Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Anybody see any issues with creating an adapter to flip the stock intake directly upside down?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

I feel like I'm missing something really obvious or just really stupid when it comes to measuring rake and trail. All the bikes I'm looking to mimic are in the range of 22 degrees of rake with 3.5" - 4" of trail, and I'm over here bumping up to 28 degrees to get 3.5" of trail. Even the kx125 is looking at 4.13" of trail with a 26 degree rake. Obviously the front wheel is WAY bigger, but the offset is almost definitely the same so I'm pretty blown away by these numbers. Also comparing with Joe S's build, (he used a kx65 front end, but looks to be identical offset), he was telling me he had about 4" of trail but my measurements are showing 3", SO I'm probably measuring wrong. Any help you could give would be greatly appreciated!

rakeandtrail.jpg
rakeandtrailv2.jpg

Re: Crazy Custom Frame Hobbit

Looks like you're measuring correctly :

Re: Crazy Custom Frame Hobbit

Measure from the center of the head tube

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

OK cool we good. Whew

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Bumping this after a long time with some updates! Frame is mostly done, as well as the engine brackets!

Next big step is going to be getting exhaust for it. I spoke with Daniel from Magic Touch, who has been a HUGE help throughout this entire project, and he recommended the Doppler pipe for the Moby, as it's going to be following a similar path etc. I just wanted to reach out and A) see if anybody had one they would be interested in selling B) any other recommendations? I was thinking there might be a 100cc bike exhaust that would also work (something like the ones on the race RD350s). Bike is running a malossi h2o kit, mikuni vm20, and some Chinese reeds similar to the v force.

Re: Crazy Custom Frame Hobbit

Dirty30 Dillon /

Any full size race pipe is going to be more money that just buying a doppler. I would start looking for something for Pug, as it's flatter than the Moby variant of the same pipe.

Doppler is right for this setup, once you chop and weld it into place.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Cool! The bike will be quite a bit longer than a Moby/Pug. Thoughts on extending the stinger? Can't remember what that does to the performance.

Re: Crazy Custom Frame Hobbit

Looks good

Re: Crazy Custom Frame Hobbit

Emil Kniemel /

Crazy. You made it into a derbi.

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Hahaha, yep, pretty much. Hopefully the payoff of the effort for the brackets will be that it's easier / cheaper to tune in the long run.

Also I have a dream that my machinist friend who built this could cnc these brackets for a lot less $$ than the initial build (for obvious reasons), and set others up with the ability to do builds like this.

Re: Crazy Custom Frame Hobbit

Moar picts plz

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Re: Crazy Custom Frame Hobbit

Oh man those pics failed on my phone. I even changed to the desktop site and it was a no go. Super excited to see this build.

Re: Crazy Custom Frame Hobbit

> Jay Rivett Wrote:

> -------------------------------------------------------

> Oh man those pics failed on my phone. I even changed to the desktop

> site and it was a no go. Super excited to see this build.

that's because Google does not host third party ...

To see those pics the poster has to posts links to each pic .

Or right click the space that the pic should have been in the post and hit 'Open link in a new tab' .

Re: Crazy Custom Frame Hobbit

Emil Kniemel /

> Colin Ratcliff Wrote:

> -------------------------------------------------------

> Hahaha, yep, pretty much. Hopefully the payoff of the effort for the

> brackets will be that it's easier / cheaper to tune in the long run.

>

> Also I have a dream that my machinist friend who built this could cnc

> these brackets for a lot less $$ than the initial build (for obvious

> reasons), and set others up with the ability to do builds like this.

I would be and im sure many hobbit dudes would be interested in this. probably could sell thru treats or dos too.

what belt did you end up having to use? also whatd you do for the sprocket?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Sorry for the delay on this! Here's an album

https://photos.app.goo.gl/qxzsvnAoTFCttJZt8

Here's some more photos:

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Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Ended up using an AX20 belt (we'll see if stretching is an issue, fingers crossed it isn't). Sprocket is a Puch sprocket attached to the Hobbit hub (which I'm stoked about - this means I can change gearing ratios!) with a Puch rear wheel.

Using a pull-start, but also have a one-way bearing so I can push start if I want to.

Re: Crazy Custom Frame Hobbit

fuuuuck!

put a slot on the bottom of the bracket for the rear transmission bolt so you can adjust belt tension - or am I missing something else?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Considered that, but it would bugger up the chain to the rear wheel. I'm thinkin a bit of stretch is okay, as I don't need to pedal start it

Re: Crazy Custom Frame Hobbit

Emil Kniemel /

Can you take a pic of the sprocket side?

Re: Crazy Custom Frame Hobbit

Looks cool. Glad you updated this. More progress please

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Hahaha absolutely! I'm curious what the effects of extending the stinger on the Doppler exhaust would be - I would love something that matches the length of the build, and it's a 50" wheelbase.

ALSO, as far as I can tell making V-Force reeds work for this would be bloody expensive. $150 for the reeds, $150 for the intake/mount for them (if you take a look at the engine positioning it'll need to be something custom that angles up). I was planning on just making one myself, but I moved cities about 2 months after this project started, and it's still at the machinist's in Seattle (I'm in Portland now), and I'm just not super confident about fabbing it in a trip up there.

One idea from Magic Touch (Daniel) was to use some other 4 petal reeds that were cheaper and smaller, so would be easier to fab the intake for them, but I wanted your thoughts on the whole thing!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

If you want to check out his work, hit up @mckinleyalansmith on instagram!

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Also also, down the road I'm considering going to a stage6 kit (in a few years probably). Would I need a different exhaust for that? Doppler probably would be too small right?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /
IMG_6886.jpg
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Re: Crazy Custom Frame Hobbit

The doppler exhaust is a fine pipe, alternatively a puch simo could be cool too. Those are very high rpm hitters, where as the doppler is mid-high and is pretty much done at 11k. But realistically you should probably be maxing out at 10.5 and setting it up for torque. This is gonna be a 200 lb bike when it’s wet. I think I recommended am6 reeds since you were going to try to run the intake upwards, but I don’t remember. (edited)

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /

Awesomeeeee, thanks for the followup on this! I'm hoping a bit less than 200lb fingers crossed (Joe's weighed 135lb, and we're adding about 10lb with heavier tubing, but taking off some with a front disc instead of that giant drum). Torque definitely sounds like a solid plan to me.

Any idea what lengthening the stinger would do?

Re: Crazy Custom Frame Hobbit

Colin Ratcliff /
IMG_6896.jpg
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Re: Crazy Custom Frame Hobbit

This shit is dooope

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