Monday, October 16, 2017

 Starting the little big bike: mid fat, 148mm rear. Size Extra Medium
I chose the stainless dropouts this time as the last (1018 steel) thru axle drops that I used seemed to have too tight of tolerances for any kind of coating. 

A 20mm QR axle that I had in my old parts box measured 148mm and the slots of the dropouts are 20mm. All I needed were a few Gyro tabs and a new slot for the slightly smaller diameter dummy axle.
I forgot to order barrel nuts for the brake mount so I had to make a few out of stainless. The ones Paragon sells are AL or brass, so these might actually be better than what they sell.

Saturday, October 14, 2017

Trials 24"

 Finally got the 24" close to coating. Tensioners and a brake brace are next
 The first set of stays below had the bosses too narrow. At 83mm, the brake arms had to aim too far outward, even with the convex washer removed. The good ones here are sitting at 91mm apart. This wouldn't have been a big deal had I not had to make the removable V brake mounts each time (my usual sources are out of them).

Friday, October 6, 2017

The trials frame is awaiting some details on sprocket size
I was thinking about trying to sell my 8.3"s but they might just go on my road/commuter bike. My back has been hurting after riding long distances with the bars that sit even with the seat height. My dad asked for taller bars on his road ride and I think I'll do the same (2-3" above seat height)
Brent's 17 backsweep bars are ready to go


Thursday, September 28, 2017

31.8s


 
Rob's 22 frame is ready to go. Most of the past few week's work has been outsourcing

 One hard peg chink and the aluminum 20mm axle that I made stripped out. I lathed down a hollow steel one, but I'm not sure a shitty old thru axle hub can take peg abuse like a BMX hub. If this fails I'll just make a thru axle rigid fork.

 Apparently, the unintended micro knurl grips better than expected (after coating) Best of these three actually:



Tuesday, September 19, 2017

knarly knurling the sequel

I figured out some things:

I could/should have bought a scissor/clamp knurling tool that would not require side pressure on the rotating tube. This side pressure can deflect the tube and the result is a messy, unintentionally repeating groove (micro knurling). This might have been okay except that powdercoat is pretty thick and requires larger, deeper grooves... Otherwise the knurls just get smoothed over and don't bite into the stem like they should.

The live center that should have prevented the deflection appeared to creep away from the rotating tube. The force of cutting the grooves was enough to wiggle the tube into the lathe chuck and away from the live center. I could probably have reversed cutting feed direction but I had thought of a better solution:

The solution was to use bearings instead of a live center:

With a chuck in the tail stock, I ran a bolt through a few 7/8" diameter bearings and clamped a tube block on the rotating tube and the bearings. This made it so that the tail stock didn't need to apply any force towards the chuck and could move with the rotating tube without consequence. With minimized deflection, the tube was rigid enough to have clean, intentional grooves... at least some of the time. It turns out that this takes some trial and error. The amount of force applied to the rotating tube (when first contact is made) affects the radius at which the knurl wheels sit and this can determine whether the initial cut is in phase or slightly out.
I had been content to just pay for pre-knurled clamps (for the production run bars) but it is time to cut some costs and start to make them on the manual mill. I need to figure out how to do multiple passes and get the cutting wheels hooked up perfectly in their little grooves on subsequent passes.

I'll probably stick with the smaller diamond pattern if further little tests don't prove too wasteful. The larger knurls (middle) produced mixed results on the few that I made today. I made the straight knurls (top) by holding a manual tool on the rotating tube and pulling but this also led to mixed results. A tool post-mounted straight/horizontal knurl might be a good option that I have yet to try. That tool is only $20 so its worth a shot.

Saturday, September 16, 2017

Cody is still rocking his 9" bars. In reference to the rust on the bends: "that's from all the hang five bails"... Inferred subtext: (and I've never regretted a single decision since riding with these bars)

Monday, September 11, 2017

Moto Grom bars





These bars sit between stanchions/fork legs that are 6" apart and within a 4" wide clamp. The vertical sections were ovalized to allow the weld area some room. 29" wide, 3 up, 6.5 back and pretty heavy as they are .083" thick (my BMX bars are .065")


Saturday, September 9, 2017

Huntsville

Ran into Chance and Josh out in Huntsville. They let me get a few clips with them before the sun dropped



Chance's Stout from a little more than a year ago: "Iv'e beaten the shit out of this thing" (..have more confidence, I'm knee deep in bitches and I can sink an eight foot since I started riding this frame)

I got some Profile DJs on there, but they required a two foot breaker bar to get them on the spindle. The tolerances of the "new old stock" cranks and the current stock spindles was a bit too tight. I did get a stiffer spring for my fork but still managed to bottom out on a big 8-10' drop that had a little transition... er, it had a decent transition that was full of thorny weeds that I had to skip over. Was that a "cool story bro"? 

https://www.youtube.com/watch?v=zIvR32lEzPY&feature=youtu.be

Friday, September 8, 2017

Steve's 7"s and some 4" rise, 10 back 3 up (25.4 clamp) that are for sale

Thursday, August 24, 2017

I have a few things for sale up on the PB page:

https://www.pinkbike.com/u/mattty/buysell/

The 22" fork and the 24" have been laying around as references but I don't need them anymore


Dustin's 4.5 bars are ready to go. Nothing will likely be shipped for 5-6 days due to the inclement weather supposedly on its way.

 Here is the 22" fork that I have for sale and a new radioactive trans color going out

Tuesday, August 22, 2017

 I don't like how much time they take, but the wishbone chainstays do look cool. 
Kid bike BBs
 4.5" 31.8s and some 8.5"s

Saturday, August 12, 2017

Aarons 26" and some old sketches

83mm Spanish BB and internally machined headtube. Almost dirt geo but a slightly higher BB for a smaller rider and more street bike feel. I personally like the lower BB for everything but I'm on the tall side. Some short people have said they dislike the "in the bike" feeling associated with a lower BB.


I am looking for a new action cam and noticed a few that look like the ones that I drew, back before action cams or even tablets/smart phones had existed. The word in ID school was that everything would revolve around tablet computers. 

My idea had been a small camera that worked in conjunction with a small tablet computer of some kind. I wanted to see a rugged waterproof screen/tablet with which you could review footage in the field.

 These are a few of the ideation sketches that I found without digging too much. I'll dig out my presentation sketch later.


Now that both of these technologies exist, I'd rather have a tiny camera and gimbal (stabilizer) that can be controlled by a really user friendly phone app.

Also, the helmet mount is my favorite view, so maybe a helmet with a dedicated mold for a system. I have wondered why GoPro never got into helmet design, given that their product has been mounted to so many.