Question about slide travel.

freewheeling · Post by **freewheeling** » December 12th, 2007, 6:35 pm

After a move I set up my slides as recommended, with an 18 inch gap. For some reason the slide travel during a session seems to have moved "forward" so that it takes place in the forward 2/3rds of the slides. I don't recall this having been the case before. When I stop rowing and get off the device the erg re-centers. I find this forward drift very irritating even though I usually don't end up bumping the front. (I does happen more than I'd like though.) Am not sure what's causing this or how to correct it. Have used a carpenter level and the bubble seems to be centered longitudinally. I've cleaned off the seat track and the slide roller tracks (those plastic things, whatever they're called). Would getting new slide tracks and new bungees help? Shouldn't the erg travel be centered? I never noticed this being a problem before, and I have millions of meters on these slides.

Note: I have replaced the slide tracks several times after they cracked, but they seem intact now. I've never replaced the bungees, though.

johnlvs2run · Post by **johnlvs2run** » December 12th, 2007, 6:45 pm

What matters here is that each slide is level, not necessarily in relation to each other.

If you have the front of each slide level with the back of each slide then you should be balanced in the center.

In lieu of this, if you are constantly going more to the front, just raise up the front of each slide so your motion ends up being balanced in the middle. I did this by wrapping rubber pieces under the front legs with duct tape.

freewheeling · Post by **freewheeling** » December 13th, 2007, 12:31 am

John Rupp wrote:What matters here is that each slide is level, not necessarily in relation to each other.

If you have the front of each slide level with the back of each slide then you should be balanced in the center.

In lieu of this, if you are constantly going more to the front, just raise up the front of each slide so your motion ends up being balanced in the middle. I did this by wrapping rubber pieces under the front legs with duct tape.

Prior to this I had the slides set up on an irregular surface, and used a level to maintain the level of the slides. I shimmed things so that the bubble was centered, and that generally meant that the erg was centered in its to/fro travel. For some reason that's no longer the case. I could raise the front higher than the rear to counter the drift, but I just wonder what may have happened. I had the slides in storage for a couple of months, so that might have altered the tension on the bungees. However, I've tried shortening the rear bungee to the point that the front is quite slack with the erg at rest, and it still drifts toward the front when in use.

It may be that something is creating more friction in the system, and that the "drive" (which pushes the erg forward) is just never countered by the much slower return. That is, the power of the drive overcomes the friction, while the more innocuous return just doesn't do so. But I'm not an engineer, so that's just speculation. One would think the resistance from friction would be symmetrical.

Finally, I don't know what would be causing more friction, unless the slide rollers have worn out bearings or something.

Has anyone else experienced this?

johnlvs2run · Post by **johnlvs2run** » December 13th, 2007, 12:45 am

It sounds to me that your slides are not level.

If you think that's not the reason then turn the slides around in the other direction.

freewheeling · Post by **freewheeling** » December 13th, 2007, 1:25 am

John Rupp wrote:It sounds to me that your slides are not level.

If you think that's not the reason then turn the slides around in the other direction.

They're level, or at least as level as it's possible to make them without nuclear technology. If turning them around makes a difference then there's some sort of irregular surface that favors one direction over another. Either that or microscopic creatures are throwing themselves suicidally on the tracks just to mess me up. Worth checking out, I guess.

c2jonw · Post by **c2jonw** » December 13th, 2007, 8:32 am

Freewheeling, The slides can be pretty sensitive. A 1/4" blocking at one end can make a big difference, and that only changes the slope by about 1/3 of a degree. So your bubble level probably wouldn't pick up that discrepancy. Try a little shimming before you start replacing parts.....C2JonW

Byron Drachman · Post by **Byron Drachman** » December 16th, 2007, 2:18 pm

I didn't realize it was that important to have the slides level. I don't have any problem with mine, but if you want to measure how level yours are with good accuracy, and if you like collecting nice tools, and who doesn't?, a digital protractor is more accurate than a bubble. For example,

http://www.globalwebsupply.com/product/ ... ENSOR.html

I have this model, although I got it a few dollars cheaper elsewhere. It works great. I prefer it to a pitchmeter that uses a bubble when adjusting the rigging on a boat.

Byron

johnlvs2run · Post by **johnlvs2run** » December 16th, 2007, 3:02 pm

You could use a length of pvc, with elbows pointing upward at each end, filled with water. The level should be the same at each end. If not, raise up that end.

It's easy enough though, to just shim up the pads where the erg is coming closest to the ends, and no level is needed for this.

I've been wondering about raising the front and back both up an extra inch, to see if this would create a rocking motion with the erg.