Modernising an Optima Mid Custom?

[Wooders28 4723]

2 hours ago, Yalson said:

I was actually referring to the ZX-R in the picture. The ZX-R came with 2.2" wheels

Everything was 2" when I stopped racing, and when came back,everything is 2.2", so in my head, 2" = vintage 😎

[Wooders28 4723]

Couple of wheel and tyre options 

 

 

 

 

 

 

 

 

[Yalson 514]

Nice. BITD the standard starting set-up on a new track of dry, short grass (we used to lay out a new circuit layout every week using rubber pipes and old tyres) would be narrow Schumacher minispikes on the front and either full Schumacher spikes or cut Schumacher spikes on the rear. That was in the days before the yellow compound was introduced, which I think is softer than both the green (medium) and blue (hard) compounds. I used to like my car a bit slidey and the LWB Mid was always a bit understeery anyway, so I used to start with cut spikes on the rear, but most other drivers used to go with full spikes and then dial the car in from there.

Wet or damp conditions would need something spikier. The Schumacher square block pattern were useful, too, when it got a bit drier.

[Wooders28 4723]

On 9/26/2018 at 11:02 AM, Yalson said:

narrow Schumacher minispikes on the front and either full Schumacher spikes or cut Schumacher spikes on the rear. 

Got to the track last night, tried a couple of different options (Not all, as I'd run out of time) but found the minispikes to be the best/most predictable on carpet, tyres I used to use on the rear of the Ultima bitd! 

I hadn't glued them or fitted inserts, as I've not that many wheels to choose from, so predictably,  they fell off! 😂

The hopes of staying with modern stuff didn't materialise, corner speed on a tight track just wasn't there, neither was the amount of steering lock! (But still manage to grip roll)

Good fun was had though 😀👍

 

 

 

[Yalson 514]

1 hour ago, Wooders28 said:

Got to the track last night, tried a couple of different options (Not all, as I'd run out of time) but found the minispikes to be the best/most predictable on carpet, tyres I used to use on the rear of the Ultima bitd! 

I hadn't glued them or fitted inserts, as I've not that many wheels to choose from, so predictably,  they fell off! 😂

The hopes of staying with modern stuff didn't materialise, corner speed on a tight track just wasn't there, neither was the amount of steering lock! (But still manage to grip roll)

Good fun was had though 😀👍

 

Nice video. I'm presuming someone else took it, as otherwise you should be able to marshal yourself while driving.

The car looks good, but I'd hazard that the suspension is either a fraction too high or a fraction too soft, as it shouldn't be grip rolling like that. If you have got the suspension down to its lowest possible setting, then you could lower it further by inserting some rubber or plastic spacers inside the the shocks, effectively making the shocks shorter and the car lower to the ground. If you're using the Kyosho Gold shocks (which I think you are) then you could also lower the shock collars so that the spring settings are much harder. On a grippy, billiard table surface like that you're not going to need a lot of height or suspension travel, so the idea is just to get the thing as close to the deck as you comfortably can and lower the centre of gravity accordingly. It will make the handling a bit more 'brittle' and slidey, but if you are having trouble with turn-in (as it seems you might be) then loosening the rear end a little might actually help.

[Yalson 514]

1 hour ago, Wooders28 said:

Got to the track last night, tried a couple of different options (Not all, as I'd run out of time) but found the minispikes to be the best/most predictable on carpet, tyres I used to use on the rear of the Ultima bitd! 

I hadn't glued them or fitted inserts, as I've not that many wheels to choose from, so predictably,  they fell off!

 

Had to go into the garage earlier, so thought I'd send you a picture of the tyre boxes which I liberated from my parents' loft recently.

Bizarrely, I found I had at least two pairs which had a tyre missing. No idea how that came about.

I think that is also my old BRCA membership card attacheed to the lid of the wooden box.

[Wooders28 4723]

10 minutes ago, Yalson said:

I'm presuming someone else took it, as otherwise you should be able to marshal yourself while driving.

Yeah, it was one of lads of one of the other heats that wasn't racing or marshalling (no phones allowed whilst marshalling).

11 minutes ago, Yalson said:

The car looks good, but I'd hazard that the suspension is either a fraction too high or a fraction too soft, 

Both! 

If I stiffened up the rear springs, it would wheelie instead of squatting, and I ran out of adjustment on the slipper, so I'll need to either cut down the slipper spring or find a lighter replacement.

