VegasHB

My latest set were the avid bearings, same deal, pull them out and smooth as butter but install and incredibly gritty. That's what makes me think the axle bearings aren't aligned perfectly so when installed the bearings they're seeing uneven wear. I can tell it's off a bit because when I just push the axle through it catches the inside bearing and wants to pop it out so i have to hold it in place and wiggle/force the axle through both bearings. Once done it feels like dog s**t unless the bearings are brand new. Even with brand new bearings it doesn't feel very free, just not gritty.

The centered 3mm inserts feel the best but when going to the 2/4 inserts it's crap. There's definitely something off with some of the molds of these inserts, i don't think the crush tube was ever an issue at least with mine. The screw tightens up fine and puts no pressure on the bearings since I can pull the axle in and out slightly with play from the bearings.

Pittsdriver

iTrader: (11)

I have gone from 4-3-2 inserts and have had zero issues with bearings, no crush tube change, no bearing change and all spin free as a bird. These bearings are gonna make a little noise as they are not super high quality bearings.

StadiumRC

The slop or play was forward and backward movement on the inner hinge pins. I used the set screws in the front and rear hubs and I agree they work great - didn't think it would do much but it snugged the hubs up nicely. I couldn't find the AE 3 x 8mm screws anywhere so I bought some Protek 3 x 8mm screws from Amain and they worked great, made in the USA too if that matters to anyone.

suby723

iTrader: (21)

The kf really isn't the greatest dirt track car. I have my b5m paired with a k1 btw. Get the b5m if you want a better working mm car for dirt tracks.

Grasschopper

iTrader: (54)

Then it isn't right. You shouldn't have to force anything like that and yes if you have to do that you're going to kill bearings.

Have to ask the obvious question, are you sure you have it built right?

mdowney

iTrader: (21)

Just search any RC store for 3x8mm set screw and you'll find a ton of options in stock. No need for the AE version. I opted for stainless made by TOP racing. Just be very, very careful not to overtighten because the head strips VERY easily. I currently have a caster block that I need to cut off the hinge pin because the set screw stripped.

Keep in mind that Amain allows for no commitment back ordering so when they get popular parts in they need to fulfill those back orders first - and there is a length of time that they need to hold them before they'll put them back into the general inventory. It's a feature that I use all the time. Just back order anything that you want and they will notify you when it comes in stock.

The forward/back movement is effected by the set screw. I had a lot of play and it was significantly reduced when I added the set screw. That said, yes, it's easy and obvious to just add shims to the hinge pin to further reduce slop. I prefer the KYO96641 shim set. It comes with 3 different widths.

mdowney

iTrader: (21)

Definitely worth using. My mistake was using stainless steel as it's softer. I'm switching to standard. They're cheaper anyways.

Great idea! Thanks!

nordfink

+1

vito

got my new b5 kit time to opend it up

Bracer11

iTrader: (3)

Yeah I agree about the KF not being a good dirt track car. Im wondering how they compare on carpet.

VegasHB

For sure, been building kits for 20+ years. When I say "force" it's not pulling out the pliers time. Have to press it in with my thumb while I hold the bearing with a couple fingers.

vito

AlderBoy

iTrader: (17)

Now that the low traction kit is out for the KF it will be great on dirt too. No mid motor corners or jumps quite like the KF. Combine that with traction on dirt and it will hang with the B5M I am sure. But price wise the B5M is the way to go.

vito

what gearing to run for a viper 17.5 got a 30 tooth to start with

mxracer458

iTrader: (47)

69/32-34 vito