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RPR Concave System

Rated 5.00 out of 5 based on 24 customer ratings
(24 customer reviews)

5.00 out of 5


How much yield are you leaving in the field? Every rotor combine loses 3-5 bushels per acre, that’s anywhere between a $12,000 to $20,000 LOSS per one-thousand acres. But there is good news, Estes RPR Thrashing/Separating Concave System. The #1 Best-Selling Concave System Worldwide.


  • ZERO Rotor Loss
  • 2-3 MPH Faster Ground Speed
  • NO Changing Concaves
  • 30% MORE Capacity
  • CLEANER Grain Sample
  • 5,000 Hr Life




Models: John Deere S & STS / Case IH 88 & Flagship Series
Crops: Corn, Soybeans, Wheat, Milo, Rice, Canola, Green Stem Beans, Popcorn, Raddish Seed, Sunflower, Rye & More
Includes: Threshing/Separating Concaves, Cover Plates & Disruptors



  • For ALL Crops
  • Eliminates Rotor Loss
  • More Capacity
  • Faster Ground Speed
  • Cleaner Grain Sample
  • 5000 Hour Life
  • No Changing Concaves
  • Less Fuel Consumption
  • More $$$ In Your Pocket

Stock round bar concaves work reasonable well in that they don’t plug often in good conditions, and therefore can be “universally” used across crops and conditions, but the rotor loss and grain damage in corn is unacceptable. There is more mechanical damage done to grain by round bars than anything else. Our patented RPR Concave System is the best of all worlds, no plugging, no rotor loss, less broken cobs, less fines, more capacity and significantly better sample from running a slower rotor speed.



The Estes RPR Concave System has addressed all of Thrashing-Separating Issues. Our patented round bar with a notch milled in it to restrict the crop flow and force material to rub on material, giving you a cleaner sample. Then the bars are placed progressively open to increase capacity and to ensure more crop is “unloaded” as it flows through the concave system. The flow was increased by 68%. This is all followed up by the placing of the 7 Disrupter lugs into your existing separating grates to finish the separation operation.


R | Restricted Flow Threshing forces more grain-on-grain threshing

P | Progressively Open to increase capacity so grain can be separate quickly

| Round Bar with our patented notch gives a cleaner thresh yet still prevents plugging



Don Estes invented the disruptor and tested six different sets in 1994 before going into commercial production on the product in 1995. The Disrupter pulverizes the corn shucks that would otherwise flow out the back of the combine, taking a lot of kernels with them. Farmers saw increased yields and Don sold more than 20,000 sets. Farmers were happy but wanted more so Don listened developing the Rotor Loss Kit which he released in 2010. The Rotor Loss Kit cut down on rotor loss by 33% but Don still wasn’t satisfied. He wanted a system that stopped 100% of rotor loss, increased capacity for the farmer and did less grain damage. Over the next several years, after hundreds of iterations and tens-of-thousands of engineering and testing hours, he developed the RPR System. The RPR Concaves system is now the best-selling concave system worldwide, having systems in Australia, South Africa, Italy, Denmark, and New Zealand, to just name a few.

The RPR Concaves System is the culmination of over 30 years of experience and testing. The product speaks for itself and with thousands of RPR Systems installed all around the world, there are many farmers that say the same.


24 reviews

  1. Rated 5 out of 5

    Chad B.

    I don’t know where to start. I cut 300 bu corn, with a 16 row head, 18% moisture, 5300 Bu per hour, at 4.5 MPH with no loss. There is nothing on the market that compares to the performance. I can’t recommend them enough, they are a must have.

  2. Rated 5 out of 5

    Daniel E.

    I went with RPR concaves and disrupters, doing barley now and a fantastic job. Zero return and clean sample and nothing out the back. I really can’t believe how well these work, I’m getting too old to be changing concaves for each crop, now I won’t have to for at least 2500 hrs, life is good.

  3. Rated 5 out of 5

    Darrell S.

    Put a set in Case IH 9120 last day of corn harvest, rotor loss seemed to go down. For soybeans my dealer suggested cutting back 2″ off each cover plate which I did. Here we have some green pods when we harvest, and sample only had a few single bean pods. After first load elevator man told my driver he did not have to check our grade sheet because sample was so good.
    A lot of guys running them in green combines last two years.

  4. Rated 5 out of 5

    Eric L.

    I ran RPR’s last year, no more rotor loss and I haven’t looked back! We are very happy and recommend them to everyone, you won’t be disappointed.

  5. Rated 5 out of 5

    Kemper B.

