Resistance Issues

[fatboy]

I instruct at the Y and we have been slowly replacing our bikes with M3s. The problem is the 5 we got last year seem fine but the 5 we got this year seem to be too easy. The older bikes have black handles and the newer one red. I can put them eack in the same gear and the differance in resistance is like night and day. I there some want to adjust this or a procedure to cailabrate them so they are all close to the same?

[TuscanPhil]

Hi fatboy - did you ever get to the bottom of this? I've just recently qualified on the Keiser M3 bikes and am keen to get my studio bikes (18 of them) all working in a similar way. I found some great servicing information on the Keiser UK website but have yet to apply it to the bikes in the studio I use. We have 'the devil bike' (bike 10) in our studio that is at least 3-4 gears up/down (depending on your viewpoint) from the rest of the bikes, so if the instructor is in gear 10, the devil bike is in gear 6-7.

[Vivienne]

Hi fatboy - did you ever get to the bottom of this? I've just recently qualified on the Keiser M3 bikes and am keen to get my studio bikes (18 of them) all working in a similar way. I found some great servicing information on the Keiser UK website but have yet to apply it to the bikes in the studio I use. We have 'the devil bike' (bike 10) in our studio that is at least 3-4 gears up/down (depending on your viewpoint) from the rest of the bikes, so if the instructor is in gear 10, the devil bike is in gear 6-7.

In practical terms, this shouldn't be too big a deal, if it's one bike that's consistently inconsistent. It's irksome when things don't work perfectly but the "gears"/resistance on any bike are specific for the user. Your *10* might be the equivalent of a *4* for someone deconditioned (and vice versa)

With use, the brake pads on bikes that use them become worn......the reason why it'd be wrong for an instructor (usually riding the bike that gets most use/brake pad ear) to prescribe, say, half-a-turn


Vivienne

[TuscanPhil]

In practical terms, this shouldn't be too big a deal, if it's one bike that's consistently inconsistent. It's irksome when things don't work perfectly but the "gears"/resistance on any bike are specific for the user. Your *10* might be the equivalent of a *4* for someone deconditioned (and vice versa)

With use, the brake pads on bikes that use them become worn......the reason why it'd be wrong for an instructor (usually riding the bike that gets most use/brake pad ear) to prescribe, say, half-a-turn


Vivienne

Hi Vivienne - the Keiser bikes don't have pads - they use magnetic resistance, so nothing to wear out as such. Ref my 10 to someone else's 4, it's not that as I've ridden several of the bikes in the suite, so I know it's just that bike. The gears are specific to the bike, not the user on the Keiser M3 - any bike set to gear 10 will (should) have the same resistance as any other bike in the suite.

[Spook]

I have Keiser M3 in my studio with the black handles and I have been on the red handle ones as well. There is a definite difference. I believe the newer red version has different software and some different hardware. I have attached a document from Keiser that really show the comparison. Riders just need to use HR monitor, RPE or how hard their breathing is to figure out how to make the adjustment between the two.. Hope this helps. M3 Bike Computer Comparison.pdf

[liveon2wheels]

Unfortunately this issue just won't go away for Keiser. Thanks Spook for posting this pdf on the comparison between computer software versions, not sure why I never saw that before but it does "explain a lot". The new bikes are much different - the PDF though makes it look like they would be harder, but 100% of the people (owners and riders) I've spoken to agree that the newer versions are much more generous than previous versions. This is not only computer specific though since we upgraded all of our old bike models with the new computers and the differences are less, but still exist.

In fact, this issue has so perplexed and befuddled me that I spent a good bit of time and money trying to find a way to calibrate the bikes against an objective source of power measurement. I have reported my process & findings through ICI/PRO, and you can read (and watch - as they are mainly video blogs) about it here http://www.indoorcycleinstructor.com...ng-with-power/. My last 1 or 2 reports to finish up the project will be posted this week and next.

[TuscanPhil]

Hi Spook, great post and thanks for linking the document - it also goes to explain what I've thought all aong - that the handle position (even for the same displayed gear) does have a range of resistance. I wonder how easy it is to upgrade a black handle M3 to the later software or whether it needs some hardware changes as well. Sad to say it also means my ave power output isn't what I thought it was (due to the black line being under the Keiser power output line) so I guess I'm just going to have to work harder!

[tking]

At the Y I coach at we had the black handled Keisers for several years, software version 1. We started a 15-week power based progressive training class (now in it's 6th season) and when we started we wanted to measure the athletes' power to weight ratio but we knew we had to calibrate the bikes to some known standard. The only thing we came up with was to bring in a road bike (Felt) with a PowerTap rear hub on a resistance trainer and ride the Felt and Keiser side-by-side at the same cadence and same watts and adjust the Keiser until the pedal feel was aprox. the same between the two, that is 200 watts felt the same on both bikes. We repeated this with the other 15 bikes. Yes, very tedious. By the way, with the black handled Keisers the "magic gear", I call it, is gear 7, that is at gear 7 the cadence and watts will be the same.

We now have the red handled Keisers, software version 4 I believe. On the "red" bikes the magic gear is gear 10, that is in gear 10 the cadence and watts will be the same. While we still had the black handled Keisers we did a side-by-side comparison of the black and red. We found that 200 watts felt the same on the red and black bikes but the red bike had to be 3 gears higher in order to provide 200 watts. Lesson learned - forget about using gears when comparing bikes. Compare the bikes using watts.

We also learned that our "calibrated" black handled bikes provided the same resistance (comparing watts now) as our new red handled bikes. This demonstrated to me that Keiser engineered their new red handled bikes to offer the same pedal feel at a given watts as a "real bike", that is the Felt we used with the PowerTap rear hub on the resistance trainer. This is important because now our athletes can take their power to weight ratios on the Keisers and compare their performance against published standards, that is the Cat 1-5 table.

Note that on the old black handled Keisers you could adjust the magnet assembly at rest position and then calibrate which means you could manipulate the pedal feel at a given watt. On the new red handled Keisers the calibration procedure uses a tool that clips onto the flywheel and the magnet assembly is driven up into a pocket on the tool establishing "home position". It's a much improved calibration procedure and, the best part is, after the bikes are all calibrated, they all have the same pedal feel at a given watt, at least as much as your legs can tell.

Needless to say I'm a huge Keiser fan. Their latest bike version offers the same pedal feel at a given watts as a "real bike" thus enabling one to compare their power to weight ratio against published standards. The new calibration procedure provides a group of bikes that all have the same pedal feel at a given watts.

[amyindm]

We've had the same reports at our Y. We just got a batch of new bikes and everyone says that they feel easier at the same gear as riding the old bikes.

[KAriadne]

From a detailed aspect, it does bug the heck out of me that the numbers from bike to bike aren't the same. But (uncharacteristically for me) I breathe and let go. Teaching a class, I let participants know that over time the calibration can get off. I have them find the flat road for the bike they are on that day. When we do intervals where the goal is to hold a certain wattage I have them settle in based on RPE, then look at the watt number, and then hold that.

I will watch this thread because it does bug me that among the red levered bikes we have the feel can very so much. Just offering a "work around."

[SamIAm]

We have all M3's where I teach (with the red handles) and power varies considerably from bike to bike. Is there a way to calibrate the bikes so that they all read approximately the same power for a similar level of effort?