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juan antonio said:
Is it just me or have Kreitlers belts quality gone down since Al passed?
Has anybody found a durable, quiet, 1/4"polyurethane replacement for them in both the 72" and 42" sizes?
I wouldn't know as I've been using the original belt for all these years. Have you had problems with new replacement belts? Are they breaking at the original joint or elsewhere? McMaster has 1/4" belt stock that you can buy, cut, and weld yourself.

What model rollers are you using? Fan, too?
 

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My alloy rollers' belt lasted for something like 7 years until this winter. The original weld has held but there were a few cracks in the belt that are now breaking during short anaerobic interval workouts. The 2nd break wasn't at the first repaired joint so I think it's possible to weld it yourself and have hold.

I found that if you don't weld it really well, it'll break, but if you do it right, it could last a long time (or at least a week so far since my first repair). I used a soldering iron and melted the ends quite a bit--about 1-2 mm should be turned into liquid. Then quickly push the ends together and check the alignment. Then you have to hold it for quite sometime. I did 30 seconds but would hold it longer in the future because I've seen 5 mins recommended. Then don't put any stress on it (don't even test it) for 15 mins or longer. I found that if I didn't do a good job, it would break almost immediately. I cut the belt at the big cracks and welded them to prevent future breaks so I have like 4 welds in the belt right now. So far, so good.

I think I'm going to order some belt material from McMaster and start making belts for myself and maybe other people if the new ones from Kreitler are that bad.
 

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juan antonio said:
I'll try the soldering iron, maybe I'm loosing something to the flame.
Let me know if it works better. So far, my joints have held up under my use which, so far, has only been up to around 400W (1 min intervals). That's the workout that always makes the cracks in the belt turn into complete breaks.


Here are the instructions from a splicing kit that I found online:

B u t t S p l i c e P r o c e d u r e s

A proper butt weld should yield upward to 100% of the beltings ultimate tensile strength.

Preheat heating tool for approximately 10 minutes before welding.

Cut ends of belt perfectly square using cutting shears.

Set belt clamp to proper spacing. Insert and tighten belt in clamps. Position belt ends in clamp until ends butt together. Ensure that ends are properly aligned.

Use side thumb screw to move belt ends slightly apart from hot knife. Insert tip of heating tool between belt ends. Best welds are produced when blade is "close" but not touching belt.

As belt begins to melt, watch carefully until material mushrooms or 1/16" bead forms all the way around each end of the belt. Withdraw hot knife and gently squeeze handles and/or tighten side thumb screw.

Be careful not to exert excessive pressure on splice.

Leave belt in clamp for a minimum of 5 minutes to allow for initial cooling. Allow an additional minimum of 15 minutes before tensioning or operating the belt. Do not strain belt before the full 15 minute cure time has elapsed.

Remove flashing from splice.

PRACTICE MAKES PERFECT
 
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