They are gold shocks, and I think the fronts are the medium length fronts, so I've got the short length that can go on, and can lower it another setting on the wishbone,i went for core rc 400 weight oil, the mid range of what I've got, so that can swapped out , plenty to go at, but it's just getting the track time! 

Also going to try and make a roll bar front and rear, not sure how much difference they would make, but worth a try.

With only a couple of hours, and a few heats to run, I didn't get all the track time I wanted/needed to get the car dialled in, but I've a feeling I won't be catching the modern cars.

20 minutes ago, Yalson said:

Had to go into the garage earlier, so thought I'd send you a picture of the tyre boxes which I liberated from my parents' loft recently.

Wow!

Are they wheels with tyres!?!? 😲

 

[Yalson 514]

6 hours ago, Wooders28 said:

Yeah, it was one of lads of one of the other heats that wasn't racing or marshalling (no phones allowed whilst marshalling).

Both! 

If I stiffened up the rear springs, it would wheelie instead of squatting, and I ran out of adjustment on the slipper, so I'll need to either cut down the slipper spring or find a lighter replacement.

They are gold shocks, and I think the fronts are the medium length fronts, so I've got the short length that can go on, and can lower it another setting on the wishbone,i went for core rc 400 weight oil, the mid range of what I've got, so that can swapped out , plenty to go at, but it's just getting the track time! 

Also going to try and make a roll bar front and rear, not sure how much difference they would make, but worth a try.

With only a couple of hours, and a few heats to run, I didn't get all the track time I wanted/needed to get the car dialled in, but I've a feeling I won't be catching the modern cars.

Wow!

Are they wheels with tyres!?!? 😲

 

Gold shocks are lovely. If you have mid-length versions on the front (which Mids didn't come with as standard) then you could theoretically try them on the rear with the shorts on the front. The ZX-R had longer versions of the gold shocks on the front which Kyosho developed especially for it. They came in between the short Mid fronts and the long Mid rears.

When we used to race the Mid on tarmac during the winter we tried pretty much everything to get it to sit lower, including inserting rubber spacers on the shafts inside the shocks, making new shock mounts and swapping shock lengths about. If we'd have had a set of the longer ZX-R fronts (and not had a ZX-R to use them on) we would have definitely tried fitting them to the rear and leaving the short golds on the front. One thing you definitely shouldn't bother with is fitting the short golds on the rear. We tried that one and there is no way of getting adequate ground clearance. We also tried removing the shocks altogether and replacing them with turnbuckles adjusted to a suitable length. I wouldn't advise that, either. The car drove surprisingly well, if a little like a plastic saucer skipping across the surface of a lake, but removing the shocks just means everything in the car gets shaken loose. You'll get it back, take the shell off and inside it will resemble a sewing box that a kitten has broken into.

I forgot the difference in power, though. BITD I'd generally use 1700 SCEs with either a Revolution 16x5 or a 14x2 of unknown provenance. In terms of duration you could get away with hotter winds with the same cells on tarmac, as the friction levels are much lower. But even then you usually couldn't use too much as you'd just end up travelling quicker when you inevitably hit something, because the grip levels were so low. Brushless tech and the loopy batteries available now mean that there's just a lot more go. Nobody's car ever wheelied back then unless you had a Wild Willy. Now it seems that it is something everyone has to dial their car in to avoid. Ditto lifting an inside wheel when cornering.

The ARB might be worth trying if you are racing on carpet, but I generally couldn't see any benefit from it and it ended up in the bin pretty quickly. The original Kyosho version was extremely weedy, though, so it could be that it just needed to be stiffer.

Most of those tyres have wheels inside, yes. Some are old ones which have been removed from the rims and were just there for bashing and testing. There is also a set of unused Belsport Platinum foam tyres which we never got around to mounting. There was a proper tarmac RC circuit near us in Mildenhall (which I think was called Smokehouse Inn after the restaurant whose grounds it sat in, but I could have misremembered that) and they had a winter tarmac championship for 1:10 buggies called the Frozen Finger series. When we were just racing round on the sports centre car park on Saturday mornings I stuck to rubber tyres as the surface was too rough and abrasive for anything else (hence all the treaded and slick tyres in the box). Smokehouse was smooth, specially laid tarmac, though, so my Dad went out and bought three sets of Belsport Platinums, which were tyres for 1:10 on-road circuit cars. He had them sanded down to the correct size at work, then we fitted them to a set of the three-piece Kyosho split-rim wheels with the black plastic beadlock removed and a specially made plastic spacer fitted between the two remaining parts, to make room for the greater tread width. They were – strictly speaking – probably illegal, as there was a maximum tyre tread width for BRCA-sanctioned events, but they passed scrutineering, so... The unused set in the box were a new set we were going to make up into a set of wide fronts, but never got round to. I gather that foam tyres go off after a while, so they're probably useless now.

