70 ton roller bearing trucks - Exact

Discussion in 'General' started by meteor910, Jul 23, 2013.

  1. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    We were talking about what ASF A-3 Ride Control 70-ton 33" roller bearing trucks (HO) to use under a model of Frisco's GSC bulkhead/cordwood flat cars a few weeks ago, and that there were not many good examples of these trucks to be had in HO. Tom Holley noted that ExactRail has come out with a model of just this truck, as well as one of the competing Barber S-2 70-ton 33" r/b truck. The Frisco loved the ASF A-3, but also used quite a few Barber S-2's.

    Being a truck geek, I ordered a couple pair of both the A-3 ad S-2 trucks from ExactRail. They were here waiting for me when we returned from Florida yesterday. The ASF A-3 is ExactRail item ET-102; the Barber S-2 is ET-103. Given the trackwork of my "layout", I ordered both with the RP-25 wheelsets, not with the thinner tread optional wheel.

    The trucks are very free rolling, though not as free at the Kato A-3 standard bearing truck (which I swear will roll uphill). But, the ExactRail trucks roll very nicely, with full metal 33" wheelsets that have a nice contour.

    The sideframes are very nice castings, with micro details including prototypical lettering on the sideframe. I like the Barber S-2 the best - a very nice looking sideframe, self equalized, with brake rigging and bolster detail. The roller bearing caps do not rotate. The ASF A-3 is also very nice, but looks a bit too stark to my eye. It also has the casting lettering and other details noted above.

    It is interesting, finally, to have two fine examples from one manufacturer, with consistent details, of the A-3 and S-2 that can be compared side-by-side to see the subtle differences in the two - spring positioning, bolster detail, and sideframe spring trays. The ASF wedges are there, but harder to see than I would have liked, and the distinctive A-3 spring tray is a bit too apparent. But, I'm being picky!

    In all, a "Well Done" to ExactRail. I'll use a pair of the A-3's under the Walthers Frisco bulkhead GSC model.

  2. Rancho Bob

    Rancho Bob Member

    Ken...I have a pile of these and they are nice, aren't they?

  3. gjslsffan

    gjslsffan Staff Member Staff Member

    Now I really gotta get some of these trucks. A question guys. Are they Gray or black? Thanks for the info guys.
  4. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

  5. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Ken, the truck guru, is there an ASF ride control 50 or 70 ton Timken roller bearing truck available that you would recommend? I am in the process of modeling a Frisco 40000 series 50' combo car (pg. 65 #43542 in Molo's book in reblt. condition), and I am to the point that I need to get the correct truck. The specs listed in another post concerning this car do not say if the truck was 50 or 70 ton. The capacity of the car was 110,000 pounds, so do I use 50 ton or 70 ton trucks under this car. I am also in the process of modeling a double door 50' box (pg. 64 #154409 again in Molo's book), but this car has friction bearings as best I can make out. Again, should I use 50 or 70 tons trucks (capacity 110000 pounds) under this car? I appreciate any help I can get because I have done some modifications to both of these cars to be as accurate as I can reasonably be, and I would sure like to put the correct truck under them.

    Thanks, Terry
  6. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    Terry -

    Yes, use the ExactRail #ET-102 ASF A-3 Ride Control 70-ton roller bearing truck. Very nice truck, rolls close to how well the Kato standard bearing A-3 does (almost!). Can't tell if the RB is a Timken or not - it has the triangular cap. But, it is close enough, and is your only good choice. BTW, the truck also comes with a more scale width wheel set. See the ExactRail web page. The ET-102 uses a RP-25 wheel set - that's what I selected for my somewhat primitive "layout".

    There is a similar set of ExactRail trucks based on the Barber S-2 70-ton roller bearing truck, also a Frisco favorite (but the A-3 was #1 with the SLSF). See #ET-103 (RP-25 wheel sets) for the S-2 with RB's.

    You should use the 70-ton capacity truck. The 70T is rated at over 140,000 lbs (more like 165,000 lbs). Remember, the truck not only has to hold up to the load weight limit (110,000 lbs in your case), but also has to carry the tare weight of the car. 70-tons was a very popular capacity until the big 100-ton trucks started being used on big hoppers, covered hoppers, tank cars, box cars, etc. The ton rating of the truck (really the bearings) ... today ... understates what load they can carry.

    Ken (An amateur truck guru compared to my mentors - Richard Hendrickson and Pat Wider)
    Last edited by a moderator: Jan 11, 2014
  7. r c h

    r c h Ft Worth - Tulsa Engineer

    Great review, Ken. I have several Exactrail cars and have also purchased their trucks separately to upgrade some of my other HO equipment. In all, I'm pretty satisfied with their trucks. The appearance is right up there with Genesis trucks, which are my favorite.

    As far as operation is concerned, some of mine haven't been the best in terms of rolling ability or the equalizing function. The equalizing function just took a little bit of flexing to eliminate stiffness from a few examples, but the majority of them equalize just fine from the package. By comparison, they are a vast improvement over the self-exploding trucks that old Intermountain kits are known for.

