1/2 belt & 5/8s belt

[Big Mike]

How much of a size difference is there between a 1/2 belt and a 5/8s belt. I know the 5/8s runs on the outer side of the pulley.

Example: i run a 85" 1/2" belt if i run a 5/8" belt would it be a 85" or a 86" since it rides on the outside

thx for your time

[Burwell555]

To get the best belt traction possible you should run a true A or B style pulley depending on the belt style you choose to run. The A/B type pullies often cause troubles due to optimal belt traction not being possible since the belt doesn't ride in the full contact surface of the pulley. Makes heat, we all know heat kills belts. Some of the fastest v twin mowers out there run 1/2 inch A style belts. I think I would look into true A type pullies before making the switch to a 5/8 belt. Those are not good in a clutching application and that leads to ate up shift keys and possibly exploded trannys.

[Big Mike]

ive spent a year and a half with these 1/2" belts and they dont work for me i tried all kinds of pulleys and my pulleys are alined they stretch and break  and snap. I have made my desision to use a 5/8" belt due to my weight, and track,motor being a factor

[saltyAMF]

im 300lbs and run a 1/2 belts on all my rigs including my b/p with a pretty angry vanny  something your doing must be off alittle.

[The Tank]

Something definitely isnt right. If you are sure all your pulleys are aligned and nothing is touching or rubbing the belt, sounds like a flexing issue on your frame to me. At one time I ran 5/8" belts and I will never use them again. The clutch would never completely release and it would burn the belts. Some of the highest horsepower mowers out there are using 1/2" belts without a problem.

[Big Mike]

well  it has happens Both of my 1/2" v belt have gotten to a point were it either snaps or it destroyed the out size of the belt and will twist it up. I can never tell when it happens when racing because i cannot smell any burning belt or hear it slipping it just goes out of no were

[russell jennings]

be sure to check all your pulleys,i had a new one from grainger that was machined on a tilt. didn't relize it until i took it off my trans and spun it on a 5/8's rod...just a thaught....

[Burwell555]

Generally 'snapping' a belt in half is usually result of too much spring tension pulling back on the clutch.

[Toadworks]

Belt breakage is too much immediate tension load, like dumping the clutch type of load. Not that you are dumping the clutch as it could be too much slack in the belt at deceleration, then when you hit the throttle the belt gets 'snapped' as it it loaded back up. A belt that twists is a sure sign of mis-aligned pulleys. Adding a guide roller or two on the slack side might help with the belt unloading as much at deceleration. Another thing may be a small increase in spring pressure on your clutch. Your belt could be 'bouncing' at the higher RPM's. Since your pulleys are twisting belts, I would say that you do have a belt that bounces. That bounce is part of the tension load you need to get rid of. Even just a small amount of unevenness in your pulley line can cause a belt to bounce. The belt, as it reels off the drive pulley is now higher (or lower or a different angle) then the driven pulley it is going to reel onto, the belt gets a little bump every time it changes direction and that sets up a wave of bounces. One of those bumps is going to mis-align the belt in the groove and the result is a twist in the belt.

Hope this helps you find your problem.

[royalblu68f100]

Do you have your pulleys perfectly flat with each other?  By this I mean is everything in a perfectly straight line including the clutch pulleys?  What type of clutch are you using (single or dual pulleys)?  Can we get some pics of the belt setup?

[Johnson Mowersports]

I run the carlisle belts on both my mowers I have run napa advance auto zone tractor supply )eluded they all slip or bust I have.the ec clutch with the billet  8" front with billet 5 on. The rear and a v groove idler on the slack side .with a big intek its the only belt that  will work for me.

[Big Mike]

i have plenty of tension on the clutch with a heavy spring and i havent had a problem with the belt slipping on De acceleration or take off. I do drop the clutch hard when the green is dropped.

Also added info some one asked me in a PM yes my CLutch is the same pedal as my brake.

[more4les]

I have always run 5/8 belts. I've run them all and the Gates/Napa seem to work equally as well as the red Aramid belts. I've never tried a 1/2 so I can't say alot to compare side by side but I've finished races with an almost destroyed one where the guys running 1/2 belt break with a couple laps remaining. One of my machines has run 2 seasons on the same belt and will run another this year. on my Supermods i change belts every 6-8 race days which include practice, heats and features (35-50 green flag lap features). The guys running 1/2 are changing at best every 3 most every other and some every race day. The 5/8 cost more but we spend less in belts overall. Just my 

Lester

[royalblu68f100]

I wonder if you are slipping the clutch just prior to the green flag at high rpms from the clutch dropping and this results in a twisted belt which would build enormous heat in the belt and destroy it?  Plus, why have your belt and clutch on the same pedal, I understand many do this but it affects the way your mower handles and drives on the track?  Sounds like your putting undo stress on multiple things at one time.

Plus, I ran 5/8ths belts because that was all I could get locally and I could not keep a belt on my mower until I switched to 1/2" belts and magically all my belt issues disappeared.I wonder if you are slipping the clutch just prior to the green flag at high rpms from the clutch dropping and this results in a twisted belt which would build enormous heat in the belt and destroy it?  Plus, why have your belt and clutch on the same pedal, I understand many do this but it affects the way your mower handles and drives on the track?  Sounds like your putting undo stress on multiple things at one time.

[Big Mike]

I wonder if you are slipping the clutch just prior to the green flag at high rpms from the clutch dropping and this results in a twisted belt which would build enormous heat in the belt and destroy it?  Plus, why have your belt and clutch on the same pedal, I understand many do this but it affects the way your mower handles and drives on the track?  Sounds like your putting undo stress on multiple things at one time.

Plus, I ran 5/8ths belts because that was all I could get locally and I could not keep a belt on my mower until I switched to 1/2" belts and magically all my belt issues disappeared.I wonder if you are slipping the clutch just prior to the green flag at high rpms from the clutch dropping and this results in a twisted belt which would build enormous heat in the belt and destroy it?  Plus, why have your belt and clutch on the same pedal, I understand many do this but it affects the way your mower handles and drives on the track?  Sounds like your putting undo stress on multiple things at one time.

Our track is smooth enough that i do not need to use breaks i let of the throttle

I have always run 5/8 belts. I've run them all and the Gates/Napa seem to work equally as well as the red Aramid belts. I've never tried a 1/2 so I can't say alot to compare side by side but I've finished races with an almost destroyed one where the guys running 1/2 belt break with a couple laps remaining. One of my machines has run 2 seasons on the same belt and will run another this year. on my Supermods i change belts every 6-8 race days which include practice, heats and features (35-50 green flag lap features). The guys running 1/2 are changing at best every 3 most every other and some every race day. The 5/8 cost more but we spend less in belts overall. Just my 

Lester

i have been hearing good things from those belts some guys at our track mostly heavy set guys running the 5/8s belt get 2 seasons on them. i was replacing my 1/2 every 2 racesalso i may add i have just a little flex on the very front of the mower when the engine is.