[Yalson 514]

9 hours ago, Wooders28 said:

The hopes of staying with modern stuff didn't materialise, corner speed on a tight track just wasn't there, neither was the amount of steering lock! (But still manage to grip roll)

Good fun was had though 😀👍

 

Also, whatever set-up you choose to put on the car, don't copy whatever the driver of that Beetle convertible did.

[Wooders28 4723]

23 hours ago, Yalson said:

If you have mid-length versions on the front (which Mids didn't come with as standard) then you could theoretically try them on the rear with the shorts on the front.

Maybe worth a try! 👍

 

23 hours ago, Yalson said:

We also tried removing the shocks altogether and replacing them with turnbuckles adjusted to a suitable length.

Yeah, don't thinking the car would appreciate the jumps, especially as larger jumps are in the process of being built (taller kicker ramp, for height, not distance, more to slow the cars to try and increase lap times more than anything else)

23 hours ago, Yalson said:

BITD I'd generally use 1700 SCEs with either a Revolution 16x5 or a 14x2 of unknown provenance. 

I used to run, Magnum SCR's (I think they were 1700's?) Mainly as I ran stick packs, as I ran the same packs in the Ultima in the 2wd drive class, and with the same lemans 240st too! (Paper round didn't pay enough to have the luxury of spare motors 😟) 

 

23 hours ago, Yalson said:

Brushless tech and the loopy batteries available now mean that there's just a lot more go.

Oh yes, even with the 5.5t, I got 2 heats out of the 4800mah, 70c lipo. (I would love to, back to the future, it back to the late 80's 😂

 

23 hours ago, Yalson said:

The ARB might be worth trying if you are racing on carpet, but I generally couldn't see any benefit from it and it ended up in the bin pretty quickly. The original Kyosho version was extremely weedy, though, so it could be that it just needed to be stiffer.

I'm going to try the roll bar off my KF2 / K1 and see if it will adapt, they are £13 new, so worth a punt.

 

23 hours ago, Yalson said:

Most of those tyres have wheels inside, yes. Some are old ones which have been removed from the rims 

Are the old kyosho wheels ok for steaming, or are they like the tamiya's, and deform? Best way to get old tyres off? I've not got a great selection of wheels to start supergluing tyres on to, if it's a one way ticket. (And the turbo optima wheels didn't come with the plastic inserts!?!) 

22 hours ago, Yalson said:

Also, whatever set-up you choose to put on the car, don't copy whatever the driver of that Beetle convertible did.

😂😂

No idea where that came from, it's been there for weeks, just no one has bothered to move it! 

[Yalson 514]

On 9/28/2018 at 11:10 PM, Wooders28 said:

👍

Yeah, don't thinking the car would appreciate the jumps, especially as larger jumps are in the process of being built (taller kicker ramp, for height, not distance, more to slow the cars to try and increase lap times more than anything else)

I used to run, Magnum SCR's (I think they were 1700's?) Mainly as I ran stick packs, as I ran the same packs in the Ultima in the 2wd drive class, and with the same lemans 240st too! (Paper round didn't pay enough to have the luxury of spare motors 😟)

I'm going to try the roll bar off my KF2 / K1 and see if it will adapt, they are £13 new, so worth a punt.

Are the old kyosho wheels ok for steaming, or are they like the tamiya's, and deform? Best way to get old tyres off? I've not got a great selection of wheels to start supergluing tyres on to, if it's a one way ticket. (And the turbo optima wheels didn't come with the plastic inserts!?!)

No, I don't think it would appreciate anything at all beyond flat tarmac. To be honest, it didn't like that much either. We got much better results from fitting spacers inside longer shocks to make them shorter.

