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Ok, I was finally able to get a set of SD70 sideframes for the SD40-2 trucks im using on my RPP SD90Mac. Not thinking there was a difference i was all set to mount them up and just do a test fit with the trucks on the frame. Well come to find out the Genesis sideframes do not come close to mounting like every other Athearn side frame i've seen. The two long flat pins are further apart then the normal round tabs.
Why the hell did athearn do this? Do I have any options for the SD70 side frames? Im not buying Genesis trucks for this. Is there anyway to get the 2 to work together?
I don't think a set of SD40-2 sideframes will fit an SD70 of any manufacturer. There's a big difference in the length of the trucks.
Yeah, the truck wheelbase is different. The center axle is off-center.
Buy RPP trucks. They aren't wasy to find but they show up from time to time.
smokey valley offers sd90mac sideframes also for the sd40-2 bluebox style trucks or the newer type.
I have the SD40 trucks on the frame now. The sideframes i've held up to them and they seem to be almost the exact same size. The small holes where the axle would fit into are almost on center with the trucks. I'll double and triple check to be safe and see what happens.
Yeah, the truck wheelbase is different. The center axle is off-center.
Buy RPP trucks. They aren't wasy to find but they show up from time to time.
PPW-Aline's site sells the RPP trucks with the correct sideframes. But for $24 i dont want another set of trucks. Are these genesis trucks?
The smokey valley side frames look to be the best choice. They have 2 different kinds, one for the dash 2 bb trucks and a pair for the genesis trucks.
smokey valley offers sd90mac sideframes also for the sd40-2 bluebox style trucks or the newer type.
Dont fit. The BB/SD40-2 sideframes do not fit. Mounting tabs are spaced further apart then the holes on the trucks. Im so pissed off. I do not want to use regular six axle emd sideframes for them.
I contacted ppw-aline to see if the trucks w/side frames are genesis/rtr or if the side frames are available seperately. This is the only thing holding me up from putting the model thru the paint shop. I want to do everything at once and not wait or do it seperately.
Gomez Addams
Staff member
I've had good luck simply picking up the phone and calling Athearn for parts. You can ask for the repair department, and if they're not covered up with projects, they can take the time to help you, either by telling you what trucks will fit what sideframes, or by selling you a pair of correct trucks. There is a difference in axle spacing as well as sideframe length and height between an HTC and HTCR truck.
i called PPW and spoke to a women who took my info as the RPP guy wasn't in yet (11am in NJ, 8am in CA), I got called back around 8pm ish and talked to a guy, can't remember his name. I explained my situation and he was a little dumb founded. He went and checked his parts, which worked together. I looked up the auction I won my trucks from and the part numbers are 44011/12, which athearn shows as SD40-2 trucks. He said he was going to give me a call after he does some investigating into why this pair of trucks I have does not accept the Smokey Valley side frames (PPW/ALINE) uses smokey valley also.
So after I got off the phone I took a look at the dummy pair of trucks I have on the other SD90Mac. What do you know, the Smokey Valley sideframes fit PERFECTLY!!!!
WTF? I dont get it. So now it looks like i'll have to find out what trucks I have that dont work. Going to also send them to mgwsy to get the frames milled a tad. There is almost no room between the top of the sideframes and the bottom of the frame.
Also keep in mind that the prototype SD80/90 use 42" wheels vs the standard 40" that athearn uses. That might make a difference in sideframe height.
hmm, interesting. who makes 42" wheels?
ok that works. What is the difference between the P:87/64 weathers, HO Gauge/110 and the HO gauge/88?
Not sure about the first one you listed, but the "110" and "88" refer to the width of the wheel in thousandths of an inch - 0.110" and 0.088", respectively. The 110s are standard width, while the 88s are narrower have more of a prototype appearance [even though they are still wider than true 1:87 scale].
The P87/64 are scale size wheels at .064" Thick and a scale flange. They will only run reliably on Proto 87 track made to exact scale specs.
Code 110 is the standard wheel tread that you would get on a RTR car such as Athearn RTR and Atlas. (Walthers is slightly wider, but I'm not going to go into that here)
Code 88 is semi-scale which is a narrower wheel tread that makes it look closer to scale appearance*
*appearance in relation to the track. Since regular HO scale track is not scale sized, the wheels are not actual scale width. Actual scale width wheels would not work very well on regular HO track as regular HO track does not have a scale railhead, spacing (due to the wider railhead), or height.
Code 72 is the semi-semi-scale in which the treads are very close to scale size, and will run on regular HO track (but the trackwork would have to be absolutely perfect)
Code 64 is the Proto:87 tread width and is scale width. It will not operate on regular HO track. You would need to buy Proto:87 track and switches in order to use the code 64 wheels.
ahhh ok. So its best to just get the 110's. Once funds ever become available i'll see what the wife will do for me. Both the catalytic converters on my truck are clogged and shot. Praying it won't cost me an arm and a leg.
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