With a 15% pulley, I have read that, among others, Gates K060535 (6PK1364) and BANDO 6PK1360 are used interchangeably. Is this possible? Is it just a variance between manufacturers...or is 4mm shorter in length acceptable?

 

Belt 1 : Gen 1 MC Stock : Gates 1050mm / K060406
Belt 2 : Gen 1 MCS Stock Length or Stock SC Pulley w/ 2% Crank Pulley : Gates 1404mm / K060547
Belt 3 : Gen 1 MCS JCW or 15% Pulley: Gates 1379mm / K060535
Belt 4 : Gen 1 MCS 17% or 19% Pulley: Gates 1367mm / K060532
Belt 5 : Gen 1 MCS 15% or 17% Pulley w/ 2% Crank Pulley : Gates 1385mm / K060539
Belt 6 : Gen 1 MCS Air Conditioning Delete Belt. Will run Crank, Alt., and Supercharger : Gates 856mm / K060331 Note: Must remove idler pulley (see photo).
Belt 7 : Gen 2 MC/MCS All Models N12 & N14 up to 04/10 : Continental 6K906 Length: 906mm Long (11-28-7-566-789)
Belt 8 : Gen 2 MC/MCS All Models N16 & N18 04/10 - 2015 : Continental 6K895 Length: 894mm Long (11-28-7-604-014)
Belt 9 : Gen 2 MC/MCS All Models N12/16 & N/1418 Air Conditioning Delete Belt Dayco 6PK0692 Length: 692mm Long
Belt 10 : Gen 3 MC/MCS All Models F Cars : Continental 6PK1715 Length: 1715mm Long (11-28-8-573-252)

Source: https://www.detroittuned.com/mini-cooper-belts/

 

I appreciate the list but it doesn't answer my question. In addition, the Gates K060535 listed as being 1379mm is the outside circumference measurement which is confusing the issue when the same belt is referred to as a 6PK1364.

 

Metric is so much easier to understand and grasp,
I really don't like tenths of an inch!



As for your original query --- from searching old posts on NAM it seems like the Gates K060535 is the most popularly cited belt as being used.

But if the 4mm shorter Bando 6PK1360 is known to work well, then I'd likely prefer that option. Can't be of much help here because I'm still on the stock 11% JCW pulley and have only ever used 6PK1374 size so I lack experience in that department.

What size belt are you currently running?

 

Why does the Gates sleeve pictured have a dimension of 1379mm when 6PK1364 decodes to 1364mm... is 1364mm the ID and 1379mm the OD?

Related to the OP's question, what +/- tolerance would acceptable assuming the belt length stated on belt is accurate, and would 4mm really make a difference if not at a limit? The Detroit Tuned chart adds to the confusion if you look at the numbers closely. The difference in belt size for a 15% and 17% in the chart above is 12mm, yet combining the same size 2% crank pulley with a 15% or 17% uses the same 1385mm belt?? That's 6mm longer than a 15%, but 18mm longer than a 17%. Then it shows a stock pulley, with or without a 2% crank pulley uses the same belt. Plus, I thought a JCW belt would slip if used with a 15%, but they say you can use the same belt for both even though there's a 4% difference in reduction.

 

Thanks for the replies, Old Boy and RB. You've joined me in my state of confusion over the various belt recommendations. Yes, the 1379mm dimension is the outside circumference. Why they bother to throw that dimension into the mix is beyond me. I've just installed a 15% pulley on the GP, along with a Gates K060535. With the tensioner captured in the 2nd hole, the belt was a struggle to fit over the idler pulley but it finally made it. That caused me to wonder about the BANDO 6PK1360. If it's 4mm shorter, that would really present an even more difficult job. Hopefully, someone who's installed one on a 15% pulley will ring in. Old Boy, if you need a spare 6PK1374 or two, let me know. I have a bunch of new OEM MINI and other manufacturers that I'll be glad to let go for ridiculous prices.

 

I just installed a 17% pulley with a 532 belt. It was a PITA to get on! I had my wife hanging on the tensioner while I walked the belt on, while turning the motor. After all said and done, I can see both holes in the tensioner tab.
Should I put on a bigger 535 belt?
TIA

 

Yes on those 1374's!

Will send a PM

:

Wish that there was a definitive guide for all the different applications of belt sizing.

Mathematics ain't my forté LOL

Found this old post on MT:

https://www.minitorque.com/threads/p...emystify.6469/

quote:

"Stock setup

Belt - 1380mm
S/C - 65.5mm
Crank - 134.9mm
Alternator - 49mm


Then, for a random setup (mine), we have:

S/C pulley reduction - 17% = 54.365 (-11.135)
Crank Pulley + 2% = 137.598 (+2.698)
Alternator + 5% = 51.45 (+2.45)

This means that the new belt has got to have: 1380 - 11.135 + 2.698 + 2.45 = 1374mm

So, the right belt for me would be the one with the closest value to 1374mm and that would be the K060539, with 1371mm.

Another classic example:

S/C pulley reduction - 17% = 54.365 (-11.135)

This means that the new belt has got to have: 1380 - 11.135 = ~1369mm

Again we should go to the closest value to 1369mm and that would be the K060539, with 1371mm.

