YZ-24 MotoBike ...now SOUTHERN FLYER (6th Place) *revised*

[jats]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (tank started)

love the hole shape, size and fit of that tank

Troy

 

[LukeTheJoker]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (tank started)

Luke, based on your builds, I would never have guessed that you would like anything wide. :mrgreen:

:lol: :lol: :lol:

Luke.

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (tank started)

Been trying to get the design for the rear triangle worked out on the computer before I actually start working on it. I plan to use the BB on the motobike for the pivot instead of the original mount which just had a bolt and bushings.

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

As I said in the last post, the pivot point for the original moto bike was a very basic hinge sort of design.

I'm sure it was adequate for the 20" wheel and short trailing arms at the time, but for the much longer rear triangle and larger wheel this bike will have, it seemed obvious to put the unused BB on the frame to the task. Luckily, this frame has the threaded BB so it will be much easier to adapt to my purposes.

This is the first prototype for what I'm calling the bottom bracket knuckle. It's made out of an aluminum/pvc composite material that will later be replaced with steel after I make a few tweaks. From what I can tell at this point, I'm pretty close to the final design. Even with the soft material and the small machine screws, it feels very sturdy!

 

[kingfish254]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

That is some seriously cool bolt on engineering!!!!

 

[noodlenoggin]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

:shock:

Wow. Just...wow.

 

[jats]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

:shock:

Wow. Just...wow.

ditto

 

[OneHorsePower]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Nicely done 8)
but iam not sure i understand ... the GT bb just serv as a spacer ? or will hold the shock extension ?
iam cunfused :?

 

[outskirtscustoms]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Nicely done 8)
but iam not sure i understand ... the GT bb just serv as a spacer ? or will hold the shock extension ?
iam cunfused :?

Correct me if I am wrong but I think the GT BB will thread into the frame and hold the assembly to the frame and lower the whole crank area.

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Nicely done 8)
but iam not sure i understand ... the GT bb just serv as a spacer ? or will hold the shock extension ?
iam cunfused :?

Correct me if I am wrong but I think the GT BB will thread into the frame and hold the assembly to the frame and lower the whole crank area.

That's correct outskirts. It actually serves two purposes, it does lower the crank by 4" and it is also the pivot point for the rear suspension.

I did a crude mockup to show it in position. In this picture I used a cottered crank instead of the square tapered GT. I will probably use the GT, but wanted to try the other because the round shaft might be easier to attach the knuckle to.

I also mounted the 24x3 knobby tire that I recently acquired from jats! I'm still searching for a 2" (+-) wide rim.
Any suggestions? :?: :?: :?:

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

That is some seriously cool bolt on engineering!!!!

:shock:

Wow. Just...wow.

ditto

Nicely done 8)

Thanks ya'll!

:shock: That took some work to edit the pictures out of the quotes! :wink:

 

[OneHorsePower]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

oh ! i see now . nice ingeneering 8)
these mods gave you a nice little space for a engine kit back there to :wink:

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

these mods gave you a nice little space for a engine kit back there to :wink:

That is a very good idea! I've been wanting to try one of those on a board track bike but haven't thought about this bike with a motor. That sounds like a good winter project if I can get past this build-off first. 8)

 

[jats]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Nicely done 8)
but iam not sure i understand ... the GT bb just serv as a spacer ? or will hold the shock extension ?
iam cunfused :?

Correct me if I am wrong but I think the GT BB will thread into the frame and hold the assembly to the frame and lower the whole crank area.

That's correct outskirts. It actually serves two purposes, it does lower the crank by 4" and it is also the pivot point for the rear suspension.

I did a crude mockup to show it in position. In this picture I used a cottered crank instead of the square tapered GT. I will probably use the GT, but wanted to try the other because the round shaft might be easier to attach the knuckle to.

I also mounted the 24x3 knobby tire that I recently acquired from jats! I'm still searching for a 2" (+-) wide rim.
Any suggestions? :?: :?: :?:

you were right that tire is a perfect fit for the frame!!! this thing is going to be more then awsome!!!

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Well Troy, you and I agree on the fat tire, but unfortunately the chain stays disagree. Looks like another mod will be added to the list.

 

[jats]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Well Troy, you and I agree on the fat tire, but unfortunately the chain stays disagree. Looks like another mod will be added to the list.

Dang I guess it is tight!! my psychic abilities see a bolt and screw jack in your future

Troy

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (front fork)

Finally got the other tube welded in the fork. This ended up taking several hours to get everything square and parallel so that it slides together smoothly.
Now I'm back to removing the brace on the lower half. This fork was originally made for a 24" wheel and since I've decided to use a 26" on the front, it has to go. I didn't like it anyway.

I remember having a fork brace back in the day that will go perfectly with the period of this bike and will serve the purpose that I need. So now I have MORE to do! :shock: I need more time!

Here's an example...

 

[kingfish254]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

I love watching the engineering come together on this build!
I know it's just a mock up, but have you checked your chain lines yet? It doesn't look like the upper chain will clear the chain stay as it sits now.

 

[The Renaissance Man]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (BB Knuckle)

Thanks Kingfish.
Yes, I have checked that and as it sits in the picture, it's very close (less than an inch) in the highest gear. I'll probably rotate that rear triangle down a little to give it at least an inch. It's been tricky getting the parts to come together in the right places so that the travel on the shocks will run straight through.

Thanks for asking! There's so much to think about I really appreciate all of the help and suggestions that I can get. :!:

 

[LukeTheJoker]

Re: bmX-RATED for ADULTS ONLY - YZ-24 MotoBike (fork issue)

Loving this build, very inspiring!
Just wondering how will you be attaching the frame knuckle to the bb axle? had a similar idea a while back, and came up with a solution but just wondering what you are planning, as my idea was a bit rough for want of a better word...

Luke.