LTJ custom framesets are becoming a reality! (JIG BUILDING)

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Looks like some big news coming in 2017!

There is an idea that has been floating in my head for a while, and started to really take shape during the latest MBBO, that is building a limited production LTJ frame...

There are some issues though, obviously my health will limit production, and postage costs, weight and box sizes are important considerations. Also I don't want to build a frame that is only good for one style of build...

So with those limits in mind, I have been slowly coming up with a plan!

The framesets will be built using new tubing but recycled bottom bracket shells, headtubes and forks, that way I can keep costs down, (approximately halving the costs) I will not be making any money on the frames either, so that saving gets passed straight on.

The frame will be 4 bar looptail design with one piece 16mm (5/8") chainstay/seat stay/dual top tubes, and a straight 32mm (1 1/8") downtube, it will accept a standard 1" seat pole and threaded stem. Each frame will incorporate the letters 'LTJ' on the brake bridge and will be individually numbered as production will be limited, probably a total of 10 for this design (depending on how many forks I can find, currently I have 8). I'm planning sliding dropouts similar to those on Back40, they will also incorporate a coaster brake slot, disc brake mounts and a derailleur mount, basically it can be set up to use whatever rear gearing/brakes you want, opening it up to being a viable commuter, cruiser, or muscle bike. (The extra mounts can be easily removed if desired.)

The frames are designed for 20" wheels, but will have plenty of wheelbase and cockpit room for adult riders too.

Been planning and designing for months, finding steel suppliers that stock the correct size tubing for seat tubes has been the hardest bit, but it looks like that is sorted now and I will order it tomorrow. After getting the 2nd prototype done I will have the designs and dimensions to order the laser cut parts that will make up the brakebridge and sliding dropouts, and will be able to finalise the design of the build jig.


Built up a rough design mule this evening...

Made some adjustments to the design as it went along, it was originally going to have less rake and longer chainstays, but it just didn't look the way I wanted...

This frame only shows the basic design, it is made from tubing from 3 different scrap bikes and none of the welds are cleaned up. The only thing that is the same as the production frame is the loop bars, and they will gain more curve towards the front. It also has standard dropouts harvested from a bent FreeAgent BMX instead of the sliding dropouts of the production frames.

2017-01-17 00.48.22.jpg


There will be some slight style adjustments coming, but I will throw some parts at it in the coming days and ride it around to make sure I like the geometry before I do them.

Having the frame in front of me now meant I could get dimensions for shipping, and unfortunately it is longer than the 1 meter limit imposed by AustPost, so shipping is going to have to go through Pack&Send instead, which means slightly higher shipping in Australia (Still under $100 AUD for worst case locations) and much more expensive for overseas. ($270 AUD for USA.) :(

Not much I can do about it, if I shorten the frame to fit the dimensions it ruins the whole point and design of the frames...

Still, the hope is to have the frames available for under $150 AUD before shipping, (It is only a hobby for me, so only covering costs) so total outlay will still be much better than pretty much any other custom frame available.

It may be possible for me to supply the frames painted for a reasonable price too, as most will know, I am set up for solid and metalflake automotive paints, only thing that worries me is damage to the paint during shipping.

If the frames are in demand, I may come up with a similar design but to suit 20" BMX forks instead of the 27"/700C roadbike forks, that way people can just swap parts from a cheap BMX, maybe throw on a bigger chainwheel to suit an adult rider...

If my forks run out but people still want the frames, I may be able to build to suit forks people already own, I'm not promising this though, as I can't rely on my health being OK when building to order as opposed to offering frames for sale as I get them made.

I will update as things happen, let me know how much interest there is out there, I already have some solid buyers chasing me for a frameset, so I will be building at least a few, but if the interest is high, I will order more parts cut...

Luke.
 
Sounds good , just like to add 24 " wheel frame set up would be a good idea as it would be more in the middle as aposed to 20 " ?
 
That's great news Luke! Congratulations on this exciting venture!

Those long frames give me so many different ideas for buildup ;-)

How wide of a 20 do you plan for? Think I might be able to toss a 4" OCC stingray wheel in one? [emoji48]
 
Thanks for the support everyone!
How wide of a 20 do you plan for? Think I might be able to toss a 4" OCC stingray wheel in one? [emoji48]
I only designed it for standard style wheels, otherwise it would need the wider bottom bracket too, so max width would be 2.4-2.5".

Sounds good , just like to add 24 " wheel frame set up would be a good idea as it would be more in the middle as aposed to 20 " ?
It is interesting that you say this, I was just outside messing around with it and decided I didn't like it with 20" wheels, it was too LowRider and not enough Dragster/Muscle, low bottom bracket, long stays...

