Competitive 17.5 in a 2wd buggy? Soon...very soon.
07-15-2008, 12:31 AM
#1
Competitive 17.5 in a 2wd buggy? Soon...very soon.
Allrighty...they're almost done. And they work just fine. 
Now you can gear a 17.5 where they need to be geared...which is WAY taller than you can get with a standard gearbox. Wanna beat a real 27T with a 17.5? This is how you do it. The standard response is: "THAT'S A 17.5 ?!?!?!?"
Before people start talking about losing the slipper...yeah..yeah. I talked to a BUNCH of the local big dogs around here that run stock and 19T...and the consensus is that most of them run the slippers locked out anyways. These are for 13.5, 17.5 or 21.5 brushless motors...not mods...and you aren't going to kill diffs with a 17.5. A couple of us have been running these for the last month or so at our local club races and there haven't been any problems with anything at all -- and it's not like I gave them to pro guys who are nice to parts.
I have one adapter for the RB-5 and one for the Losi and AE cars. The shafts for all three have the same diameter shaft, but in order to get a good fit, we had to do two parts with slightly different dimensions. They bolt on in seconds and you can swap it back to stock in a few moments. Unlike some older slipper eliminators, these have the exact same "double D" shape as the slippers and they won't mar your input shaft, because they don't use a set screw. They slide on and attach using the original slipper spring and nut and they accept any standard 48P (or even 64p if you like) spur gear.
Another cool benefit is that even if you don't run a really tall gear...say you run on a smaller track...you can run the same gear with a smaller spur and get the motor farther forward.
I'm hoping to have them done and ready to ship by next week...and I'm trying like heck to keep them at $15 shipped...and I'm hoping to have them available through at least a few different shops and motor suppliers.
Now you can gear a 17.5 where they need to be geared...which is WAY taller than you can get with a standard gearbox. Wanna beat a real 27T with a 17.5? This is how you do it. The standard response is: "THAT'S A 17.5 ?!?!?!?"
Before people start talking about losing the slipper...yeah..yeah. I talked to a BUNCH of the local big dogs around here that run stock and 19T...and the consensus is that most of them run the slippers locked out anyways. These are for 13.5, 17.5 or 21.5 brushless motors...not mods...and you aren't going to kill diffs with a 17.5. A couple of us have been running these for the last month or so at our local club races and there haven't been any problems with anything at all -- and it's not like I gave them to pro guys who are nice to parts.
I have one adapter for the RB-5 and one for the Losi and AE cars. The shafts for all three have the same diameter shaft, but in order to get a good fit, we had to do two parts with slightly different dimensions. They bolt on in seconds and you can swap it back to stock in a few moments. Unlike some older slipper eliminators, these have the exact same "double D" shape as the slippers and they won't mar your input shaft, because they don't use a set screw. They slide on and attach using the original slipper spring and nut and they accept any standard 48P (or even 64p if you like) spur gear.
Another cool benefit is that even if you don't run a really tall gear...say you run on a smaller track...you can run the same gear with a smaller spur and get the motor farther forward.
I'm hoping to have them done and ready to ship by next week...and I'm trying like heck to keep them at $15 shipped...and I'm hoping to have them available through at least a few different shops and motor suppliers.
07-15-2008, 04:38 AM
#2
Pardon the dumb question, but from what I can see it looks like you will drill two holes through your spur and lock it with two screws that go through those plates. Is that correct?
07-15-2008, 09:08 AM
#5
These are the gears we've been using:
http://www.speedtechrc.com/store/ebp...?catmainid=392
It's pretty cool, because you can get gears down to 65...but I've seen them down to the high-50s elsewhere.
07-15-2008, 09:48 AM
#11
They allow you to use small spurs and large pinions to take advantage of the 17.5's powerband. Current limit on RB5 is around 76 spur and 30 pinion. I tried this adapter with a 65 spur and 34 pinion and the results were...amazing 
07-15-2008, 10:00 AM
#14
A 17.5 doesn't have very much RPM and you have to get down into the 3.00-4.00:1 range in touring cars and then they work pretty well.
Buggies have a 2.4-2.6 gearbox, so you can't really gear a 17.5 high enough to make them competitive on anything but the smallest tracks. The target for a 17.5 is 5.00:1...and they need an even taller gear. They aren't geared correctly unless they're getting warm (and pulling wheelies...LOL).
I was talking to a guy at the track last weekend and he was telling me at the Shootout, there were guys pulling the max gears with 13.5 motors as well...I know I used to run 76/29 or 76/30 with mine and it wouldn't even get to 100*.