We started with various brands of 1200 Sanyo SCRs, then moved on to various Sanyo 1700 SCEs and finally moved to the Panasonic 1700 SCRs when they came out. The advantage of SCRs over SCEs was supposed to be that SCRs had a better power curve and could deliver snappier, sharper acceleration. To be completely honest, although 1200 SCRs were noticeably better in that regard, I found 1700 SCEs and SCRs to be equally wimpy in terms of their power delivery and couldn't tell the difference between them.

Fair enough on the ARB. I am increasingly of the opinion that I just wasn't a good enough driver at the time to notice any difference it may have made.

i only very rarely stuck tyres down to the rims. I never found that they used to come off while driving, to be honest. It was really only a problem with softer, grippier compounds and since Schumacher didn't introduce soft yellows until I was virtually out of the game, it wasn't much of an issue for me. Greens and blues would stay on standard Kyosho rims all day and all night, as would any Kyosho, Tamiya or other brands you care to mention. To combat the rims spinning round inside the tyres (which did happen, especially with harder compounds), we used to put a flat rubber band inside the groove the tyre bead sat in, usually the one on the outer edge of the wheel. This would provide enough friction against the tyre bead to prevent the rim moving inside the tyre, while still allowing us to swap the tyres over if needed. The three-piece Kyosho split rims didn't need any of this as the inner section inside the tyre locked them in place on the rims very efficiently.

[Yalson 514]

I was just trying to remember what the standard response to glueing the tyres was BITD. I think some people did, but it was a last resort, for obvious reasons. I seem to recall Yokomos having a particular problem with rims moving inside the tyres, meaning their owners used to do a lot more glueing, which meant the dried glue seeping out between the tyres and wheels was just another thing that made them look untidy.

Even without the rubber bands, I don't remember the wheels moving very much as the tyres used to fit the rims very tightly. Especially Scumacher tyres, which I feel may have been made to be a fraction less than 2" in diameter, just make the fit more snug.

Then again, we used brushed motors back then, and frequently gutless ones at that. Brushless motors have probably caused the power available to reach glue-ripping, rim-distorting levels.

[Wooders28 4723]

3 hours ago, Yalson said:

i only very rarely stuck tyres down to the rims. I never found that they used to come off while driving, to be honest. It was really only a problem with softer, grippier compounds and since Schumacher didn't introduce soft yellows until I was virtually out of the game, it wasn't much of an issue for me. Greens and blues would stay on standard Kyosho rims all day and all night

I never stuck them down back then, but the tyres were ripped off the rim with the 5.5t the other week, but I still didn't have any bother with the wheel slipping in the rim. I ran blue blocks and had no issues whatsoever with spinning or coming off the rim, so thinking on, may try them on carpet next time!! 

 

[Yalson 514]

42 minutes ago, Wooders28 said:

I never stuck them down back then, but the tyres were ripped off the rim with the 5.5t the other week, but I still didn't have any bother with the wheel slipping in the rim. I ran blue blocks and had no issues whatsoever with spinning or coming off the rim, so thinking on, may try them on carpet next time!! 

 

If they're coming off the rims it's almost certainly down to the fact you're running grippy tyres on carpet with a lot of power. You've already said you have been grip rolling and this is the other side of that coin. The car has sideways momentum, but has too much grip to allow it to follow that path. The fact that you are having to run the suspension fairly high and soft is allowing the tyres to dig in and centrifugal force is doing the rest.

You could run blue blocks, but they're a lot harder and you may find them too slidey and uncontrollable, especially since that circuit is very tight. Green blocks might work, but I don't know if you have any.

Are you running foam inserts? If not, then they may help. One of the reasons very grippy tyres can come off the rim is because they are biting into the surface too much, the soft sidewalls are deforming and stretching and they are just rolling off the rims. Foam inserts will reduce the levels of mechanical grip a bit by preventing the sidewalls from deforming so much, as well as reducing the size of the contact patch by maintaining the cross section of the tyre. That's the theory, anyway. I don't have much experience with inserts, but they're cheap, so it might be worth trying to see what happens.

What compound are you using? It might work to go one compound harder (yellow to green, or green to blue) on the same tread pattern. You would lose some grip and it would again make the car more slidey, but it would be better than the tyres coming off the rims.

