RC10Talk - The Net's Largest Vintage R/C Community

This Yokomo 834B last saw action in 2010 when we had a local vintage event - after which it was put on a shelf and untouched for the last 7 years. lol!



Standing proud at NOOB Vintage 2010.


I happened to visit rc10talk recently and as it so often happens the itch to work on the car started again (rc10talk is dangerous I say!)

So here's some 2017 updates to a 1983 car. I really wanted to keep the kydex chassis with the huge bumper as well as the original rollcage as I felt these are very iconic parts of the car. However, the plan was to see if I could make this a more decent runner by adding some touches of my own.



Here's the car after I replaced the rear monoshock with twin shocks in the rear, made a new shorty-capable battery holder and also a custom top-deck reinforcement plate. Also put on some parts I've collected over the years like the Lohas front and rear plates (red parts) and Pargu's aluminum front lower arm.



Carbon fiber goodness... I wonder if I went a little overboard. lol!
The top deck reinforcement is aimed at stiffening up the otherwise very flexible chassis.
The battery mount was created to hold shorty lipos securely and without the need for any battery straps. There are actually multiple positions to shift the battery sideways - particularly to offset the weight of the motor on the right of the car. The battery retainers are designed for ease of use - the charging ports (including the balancing port) are all exposed so you can charge the battery in the car if needed but to remove it, all you need to do is loosen 2 thumbscrews without even removing them and the battery will slide right out.



Rear suspension mounts were designed to integrate to the vintage rollcage while being very rigid. Multiple holes allow for different shock configurations (also because I have no idea what works. lol!). It's not installed yet but the design will integrate with the little carbon fiber tab on the back of the gearbox to install turnbuckle stiffeners.



Sideview of the car. I've still to install the steering and also plan to design a front shock tower to run dual shocks up front. I know many guys feel the monoshock is part of the car's charm... but I think the performance of dual-shocks for a runner far outweights the look of the monoshock. We'll try and see. lol. I'm hoping the Pargu front arms are durable as the plastic stock ones are too flexible for my tastes.


I hope to update this as I add to the car. Any ideas on how to make this a better runner would be much appreciated. I'm considering the easiest way to add some width to the car... any suggestions?

Awesome...I wish I could make parts like those. I think front twin shocks are a must. Would the rear roll bar help too?

naushad wrote: ↑Wed Jul 05, 2017 4:56 am Awesome...I wish I could make parts like those. I think front twin shocks are a must. Would the rear roll bar help too?

I will definitely be trying to add in that rear roll-bar in a nice fashion.

Meanwhile I popped by the hobby store and althought they didn't have any turnbuckles long enough for my purposes, they did have these cool looking long ball-ends which I think look very nice. They are installed on the rear and do a great job in supporting the rear end so the chassis is more rigid and the suspension compresses without tweaking the roll-cage.



Plus I think they look really cool.

Great looking runner!

BloodClod wrote: ↑Wed Jul 05, 2017 7:54 am
Plus I think they look really cool.

Yes...yes they do

keep up the updates. I've always had a place in my heart for the 834...just not a place in my wallet for it

Todd

Designed and cut out a front shock tower - it was designed to fit modern 3" buggy shocks. Also widened the rear a tad.



Quite like how the car is turning out so far. The shocks definitely need some setup as the fronts are way too stiff and the rears too soft as it currently stands.



Was deciding whether to go with the "Y" shape design (which I went with) or a the "U" shape. I do like how this looks but I will have to consider how to fit the shell without losing too much of the look of the car. A "U" shape could allow the front of the shell to possibly still fit but it would weaken the tower. What do you guys think?

Tried another version of the front shock tower. Please forgive the very old basher body that came with this car when I bought it years ago. This new tower should allow the cover to be cut so that the front can still be retained to extend in front of the shock tower itself.



Which shape do you guys think looks better?

Here's a picture of the battery tray and how to remove the battery by just loosening the thumbscrew. This way there are no pieces to roll off the table and lose. lol!



With the battery removed you can see the different adjustment positions to offset the battery to the side to balance the left-right weight distribution of the car. Not sure how big a difference it makes on an old design like this but it looks cool.



Let me know what you think.

It looks very tidy , I could never change mine from mono shock but your shock tower look very neatly done , you mentioned widening the rear , how did you do that ?

The suspension didn't feel right on the bench so I designed some new blocks for the rear to revise the geometry - particularly to stand the rear shocks more - and it was just so much better. With everything in the ballpark I carefully cut my shell to fit around the new suspension mounts front and rear and here's how she looks!




Here's the side view. I think all the 834B shells are amazing because they are so unique but this original shape will always be my favourite. I believe this is a Mr Lexan shell that I bought probably around 2010... awesome quality!




Here's another view before the car gets roughed up at the local offroad track.
The second version front shock tower designed with a "U" shape allows the shell to fit over it so I don't have to cut the front off. Overall I think it really changes the look of the front end of the car.




Not that many guys will bother but this shows the reworked rear upper mounts that really transformed the rear suspension action. I think the turnbuckle supports do a nice job of filling up the space between the shell and the rear wing.




There are a few more things I'd like to try on this car but as it is I'm ready to put in my electronics and take it to the track. Planning for a 13.5T brushless setup that should provide for a reasonably peppy ride.

Dadio wrote: ↑Fri Jul 07, 2017 2:36 am It looks very tidy , I could never change mine from mono shock but your shock tower look very neatly done , you mentioned widening the rear , how did you do that ?

Thanks!

You're not the first 834B fan to tell me that they would never remove the front monoshock - my friend tiger1 said the very first thing years ago when I told him I was considering doing so. lol! I'm fortunate enough to have 2 other versions of this buggy so this one is going to be the one for me to go a little wild with.

The rear was widened by cutting some spacers. I will take some pictures for you next time... they seem to work so far and I intend to cut some new ones from 5mm carbon-fibre plate to widen each side by 5mm for the front and rear.

So you put the spacers between the wheel and the drive hub ? 10mm increase is not bad at all .
The only concession to improve the handling on mine is modern shocks , I just love the old school original look , just takes me back to my childhood , I'm quite jealous of you having three ! If I had a second then I think an RPS version would be nice and with a third maybe I'd experiment too !

The body looks good and I really like the turnbuckles , they do fill that space as well as being a functional support to the roll hoop , do they add any torsional rigidity to the chassis ?

Always good to see you around here. I love your cars and all the not-of- the- shelf stuff you have in them.

Hmmm... I wired everything up and on testing found that the front sprocket is worn quite badly. Are these rare items? For now I'm going to take one off one of my shelfer car to run but it'd be a pity if I'm going to have to baby it.

Pics to follow soon.

Just about every part is rare , I've seen a few rear drive pulleys for the slipper type pulley come up on eBay but not a front one for about a year and I check virtually daily for 834 parts , good luck , I ration driving mine because of the down time if I brake anything.