Upsizing 20" 1970's BMX bikes to cruisers

rev106 · Oct 24, 2024

Goals are as follows:

1. Get more welding and frame fabrication practice

2. My materials are beginning to rust because I got stuck behind a hot rod project for a year and a half so use up my metal before it goes bad.

3. Use up some my parts that I am foolishly holing onto for some vintage cruiser frame that will never land in my lap.

4. Most importantly, get rad on the bikes I made.

I picked a Dave Shwerma Champion and a GarylittlejohnMurphy for my choices. I got the LJM bikes mostly finished first, they upsized ok, some of the look gets lost in upsizing unless you want to make a lowboy which I'm too tall for. Then I got into the Champion and that has to be the hardest bike to make! 10_ hours just in the dropouts. More to come...Enjoy the progress so far.....

Fixed the munched Poe

Fixed this Powerlite fork....mostly...

rev106 · Oct 24, 2024

A few more glamor shots before I stuff it in a bush somewhere and mess it up.....

BartRidesEternal · Oct 25, 2024

Awesome work, looking very good.
Hmm, is that a high flange coasterbrake?

Can I ask you Wizard: What tubing are you using? CroMo or mild steel (thick wall) or Reynolds, Columbus etcetera.

I found out that most stock cruisers have mild steel thick wall tubing.

rev106 · Oct 26, 2024

BartRidesEternal said:
Awesome work, looking very good.
Hmm, is that a high flange coasterbrake?

Can I ask you Wizard: What tubing are you using? CroMo or mild steel (thick wall) or Reynolds, Columbus etcetera.

I found out that most stock cruisers have mild steel thick wall tubing.

Coaster brake is a NOS Shimano B type shell made in the 1970's with some guts from another normal b type hub. MX ones had MX stamped on the torsion arm.

16 gauge steel tubing, the white one was made 3/4 .049 4130 because I had just enough scraps left over from another project to do it. Schwinn made millions of bikes out of mild steel, I see no fault in using that material.

Robertk · Oct 26, 2024

When will we see the 26” Littlejohn?

BartRidesEternal · Oct 27, 2024

rev106 said:
Coaster brake is a NOS Shimano B type shell made in the 1970's with some guts from another normal b type hub. MX ones had MX stamped on the torsion arm.

16 gauge steel tubing, the white one was made 3/4 .049 4130 because I had just enough scraps left over from another project to do it. Schwinn made millions of bikes out of mild steel, I see no fault in using that material.

Thanks for responding Paul, I see no issues either and I'm learning everyday :thumbsup:

rev106 · Oct 29, 2024

Moving on to the Littlejohn Murphy cruisers. Finished all the welding, second straightening out, made the gussets and put those in there. This frame did not upsize as well as the Champion did, the 20" was a very low frame so when I made a bigger version, some of the look was lost in the upsizing. Still looks cool though! Thing is a tank. SO why not make it super heavy with some motorcycle rims? I have some 40 spoke Akront motorcycle rims that I laced a moped front drum into, it had the rear drum already when I got them. Trying to keep things era looking without going overboard and not buying parts as I can make or have whatever will work somewhere in my piles of bike crap. Schwinn varsity crank set should be the go to and rat trap pedals....more to do...Enjoy!!

rev106 · Nov 2, 2024

rev106 · Nov 5, 2024

Here is this pig. I tried to weigh it on my postal scale, it is about 44-45 pounds. The upsizing lost some of the look but I think it came out ok. GarylittlejohnMurphy 26" upsized for radness. I can ride it with no hands, tracks straight etc. Parts are as follows:

Custom build high ten steel frame in Chevy hugger orange.

No name fork and seat post clamp.

Schwinn varsity cranks and head set, rat trap pedals, and butt slaying seat.

Wald 42T front sprocket

Fakey Redline double clamp stem.

S & M bars that are new school and don't have enough back sweep, they may be swapped for something good.

Mushroom copy grips

Akront 21" motorcycle wheels with atom drum rear and moped drum front. Had to add some holes to the front hub because they are 40 spoke rims.

OGK motorcycle brake levers.