Stretched BMX Supercruiser!

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Aug 27, 2022
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Ok so i made up the, supercruiser bit,as in ...not many seen etc! and zero off road capability, only a show cruiser sort of thing.
So this old mongoose was another kerbside throw away, bits of this went on to "Direction Unknown", So with the left over parts pile now bigger and taking up more space than a couple actual bikes, I decided I cant wait and are going to keep honing my bike fab skills!
1st up the chop session

This step through I thought was a 24" but its got 26" wheels, the bars off this went to The last build off but its got a small curve in the top tube and its in good nick, im also chasing that long down tube.
After this i'll part this out for spares etc!

I kept at it for most of the day! its taking shape really well, you can see "direction Unknown" is alive and well in this design! in fact it'll be almost a carbon copy but without the spring and swivel, it will look likes its younger bro. the mongoose frame didnt have the same lines as the build off bike so the rear top tube dips off line quite a bit to meet up with the stay's at the rear.
Some welds are finished but others are super tacked till finals day. The forks on this thing are complete rubbish and are no better than a show of peacock feathers, i'll be chopping those spring assemblies off and i'll weld some tubing onto some BMX forks...I think!!!
I still have to weld in a support from that bottom rail up to the BB, i'll put in a small support at the stays where it all meets at the rear!
Starting to look a racy little thing even though it'll probably never see dirt! Just a cruisy show BMX.
Tomorrow I can only put in a few hrs as after lunch I start my hernia operation prep. tuesdays the OP, then recovery for the rest of the week!
Anyway my friends thats the end of day 1 for the "Direction Unknowns" little bro..."so aptly named.. "Confused"
OK so im a bit nervous about my operation tomorrow so I only slammed the frame together today, I still have to run a support for the BB and I may still put one in at the rear! im thinking I may get away with something lite, like a seat stay or similar, the load bearing is straight up n down so they dont have to be giant tubes!
Shes running pretty low here, its gonna roll about 2' off the ground so its a definate show cruiser this one! nothin else but very different.
And sooner or later im going to get that curve right, the one behind the front wheel, its tough trying to get that right without a bender!
So not much today but thats was day 2, be a 3 or 4 day break after this, we'll see what the doc says after the hernia OP!
I have an ambitious task ahead of me, im really impatient, im not allowed to lift anything over 5kg for another 5 weeks yet, I cant build anything or even cut stuff etc coz we all know that by the end of the day we've turned and grabbed this n that and eventually bang, Oppps!
So to avoid this ive come with a plan to teach the young bloke some metal working skills, he's only had a couple welding lessons and then lost intrest so...ummmmmm......errrrrrr well when he comes back from the skate park :21: ..... and im lucky enough if he aint staying at a mates:rofl: i'll see if I can con him out to the shed and cut that big curve out of the bike, the draw card is..."son" I think its time you learnt how to use..The angle grinder":rolleyes:
So the plan will be to get him to cut from the top weld , on the down tube, and the very bottom weld and we'll spin that whole length upside down and weld it back in. I think it will solve the ugly curve that its got ATM. we'll be bringing the bigger curve down around the wheel and the small shallow curve will join up the top instead! everything is long enough to squash it back together for welding, meaning we will be losing about 3-4mm in length with the 2 cuts to the frame, but the frame is long enough that theres very little tension when we weld it back together.
OK so the young bloke went and stayed at his mates the night ,I left it all, waited, came home, school night etc .
anyway I done a small bit today, I figure the angle grinder weighs 3kg, moving it around would put it at a good 5kg so its the only thing I can use, the welder and cables are light so they dont pose a risk of over lifting. I had to get the mrs to move the welder about and move the bike about and I just worked from the chair and cut tubing up at the work bench.
I managed to make some progress on the experimental build,
Ive decided ti raise the bottom rail and have it lifting after the front wheel , instead of running parallel with the ground, it now has a good bit of clearance so if we do end up off road we wont get hooked up on something!, its comming along better now, im liking whats unfolding. I can see a drama in the near future as I try to line the chain up with the front sprocket, the geometry has changed a bit at the back so we'll see how a chain wraps around everything in a day or two! its the stays that will be a worry!
We've had a design error, The BB is sitting about 90mm too high!, I cut up some more tubing off the donor pile and made up a sleeve system, this will have me sitting about an inch and half above the bottom rail, @ 295mm from the ground to center spindle.
Yes, a couple big welds to ground out and re-done! Grrrrrrrr

