5 ms·

http://www.vivax-assist.com/en/produkte/vivax-assist-4-0/vivax-assist_4-0.php http://www.vivax-assist.com/en/produkte/vivax-assist-4-0/viv... “This model has t

by zootam 11y ago

http://www.vivax-assist.com/en/produkte/vivax-assist-4-0/vivax-assist_4-0.php http://www.vivax-assist.com/en/produkte/vivax-assist-4-0/viv... “This model has three settings,” he explained. “It produces between 50 to 75 watts for about an hour and a half, does 150 watts for an hour and in its highest setting, produces 250 watts for up to 30 minutes." It can provide a substantial advantage at the high levels of competition.

RockyMcNuts 11y ago
for sure ... average power on a stage might be in the high 300 Ws for a tough mountain time trial, lower over the whole race when you're in the peleton, an extra > 50W or 0.5 W/kg would turn a nobody into a champion. http://www.bicycling.com/training/fitness/trainingpeaks-power-profiles-cyclists http://www.bicycling.com/training/fitness/trainingpeaks-powe... http://sportsscientists.com/2011/07/the-tour-de-france-power-2011-outputs-from-the-outside-in/ http://sportsscientists.com/2011/07/the-tour-de-france-power... http://sportsscientists.com/2009/07/tour-de-france-2009-power-estimates/ http://sportsscientists.com/2009/07/tour-de-france-2009-powe...
- mc808 11y ago
  A 10% boost for an hour, or a series of short breaks without having to stop, could turn an almost-champion into a champion.
  - RockyMcNuts 11y ago
    if by almost-champion you mean someone somewhere back in the pack. Relative to me the Cleveland Browns are almost Super Bowl champions!
    - mc808 11y ago
      Yep I misread "a nobody" as "nobody".
alistairSH 11y ago
Wow. I never imagined an in-frame motor/battery would produce that much power. 250W for 30 minutes is more than most non-racing recreational cyclists can manage.
- resoluteteeth 11y ago
  My first thought was that it should be impossible, too, but the answer is that the battery isn't in the frame. It's either in the saddlebag or (in the fancier version) disguised as a water bottle.
  - nl 11y ago
    There's plenty of room in a frame for a battery. You don't need to run the motor 100% of the time - 1 minute bursts at critical times is more than enough. Shimano, Campagnolo and SRAM all make batteries designed to fit in the seat tube for electronic gear shifting.
    - resoluteteeth 11y ago
      > Shimano, Campagnolo and SRAM all make batteries designed to fit in the seat tube for electronic gear shifting. Electronic shifting uses almost no power; the derailleur just has to periodically move a few millimeters. There's absolutely no comparison. In total, there is "plenty of room in a frame" and so it's probably theoretically doable, it would just require much more work to pack it with cells and wire everything up. The companies currently making these motor kits are probably using off-the-shelf battery packs. Maybe you're right, though, that a smaller battery providing "bursts of power" would be enough to make a difference though.
      - alistairSH 11y ago
        Absolutely - in a climbing stage of le Tour, a racer would just need a few bursts to match the acceleration of the other tops riders as they try to drop the peloton on the steepest sections. 20-30s bursts, 100-200W, would be more than enough to stay in the race. In something like cyclocross, the difference from a frame motor would probably be even bigger. The races are shorter (60 minutes vs 4-6 hours) and the power bursts are short and intense - power through a mud pit, stay on bike instead of running a super steep hill, etc.

by zootam 11y ago

RockyMcNuts 11y ago

for sure ... average power on a stage might be in the high 300 Ws for a tough mountain time trial, lower over the whole race when you're in the peleton, an extra > 50W or 0.5 W/kg would turn a nobody into a champion. http://www.bicycling.com/training/fitness/trainingpeaks-power-profiles-cyclists http://www.bicycling.com/training/fitness/trainingpeaks-powe... http://sportsscientists.com/2011/07/the-tour-de-france-power-2011-outputs-from-the-outside-in/ http://sportsscientists.com/2011/07/the-tour-de-france-power... http://sportsscientists.com/2009/07/tour-de-france-2009-power-estimates/ http://sportsscientists.com/2009/07/tour-de-france-2009-powe...

mc808 11y ago
A 10% boost for an hour, or a series of short breaks without having to stop, could turn an almost-champion into a champion.
- RockyMcNuts 11y ago
  if by almost-champion you mean someone somewhere back in the pack. Relative to me the Cleveland Browns are almost Super Bowl champions!
  - mc808 11y ago
    Yep I misread "a nobody" as "nobody".

alistairSH 11y ago

Wow. I never imagined an in-frame motor/battery would produce that much power. 250W for 30 minutes is more than most non-racing recreational cyclists can manage.

resoluteteeth 11y ago
My first thought was that it should be impossible, too, but the answer is that the battery isn't in the frame. It's either in the saddlebag or (in the fancier version) disguised as a water bottle.
- nl 11y ago
  There's plenty of room in a frame for a battery. You don't need to run the motor 100% of the time - 1 minute bursts at critical times is more than enough. Shimano, Campagnolo and SRAM all make batteries designed to fit in the seat tube for electronic gear shifting.
  - resoluteteeth 11y ago
    > Shimano, Campagnolo and SRAM all make batteries designed to fit in the seat tube for electronic gear shifting. Electronic shifting uses almost no power; the derailleur just has to periodically move a few millimeters. There's absolutely no comparison. In total, there is "plenty of room in a frame" and so it's probably theoretically doable, it would just require much more work to pack it with cells and wire everything up. The companies currently making these motor kits are probably using off-the-shelf battery packs. Maybe you're right, though, that a smaller battery providing "bursts of power" would be enough to make a difference though.
    - alistairSH 11y ago
      Absolutely - in a climbing stage of le Tour, a racer would just need a few bursts to match the acceleration of the other tops riders as they try to drop the peloton on the steepest sections. 20-30s bursts, 100-200W, would be more than enough to stay in the race. In something like cyclocross, the difference from a frame motor would probably be even bigger. The races are shorter (60 minutes vs 4-6 hours) and the power bursts are short and intense - power through a mud pit, stay on bike instead of running a super steep hill, etc.