Losi XX~RS

[Coelacanth]

Alloy Trinity ones are nice,but rare and super sought after.
Took me 5 years to find mine,and it cost a lotta money.

That part is a work of art! On the other hand, the original plastic (nylon?) design is just a really bad idea, structurally. I'm not familiar with the car but why wouldn't the design have simply been one solid tube with the upper chassis part hinging into it having two much thicker tube sections on either side? Increasing the surface area of the adjacent hinging parts like they did is a recipe for problems.

[knixdad]

I've lost quite a few of the front bulkheads on my XX/XXTs.

I have a few of them NIP, all of them white I think.

I would love to find an aluminum one, but they are quite scarce.

[slapshot1979]

I see the xx as a car that grew in an era when r/c were still evolving and rapidly. To use the quote "if you do what you've always done you'll get what you always got. they designed it that way to overcome some other design issue Im sure. Every car has its weak point. the happens to be the xx's.

We are kinda screwed to a degree becasue this part ties alot of other parts together and its hard to reproduce the hinge areas. So complete re-designing is complicated..unless someone builds a total one off car like this one and could possibly go another route, and eliminate this problem.

[jamin]

Run an aluminium bulkhead if you are prepared to replace a chassis instead - I've seen lots of snapped chassis this way. Just use the plastic bulkhaed and the additional brace, that should be strong enough.

[DerbyDan]

Run an aluminium bulkhead if you are prepared to replace a chassis instead - I've seen lots of snapped chassis this way. Just use the plastic bulkhaed and the additional brace, that should be strong enough.

^I agree^ - also front arms are more likely to break, & they are getting super rare also!

The hinged bulkhead design is a curious one - since it seemed that it could allow for adjustable kick-up/caster angles but of course it was locked solid with the top X brace. As it happens, when I owned my original XX buggy during the 90s, despite it being my main racer for around 5 years, I never suffered from a front bulkhead breakage. Last year however I did break one of the black bulkheads on my Kinwald racer after hitting a railway sleeper pretty hard during a demonstration event (the sleepers were used to border the track) I wondered if the plastic is becoming more brittle with age, but to be honest I would have expected a breakage from any buggy hitting something so solid at the sort of speed I was going! I've now fitted one of the white bulkheads which I understand are made from a more durable material?

[Coelacanth]

Run an aluminium bulkhead if you are prepared to replace a chassis instead - I've seen lots of snapped chassis this way. Just use the plastic bulkhaed and the additional brace, that should be strong enough.

That's probably true...strengthening one part without addressing the parts it attaches to just changes the weak link to the next one down the chain.

[RobScott]

The bulkhead is screwed though its bumper mounts, to an aluminium plate that kicks up, and is bolted to the chassis. there is no way that strengthening the bulkhead would snap the chassis

Yeah. if i can find a stock bulkhead, then i'll make an alloy or carbon brace for the hinge pins, as thats where its snapping. and yeah, the plastic is defo getting brittle with age. I remember they had a certain amount of flex, but now it just cracks.

I have Loads of wishbones, so not a problem there, and a guy at my local club has a XX in his attic, which he said i can have for free yey. I'm finding the only way to get bulkheads is to buy complete cars :S eeek.

I'm at work at the moment, but i'll get some pics up of the chassis later. Sorry no vids. i'll try and get the wife to record it

[RobScott]

I'm thinking, maybe a modified RC10 b4 bulkhead/shock tower mount may work, the parts are easier to get too? I'd just be a shame to loose more losi out of the car

[RobScott]

ooooh, duratrax evader front bulkhead might just do it

[knixdad]

The Evader Bulkhead requires modification to the chassis which reduces the strength of the chassis side attachment area. So you end up snapping the chassis attachments rather than the bulkhead.

[RobScott]

yeah but mine isnt on a XX chassis, so no problem with that

[janaya]

This is pretty genius. I see a lot of ingenuity here on this forum.

[fakiee]

The hinged bulkhead design is a curious one - since it seemed that it could allow for adjustable kick-up/caster angles but of course it was locked solid with the top X brace.

Apparently that's what it was intended for, adjustable kick-up. But Losi decided that it ran so well with the current setting that there was no point in changing it.