After I put that together and line it up I then have to put this small support underneath it all!, This was real fidgity to make, it comprised of 2 different angles at each end and then the bottom rail , to which it attach's, is running perpendicular to the BB, so those two knotch's are of opposing size's and angles!!
I got there in the end but real fiddley. all good practise really coz this is actually what this build is about, just trying to hone dem skillz!

So in this pic the sleeve system is in, it all fits well and is quite tight so theres no welding on that bit yet! but it is sitting there in its exact position!
I managed to cut off another top tube from the donor pile and i finished the front of the frame, I still have to install the small support under the BB and then one last support at the rear to help the back end!
Those who have followed so far may be able to see ive cut the bottoms off those green kids MTB forks, I had a set of mongoose BMX forks and cut them just above the brakes and slid them onto the ,"Kids Fake Tripple Tree's"
Its actually starting to look a bit better now, still very different, still dont know if its a BMX, a Cruiser, a shop go getter??? I suppose the name "Unsure" is quite fitting at this stage!
Mrs made me a sammich so i had a spell inside for lunch, back at it again and I welded in the small BB support and also used that curved piece ,that was the front down tube, and he now resides at the rear and fits nicely in front of the rear wheel!
Iva also shortened the bike by about 3 inch's at the rear and those Fake triple trees coupled with the BMX fork add ons push the front wheel forward an inch and a half!, so all up she's about 1.5 inchs shorter!, it has a made a difference, it still looks stretched but no so ridiculously now!
I decided to kink the lower BB support back a bit to aid in styling! but if you can remember this bike is a follow on from "Direction Un known", its in this pic you can see the family trait's of which is an idea im trying to nurture and grow into my very own styled frame's.
I moved onto the forks today. they had to be welded permanently and I also wanted to fit some brakes! the biggest issue is Im running a small fork pole through a larger mongoose head tube, the bearings didnt fit the cup properly and we had movement! once I have got these off i'll clean up and fold the excess from the brake boss's,
its in this pic you can see why I call thses forks...Fake triple trees! they are welded at the bottom plate, or are they all like that and only the top can come off, in any case they are pretty light gauge so they'll only be good for cruising anyway!

So I looked at this for a while and had a few changes of plan! I had another head tube with the correct sized cups n bearings, I was gonna cut that into the job, Nahhhh!...then I was gonna weld the top of the mongoose forks that was left over and weld it onto those triple forks, this was a good idea but the oversized pole was too big for the top clamp.
So then I was going to just place the bearing cups inside the larger ones and guess what , it all fit but then i'd run out of height to tighten the top clamp.
So what I did was I punched out the cups from the mongoose....

I then cut the smaller cups , while still seated inside the replacement head tube, and checked the size , whallah... they were a match made in heaven!

So these new cups ive put in still have the old head tube seated around them but that whole assembly is now pressed into the mongoose head tube! the smaller cup itself is still way too big to pull through the head tube so I really think this is the best possible solution I can come up with....with out chopping and welding LOL.