    Most of mine are pretty free rolling, but a few required a little work with the Reboxx Exxact Socket Hand Tool (http://www.reboxx.com/Tools.htm). I had to trim the center part of the brake rigging a bit to get the tool to fit in the sideframe, but it isn't noticeable from the side. I highly recommend this tool if you don't already have one. It won't get much use on Exactrail trucks, but if you have older Walthers, P2K and other sideframes that you've replaced the wheels, you will get your money's worth.
  8. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Ken, thanks for the quick response. I figured the car's weight needed to be figured in, but I had never seen any discussion on that point. After all, I was just an engineer:p and didn't concern myself with the types of trucks under the cars. I just wanted to be sure they were all there and rolling freely. I have had a lot of fun modifying the two cars I am working on to more resemble the Frisco cars. I have them painted and now comes the decaling. I will post them here when I get them finished.

    Thanks, Terry
  9. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Hey, Ken, would you look on page 62 of Molo's book and tell me what truck is under the 7088 dbl door box car. The 7064 is a reblt version of that car, and both cars clearly have friction bearing trucks under them. I have just finished working on an Accurail 50' dbl door box car to model this cool Frisco car. I don't have any trucks except for the one (Bettendorf) that came with the kit. I have placed it temporarily under the car until I can get the correct truck. When my daughter returns my camera, I will take some pictures of the car and post it here with a complete run down of what I did to the Accurail car even if I haven't gotten the correct truck, yet.

    Thanks, Terry
  10. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    Can't provide much help right now Terry. I'm down at our place in Naples, Florida doing some work and don't have any books with me.

    If they are regular bearings (non r/b) odds are they are ASF A-3Ride Control trucks. Put a pair of Kato A-3's under it after you weather them and don't look back.

  11. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Thanks, Ken, that is what I will do. I am not looking back, but forward. I need to get my camera back from my daughter so that I can take some pictures of the car and share them here.

  12. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    When I get mack home, I'll be able to use Molo and my pics and diagrams to see just what these cars rode on. Until then, I'm still betting on the ASF A-3.

  13. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Ken, that will be great. I was trying to compare the Exactrail trucks I just bought with the pictures in Molo's book, and I thought I had figured out how to tell the difference , but when comparing them to the Exactrail trucks, I found I was incorrect. Thanks, for your interest in the trucks and your advice in this area.

  14. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Sorry to bother you again, Ken, but would you tell me which truck is under the 6607 on page 81 in Molo's book? I have both of the Exactrail trucks, but neither looks exactly like the truck under this car. The side frame under the car looks larger than either of the 70 ton trucks I have, so I was wondering if the 6607 has a 100 ton truck under it. I have been working on this car for some time now, and I am ready to put the trucks under it, so any help would be appreciated.

  15. Karl

    Karl 2008 Engineer of the Year Frisco.org Supporter

    The diagram book lists a Symington side-frame..

  16. meteor910

    meteor910 2009 Engineer of the Year Staff Member Frisco.org Supporter

    Terry -

    Thanks to Karl for his response. I'm away from home right now (again!) and thus have no access to all my truck "stuff", or my books. I'd wager that Symington is just another of the truck manufacturers making a version of the ASF "Ride Control" truck. I'd suggest using one of those on your model.

    The tonnage rating of a truck actually is based more on the truck axle bearings than on the side frame. In many cases there is only a slight difference in the side frame appearance between a 70-ton and 100-ton truck.

  17. tmfrisco

    tmfrisco Member Frisco.org Supporter

    Thanks, Karl and Ken. Since the visual appearance is slight between the 70 and 100 ton trucks, I will use my 70 ton trucks on hand. They do look good and are great rollers.

  18. yardmaster

    yardmaster Administrator Staff Member Administrator Frisco.org Supporter

    Possibly a little bit of scope creep, but Tony Thompson's blog has a reprint of an RMC article he wrote that focuses on modeling reweigh data. It includes a table with data on the axle loads and subsequent calculations for determining capacity (basically the tonnage of the axle x 2,000, if I understand it correctly), light weight, etc.


    As an aside, FMIG Newsletter 44 has a listing of Frisco reweigh abbreviations.

    Best Regards,
  19. nickmolo

    nickmolo Member


    I'll weigh in a little here.

    Basically most 70t trucks were of the Ride-Control design or Barber S-2 design, of course there are minor designs that come into play.

    Each "design" has their sub-design which in the case of Barber can be S-2-A, S-2-B or S-2-C.

    Then you have the foundry where the trucks were made, ASF, Scullin, National, Symington, etc. Sometimes each of the foundry changed the profile of the frame slightly, but the "design" or mechanics of the truck (Ride-Control or Barber S-2) stayed the same.

    Of course the design would change slightly to deal with Roller bearing or Solid bearings.

    Most of the later 70t trucks purchased for the Frisco RBLs, were of the Barber S-2-C design, made by Scullin if I remember correctly. The closest model truck for this design is the Accurail, "roller bearing" truck. Tangent scale models has the 70t Ride-Control with Solid bearings. Although I think Kadee and ER also make some of these. But they are not one-piece designs and can make the wheel not roll as freely on occasions.

    Nick Molo

Share This Page