Another classic example:

S/C pulley reduction - 19% = 53.055 (-12.445)

This means that the new belt has got to have: 1380 - 12.445 = ~1367mm

Again we should go to the closest value to 1367mm and that would be the K060535, with 1364mm. Here we might remember that we are talking about a difference of 1mm in choosing between the K060535 and K060539 (1367-1371 = -4mm); (1367-1364 = 3mm)
One is looser, and the other tightened, this should also enter the equation.

So, we are talking of barely noticeable differences, such small variances that are not accompanied by a wider range of belt sizes. And if you consider that the math done here should also take in account the contact surface of the pulleys, then the differences would be even more marginal."

 

Thanks! I follow the math and all that, but according to that, I am suppose to run the K06539 (1369.06) and not the K06532 (1351.28). I came from a 15% which had the K06535 and WMW sold me the K06532 with the 17%. So there is a 17.78mm difference. Now my head hurts!

 

If the DT chart is correct the 1369.06 is closest to the K060532, 1367mm belt so the new belt WMW sent seems correct. Where is the 1351.28 number from?

Also, not sure how it affects the belt length calculations but the reference given above for the crank in a stock setup being 134.9mm seems way off. Using this, a 2% crank pulley should be about 137.6, yet the ATI website lists the 2% at 5.75" which converts to 146.05mm. If my math is correct, from 134.9mm a 2% ATI pulley would be over 8% larger.

 

That was just converting from freedom units to SI: 532 x 0.1 x 25.4 = 1351.28
I am still waiting on a bung to be welded onto the headers, once I have that installed I will start and see if the are any weird noises! Maybe it settles a bit.

 

I have a 15% pulley and I could not fit a 535 belt. Had to use the 539 belt.

 

Hello All, The belt chart that we have put into place on our website are the belts that we use for all of these applications. https://www.detroittuned.com/mini-cooper-belts/ They only make so many belts (sizes) and while say a perfect belt for a 15% might be a 1380mm or a 1378mm they only make a 1379mm belt. So when you look at the chart and you see that stay a stock SC pulley and 2% crank pulley use the same belt. It's close enough that it's going to work the same. The tensioner will be in a touch different location but will take up the slack as needed. Also, the odds that someone is running a stock SC Pulley and a 2% crank are also very slim. Most everyone is using a 15% pulley or more. we tried to make a long list of what works on our website and the info you see if off the boxes from that manufacture and what we use them on. We are a full-service shop as well as web sales and every belt on that list has been installed and tested by us to work.

Chad
DT

 

Just curious for an update on how it worked out?

Or if anyone else can comment would love to hear various opinions and experience.

Changed my belt yesterday and was going to put on a Gates K060535RPM as my sister works at NAPA and got it for my birthday but she inadvertently got the 535 size instead of the 539 --- it was a massive task to fit it by myself and required pushing the tensioner while walking onto the idler pulley, but it was so tight that I got paranoid and went with a green 539HD that I've been running lately, and it shows 1 hole after install.

(still got stock JCW 11%)

My question is how tight is too tight?

With the 535RPM installed I had 1.5 hole showing, would it stretch a bit after running in and be okay?
Or would there be a risk of premature bearing/component wear due to over-tightness?

 

~

I learned about those green Gates FleetRunner belts by reading various muscle car forums, the pic above shows a Hellcat Redeye which uses the green belt as stock from factory, but haven't really heard much buzz about them from R53 cult.

Counting this latest install, it will be my 3rd green belt, in my limited experience they seem pretty stretchy to me.

But,
I prefer ~stretch~ over >snap!< and that's one reason why I was paranoid about the RPM belt because they are reportedly less stretchy and will snap instead, but in my opinion deffo worth a try if rightly sized and I'm gonna go to NAPA and exchange for a 539RPM to see how it performs.



RPM has aramid core vs polyester core on green belt.

Honestly wish that someone had came out with an updated bulletproof tensioner because the stock design truly is an Achilles heel.

Have seen aftermarket s/c feature uprated tensioners and they look the doggies danglies, and some even offer a wider 8pk instead of the skinny 6pk and that seems good too.

 

I've been using the green belt on my track cars for quite some time, 17 % and 535 belt, it's a real pain in the behind to fit, much harder than a regular 535

 

The green ones do actually seem more stout than the regular, but I've never done any sort of formal test or anything, wonder if there are any youtube videos from like Project Farm or somebody doing tensile strength tests? Would be cool to see on a jig measuring force and stretching until breakage, wonder how the various brands would fair? But there aren't very many brands really are there? Gates, Continental, Bando...

...I have seen some of the musclecar guys swearing by Gatorback but I've never investigated if they have the right size fitment for me...



...because I've been happy enough with the green Gates belt,
and your testimony adds confidence as well,
thanks for commenting.

 

:

My jobsite location today was at a Parts Authority distribution warehouse, and oddly enough right in the main area I was working there sat staged two RPM belts...



...some weird synchronicity or sumthin,
hadta snappa pic.

 

do you happen to have the part number for the green belt? I can find the regular and the rpm, but the green or HD isn’t as easy, and thank you in advance.

 

Gates may have stopped making them in that size?

I could only find it listed on various cross-reference interchange catalogs as shown above.

Gates doesn't list it on their site anymore.