So then it was a 10 minute exercise to find a spare lever, an old cable and outer, and attach the brakes to the front, The forks came out good even though not finished, with the method i'd used the brake boss's are already lined up and everything fell into place really good!, the brake works fine!
PXL_20230817_042345128.jpg Ive had plenty of time to look at this, all these things im doing are small jobs really but im still working incredibly slow,
Ive had a major design change come flashing through my mind and im at the stage where im ready to take the plunge and just do it. this will still be a stretched BMX, Cruiser Hybrid thingy something and for now at least will carry "Unsure" as a name to pay homage to "Direction Unknown" of which this bike is carried on from!
But im starting on it tomorrow but heres a sneak peek,
It will have a lot to do with the bike being aimed at a go-getter, heavy transport etc, groceries!
Thats right, im going to make me a......BMX Tray back Ute!!! I will try my hardest to make a small tray sorta like this one here! then ill run some brake boss's off the supports for the tray!
Screenshot 2023-08-17 at 2.55.56 pm.png
Started work on the rear tray frame, with my haste to build I didnt relise that when adding in the last frame support at the rear i'd made it too close to the brakes and they worked but not to my liking!, so I have this Chain stay off the donor pile and it has brake boss's on it and its from a BMX so all I had to do is cut it to length where I want it and then adjust the brake arms and pads, pinch them together hard with zippy ties, and that was enough to hold them in place! there will be another support half way along as the tray is intended to be useful and will be about 400mm X 700mm with a slight taper to the seat post area!
I run an angle grinder down the join to give me a decent bevel to weld the rear on, even though NOT ALLOWED the young bloke will still , at some stage, double a mate on this , maybe even a couple...cmon, who hasnt gone 3 up back in the day! remember that :rofl:
So I got to thinking , If theres going to be a load of whatever amount on a tray, for this bike, then there's gonna be a significant amount of extra weight , Hence A better braking system is needed to pull this up when loaded .
Seen as this build is coming from the donor pile my choice is very limited . So I cut some mounts off an old set of seat stays and welded them in place on the other side of the wheel!
Whallah!! we have a twin brake system on the back wheel, Ive given up tonight so all I have to do is connect the twin connectors ive found and modified, will be a bit of mucking round but it'll be the good onecs its set up right, should be quite noticable when done, even with a good 40kg on the back.

was in the process of welding this small brakey bit on and got a call from a bloke selling a bike, I gotta make a dash!
But I cut this off and are gonna weld it in front of the twin hook up for the rear brakes, making one cable pulling two sets etc!
Rear brakes all done, they work well but ive since found a small buckle in that rear wheel, didnt notice it till I started fine tuning the brakes, it'll iron out with pad wear a tiny bit but its till very rideable.
in the pic you can see the two cables and how I set up the twin pulley system! crude but fit for purpose.

So thats it...we have a roller, the frame is structurally sound but does still need going over with the welder to put small gussets and supports at the rear, and then a grind down etc! theres something thats happened with this frame, it was never meant to have a racy rampaging bull look but its sort of starting to flow that way and im actually liking it a lot, I still cant ride a bike for 2 whole weeks!, I have a test rider though, i'll see if I can get him off the consol!... and yes after taking pics of that free stuff I got was left there till the morning LOL.
And here's my test rider,

Dammit, sorry everyone , I posted the same vid twice Grrrrr, ok heres the re-edit!... so You can see how ive made the bike so as its sweeps along the frame its height raise's underneath, so we can now go up n down gutters etc, makes for a more dual purpose use, a carrying go getter and an off road fun machine!... I have a secret plan to even use this for a small business enterprise the young bloke and his mates have started, more on that later but the bike will be invaluable to them!

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ive begun the wheel swap out from the muscle bike I picked up on the weekend, im going to run the 72 spokers on the BMX Ute, they're a heavier wheel but much stronger and will foot the bill on this machine!
We have run into problems right from the start! the front tyre is too wide to fit through the brakes, even when disconnected,

So I removed the front brake altogether and still not enough room, and even if it did fit right down to the drop outs it has zero clearance at the back, I now have to do some super modifying if I want this wheel in here!


I chucked an older wheel set on the muscle bike, it now is starting to resemble my very first bike, ive decided when ive got spare time this bike will be rebuilt to a replica of my very first pushy! I also replaced the crank to full size one! Re-packed bearings and all!
well ive just spent the entire day trying to fit that 3 inch tire inside the rear frame ive made, what an absolute disaster, firstly I couldnt get the tire to fit the replacement rim with the 16mm axle, the rim was too skinny, so I had to re-fit that tire to its original rim and pack out the drop outs to accommodate, I got there in the end but had to use a smaller drop out , cut off,and used as a spacer, I had to widen the rear stays and used an old car scissor jack, worked fantastic and everything fit!, the allen keys are in there to pack out 4mm space under the axle shaft, i'll fab up some good ones tomorrow. its all straight and tight and the wheel spins freely.

