# Adding resistance to rollers



## andulong (Nov 23, 2006)

Hi all,
I have been riding all my life but just recently purchased a set of rollers. Minoura action advance. Nice rollers, smooth, fairly quiet but not enough of a workout. I find I am riding in top gear for 20 minutes at a stretch and would like to know if anybody has come up with a way to add resistance to rollers...besides the mag units that can be purchased and added on. They seem to be quite expensive and not readily available. And I am having no luck on eBay. I have heard of guys putting folded towels under the rear roller to add rub resistance but I was thinking more of trying to drive something with a belt off the rear roller...generator...fan...etc? 
Thanks for any advice.
A


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## shawndoggy (Feb 3, 2004)

Currently using the towel method. It works, though it's a little hard to "tune". The other thing to do is let some air out of your tires.


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## FrancisB (Sep 10, 2006)

www.insideride.com 

rollers, resistance, balance, out of the saddle hammering. Best training tool I've seen in 20 years of riding.

I'm not a shill for the company, just a satisfied customer. 

Only drawback is it's fairly expensive, but you'll have it for life...

YMMV

Francis


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## Kerry Irons (Feb 25, 2002)

*Simpller solution*



andulong said:


> would like to know if anybody has come up with a way to add resistance to rollers...besides the mag units that can be purchased and added on.


Quite simple, really. Let some air out of your tires.


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## uzziefly (Jul 15, 2006)

yeah let some air out.. of course not too much!


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## magic (Dec 8, 2005)

You can also go the cheap old school route. Weave some cardboard strips in your wheel or wheels. Kinda budget way to add some wind resistance but it works well.


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## andulong (Nov 23, 2006)

*What about???*

First off, thanks to everybody who offered some advice to my original question. I will try them out to see how they work. But here is another question I am hoping someone can help with...along the same lines. There is currently not a mag unit on the market (at least not available now) for my 80mm Minoura Advance rollers but I keep seeing the magnetic unit for the Cycleops alloy rollers. This unit does not spin like most resistance units but uses a magnetic bar that can be moved near the roller drum to "somehow" create resistance. Does anybody use this or know how it works? The drums are not magnetic and in the photos I can not see any way the magnet could have any affect on the roller speed. Maybe some sort of iron weights added to the inside of the roller or strips on the outside of the roller? The unit looks like it could easily be adapted to fit my brand of rollers but first I would like to understand how it works and I can not find anything online that explains it......thanks!!!!!!!!!!!!!!!!!


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## NomadVW (Jun 30, 2006)

I have the minoura rollers with the mag resistance unit. I'm not sure how any other resistance unit would fit the item. I haven't even seen the resistance unit in the local catalogs for Minoura here in Japan as a "part." While you're considering your options, I'll check the LBS to see if they can order it as a part for you and I would ship it to you from Japan if they can.

VW


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## andulong (Nov 23, 2006)

*Thanks VW*

Thanks for the offer, but I was able to locate a LBS that said they could get the mag unit for my roller set...just not available until mid December. 

T


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## danl1 (Jul 23, 2005)

*Magnetic Induction...*

They work on the presumption that the roller is made of aluminum. Since Aluminum conducts electricity, passing a bit of Al through a magnetic current induces a small electrical current within the roller. In turn, that current posseses a magnetic field of it's own. Courtesy of the handy laws of physics, that magnetic field opposes the field of the stationary magnets, creating resistance (and also helping to add to the currents produced.) I could go on about the physics of it all, but I'm old and forget the details (and am too lazy to look it up.) Essentially, this is the way electrical generators work, or the dynamic brakes for various electric vehicles and locomotives.

One potential drawback to this method is that the current flow can generate considerable heat in the aluminum. It would be equal to the amount of work you put in (that is, equal to the added resistance) and should dissipate reasonably well. I don't have any experience with this sort of unit to know if it would be particularly undesireable. 

A "mag" resistance unit works in precisely the same manner, only it's an aluminum disk running within the unit rather than the drum itself. The resistance dial works by adjusting the distance between the disk and the magnets. The "bar" unit has adjusting screws at each end to accomplish the same adjustment.


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## Squint (Jan 22, 2004)

Ride Armadillo standard tires. My 700x25C Armadillos required 200W to ride 20 mph on 4.5" Kreitlers...with the fan disconnected.

My race wheelset required around 80W at the same speed.


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