Concept2 Forum

My Model B's skewer bar has a *slight* bend along its length. This bend is currently oriented opposite how the manual says it should be.

Am I supposed to be able to reverse the bar, so that the bend is oriented correctly (i.e., so the traveling pully is on the concave side)?

It looks like I *cannot* reverse the bar this way, since one of the 4 axle sides is of a larger diameter and shorter length than the others.

By the way, I have this open because I'm trying to diagnose a *loud* screeching/creaking noise. There's no wear on the traveling pulley plastic, but there is a stripe of light wear along the side of the bar where the traveling pulley travels. Perhaps the pin in the traveling pulley is scraping the bar and causing all the racket (though I wouldn't expect that to sound nearly so loud)?

Thanks.

The four axles on the skewer bar are the same diameter so you should be able to reorient it to get the bend in the right direction. You might also be able to change the bend by slightly loosening the four mounting screws. Watch the bend as you loosen each screw slightly. The screeching is very likely what you describe- the axle of the traveling pulley being pinched between the skewer bar and the wall of the rail. C2JonW

Right you are: they're all the same diameter. Really dumb mistake on my part.

I just want to confirm: I can safely reorient the bar even though one axle side is a shorter length than the others (protruding from the bar approx. 1.5cm rather than 2cm)?

Thanks.

Hmmm, I'd forgotten about the different axle lengths. Are you sure it's not just the screw tightness that makes it look like there's more axle on one side than the other? Try this: loosen all four skewer screws a few turns, then tighten first the two on the right side (non-traveling pulley) to pull the skewer bar as far away from the traveling pulley as possible. Then snug up the two on the left. If playing with the screw tightness has not worked, I think what I would do is remove the entire return mechanism and simply bend the skewer bar in the desired direction. C2JonW

I removed the skewer and measured again. It looks as if the front axle shifted, if that is possible. One side (the side that the chain slide was on) is shorter than the sides on the rear axle, and the other side on the is longer than the sides on the rear axle. I tried tapping it with a hammer, but it I didn't see any movement. Is this something I can adjust?

Or could this be an intentional design of my version of the Model B? The date stamped on the back of my right footboard is AUG 29 1988. (A great machine, to keep going all these years.)

Thanks.

It's possible the axle shifted- it's pressed into the bar and its fit and location is somewhat variable. There just needs to be enough room for pulleys to turn and for the traveling pulley to move without interfering with the chain and bungee. C2JonW

Thanks, c2jonw!

I'm going to reorient the bend, as soon as the new shock cord I ordered arrives.

This machine should then be good for at least another 20 years.

It's fixed and works great. Thanks again.

There is a minor problem with the chain rubbing against the side of the chain slide. This is due to the chain slide now being on the short side of the shaft. Next time I am feeling ambitious, I will take the skewer back out, and either move this shaft to the rear, or try to adjust the shaft.