    I’ve got about 100K bushels of milo through a set, less rotor loss for sure. Sample was good but easy to get trashy.
    Corn, VERY clean and ZERO rotor loss. Only thing I did see occasionally were small cob pieces with a few seed and I think they are simply passing through the larger concave openings. I did run very wide on concave in both crops.
    Started in beans in very high humidity, running one cover plate in front. After 3:00 cleanest in and behind machine I’ve ever had. Less rumbling as well. I do have only 4 disrupters in. I wasn’t smart enough to figure out how to put the rest without them hitting.

  6. Rated 5 out of 5

    Matt C.

    We put 3 RPR Concave Systems and Disrupters in our JD 9760 and we are finding a lot less fines and very minimal rotor loss. We dry our own corn in bin dryers and a batch dryer and have seen a reduction in fines.

  7. Rated 5 out of 5

    Sean W.

    Running them in Case 2188. Really like them in both corn and beans. Run two plates with the 2″ open on the far plate for beans. Does great in corn. Have a buddy put them in green machine and loves them. No rotor loss after he added them (his words not mine) and this is compared to OEM. Would buy them again, no question.

  8. Rated 5 out of 5

    Brandon S.

    I put them in my John Deere 9760 two seasons ago. Really does a nice job in beans with one cover plate on. Able to run the rotor slower in corn and keep more of it in the machine. Built heavier than the round bars too. Convinced me when I found out local Deere dealer takes new round bars out and installs RPR’s on a big percentage of new machines.

  9. Rated 5 out of 5

    Derek N.

    I ran RPR system in my 9770 along with disruptors. Losses really dropped off on corn and helped allot on green beans. I wouldn’t run anything but RPR. Will be putting it in my new S670 as well. Just my opinion.

  10. Rated 5 out of 5

    Steve A.

    I run them in our Flagship. We harvest Corn, Milo, and Soybeans. They couldn’t work better and not having to change concaves is a big plus. The adjustable cover plates are great too when fine tuning for each crop. Very happy with the system.

  11. Rated 5 out of 5

    Lloyd F.

    We installed a set of your concaves in one of our S680’s and we are really pleased with results we’re seeing! We run JD wide wire in the other 2 machines also 680’s and although they work ok we really like the performance of the RPR concaves! We have harvested wheat, oats canola and peas so far using your concaves and they work great! For next year we would like to order 2 more sets!

  12. Rated 5 out of 5

    Dave M.

    I have ran RPR concaves for the last 3 seasons and have been nothing but impressed with them. I have tried all the different concaves over the last decade and they are hands down the best concaves on the market. I won’t own another combine without a set in them.

  13. Rated 5 out of 5

    Todd H.

    I was running a set of RPR concaves in green stem beans, was almost done with harvest when it started pouring down rain. We decided to keep going, cut green stem beans in the rain for two hours with NO rotor loss and a clean sample. We couldn’t believe it! Highly recommend, you WON’T be disappointed.

  14. Rated 5 out of 5

    Tyler B.

    I second them as well! Third season with them, still very pleased. I seem to make fewer adjustments to get things right as compared to the John Deere setups.

  15. Rated 5 out of 5

    John S.

    I have them on my 9560 JD and love them. Solved all my problems.

  16. Rated 5 out of 5

    Andre L.

    I am a farmer from South Africa. We had been having some problems in harvesting our corn crop without damaging the grain and at the same time limiting our rotor loss. We own a John Deer S660 combine with a 6-row header. We use the 6-row simply because it suits our requirements on the irrigation fields and the limited space for manoeuvring the combine. We were trying to harvest the corn using the round bar concaves at first because John Deer recommended that they wouldn’t damage the grain as much, but because of the high moisture (20%) we just could not get all the kernels rubbed off without lifting our rotor speed to such an extent that we had to much grain damage. We then continued to use the first concave a round bar and the second and third concave large wire with every second wire pulled. This gave a better threshing result but we still had broken grain and rotor loss to such an extent we were losing 250kg per hectare of grain out the rotor (that is 4 bushels per acre). Our ground speed was between 3-4 km per hour that is 1.8mph to 2.4mph, the faster we would go the more grain would go out the back. The yield was between 12 ton per hectare that is 208 bushels per acre.
    I then got onto the internet and started searching for a solution to our problem, I found the RPR system and had a look at all the videos on youtube. Donnie Estes and I spoke for the first time and he assured me that the RPR system would be the answer. I was sceptical at first but I ordered a set and they had it shipped over to South Africa for me. Once I had installed the RPR system into the combine and tested it for the first time I was amazed at the result and couldn’t believe the effectiveness of the combine with these new concaves. Under the same conditions we were harvesting at a ground speed as High as 9.3km/h that is 5.8mph with almost no grain damage and a rotor loss of 40 kg per hectare that is about 1/2a bushel per acre including header loss, if you subtract the header loss the Rotor loss is less than 1/5 of a bushel
    Ever since I have installed the RPR system I have noticed that the capacity on the combine has improved because I was able to drive a little faster without losing corn out the back, I was able to bring my rotor speed down more, I was able to optimize my settings so much faster and easier because these concaves are so forgiving.
    I immediately realized the potential to distribute the system in South Africa as we have grain loss issues in all of our single rotor combines. Most of our corn here in South Africa is harvested dry, from 14% down to 10% depending on the time of year. Up to date I have not met one farmer with a grain loss issue that has not seen a significant improvement to his combine’s performance when installing the complete RPR system.

