I purchased a set of both the front and rear shocks and am writing this review for both as my experience was the same for both sets. The build quality of these aluminum shocks is quite nice, however I very quickly noticed some major design flaws that render them almost useless, if you intend to ever dissemble them. There are small, thin O-rings that are used in both the rebound collar adjuster and also under the bleeder shock cap; these are the weak point of this entire package. I dissembled these pretty much out of the box as I knew I wanted to run thicker weight oil; the first issue I encountered is the O-ring that goes under the bleeder cap is so thin and flimsy, that even the tiny amount of pressure from just finger tightening the cap causes the O-ring to twist and pop away from the shock body, which doesn't allow a proper seal to form. I tried just removing this O-ring entirely as I could not get it to sit flush after many attempts and it doesn't seem that the tolerance of the machining of the cap and body alone is tight enough to prevent oil from leaking out, as after just a couple pumps of the piston, oil was already coming out from under the cap. The other issue, as noted also in the other review below me, is the O-ring in the rebound adjuster collar. I'm assuming the intent was to have this in the collar to keep it firm and prevent vibration from spinning the collar, however, this O-ring is too thin and after just a couple of turns of the finger, the entire collar gets stuck on the O-ring binding in the threads, and you can't get it to spin without pliers. I was able to work it back and forth enough times to get the O-ring to pop out entirely, which freed up the collar and allows it to spin like normal now.
I'm going to attempt to find an O-ring of similar diameter for the shock caps either at my LHS or hardware store that won't fold under finger tight pressure, but if I can't find something, I'm afraid I'll have to try returning these as these are basically useless if I can't keep the shock cap from leaking oil. It's a shame because the shock body, piston and machining of all the metal parts seem top-notch. But these fragile O-rings are an Achilles heel and basically make this product unusable for me.
Great idea, poorly executed.
So these shocks can be great, just be ready for some work. I like the bleeder screw and the fact the cap can be removed for maintenance/oil filling as opposed to the aluminum shocks that come with the pro roller.
The 3 beefs I have with the shocks:
1. The shock cap o ring doesn’t work. 2 of the 4 shocks I received had the o rings already cut. Furthermore, the o rings are too big to actually seal the shock cap to the body. Be prepared for a trip to the hardware store for good o rings or using strips of Teflon tape to seal.
2. The o ring on the shock adjuster collar is absolutely useless. It completely binds the collar so you can’t adjust it up or down. Ditch this o ring and it works okay.
3. The threading on the shock body is very minimal so getting a wide array of ride heights is not really feasible without getting different springs.
Once you replace then shock cap o ring with a good one, and ditch the shock collar o ring, these are good shocks and the bleeding process is significantly easier than other bottom fill losi shocks.
For the money however, these things should not need this much work to get working properly. Be prepared to work to make these things as good as advertised.
If there was a way to keep the gasket on the top from leaking I would love these. But unfortunately they brake as soon as you open the top.
Purchased these for my Mini B and out of the box they look great! Unfortunately as the review above mentions the o-rings on for the shock caps will not stay and slips out from under the cap making the rebuild very difficult. I put the stock ones back on and reached out to Losi about how to fix this or procedure on rebuilding the shock.
Overall shock is pretty good and it is nice that they allow you to open up the top of the cap. However, the shock colors get quickly fused onto the shock body because the O-ring is the wrong size. Scavenged all over the Internet and outside of ordering custom O-ring there are no sizes available that will fix your problem. The only solution is to simply remove the O-rings and then constantly check the preload and height of the vehicle as the collars will move there is no O-ring or way to lock the collar.
These are nice (tiny) shocks. The stock shocks on my Mini-B were awful, leaky, stictiony nightmares. Junk. These, on the other hand, are nicely made, operate very smoothly, and look great. After replacing the very light stock oil with 37.5w TLR oil, chosen as I race this little buggy on a 1/10 scale outdoor track with some nice jumps, I'm very happy with the operation of these TLR shocks.
They come pre-filled with some really light fluid, 20w or something, and they clearly just dumped it in the top of the shock body with the piston full extended, then sealed it up (more on that). The first time I went to compress them they felt "stuck", then it made the tell-tale noise of the new-shock-piston-air-pocket being released. That, combined with the uselessly light weight of the stock oil, meant it was time to fight the dreaded top cap o-ring.
So: the o-ring. I'm not sure what its made of but it clearly swells when exposed to the silicone shock oil. Becomes very soft, its diameter expands, and just becomes a pain to deal with. Once re-assembled correctly, it does its job of keeping the oil inside the shock body, but it is DEFINITELY a fight to get it re-assembled.
Basically what worked for me was to start with these steps:
1. Fill body up with oil to the rim.
2. Operate piston, let air bubbles get out, etc.
3. Unscrew bleed screw from cap. (Bonus points if you immediately loose the little washer, like I did)
4. Screw the cap back on until its JUST above the o-ring.
Now you fight. I rotated the shock body around, constantly poking the o-ring in and under the shock cap with my fingernail as I slowly screwed the cap down. Takes a couple tries, but if you see it starting to poke out, try just shoving it back under the cap with your nail. Sometimes it will still get pinched, and you have to back it off a little bit and star over. Eventually, with the alignment of the stars and the correct sequence of curses, it will seat itself under the cap and you can tighten it down.
Don't forget to put the bleed screw back in after you've gotten the rebound set as you like (remember, bonus extra points if you've lost the washer).
Oh, and the same o-ring is used in the spring preload adjuster, so have fun fighting the stupid thing when adjusting preload. I'll definitely be seeing if McMcaster-Carr carries nicer o-rings in this size before fussing with these again, because yeesh are they annoying and crap.
Its a shame, as everything else about these little shocks is really quite nice.
