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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => Project Custom Motobricks => Topic started by: Swingmanu on September 06, 2025, 04:06:50 PM

Title: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Swingmanu on September 06, 2025, 04:06:50 PM
Hi everyone,

Just joined the forum — my name is Manu and I live in France. I’ve been riding motorcycles for quite a while now, and currently own a nicely rebuilt CB750 Seven Fifty, along with a few vintage trail bikes.

A friend of mine recently moved abroad and gave me his unfinished K75 project. It’s in pieces and the frame has been cut, so I’m basically starting from scratch with what’s left.

Here’s what I’m planning for the build:
- Install the Retro Rides rear shock/swingarm mod
- Clean up and simplify the wiring — considering using a BEP or Tenet unit (open to advice here!)
- I'd like to remove the airbox, but I’ve learned that the MAF sensor needs to stay unless I fully convert it to carbs. Someone suggested 3D printing a custom airbox, which I’m considering. I have a solid 3D printer and I’m actively learning Fusion 360
- Front end swap
- Full paint job

I’m not aiming for something radically unique — I just love that clean Retro Rides look. Not sure if I’ll ever get it road-legal, but even if it ends up as garage art, I’ll enjoy the process and the learning experience.

I’m not starting right away since I’m currently building my house (a timber frame build), but in the meantime, I’m gathering parts, doing research, and planning everything out.

Thanks for reading — looking forward to learning from you all!
Cheers,
Manu

Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: frankenduck on September 06, 2025, 07:43:36 PM
Here's how to turn a motor into a finished K75.

https://www.kbikeparts.com/classickbikes.com/ckb/1.my.k.bikes/10_K75F/k75f.3.build.htm
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Swingmanu on September 07, 2025, 08:15:12 AM
Quote from: frankenduck on September 06, 2025, 07:43:36 PM
Here's how to turn a motor into a finished K75.

https://www.kbikeparts.com/classickbikes.com/ckb/1.my.k.bikes/10_K75F/k75f.3.build.htm

Sweet ! thanks for this, I'm gonna print it and read it carefully :)
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Kaos on September 07, 2025, 11:49:34 AM
Welcome Manu.
As it happens to be, today I met another k75 on the road, which is not uncommon, but this was was also -carburated-
Thought about chasing him to ask some questions, but I reckon being chased by a larger fellow on a K would potentially feel uncomfortable.
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Swingmanu on September 07, 2025, 02:42:08 PM
No way !
Where do you live? I never see k75 around here :)
I’d say chasing anyone on a bike seems off
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: lewisnort on September 08, 2025, 03:29:23 AM
That's quite an aggressive frame chop, it will be interesting to see what kind of subframe you build off of that and how.
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Swingmanu on September 08, 2025, 04:49:27 AM
Quote from: lewisnort on September 08, 2025, 03:29:23 AM
That's quite an aggressive frame chop, it will be interesting to see what kind of subframe you build off of that and how.

Its fairly common for the modification that is based on retrorides
I will be welding another 2 bars across to strengthen it
Here is a pic
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Swingmanu on September 08, 2025, 04:50:33 AM
I am going for very similar look as wooboodoo
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: lewisnort on September 08, 2025, 06:22:15 AM
I've seen ones with those bars acting as a subframe but I don't think I've seen them supported in that way before.
Title: Re: I was donated a K75 in pieces and i want to turn into a dream bike !
Post by: Swingmanu on September 08, 2025, 06:26:26 AM
Quote from: lewisnort on September 08, 2025, 06:22:15 AM
I've seen ones with those bars acting as a subframe but I don't think I've seen them supported in that way before.
Just like this
Credits to “retrorides”