I thought I would post my dusted-off Jrx Pro. I got this car when I was about 14, and I ran it quite a bit back then. It's been sitting on the shelf for many years, but some guys at work built an off-road track behind our building this summer, so I've been running it almost daily again.
I've been having a little trouble keeping it together so far. The weak link seems to be rear suspension components. I've broken both rear shock cartridges and broken one hinge pin (at the hub carrier). We have a couple jumps at the track, but they're not overly big. I'd say the car is about 2ft off the ground at its highest. The jumps do have flat landings though. I'd appreciate any tips about how to "bulletproof" the car a little more. Otherwise, the car is fun to drive and not too much slower than the more modern ones.
welcome, nice Pro you got there. Id say you have the more durable rear suspension of the 2 (ie 5 link or H arm). with these older cars learning their limits would be the first thing. They dont have the engineering that the modern cars do but with driving practice and some setup they are just as fast as the modern point and pull trigger cars.
Sleeps with a night light on, not because he's scared of the dark but because the dark is scared of him...........stay thirsty my friends
Also remember car doesnt have a transmission slipper so there is huge drivetrain strain as you land with ANY kind of throttle on still, you will break parts doing that for sure.
Slot machine motor??
Sleeps with a night light on, not because he's scared of the dark but because the dark is scared of him...........stay thirsty my friends
shock cartridges are a maintenance item, so if they failed (after sitting on the shelf for a few years) it can be expected. now breaking an actual hinge pin (broke, not bent?)...i havent seen that. their may have been a crack or defect in the pin originally and turning some laps just finished it off.
Drop in some new shock cartridges and replace that pin and keep rolling.
--Joey --
Vintage A&L and Factory Works
Old School Racer & Vintage RC Car nut
JKRacingRC.com
Thanks for the comments. I hadn't thought about a slipper improving the drivetrain durability, but it makes sense. For sure I need to work on my driving technique.
The broken pin surprised me too. One pin was broken at the groove for the retaining clip, and the other pin was bent slightly at the same spot. I replaced them both.
I'm using a Speedworks 350 motor right now, to keep up with my brushless buddies. Although honestly, the motor makes more power than I can put down. I do have a Slot Machine motor in the toolbox though.
Well, the car durability has been much better lately. Hopefully I've found most of the weak points by now. My driving has also improved a bit so I'm not crashing so much, which obviously helps. Today at lunch I beat 3 short-course trucks with hot brushless motors in our little 3-lap race, mostly because none of them could stay on the track. I stand no chance in a drag race...
One thing I've noticed is that the car seems very sensitive to wing position. I've had days where maybe I crash or roll over early in the run, which flattens the angle of the wing, and then I find I'm nosing or barrel-rolling off the jumps the rest of the day. Yesterday was one such day... very frustrating. Today, the only setup change I made was to somewhat aggressively kick the wing up, and the car jumped beautifully. Is this typical, or do I maybe have something else going on? It just seems hard for me to believe that changing the wing angle would make such a big difference.
The biggest reliability issue for me on the JRX's is the front end not the rear. I've always had problems with the front bulkhead stripping out and pulling away from the chassis. The composite chassis that had an upper plate strengthened this area so it is mostly an issue on the graphite chassis models. I use longer Associated 8-32 screws with a locknut and the issue is gone. I've never broken a hinge pin on these cars. E-clips have always been my problem area. I use snap rings instead of e-clips on the front end. They just don't come off but they are also quite hard to get on. At the rear I've drilled small holes into the toe block that allows me to use small 4-40 set screws that push against the rear inner hinge pins and holds them in place. This way they can't move regardless of what the e-clips do. Shock ends on the rear shocks on 5-link cars can be an issue and they are hard to find if they strip out. I've rebuilt my shocks with new cartridges so no issues there. Overall I've found my JRX to be more forgiving and durable than my RC10. It isn't going to live too long on a hard packed blue groove clay track but for dirt it's been great.
Yeah, just take the wing off and try and drive.. Its a HUGE difference. You could try and replace your wing wire with some fresh, or use a slightly thicker wire. Or you could try drilling a few holes in the rear tower and using a XX4/XXX, or RB5, or B4 rear wing mount set.
losiXXXman wrote:Yeah, just take the wing off and try and drive.. Its a HUGE difference. You could try and replace your wing wire with some fresh, or use a slightly thicker wire. Or you could try drilling a few holes in the rear tower and using a XX4/XXX, or RB5, or B4 rear wing mount set.
I second that last suggestion. I did i the same on one of my cars and since then already bought 3 more of the same style wing mounts.
Personally I like the ones from the trf 201, but most mentioned are very similar...except the B4 parts; they're just too difficult to use on anything other than a b4
Thanks for the suggestions. I like the idea of a fixed wing mount rather than coping with the wire. I will check that out.
Our track is dirt... hard in some spots, soft in others, and we have grass all around it. So, chances are, if I take a tumble, it's onto something soft.
be carefull and look at how much your spending on that car.. vintage losi parts seem to cost alot,thats if you can even find what you need(thats why i got rid of my losi stuff).. if you want to run daily it may be cheaper using your old electronics and find a cheap b4 roller..
I JUST GOT ONE EXACTLY LIKE YOURS TODAY OFF CRAIGSLIST!!!! LOL WAS Like dang!!! when saw the pic pop up lol. And its RTR AN DUSTY,TEAR DOWN AND CLEAN IT and lube it.DON
be carefull and look at how much your spending on that car.. vintage losi parts seem to cost alot,thats if you can even find what you need(thats why i got rid of my losi stuff).. if you want to run daily it may be cheaper using your old electronics and find a cheap b4 roller..
Agreed. After the first few rounds of parts breaking, I was ready to shelf it and buy a newer buggy. Since then though, I haven't been breaking anything (knock on wood). I also bought an extra car for parts... much cheaper than buying parts individually.
