Profile AC-2 Hubs
- Intended for Expert/Pro level BMX racing
- Designed to provide less rolling resistance
- Developed in 2017 (approx.) and tested for two years before going into full production
- Unveiled at the 2017 UCI BMX World Championships in Rock Hill, SC
- First available for purchase at the 2019 USA BMX Grand Nationals in Tulsa, OK (11/28/2019)
- Officially released (and available for web sales) on 12/2/2019
- Features a patent-pending design with dual angular contact bearings
- Can be configured for 96 or 48 points of engagement - just take out every other pawl to reduce drag
- New and out-of-the-box, there's no brake-in period
- Easy assembly/disassembly (including bearings) with one tool - all can be done in under a minute
- "AC-2" stands for "dual angular contact"
- The inside of the aluminum shell features angled bores on each side for angular contact bearings - one bearing on each side
- Tapered hub shell bores work with angled bearing cones - to keep the hubs slop-free, even after years of use
- Bearings are preloaded by a wave spring
- The hub's bearings won't bind (they'll always spin free), even if the axle bolts are over-tightened
- The driver "floats" on the axle - there's no side-to-side load on the driver
- High lubricity coating on pawls and ratchet ring
- Fully serviceable with a pair of snap ring pliers
- Disc brake version available
- Colors: black, gold, ...
- Style (rear): cassette (with pawls and springs)
- Axle width: 100mm (front), 110mm (rear)
- Hole count: 36H, 28H (?)
- Bolts (front and/or rear): 3/8", 15mm
- Engagement (POE): 96 (6-pawls, for quicker engagement), 48 (3-pawls, for minimal drag)
- Bearings (standard): ABEC-5 stainless steel ball bearings (sealed)
- Bearings (upgrade): hybrid ceramic bearings (sealed)
- Cog interface: Profile, Shimano HG (?)
- MSRP (approx.): $535.00 USD (front & rear pair), $560.00 (front & disc rear pair)
- Tools necessary to replace bearings, rebuild, or service your hub: snap/retaining ring pliers (press/hammer not needed)
- Tested by John Pringle (2017-2019) - he never broke or damaged a hub after two solid years of BMX racing use, and the bearings in his hubs were never changed, oiled, or greased
- Made in the USA (Florida)
Sources for this Reference Page
- https://www.vitalmtb.com/photos/feature … /sspomer,2
This sounds like a pretty cool hub! According to Gus at Profile Racing, the average racer takes 8 to 10 pedals before the first jump in a BMX race and only about 30% of a race is spent pedaling. A rear hub with a high number of points of engagement (POE) is beneficial for the first pedal stroke in a series of pedals, but possibly more important is how well your hubs roll. A drawback to Profile's Elite rear hub (204 POE) is that when coasting, the pawls would work to minutely slow down your wheel, due to friction. By reducing the number of engagement points and creating a hub that has a set amount of preload on the bearings, the hub rolls faster due to less friction that want to slow its rotation.
Profile Racing, 12/2/2019 wrote:
Profile Racing’s AC-2 BMX Hub is now available!
“AC-2” = Dual Angular Contact. This describes the use of both angular contact bearings and angled bearing cups/hub bores used in the hub design.
The AC-2 hub features revolutionary bearing installation and function never seen before in a bicycle hub.
It has been designed from the ground up for ease of maintenance and optimal bearing performance.
The AC-2 Cassette Hub also offers changeable pawl/spring configurations for varying points of driver engagement to suit a rider’s personal preference.
Here are a few key points of the AC-2 BMX Cassette Hub:
- The AC-2 hubs use 20mm Angular Contact bearings with a wave spring pre-load. Bearings are pressed into tapered cups that mate with the angled bores machined into the hub shell. This design feature allows bearing/cup to be easily installed and removed from hub shell without any special tools. No more presses or hammers needed! Another attribute of the tapered bearing cup/angled hub shell bore design is how the bearings seat in the hub. The bearings/cups on each side of the hub shell are in perfect alignment with each other! This ensures superior bearing performance and less chance of premature wear.
- Hub shell and driver literally “float” on the axle. The only force on the bearings is supplied by the wave spring(which delivers the appropriate bearing pre-load needed for angular contact bearings). Tightening of axle bolts has absolutely no affect on the bearings!
- The bearings, wave spring, and shim(s) are secured on the axle by one retaining ring. The only tool used to assemble/disassemble the AC-2 hub is a pair of snap ring pliers!
*Profile Racing does offer a simple tool to aid in retaining ring installation and bearing/cup removal, but is not necessarily needed.*
- The AC-2 hub cassette driver is also unique. It allows for changeable P.O.E.(points of engagement). The hub driver comes standard with 6 pawls and springs. This option offers 96 P.O.E. -Maximum engagement. The other choice is to use just 3 pawls and springs. P.O.E. is reduced to 48 and minimal drag is achieved. This is a rider preference choice and both have a unique sound!
- The proprietary Profile Racing 10 spline aluminum cassette body allows you to use our standard steel, Elite, or aluminum cogs ranging from 12t to 18t.
- The AC-2 BMX hub has a true 20mm bolt-on hollow aluminum axle.
- You have a choice of either 10mm socket head(steel or titanium), 10mm button head(steel or titanium), 15mm alum, or 20mm alum bolts when ordering your hub. This hub can be used with any standard chromoly, aluminum, or carbon frame.
- The Profile Racing AC-2 hub is manufactured from a high grade, aerospace quality billet aluminum.
- Front and Rear hubs sold separately.
- Ceramic Hybrid bearing option available for hub shell bearings.
- Standard BMX 110mm width.
- RHD only
- Made in the USA!
- Spoke Holes: 28h, 36h
- Anodized Colors: Black, Silver, Red, Blue, Gold, Purple, Green, Matte Black
- Cogs: Steel 12t-18t, Elite 16t-18t, Alum 13t-18t
- Bolts: 10mm socket head steel, 10mm socket head titanium, 10mm button head steel, 10mm button head titanium, 15mm aluminum, 20mm aluminum
- Bearings: Steel 20mm angular contact, Ceramic Hybrid 20mm angular contact
- Weight: 325g/11.45 oz (weighed w/15mm bolts & no cog)
Source: Profile Racing
Press Release: Dec. 2, 2019
URL Link: https://www.profileracing.com/profile-r … available/
Page Created: 11/19/2019 -----> Info Updated: 12/2/2019
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