Vertical PK7 single speed conversion

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google Vertical by Dynacraft and you will get lots of recall notices. Typical low end boxmart fake mountain bike. The suspension means they use too many sections of cable housing so the brakes and gears don't ever work well. This one was pretty non-functional when I got my hands on it. There is no shortage of trashed bikes like this for projects and I am not destroying a piece of art or an object of historical interest when I redo this sort of cheap bike. I did not take any before or during photos.

Before (stock photo not mine)
VerticalPK7_zpsad056133.jpg


I tossed the welded fixed suspension fork as that is a major recall on box mart bikes plus it weighs a ton. I striped the bike down and decided on a coaster brake rebuild. I got my favorite tool (angle grinder) out and went to work removing all the "braze-ons". ie, the welded on brake mounts and cable stops and guides and also the extra 2 chain rings from the crank and the brake mounts on the new fork. I want a clean look plus those unused cable housing stops can rip your flesh open. Best to get rid of them. This aluminum main frame is quite light and thin so it's very easy to over do the grinding on that. I think the recall on this particular model was for frame failures, not the more typical welded fork collapse. I used a fine grit lap sand paper disk to finish up. I used a heat gun to melt all the decals off. In retrospect, I should have photographed them for identification and also for the mfd date for recall notices. <snap> Too late.

I found a 1 1/8" rigid fork that fit and ground off the brake mounts. I repainted the fork, swing arms and sprocket in aluminum paint in an attempt to match the aluminum main frame. Rebuilt both wheels with aluminum donor rims. A chinese rear coaster brake hub and a nice aluminum qr road front hub. Silver / aluminum paint is so runny and shows all the grind/file marks and old paint chips.

Cleaned up frame photos:
IMG_0441_zps1ab012c0.jpg

IMG_0439_zps8f57d667.jpg

IMG_0438_zps47309759.jpg

IMG_0440_zpsb9864be9.jpg


When looking for cranks for single speeds, I like to use mountain bike triples where the desired ring size is swagged to the arm and the others are riveted to the swagged ring. Grind off the rivets and the spare rings go in the recycle bin. I never liked the unused chain ring look on many cheap single speed conversions. This particular build crank didn't have the fake bolts (rivets), they just spot welded the extra rings on so that took a bit more grinding. I'm usually looking for lower gearing like a 34 x 18 for coaster brake bikes.

How does that direct chain work with suspension? Well, the chain stay swing arm is rather long, you can see the pivot point well forward of the crank. So you get a long gradual arc. Also, I got my plumbers strap pipe wrench out and cranked the spring preload down as tight as I could get it so the end result is the arm doesn't move very much and the chain doesn't need to vary in length. Not much. It will move more under a heavier rider.

side shot of the swing arm:
IMG_0442_zps17e6d999.jpg


I wanted silver tires but didn't have any in the collection. I did want 1.5" tires so I used these ancient raised letter Panaracers. I have knobs piling up all over but I wanted a sleeker and lighter bike for this build.

Tires:
IMG_0434_zps1df4ce8d.jpg

IMG_0432_zps1cf93607.jpg


I also picked up a silver saddle but it's a bit too torn up so back to a plain black padded saddle. I might get my wife to ride it some if the seat is acceptable to her. The bike is the box mart industry's "one size fits all" so the fit is pretty bad for me. A shorter stem when I can find a 1" diameter stem in a shorter length should help. And a longer seat post too.

No kickstand option with this bike.

finished bike:
IMG_0437_zpsbd72e974.jpg


IMG_0423_zps10c57e48.jpg


Total build cost: 1 can of spray primer and 1 can of aluminum spray paint. The bike was intercepted from the trash stream. All other parts came from various parts bins.

Rick
 
I Like, I have several of frames like yours to try my self.

Very Nice, I do Like
 
I found a frame, not as cool as yours, but I'm going to give it a try. My start.

DSCN2089_zpsa9f4e774.jpg
 
Ha! I have almost the same bike in reserve. SAme octagonal shaped tubing. 24" wheels on it, not 26".
 

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