, www.biketestreviews.com, and his coaching site, www.bikefitnesscoaching.com. Click to read Rick’s full bio.