I'm a bit baffled as to where to go with this, to be honest. I've only raced on carpet a few times (actually on an indoor circuit which was part carpet and part bare sports hall floor – a combination that literally no tyre combination worked on, meaning everyone had to compromise their set-up and hope theirs was less compromised than everyone else's) and I sucked at it. I have had plenty of discussions about tyres and grip, but having so much of it that it makes your car fall over or lose its tyres is not one that has come up before. Maybe you should get some foam circuit racing tyres?

[Wooders28 4723]

44 minutes ago, Yalson said:

Are you running foam inserts? If not, then they may help. 

Not yet, but Schumacher and LMR inserts have arrived to try. The front mini spikes are wheels I bought 2nd hand, the tyres are glued, and they've been fine. I could get the split rims off the Ultima (Or just use the plastic spacer out of them for the turbo optima wheels i got off ebay for a fiver, that didn't have them) as they clamp the tyre on better, (Ultima running a 6.5t with full spikes and not had any tyre issues).

44 minutes ago, Yalson said:

What compound are you using?

The only compounds available these days I think!

Blocks come in yellow or blue, mini spike in yellow and full spike in soft.

46 minutes ago, Yalson said:

I'm a bit baffled as to where to go with this, to be honest. I've only raced on carpet a few times

I've only really raced on carpet, and actually liked the half bare floor tracks, as I could make up so much time on the slippy stuff, whilst others struggled, well, tried too hard.

48 minutes ago, Yalson said:

but having so much of it that it makes your car fall over or lose its tyres is not one that has come up before

The track is one of 2 local (kind of) indoor tracks, and that one is the low grip! The Ayr track I've grip rolled a vintage boomer on original tyres! 

 

All I can do is try different set ups and tyres I've got, and see which works the best, the car wasn't designed with 50mph brushless speeds its now actually doing in mind, so it just might not have the perfect balance,  but if I can get so I enjoy driving it, and i can get round successfully, then that will be progress. 

[Wooders28 4723]

It's been a while, but just incase anyone is wondering how the mid is coping, the answer is very well!! 

I've fitted a 1258TG servo, shaved a bit off the steering bumpstops, to allow a bit more of a steering angle, and also fitted a cooling fan to the motor, so yes it's been used, alot!!

Ok, it's not been used a great deal since March, but until then, was ran at least weekly at my local club, this was in a church hall we rented during last winter, upto March, found the Schumacher Full spike to be the best controlled grip, still a bit ,bamba on ice though...

 

 

[Collin 1956]

Can I hear the diff tweeting or am I wrong?

[Wooders28 4723]

26 minutes ago, Collin said:

Can I hear the diff tweeting or am I wrong?

Gear diffs front and rear, could be one of the others, although with the grip being next to nothing I doubt it.

Upto date pic 

 

[Yalson 514]

On 11/12/2020 at 4:55 PM, Wooders28 said:

It's been a while, but just incase anyone is wondering how the mid is coping, the answer is very well!! 

I've fitted a 1258TG servo, shaved a bit off the steering bumpstops, to allow a bit more of a steering angle, and also fitted a cooling fan to the motor, so yes it's been used, alot!!

Ok, it's not been used a great deal since March, but until then, was ran at least weekly at my local club, this was in a church hall we rented during last winter, upto March, found the Schumacher Full spike to be the best controlled grip, still a bit ,bamba on ice though...

 

 

WOW! You have no idea how happy it made me to watch that! It goes well, too, doesn't it? You're basically hanging it round the corners on power alone, almost drifting it round balanced on the throttle. It looks and sounds great. Loving the tables arranged as barriers, too. Proper retro!

I forgot about shaving the bumpstops off of the uprights to get more lock. I could never understand why Kyosho put them there in the first place. Especially since the LWB Mid was so understeery by nature.

Loving the custom shock tower covers and the motor fan mounting, too. It looks really tidy inside.

I should really get one of my Mids rebuilt. I miss having a proper car to drive. The Grasshopper II I rebuilt really isn't cutting it.

[Wooders28 4723]

12 hours ago, Yalson said:

WOW! You have no idea how happy it made me to watch that! It goes well, too, doesn't it?

Thanks mate, glad you like it!!