2017-01-18 18.43.49.jpg


But I looked at the chainstays and how long they are and realised I had been using my 26" geometry calculations and not my 20" ones, so I threw some 26" wheels at it:

2017-01-18 18.44.15.jpg


That is a better looking bike! With some virtual adjustments, such as bringing the rake back to my original measurements and making the seattube longer it becomes a nice 26" BMX Cruiser:

Adjust for 26inch BMX.jpg


I love 26" BMX's, so I will be modifying this frame to suit. I will have to widen the chainstays at the point of the tire, as it was designed to taper in tighter with the smaller wheels, but seeing as I will be remaking the loop tubes anyway, that will be no issue.

Using the same jig I can make it with the shorter seattube too, which would make a cool, sleek cruiser or a BMX for smaller riders or teenagers too:

Adjust for junior 26inch BMX.jpg


I still want to build a cool 20" MuscleBike frame, but I might focus on the 26" BMX's first.

Let me know what you think?
 
Like the 26" - BMX cruiser! Probably not gonna have the dough to buy one of your frames, but I may try to hack up some old stuff I've got around here to come up with a similar "look".
 
Like the 26" - BMX cruiser! Probably not gonna have the dough to buy one of your frames, but I may try to hack up some old stuff I've got around here to come up with a similar "look".
That is fine by me! :thumbsup:
I wanted the frames to be cheap enough that almost anyone could afford one, but shipping costs killed that plan... :( Still, it will be cool to get a few out there and see pics of people riding them!
 
Have you built a complete bike with this frame?
Really like how "long" it looks. I would not be able to do the looptail tho so it would be less of a cool factor for sure. :bigsmile:
 
I still want to build a cool 20" MuscleBike frame, but I might focus on the 26" BMX's first.
Did some digital alterations to the 20" version:

20 inch short forks and stays.jpg


I like that much more than the original! Really love the long cockpit, best bit is, it can also be built on the same basic jig with just a swap out of the dropout section and the seatpole support!

Maybe I can build all three and just see what people want...
 
Have you built a complete bike with this frame?
Really like how "long" it looks. I would not be able to do the looptail tho so it would be less of a cool factor for sure. :bigsmile:
Not yet, hoping to ride it very soon though! Thinking I will drop the rake back first, and assemble it to a full rider in the coming days...
 
It is interesting that you say this, I was just outside messing around with it and decided I didn't like it with 20" wheels, it was too LowRider and not enough Dragster/Muscle, low bottom bracket, long stays...

View attachment 43437

But I looked at the chainstays and how long they are and realised I had been using my 26" geometry calculations and not my 20" ones, so I threw some 26" wheels at it:

View attachment 43438

That is a better looking bike! With some virtual adjustments, such as bringing the rake back to my original measurements and making the seattube longer it becomes a nice 26" BMX Cruiser:

View attachment 43439

I love 26" BMX's, so I will be modifying this frame to suit. I will have to widen the chainstays at the point of the tire, as it was designed to taper in tighter with the smaller wheels, but seeing as I will be remaking the loop tubes anyway, that will be no issue.

Using the same jig I can make it with the shorter seattube too, which would make a cool, sleek cruiser or a BMX for smaller riders or teenagers too:

View attachment 43440

I still want to build a cool 20" MuscleBike frame, but I might focus on the 26" BMX's first.

Let me know what you think?

Yes much better !
 
Hmmm a Moosegoose.... have got a 84 Proclass that needs a bit of work to the frame I could amost consider a frame change but the enthusiast in me says to try and source original! My brother gave one of his other Kos's to his mate and he said he really should have given it to me.... he has quite a good collection of old school Mongooses but doesnt have a Moosegoose.. ;)
 
he has quite a good collection of old school Mongooses but doesnt have a Moosegoose.. ;)
I should mention that I wont build an exact copy, the dimensions and geometry will be the same but they will have my own spin... Not interested in any copyright issues! :thumbsup:
 
Started on the frame jig today!

Went with a full perimeter jig as I believe they are more stable and solid than a base only style, more work to make though!

It is oversized to allow for whatever designs may happen in the future, barely fits on my workbench and it pretty weighty! Sat Back40 in it to give a size reference:

2017-01-21 18.47.29.jpg


The two uprights are welded on the diagonal:

2017-01-21 18.46.46.jpg


I will explain why once I get the pieces made that mount to them.

Then I moved on the bottom bracket clamp:

2017-01-21 18.48.02.jpg


Lots of steel there to draw heat away, they will bolt to the jig and then a big 9/16 bolt will bolt through the whole clamp as well.

Lots of thought is going into this jig, hopefully I have allowed for almost any design that may happen in the future... :thumbsup:

Also did some planning on 'Back20', looks like it is a go, very happy as that is a nice design and carries some of my design style with it! Modified a bend jig to make a neat feature for it too... ;)
Think I have come up with a neat way to make a breakdown version as @OddJob suggested as well, so that will help with international shipping!
 

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