XRAY - Model racing cars

sorry but the "stone theory" is not gonna cut it i havent broke any teeth yet but the last time i took my motor out it has a grrove under the bell where it hit it and made the mark. its pretty deep and i run a kinda loose mesh and i think it saved mine. slims has the same exact mark on his. this is a prob that we are looking to resolve. the chassi is flexing in such a way that its causing this to happen. its a fact

The stone gaurds made for the clutch bell/spur for the worlds was to prevent engines stalling as that was the issue with the rocks.

This topic has already been discussed here:


I've been using a complete mugen x5 diff (complete drop in no mods needed) with no more issues with the spur/bell teeth breaking.

i know what your trying to say....
the chassis flexes right at the flywheel opening, grab the wing and the front tower and push the car down all the way then squeeze, you can see the flex, and if you watch the spur/bell you can see tha tthe motor tips in relation to the spur. you cannot have a crooked gear inrelation to another, it dont move away from it, it trys to be angled. with the fulcrum point being at near the spur it has alot of leverage and will "pry" the teeth off the spur. every one i seen has 2 teeth broke off.

i notice that on the xb8 chassis, that where the mugaurds attach, the hyper7 for example has more angle which increases rigidiity. the xb8 is alot flatter in that regaurd. it would be a nice fix if they could look into that.

other wise i have a fix and will post up soon.

i had a slight mishap after a 15 min main, i didnt hear it but the marshal said i had a grinding noise, it appears that my motor moved and loosened the mesh, its pretty sloppy but doesnt look like it ruined anything, will have to look more... im sure i may have lawn darted a jump and i got lucky it didnt chip the spur and moved the motor instead. i know it was tight as i check it every heat.

alex, i was joking about that hence the relax.
ever since you sold your xb8 you have had nothing nice to say, at least i thought you said you sold it for 1500...??

Guys have a look at the vid clip of Y. Aigoins first race with the XB8 on Buggy-sport.info.....he was flying passing other cars like they were standing still!!!!!

Too bad tho, looks and sounds like he stripped the spur/bell....still reckon there no problem with the Spur/bell material?

I actually put my spur in hot coals for about 10 mins (BBQ coals), rotated it and turned it to try and get the heat into it evenly and then allow it to cool on some sand and since doing this I have not had any more issues, I also now use a piece of 160gsm paper to set my mesh (before I was using 80gsm) so the mesh is a little loose, not sure if this has fixed it completely but I have not broken one since doing this....

I'm going to say it could have been both. I've experienced both, and the chassis flex issue is seriously more doubtful than debris in the gears, but it can happen.

Chassis flex in the front (as mentioned by replacing the upper deck and brace with King Headz versions) is definitely a waste of money to fix this problem. It appears to me, from the pics, that it was debris. I can also tell you that stuff happens, especially in a 1/8 buggy.

Replace the stuff, or send them back to XRAY if you feel they are defective. I'm sure they will inspect them and replace them if they were defective. Or, purchase a few spares if you are racing regularly, you'll need spares of parts if you race, no matter what brand it is.

The steel XRAY uses is definitely a higher Rockwell than HB or Kyosho, but I don't think it's at a point of being that brittle. I know it stucks when it happens, but stuff happens when you put a 3hp powerplant into a nine pound box with wheels. I mean, at a ratio of 1/3, would a Honda Civic have problems if it was stock and came from the factory with over 800hp? Drive axles would just twist off like twizzlers! hahaha

On a second note, I don't think using HB clutch bells/spurs will eliminate your problem. I would follow the previous advice about setting gear mesh correctly.

OK, today I took a BRAND NEW XB8 Spur gear into work and ran some Edicurrent and PFD checks on it. And to my SHEER HORROR IT FAILED. It showed up 5 cracks at the base of 5 consecutive teeth with a depth of .9mm. This is just shody imo. Is all Hudy Steel like this? I intend to test some more stuff. Till then IF my spur should blow (Not blown one YET) then the spare Lightning one I have WILL be geting fited.

I too have suffered this problem of stripped spurs and clutch bells. But how is it i replaced the clutch bell with a k factory venilated bell and a hotbodies spur (yes it will fit) and have since had no problems? To be honest i believe the hudy steel is not up to the job? Are Xray looking to resolve the issue or considering alternative materials?

C'mon Xray, If the chassis is flexing, do something to resolve it like the one peice extended engine mounts or something like those manafactured by kingheadz?

The guy who mentioned X5 diffs dropping in.... what was that, a complete unit? if so i may put a x5 fioroni torsion diff in if x5 diffs drop straight in?

Darren