Complaint Dept. Why I hate my XX-4
 

No denying that this car is fast. I can stay with 1/8 scale guys with this car. But there are things I can't STAND about it. Here they are:

• It is belt driven, and hasn't shown it can handle the same drive loads as a shaft/gear driven car.
• The whole chassis layout looks like a yard sale.
• Upgrades are scarce (in USA), and front LCD's by Losi are small fortunes.
• The aluminum brace for the rear hinge pins. Almost ten years later and Losi never even tried to fix it, even though they knew it sucks.
• Every bearing surface is exposed to open air. This means one good ripping in the dust and you have hours of cleaning to be done. AE stealth trannies are nicely sealed, but not the xx-4! All bearings for the steering are like dinner plates, holding mud and dirt for your XX-4's steering assembly as you drive it.
• Dirt easily finds its way into the diff area, hastening wear.
• Motor has little open space, so you can easily smoke a motor if you are running on low grass, for example. Temps get high around the motor, and it can cost you.

Feel free to add to this list!

[*]It is belt driven, and hasn't shown it can handle the same drive loads as a shaft/gear driven car.
No problems with mine.
[*]The whole chassis layout looks like a yard sale.
True, but some creative wiring can keep it fairly neat
[*]Dirt easily finds its way into the diff area, hastening wear.
Does it?
[*]Motor has little open space, so you can easily smoke a motor if you are running on low grass, for example. Temps get high around the motor, and it can cost you.
Holes in the shell over the motor help emmensly, and also opening up the back of the shell to allow air to move through

It's a bit of a pig to work on if you snap a belt, but belts are faster than drive shafts so I reckon it's worth it. Convert it to an X-5 and have done with it. 1 belt, more speed, less to fix if it breaks.

My biggest annoyance is shock towers though, really expensive and very brittle...especially the graphite ones. I run stock plastics all round now which stand up to a beating better.

I don't really have a huge problem getting spares in the UK. Sure I have to wait a while, but they always come in the end. I can't imagine why you would have such difficulty?

Losi spares are always expensive compared to Associated, Kyosho or Tamiya for example...this is the way it is. In the UK we usually pay what you do with the $ sign changed for a £. So, $7.49 to you, that's £7.49 to us >>> really it should cost us half that due to the exchange rate.

I agree, the chassis can be tidied up with some nice wiring. But the shell is quite beautiful in my opinion. Curvy, slick, low-profile...just nice!

You have a point as regards the bearings being open to the elements though.

The only thing ive broken on my xx4 so far is 2 belts and front wishbones the and thats it I cant see how you can break it so much and the gear box is sealled its super sealled and as for bearings the b4 is worst for that look at there front wheels!!!

A

Can you explain this please? I don't understand it.

G

I just hate working on the car and the belts are certainly a weak point in my experience.
I enjoyed racing it, but I was only racing it because stu evans fixed it for me between rounds at southport National.

i blame my xx4 for my crap doings at duhram regional due to a belt issue, took ages to solve what was wrong with it, id stripped it down completely, and the worst part was nearly all the fecking radio gear had to come out !!

now im running this 501x it doesnt look half as bad, and taking the shell off this car is always a plesure, blue alloy, carbon fibre... it has to be the future of racing this type of makings with a car :cool:

If you get the car all sorted and ready and put soem good preperation into it it will go longer than any ofther car and its good to drive but its all personaly exsperiance at least it gives you somthign to do i defntly think its the easiers car to change a shock tower on and take motor out etc. And it only takes a few minutes to change a belt.

A

if youre on about a xx4 belt, i strongly disagree....

daft lad haha

Last time i changed a belt it took me about 12 minutes thats aint long its 14 screws and your in then its just pull diff out and puly and put new belt on easy peasy.

A

bollex mate..

a few mins is at the most 4 ( probibly 3 mins )

12 mins is double figures haha which is between 3 and 4 times longer...

haha !!

The rubix cube that is the XX4 needs all sorts of jiggling and manipulations to even get to the belts - by that point half the screws are lost in the grass and your 12 minutes becomes 45 + plenty of sweat and swearing.

:p

I've no idea how long it takes to change a 501X belt - maybe just as long since the top decks etc all need taking off. But it doesn't feel as long since you're not swearing and in tears -and I base that off personal experience :wtf:.

Shall I just add my usual comment about buying an X5??? :D

In fairness it wouldn't solve all of your issues, but I think 50% of them. I had a XX4 and hated working on it. I bought an X5 and loved it. I am now fortunate enough to be sponsored by X Factory but was a customer driver for 6 months at least before that started.

im actually sat laffin my head off ! :D well in jimmy haha

that was me at durham i could have easly given up that day..

Yes, this is exactly what mine looked like after driving it with an orion 11x2, 13t pinion, 84 spur and 93F heat. POOF!


Holy cow, does it ever! I am going to make some lexan covers that will act as dust shields for the front and rear. The problem is that I shouldn't have to do this. That's what the "engineers" at Losi should have done a long time ago. There was an o-ring that went around the front bearings that was supposed to seal the front diff. They don't include that with the kit anymore. I asked Losi about it: they said thier team doesn't think it's necessary. Well, I'd rather be hangin' with my friends in the pits than frantically trying to clean it so it isn't gritty kitty.

How did Associated manage to get their B4's steering linkage to be as smooth as it is minus bearings? Compare to xx-4. POOP. XX-4 is awesome right after you've just spent 15 minutes cleaning it. Not awesome after your day of racing.

Looks like we found a hot topic. For a little while I thought this place was deserted!

Ill second this question, i must be thick as well G.


I could of sworn the belts got shafted at the worlds:D

The 13t pinion will be the problem. That motor probably wants a 20.

