Hi All!

Hello! After lurking here for a while, I decided to join so I can talk about my Crazy homemade adjustable cranks…

But first, I ride a Sun 28 with a KH seat and specialized BMX pedals. Yeah, I know, a Sun, but hey it is cheap and works great for road/bikepath/light-trails. No hops or anything like that. I’ve got a computer and two water bottle holders. (I also have a Sun 24 and 20 unis, both now have conscripted MTB tires).

Fastest I’ve ridden is just shy of 12 MPH. I can easily maintain 8-9 MPH. I used 6" cranks, but I have tried 5" and could actually go 1 MPH faster and easily maintain 10 MPH, but the reduction in control wasn’t worth it. I found the UPDs offset the gain in speed, and I ended up doing my usual 13 mile ride in almost exactly the same time and average speed. Back on went the 6"ers.

The farthest I’ve gone in one session is 13.8 miles.

So you guessed it – shorter cranks for slightly more speed and smoother cadence, or longer for slightly more control and a less smooth cadence?

CrazyChris asked himself, “Hey, CrazyChris, how about adjustable cranks?”

To which CrazyChris replied, “You know, I could take my unused 5” cranks, and this piece of 2x2 square steel tubing, some small u-bolts, and like 3 hours of my time
with Mr DrillPress, Mr Grinder, and Mr metal-cutting-saw, and make some Crazy adjustable cranks!"

So I did. They can adjust from 4.5, 5.5, 6.5, and 7.5". They seem quite sturdy, and at about $20 a heck of alot cheaper than what I’ve seen in production ($700 for a pair of adjustable cranks??? Hello?!?!). They add a couple of pounds but so what, still in development. They’re my CrazyCranks!

It has 4 bolts per side (11/16" nuts, on 7/16" bolts), so it takes maybe 5 minutes to change lengths. All you need is one 11/16" wrench - I use a stubby, fits in pocket nice.

I finally put them on last night and briefly rode around, at the 5.5" setting. I then tried the other settings, took some pictures, but it was then too dark to ride outside. I left them at 7.5" - man what a Crazy big pedal circle!!! Crazy!!! I mounted it and sort of jumped up and down, short of a real hop, and I saw and felt no movement in the CrazyCranks.

I have pix if someone could tell me what would be appropriate JPG size and quality settings.


I’d like to see a picture of them crazycranks.

Please post the pictures. The .jpg width should be no more than 640 pixels to post without overlapping the page. If you have web space somewhere you can post them there in any format and just provide a link in your post.

pix of my CrazyCranks

I put them in a separate thread –
“Pix of my CrazyCranks adjustable cranks”