I then found that the tire was so far back because i'd missed the mark on the chain formula, I tried 3 different sprockets on the front and replaced links to suit on the chain, every single time the chain was either too short or i'd add a link and the chains right where it is now, so im gussing theres a magic number to follow when deciding the placement of the rear drop out...or am a mile off with that!

Anyway heres the side view, I had to move the brake boss's on the front of the rear, and the very rear 2nd set have to be moved as well but thats tomorrow, as will the addition of the front wheel brakes too, they need new boss mounts.

Youll see in this last pic ive used a short piece of down tube that has the drink bottle mounts still on it!, Right at the top of the tray frame, this is going to be for lights or whatever, im just leaving them in so I can use em later, for anything!
I use seat and chain stays for mos of the frame costuction, in fact the entire top section weighed in at 1.2kg, so with the 4 seat and chain stays use as the side suppoting arms weighed in at less than 5oog, so all up with the timber tray added we should be looking at a tray and frame weight of close to 4-5kg, which is pretty good considering it'll hold 150+kg when done!
the top corner supports (purple) have doubled as side gussets from the seat stays to the main top tube! and i'll cut off the brake boss's off those too!
Was a huge day in the shed but still working very slow, wife's starting to get a bit antsy pantsy with having to come out and lift or move the bikes etc!
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I managed to finish the tray frame today, I sprayed some black on it to keep the moisture off it over night, getting warmer here, was 29c today so lucky everythings outside!
the cross members are from a futon couch, had them for years so cut em up, they're very light and only about 1.2mm but will be good enough for this tray as we aint looking to hold more than 100kg,s...although it probably will handle up to maybe 150 but thats a bit ambitious at this early stage! at best it may carry 2, 13 yr olds, in the form of going 3 up, if the young bloke ever takes it out with his mates! you can see the fun n games ive had trying to get that wheel in there nice! was a real drama,
up the top I decided to taper the frame and tray in to avoid any possibility of a heel strike! I'll lay all the timber on after cutting to shape and staining , which will be a few days to dry out!

I took the 2nd set of rear brakes off, I had to move em anyway so im going to see how well the system works with just front n rear cantilevers, they're set up good and work well , ill do the front tomorrow! I still cant ride the thing.
Even though in this pic the frame looks a bit bent in the middle, I made it like that coz the seat stay used always have a thicker middle, ive joined them so to get them in a straight line I welded them together on a very slight angle! then I laid the cross members on top! theres still a tiny bit of work at the rear....tomorrow LOL


So far so good, Ive also decided instead of a solid rear wall on the tray i'll make a couple timber slats running horizontal to the slats on the tray! sort like a fence.
when it comes time to paint I think its time I saved myself a lot of elbow work and im gonna strip it down, make me a fire, and burn the thing!, ive heard from a reliable source it can be done and ya hit it with wire brush's after!.... I think!

I had to finish off the frame today, I really wanted to tidy up the rear stay assembly, it was held together ok but looked horrid , I doubled up and made a pair of sleeve's to wrap around the Join and act as a supporting brace as well!

so heres a pic of what im trying to achieve, the new sleeve and what its trying to A...cover up, and B...add strength and support for the rear!


It came out better than I anticipated! as per the norm the welding towards the end of the project tends to get better,
You can see I made a smaller sleeve to wrap around and support the top area too! I wish my welds at the start when I joined the frame together were as good as these ones today! even though they are still nowhere near as good as a qualified welder
Ok so i made up the, supercruiser bit,as in ...not many seen etc! and zero off road capability, only a show cruiser sort of thing.
So this old mongoose was another kerbside throw away, bits of this went on to "Direction Unknown", So with the left over parts pile now bigger and taking up more space than a couple actual bikes, I decided I cant wait and are going to keep honing my bike fab skills!
1st up the chop session
View attachment 244963

This step through I thought was a 24" but its got 26" wheels, the bars off this went to The last build off but its got a small curve in the top tube and its in good nick, im also chasing that long down tube.
After this i'll part this out for spares etc!

View attachment 244964
Read the whole thread today this thing is rad! I’m loving it

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