# Treadmill belt



## tanusgreystar (Apr 18, 2007)

Anyone know about treadmills? I've been working on this stupid treadmill for like 2 years. I replaced the belt and I had a hard time putting the deck back on. Now I'm trying to adjust the belt so it stays in the middle, but it's really being difficult to say the least! The bottom part of the belt is almost all the way to the right, while the top part is right in the middle. I've been turning the right adjuster to the left and it doesn't seem to make any difference. I'm pulling my hair out here!


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## SABL (Jul 4, 2008)

If you can supply the make and model maybe someone can locate a service manual.


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## tanusgreystar (Apr 18, 2007)

It's a Pro-Form 635CW. I have the user's manual and it does tell you which way to turn the adjusters to get the belt lined up, but the problem is, the FRONT roller also had to be removed to put the new belt on, and that also has to be lined up in order for the belt to go straight. I need to know which way to adjust the front roller, but I don't think its in the manual.


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## SABL (Jul 4, 2008)

You will need to "counter-adjust" one roller against the other. In small increments, adjust the top roller to the right and counter-adjust the bottom to the left. I am not having any luck with finding a manual at the Pro-form site and this advice is purely speculation.


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## Done_Fishin (Oct 10, 2006)

first thing you need to do is get those rollers squared off to the "run" 

Not sure how you'd go about doing it but either a carpenters square or a T-Square might help, working from one of the edges of the run. Holding the square against the side and the drum you will be able to see what adjustment does what, ie which direction moves the drum inwards or outwards. 

The point you will have to remember is that once square at both ends there should be no movement at either end of the belt to the left or right.

If any movement is noticed at one end, then there are two choices,

if the movement is to the right, it means that the left hand side is too tight compared to the right hand side. you can either loosen the left hand side slightly, and wait to see what the result is, or tighten the right hand side slightly and wait for the response.

you'll need to go slowly, be patient and don't rush it.


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## kendallt (Feb 21, 2007)

Flat belts behave differently than you would expect. They tend to climb the tight side. So adjustment is actually backwards, you have to loosen the side it climbs, and snug the side it walks away from.

It's the reason that flat belt pulleys for line shafting, and band saws etc have a crown in the center. The crown pulls the belt to the center. 

Ken.


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## Done_Fishin (Oct 10, 2006)

Interesting .. It's not quite the way I remember from ~30 years ago .. probably because we only used short widths & lengths. Possibly trying to use too much "logic" with an aged brain :grin: 

Like I said Patience is one of the real keys. Look for the way it rides, make and adjustment and see it it responds. If it goes according to plan, adjust more if required. If it doesn't, then go back the way you came.


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