  17. Rated 5 out of 5

    John D.

    I bought some last year for beans and used them in wheat for the first time this year. (9770 STS)
    Granted, it was 65bu/acre wheat, not as high as the OP was cutting, but I got a clean sample and very little rotor loss.
    Best part. I didn’t have to change concaves. Just closed the adjustable cover plates.

  18. Rated 5 out of 5

    Mike D.

    Wow, I have to admit that I was skeptical about the RPR system, we harvested 150 acres of wheat with the case small wire and skip wire combination, we switched to the RPR front concaves the next day and immediately noticed a cleaner sample, rotor loss was non-existent, and loss over sieve was eliminated. We ran machine for a whole day like that in high yielding wheat and cut 105 acres with 47 less gallons of fuel than we have ever used in a day harvesting wheat. The next morning we installed the rear disrupters in the skip wire modules and changed the rear straight bars for Spike rasp bars and noticed a complete lack of loss from the machine. We cannot find grain on the ground behind machine anywhere. The horsepower required to run in tough conditions is reduced by a full 20%.

  19. Rated 5 out of 5

    Jason N.

    We run the complete RPR concave system along with the disrupter lugs and we put the spacers in on both sides of the separator grates. We grew our corn on 15″ rows the past two years and we had some really bad stalk quality. In 2015 we ran the regular round bar deere concaves and it was horrible, the stalks were so bad that they were just breaking off and we were running stalk and leaves into the machine. As you can imagine with running 15 rows of 15″ corn at 40,000 pop our rotor/concaves were so full of trash that we could not get the grain separated from it no matter what we did. We eventually slowed way down to help but in reality that didn’t do much because there was so much trash. In 2016 season we ran the complete RPR concave system as well as the disrupters with spacers in separator grates on both sides. This was night and day difference from the John Deere concaves. Our stalk quality in 2016 was just as bad if not worse than 2015 so the RPR concaves really helped out in this regards. We went from 2 mph in 2015 with tremendous grain loss to 5mph with no grain loss at all in 2016. The RPR system really does what it says it letting the grain and more trash through the concave so the chaffer and sieve can do more of the separating. Great product and I would recommend it to anyone who has a John Deere rotor!

  20. Rated 5 out of 5

    Mike M.

    My buddy bought a set two years ago and swore by them, told me he’d never run another combine without them. So last year I decided to pull the trigger on a set and couldn’t be happier. I don’t even watch my rotor loss monitor anymore and my soybean sample is better than it ever has been.

  21. Rated 5 out of 5

    Kevin V.

    I was able to run about 5 to 6.5 mph in wheat with the RPR concaves. Last year with the John Deere small wire concaves in same conditions I was only able to run 4 mph. Very impressed.

  22. Rated 5 out of 5

    Perry J.

    I bought a set of RPR concaves for a Case IH 2388 last year and we grow seed beans for Sygenta and we came out on top for the best cleanout sample they got and I would say it was all because of the RPR Concaves.

  23. Rated 5 out of 5

    Stanley Z.

    Estes performance concaves allowed us to run faster and save fuel! Saving us time and money. Very pleased!

  24. Rated 5 out of 5

    Keith K.

    We put them in and started picking corn and amazing, the grain loss monitor went to 1 bar and the day before we were running 6-7 bars. Today we’re running an extra 1.5 mph faster. We’re totally amazed and really happy. We’re telling everybody about them, thank you.

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About Estes Concaves

Don Estes, as an agricultural equipment welder by trade invented and patented the Disrupter for Case IH and John Deere rotary combines in 1995. Since, he has developed and patented the class-leading RPR Concave System that improves capacity, eliminates rotor loss and thrashes all crops with one concave system.

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