I have to say I've never have any problem with dirt ingress. I've done a full seasons racing with no major servicing apart from after Kiddy & Oswestry - for obvious reasons.

He meant that it takes less time to change a belt than a driveshaft.

Isn't that backwards? If I ran a 25, more load/more heat. 13t, easy on the motor.

Undergearing is generally just as hard on the motor as its reving its bollocks off about 1 meter down the straight you need to get your gearing right as for getting dirt in i have never had a problem with getting dirt in the belt tunnel.

A

Gearing is a happy medium mate, there is an optimum ratio.

Dropping a tooth or ten in your case will only let the motor run cooler if its over geared, think of it as riding a bike, would you like to pedal along in 1st, with your legs going like hell but going no where fast. Thats what your motor was doing.


And i think changing a shaft is pretty easy, certainly no harder than changing a belt?:wtf:

i think people are forgetting though, isnt the xx4 like ancient compared to the new tamiya, B44 etc? yet its still up there with the latest and greates 4wds!

i dont own a xx4 but c'mon give the old timer a break!!:p

I can change a centre CVD bone in my BJ4 Worlds in less than two minutes I bet, oh wait I never have to because they don't break :p

Rich, you dont even change the setup anymore:D

ROFPMSL ;)

Nah, I don't think thats what he meant. Fiddybux, what did you mean?

G

I read somewhere that belts were faster than a solid shaft...but it appears that my point was somewhat unfounded.

I have since found information that counter both the pro belt and pro shaft arguments.

Truth is that both have pro's and con's and neither is better than the other overall.

I currently run a Tamiya 501x but years ago I ran a XX4 for a season or two.

Now, racing in Australia in very dusty conditions makes maintenace a real pain, but to be honest I found the XX-4, when assembled correctly, could run for months without any maintenance at all :o

All of the drivetrain bearings are sealed, and therefore fairly well protected from dust at least, and I always found the the upper chassis tunnels sealed very well indeed.

I could comfortably run my car in these conditions for a few months at least without any reduced efficiency in the drivetrain. I felt this was one of the best features of the xx-4.

Alrighty then, I must have major issues with the belt cover sealing correctly. I changed out the pulleys and the thing still skips. The power from the Novak 6.5 is probably plenty to get the car to do a wheelie, but it never will because the belt will skip before that happens.The bearing surfaces for the front and rear diff are very much exposed, and I am stunned that running it in Australia (a dust bowl) isn't causing major problems for you, bender. Yeah, it was an ebay buy, but that's really not the root of the problem. I have some threads stripped out on the chassis and changing it out might solve the problem (at a $50 expense). I wish there was a good way to repair the threads, but I tried already by filling them with epoxy and tapping them. No dice. All good to hear everyone put thier ideas on the car in here. Awesome! I didn't catch anyone standing up for the crappy flappy rear brace. You know why!

On a high grip surface a belt drive car usually gets off the line a bit quicker but I'm only talking the first 3 feet or so, every other situation though a shaft drive car will accelerate quicker ;)
The main advantage of a shaft drive car is the throttle feel, very direct and doesn't feel like there's a slight delay between you accelerating and the car accelerating.

This one's easy. Just use shock shafts instead of the stock hinge pins so you have e-clips to hold the brace.

and to add to this order the Atomic Carbon rear brace from Jonathan (Mr Atomic Carbon) on here. That coupled with Gayo's suggestion is what i have done and it is sorted.

Try CVD's on the front rather than lcds if they are too expensive.

Smoking motors is something i've never done in the XX4, Burning the comm on brushed motors yes (8,9 and 10 turn) but most is down to preparation and gearing.

The belt issue can only be knacked belts or pulleys. Guys in the UK regularly use 5.5 LRP/Nosram/Novak Brushless on grass and astro which is high bite with no problems so it cannot be the motor in my opinion. Only other thing could be the slipper. If it's too tight you may be putting too much of a strain on the drivetrain hence skipping belts.

Wait untill you have to change a belt on a TRF501X. You''l be swearing and in tears :p.
Luckely, that's about the only thing that breaks on the entire car, and mostly on high grip astro tracks. I guess it will be better with the long belt-18T-37T conversion.

The eternal belt vs shaft argument !
I'm going to try to explain it one more time :
A shaft car is more efficient and accellerates more directly and thus is generally a bit faster of the line. But the latter is also its weak point. With modern power systems, the power delivery can be very brutal, making the wheels spin initially faster on acelleration compared to a belt drive where the belts first stretch a little, taking a bit away from the power peak. Now this is all on a microsecond scale, but that microsecond makes all the difference. It gives the tyres a bigger chance to grip. Read the interview with the AE TC5 designer on rc-caraction

For all you guys here familiar with MotoGP racing or the old 500cc class racing, it's a bit like "Big-Bang" engines. They lost some horsepower compared to a "screamer" but it made bikes a lot more rideable because the tyre had more time to "settle" between cilinder detonations.

Geepers .... I thought I was the biggest XX4 hater in the whole world but this thread has made me think again on that score...LOL

I just hated the way it handled, or rather didn't. Absolutely, totally, utterly 100% wrong for my driving style in as much as the pred was 100% right for it.

Belts were a pain in the arse when they broke and as I used to race Standard motor class in Radio Race Car the lack off efficiency hampered me too.

I do know a few people who will miss the car greatly when it's gone though, horses for courses.

Im going to miss it if it goes :(

But im going to keep mine and run it when i make my first 4wd national A final:D:D If that ever happens

A

ashley were setting you a challenge! to repair a belt in 12 mins with no one to help and under pressure...

yeah ash 12 mins before a heat im gonna snip a belt and i expect to see your car on the line :D

I'd take that challenge:D

GO FOR IT!!!!!:D

A