Carbon Unit

Anyone use the additional 12 lb flywheel on their KK Road Machine? I am trying to determine if it worth adding one. All the new machines are capable of adding the larger flywheel but my machine was made about 6 months before Kurt made the change.

Any idea what they changed? A machine built since 2010 can add the extra flywheel for about $80.00. It would cost me $350 to add it to my machine which is more than I paid for it. I would think a machinist could make the modifications so that an older machine could accept the larger flywheel but it might not be worth the effort.

I don’t need the trainer now but in the winter months, I might start using it again.

Hida Yanra

nope - not worth it.

Silvercivic27

Why are you so concerned that you need that heavier flywheel anyway?

gsteinb

It adds more weight which gives it greater momentum which is supposed to more realistically mimic a road ride. It'll have longer spin up and coast down times. Most likely not worth worrying about it.

Silvercivic27

I know what the brochure says, but why does it matter? Besides, it's going to take a lot more than a flywheel to make a trainer ride similar to a road ride.

gsteinb

I'm not talking out of the brochure but from riding it (the larger flywheel, not the brochure). So it matters if one wants more momentum. It provides a better ride. Some spin bikes have larger and heavier flywheels. They're a better ride than the spin bikes with smaller and lighter flywheels. Same physics at work here.

surgeonstone

I have it, I used it once.

canam73

I bought my KK used and it came with one. Note that it is only recommended for steady/tt type stuff and not intervals, which is all I use my trainer for. Also, with regular tires (krylions & GP4000s) you need to crank it down a crazy amount to prevent slipping. The one time I tried it with a Vittoria trainer tire it worked better.

Carbon Unit

Thanks for responding. I had considered the heavier flywheel so ghat I could do 2 hour rides during the winter. However, the more I thought about it the less I wanted to be on a trainer for 2 hours. So I agree it isn't worth getting it. I will stick with using the trainer for intervals.

DaveWC

My Trutrainer roller has a flywheel that is fixed, always on. I find the ride much more realistic compared to other rollers I've tried.

jrobe

If I had one I would take it off. The best use of the trainer for me is for shorter interval sessions. A heavy flywheel would make these more difficult.

Spend you money on Spinervals or CTS DVD's and you will have more effective and far more enjoyable trainer workouts.

Carbon Unit

I want to use the trainer as a training tool to simulate intervals and hill climbs. My KK doesn't provide as much resistance as a spin bike but I think I can still improve my hill climbing with it by pushing it until my legs are burning.

fordmanvt

I'm in the same situation and looked at his before.

They are talking about a cross sectional area of 113cm^2 for the older model and 201cm^2 for the new/pro unit. I would take their advice on the additional weight.

As others have stated, doesn't seem worth it.

gregf83 

Why would a heavier flywheel make the sessions more difficult? With the heavier flywheel it does a better job of simulating the inertial load you have when riding outdoors.

rogerstg

The reality of using the heavier flywheel is that your tire will lose contact with the roller more easily during the acceleration of an interval. This requires backing off a bit, contrary to your goal.

Just use a bigger gear if you want more resistance.

jmX

Hrm, this is exactly why i wanted the heavier flywheel. I wonder if a trainer specific tire would have enough grip? Right now I just use worn out GP4000s's on the trainer.

darb85

i have it, no issues with intervals, I like it.

handz98

Me too!

Beaker

If you ever want to take your trainer to events for warm ups, an extra 12lbs to lug around sounds irritating.

Carbon Unit

It might be irritating for some people but I don't race so I would never take a trainer anywhere. Also, I think the larger flywheel come off in a few seconds.

rogerstg

I've used various tires including GP4000 and the Conti trainer tire and tighten the contact knob as much as I can by hand (more than the recommended amount by Kurt). Still, there seem to be others that have no issues with slipping when they sprint so I wonder what is different.

rogerstg

You can easily remove it and leave it at home for those situations

canam73

I had slip problems using worn Krylions and possibly a GP4000s (can't remember if tried it). Seems the one time I used it with a Vittoria trainer tire (red) it worked better. But I have since removed the extra weight.

Per Kurt's literature, the added weight is really only meant for endurance/tt training as it keeps your spin going at a more consistent rate. They recommend removing it for intervals, possibly due to slippage issues. And note that it doesn't add any resistance once you have it at speed, it only takes a little longer to get it there and holds it at speed longer.

And yes, it is not difficult to install or remove it.

therhodeo

I bought the "pro machine" I think it was on clearance from performance and it came with the flywheel. It makes long tempo and endurance workouts feel much more natural. Not the thing for intervals though. Overall I'm glad I have it.

MrTuner1970

Same here. If the tire is slipping, just increase the pressure until it doesn't.

I've never been on a spin bike, so can't comment on its resistance. If you are stronger than the resistance the KK provides, you should be pro. You'd have to be able to do 40-45 mph on flats to max out a KK fluid unit.