Soooo much better than just sat on the shelf! 😎

It goes great, I've still to remind myself, it's 30+ yrs old, so the corner speeds aren't upto modern ,wider buggy , speeds when on the higher grip, but on the low grip ,it holds its own! 😁

 

12 hours ago, Yalson said:

You're basically hanging it round the corners on power alone, almost drifting it round balanced on the throttle

That was the plan, but I always push it too much 🙄, tried to drift the whole section closest to me at the end, but hit the chairs....🤦‍♂️

12 hours ago, Yalson said:

Loving the tables arranged as barriers, too. Proper retro!

They're actually ramps from the old venue ( a spare section of an indoor karting track, but they found they'd earn more money, off indoor 5 a side football 😢). No longer use that venue either , Covid initially, but we've now secured the outdoor venue.

I loved the "jumpers for goal posts" vibe, no timing gear, just mates having a laugh with RC's.

 

12 hours ago, Yalson said:

Loving the custom shock tower covers

These were mk1 ones, and broke. I'm now on mk2 ones, and more flexible, much better, he was on about making a batch for eBay, so can give you a link if you want a set (3d printed, so probably just make them to order tbh)

Although to race race, I need to cover the spur (marshall health and safety), with the K2 slipper just (as in JUST, had to machine a bit of the washer!) clears the shock, so no room. Might see about getting a slightly wider shock tower made, and remove some meat of the upper shock collar, to bring it away a bit, but not far enough out it looks wrong. 

12 hours ago, Yalson said:

and the motor fan mounting, too. 

The motor cooling fan was just a trial at that point, mate had a spare fan, and I stuck it on with servo tape, really brought the temp down, so I've made a bracket for it now.

12 hours ago, Yalson said:

It looks really tidy inside

Thanks! 

First person to say that about any of my cars....🙄😂

 

12 hours ago, Yalson said:

I should really get one of my Mids rebuilt. I miss having a proper car to drive. The Grasshopper II I rebuilt really isn't cutting it.

Get it rebuilt! 

There's people out there, that'll copy towers ,chassis etc into carbon, think i was less than £20 for the shock towers (3 of) ,and rebuild time, I'll get the chassis and top plate done. Not for looks or anything, just I'd rather break something I can easily replace! 

I gave the RB5 slipper shaft dimensions to a guy, who's made a shaft for the mid, which takes the RB6 (same size I guess), I posted his Facebook sales link on another post, but it was 2 yrs ago, so not sure if he's any left.

Muzzoom models have since made the 3D printed Lipo saddle holders to fit the existing holes on the mid, as the Schumacher ones I used where only mm's out, so they've just altered the programme slightly.

[Yalson 514]

2 minutes ago, Wooders28 said:

Get it rebuilt! 

There's people out there, that'll copy towers ,chassis etc into carbon, think i was less than £20 for the shock towers (3 of) ,and rebuild time, I'll get the chassis and top plate done. Not for looks or anything, just I'd rather break something I can easily replace!

I know I should. It's annoying, as I have two Mids and a Lazer ZX-R just sitting in my Dad's loft, but because of the realities of racing a lot of parts got stripped off one car to put on another and back again, meaning only the Lazer is probably currently in anything close to a working state. I doubtless have the parts for the Mids, but it's a matter of finding them and the time to actually make them work. I have a 4yo daughter now, so keeping her working now takes up most of my time.

Plus, as I found out when I rebuilt the GH2, my eyesight and dexterity have declined sharply in the last 25 years or so, meaning everything takes so long now. I used to be like those characters you see in films, who can put on a blindfold and strip, clean and rebuild an M-16 assault rifle in 30 seconds, only with a Mid. Now I can only find the right end of a screwdriver by sticking it in my leg and seeing if it hurts!

I really should do it, though. It will bug me if I don't. I did start doing the SWB Mid about ten years ago and I even painted a new shell for it. Maybe I should start with the Lazer, since that is the most complete? Get that done quickly and move on to a Mid? We'll see.

[Wooders28 4723]

6 hours ago, Yalson said:

Maybe I should start with the Lazer, since that is the most complete? Get that done quickly and move on to a Mid? We'll see

Not sure how many parts are interchangeable? If any!

[Yalson 514]

11 minutes ago, Wooders28 said:

Not sure how many parts are interchangeable? If any!

A few. But more importantly, the Lazer just needs cleaning and tidying and maybe a new body. I need to get myself back into it.

[bartman77 16]

very nice ,,  there is one way to fix a ball diff ,,,, with metal ,,,   prob have to find a normall gear diff but there worth there weight in gold

[bartman77 16]