SRM_FINAL_15331One of the downside of the SRM power meter has always been the need to send it back into the company in order to replace the battery. Sure there are many consumers who have figured out how to do it themselves with the aid of well crafted online tutorials. However there are probably far more people who are less inclined to get out the tiny screw drivers and figure out what type of battery it needs, and are forced to ship it back to SRM and pay the $50 battery replacement fee which includes inspection and testing.

For anyone looking for battery changing convenience in addition to drastically improved battery life, SRM has announced their new UCB or User Changeable Battery design. Created in part with FSA, the crankset is based on an FSA K-Force Light BB386 EVO crankset and uses commonly available batteries. Instead of coin cells or square batteries inside the power meter, the UCB crank uses two standard AA batteries which are stored inside the crank’s spindle. After about 4000 hours, the batteries can simply be removed from the spindle by the consumer and replaced with two more for years of juice. Thanks to FSA’s one-crank-fits-all BB386 spindle and cup design, the crank can be used on BB386, BB30, PF30, BBRight, and standard threaded bottom brackets with their threaded MegaEVO cups.

Full specs including pricing after the break!

BB386 UCB ImageAt $2845.00 the SRM UCB is not cheap, but in line with previous power meters offered by the company. Currently available in a 110 compact BCD, there will be a 130mm BCD available soon.

  • Q-factor: 147mm
  • ANT+ Compatible: Yes
  • Battery Life: 4000 Hours
  • Warranty: 3-Year World Wide
  • MSRP: $2845.00
  • Accuracy: ±1% (Scientifically Proven)
  • Weight: 784 g(Including 2x AA Batteries)
  • BCD: 110 mm (50/34 Chain Rings) 130mm (coming soon!)
  • Crank Lengths: 170, 172.5, 175


  1. This is a major step forward for SRM, alleviates one of the biggest problems (after cost) that potential customers had with their product. They seem to have overshot the target a little though… I don’t think there is a honking great demand for 4000 hours in battery life. Most people who can pony up that kind of money, I am guessing, would think the tradeoff between the weight of those batteries and the tiny 2032 everyone else uses, versus the additional battery life just isnt worth the weight gain.
    They seem to be thinking in terms of trying to match their current battery life… which I’d want if I had to send it in for battery replacement. But I’m extremely happy with the light weight of the 2032’s in my quarq…

  2. I will never, ever, ever, ever, ever, ever………ever own another pair of FSA cranks after the spindle broke free from the crank on a barely used $700.00 carbon k force light.

  3. I do not get why people complain about sending their SRM in for service. With the current
    1400hr battery life that is 27hrs of ride time a week. I am thinking those that are screaming
    the loudest do not even own one. As for me I do not mind sending mine in every 1.5 years, it is
    nice to know it was calibrated by a pro.

  4. I fully agree that the battery “problem” of SRM is totally overestimated. Even 1,400 hrs of battery life are more than enough for most of the riders. There are probably not so many ppl out there reaching more than 600 hrs on their bike per year.
    And one should not forget that we are talking about a measuring instrument here, a device type that is usually inspected frequently. A torque wrench is supposed to be calibrated every 6 to 12 months.
    When reading how often I would have to change the batteries of some of the new powermeters, I would definitely prefer the SRM offering.

  5. AA’s are the most common battery found ANYWHERE… seems like they went for ease of use and long life span to focus on training, rather than battery replacement. Coin cells don’t really last that long! also it appears to only be 20 grams heavier than their shimano 11-speed meter. Not bad!

  6. Yes Travis, those complaining most loudly about the idea of having to send in SRMs for battery changes ARE those who dont own them. Because for many of us it is a deal breaker. And for those who can deal with it, yeah, it makes sense they bought them.
    That’s kind of a “duh” marketing question.

What do you think?