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Hello all,

I need to replace the dogbone pins as it seems Kyosho stopped making the OT-6/92645 units and I don't feel like spend a ton. In this video, the show how to replace them with a vice and a 5/32nd socket (2nd half of the video). https://www.youtube.com/watch?v=IeXWTE8EyUM


Anyone know what kind of pins I need? Anyone know how long these dogboens are for the Optima? When I called Kyosho and they said the are not longer producing OT6s I asked what the preproduction Utlima used and he thought they were these OT228.... IDK though. https://www.kyoshoamerica.com/Swing-Shaft-OPTIMA-2016_p_24413.html

By the way, how often do they tend to wear out? Mine probably only got an hour or so of use before one of the pins wore down and snapped off.

I had an Optima right when itgot rere'd in 16' and i raced it outdoors and on carpet, alot of running and i never wore any out. I sold it few yrs ago☹ so i cant look at it. But I do have two 80's Turbo Optimas i bought used and restored, neither had worn pins

I have some Optima dogbones with worn crosspins but far more often, they are bent. I think it's way too much work to replace the crosspins when you can probably find replacement dogbones on AliExpress or BangGood. I saw some 70mm dogbones on AliExpress that looked like they might be 65mm crosspin-to-crosspin, I bet they might work to replace the Optima 62.5mm dogbones, and they're a few bucks a pair. Even if they didn't work, it would be no big loss. I bought replacement dogbones for the Marui Shogun I restored on AliExpress, I think it was $5 or so with free shipping for a set of 4.

Coelacanth wrote: ↑Sat Feb 13, 2021 3:39 pm I have some Optima dogbones with worn crosspins but far more often, they are bent. I think it's way too much work to replace the crosspins when you can probably find replacement dogbones on AliExpress or BangGood. I saw some 70mm dogbones on AliExpress that looked like they might be 65mm crosspin-to-crosspin, I bet they might work to replace the Optima 62.5mm dogbones, and they're a few bucks a pair. Even if they didn't work, it would be no big loss. I bought replacement dogbones for the Marui Shogun I restored on AliExpress, I think it was $5 or so with free shipping for a set of 4.

Thanks for the suggestion! It looks like the ones I have in there are 68 mm end to end so it is worth a shot.I will let everyone know if they fit and if they fit in my Ultima Pri XL.

No problem. If they're indeed only 2mm longer pin-to-pin, they might just seat more deeply into the half-shafts, which isn't a bad thing, as long as they don't push in all the way to butt up against the insides of the cups.

Coelacanth wrote: ↑Sun Feb 14, 2021 8:28 pm No problem. If they're indeed only 2mm longer pin-to-pin, they might just seat more deeply into the half-shafts, which isn't a bad thing, as long as they don't push in all the way to butt up against the insides of the cups.

I got these 70 mm units from Amazon https://www.amazon.com/gp/aw/d/B07P95MQM9?psc=1&ref=ppx_pop_mob_b_asin_title as I could wait a month for the ones I ordered on AliExpress. They look like quality dogbones but the pins are slightly thicker. They seem to just fit in my Ultima pro XL but I have not driven it yet. Any longer and they would bind when the suspension is compressed. Honestly the OT6s were a hair shorter than ideal so these may end up working better. 69 mm would be perfect.

In my Raider there are little springs in the cups and it felt too tight. I probably could have taken the springs out and been ok but I put the 0T6s in from the Ultima into the Raider for now. I will report back how the Ultima runs and how the AliExpress ones compare when I get them (mug but be exactly the same).

I wonder if the folks that make them knew there was a market for 69 mm… If they would do it. Probably not because it is too close to 70. I would still really like to know the length of the OT228 Drive Shafts!

I hope they'll work for you. I found it odd that there are aftermarket generic dogbones in various sizes (using the makers' sizing from end-to-end rather than pin-to-pin), but that there's a significant size jump from 60mm to 63mm on to 70mm, something in between 63mm and 70mm would've been perfect.

That said, I found some nice, shiny dogbones for that Marui Shogun I restored, that are practically unobtainium as far as originals go...and stupidly expensive if you DO find them. I got a full set for a fraction of the cost of a single one. In the case of the Shogun, I believe the AliExpress bones were a few mm shorter, but I usually run my cars with a wee bit of negative camber instead of wheels being completely vertical, so that helps push them into the cups a bit more.

Coelacanth wrote: ↑Tue Feb 16, 2021 11:27 am I hope they'll work for you. I found it odd that there are aftermarket generic dogbones in various sizes (using the makers' sizing from end-to-end rather than pin-to-pin), but that there's a significant size jump from 60mm to 63mm on to 70mm, something in between 63mm and 70mm would've been perfect.

That said, I found some nice, shiny dogbones for that Marui Shogun I restored, that are practically unobtainium as far as originals go...and stupidly expensive if you DO find them. I got a full set for a fraction of the cost of a single one. In the case of the Shogun, I believe the AliExpress bones were a few mm shorter, but I usually run my cars with a wee bit of negative camber instead of wheels being completely vertical, so that helps push them into the cups a bit more.

Yeah, it really is a big gap.

So the re release of the Ultima has a parts list. Its dogbones are listed as OT230 and look the same as the OT-18 from the old ultima and the same as the KR-23's.

https://rc.kyosho.com/en/ot230.html

Also, the dogbones are OT228's which I would think are the same as the OT-6s?

https://rc.kyosho.com/en/ot228.html

You would think so...the Optima & Ultima originally had the same dogbones...62.5mm pin-to-pin. I don't have any re-re's so I can't confirm with those parts, but I imagine they'd be the same?

Just measured a rere Ultima and Optima....getting 62.5mm pin to pin on both

coxbros1 wrote: ↑Tue Feb 16, 2021 3:19 pm Just measured a rere Ultima and Optima....getting 62.5mm pin to pin on both

Thanks for doing that. So the OT-6 dogbones were $6 up until recently. I love how they now renamed them and charge $11!

Snaab9-2 wrote: ↑Tue Feb 16, 2021 5:10 pm

coxbros1 wrote: ↑Tue Feb 16, 2021 3:19 pm Just measured a rere Ultima and Optima....getting 62.5mm pin to pin on both

Thanks for doing that. So the OT-6 dogbones were $6 up until recently. I love how they now renamed them and charge $11!

Its a racket they have going. Designed strictly to get money from your pocket into their pocket