File to Fit

It’s been a long time since I’ve ranted about framebuilding here (I do it every day in my head but rarely have time or want to spend it writing thoughts that few really care about). But hell, what good are ideas if you don’t put them out there to bounce off the interwebs?! That’s what blogging is after all, banter that may or may not be interesting to a small clique of the world.

So anyways, I have finished my 17th frame and it was a doozy.  I can’t say I enjoyed the entire build, but seeing it done is pretty satifying.  It’s almost the frame that hate built, to use the Over-Opinionated Framebuilder’s phrase.  En sum, I went through one extra top tube (cut too short, stupid SOHCAHTOA), one extra wishbone seatstay crown (burned a hole), two extra seatstay legs (slotted too short), one Ti coated drill bit (snapped at the tip), and a lot of brain cells.  The bending of tubes and the resultant geometry changes to the miter lengths and miter angles are stifling me. I am trying to use BikeCAD to get the miter angles and lengths but for bent tubes I now am just going to draw it all out life-size.  You can see some of the differences in the mitering numbers from what I had modeled in BikeCAD to what I drew out on paper in the picture below.  I’m sure many others can correctly use BikeCAD to input the right radius numbers…but I can’t.  Like i’ve said before here, I haven’t a clue how to get a given radius from the Harbor Freight tube roller unless I buy a expensive set of gauges that only help after I’ve rolled the tubes.  Ok, so I guess I could roll/check/roll/check to approach the radius I’m looking for but I haven’t tried that yet.

So what I do instead is file to fit. I am pretty sure most builders that have milling machines and expensive fixtures still file to fit a little bit but for their sakes I’m hoping they don’t do it quite as much as I do.  There was only one miter on a curved tube I got spot on and didn’t touch after the mill – the wishbone seatstay miter to the seat tube (17 degrees).  I’ll remember that number for some stupid reason for a long time. It’s stored in the same part of the brain that remembers the lyrics to those 80′s songs you really truly hate.  Of course I won’t remember how I finally figured out the right way to measure and miter the curved top tube angles.

In the photo of the drawing only the circled numbers stayed constant. Really those are the most important since they are what control the geometry of the frame.  They’re what I set the fixture at and try not to move it more than 1mm (if i cut a tube too short).  They’re what define how the bike handles. Oops, just noticed I forgot to circle the head tube angle (but maybe that’s irrelevant as some don’t think that is an important parameter atmo).

I know over time I’ll learn to use my machinery and fixtures better, and learn to trust that ruler and my use of it so I don’t have to file to fit (as much as least).  I would like to be able to measure & mark the tube, load it in the mitering fixture on the mill, cut the tube, deburr, and load in fixture and be done with it. Paper tight miters without filing to finish.  No problem, right?

So this is what I’m going to do. No more bent tubes until I get the process for straight tubes dialed better, and when I start selling frames bent tubes will cost more because they do take a lot more time and effort.  Same goes for internal cable routing.  I do love how the frame looks without cable stops but not sure it’s worth the extra weight and effort.  Luckily for my friends I’m a non-profit framebuilder right now and willing to try anything even if it is above my pay grade. More details on this frame in post-to-come!

the finished product

Saturday Ride

Rode a nice 50-ish mile loop yesterday not too far from the house. Drove up to China Wall about 20 min up the road and then got on the bike for another 15 miles up the pavement to Robinson Flat where it turns to dirt.  I had to check out the Duncan Pk Fire Lookout and see the panorama from up there (7182 ft). I’m pretty sure I shouldn’t have been able to ride a regular bike up there at this time of year if we’d seen normal snowpack (sub-20% of normal right now I read).  After leaving the Lookout, I followed what turned out to be a very bad map (Trails Illustrated).  For you that are interested, the Western States trail does not go where the map says, and the Delorme map on my GPS was dead wrong too.  You turn on CR44 to Cavanah Ridge and that’s the trail.  But trusting the maps I headed down towards Mosquito Ridge Rd a couple miles trying to find signs and the turnoff.  Once I found the trail (it’s a dirt road for awhile) I eventually dropped back onto Last Chance road. I hadn’t seen a car all day, on a Saturday mind you, until I almost ran head first into my neighbor (literally, he’s my neighbor) coming up the hill from his mining claim at Last Chance. As luck would have it, he pushed me off the main road to where there was an upside down trail sign with an Auburn Bike Works sticker on the back.  Turned it over and the arrow pointed to the Tahoe Sierra 100 race route that follows the WS trail.  Aha! I was now certain I was going the right way.

So then it was some old 4×4 trail that had narrowed and rutted, and on I descended down to where Last Chance Rd takes you down to the end of the road – Pacific Slab Mine and the old townsite.  Pretty crazy how far out that miners town was and how difficult the trail west to the supply towns was (is).  After browsing around the town I dropped into the WS trail and down to one of the several forks of the American River.  After re-watering thanks to my lil MSR water filter I hiked the 2 miles out of there to Deadwood and rode back up Deadwood road to the truck.  I saw another rattlesnake, this time on the trail right after swinging bridge.  Five and a half hours, 8K plus of climbing and only taking a couple wrong turns! Not bad. But I followed the WS trail signs on Last Chance road and missed a huge section of singletrack unfortunately.  Newb. It’s ok though, I’ll be back.

7182ft elevation right here, no snow. Cavanah Ridge and the WS in the background.

Sierra view

Last Chance to Deadwood section

Last Chance to Deadwood section

steep switchbacks down the river on this part

one of the several forks

climbing out of the WS trail on Deadwood road

Riding with people – totally unrelated to framebuilding

This week I actually rode with 2, count em, TWO people…! Pretty crazy I know. I got to ride with an old friend of Mrs. Meriwether’s from 25 years ago. She had no idea he rode bikes. Turns out he’s kind of a honch and works at one of the 4 bike shops in Auburn. He offered to take me on a ride on some of the G-town trails around his house. Around 5 and a half hours later we ended up back at his house more or less wrecked and quickly grabbed a chair refueled with cold IPA. The ride was right around 36 miles and over 30 of those were singletrack. An awesome loop and apparently it only scratched the surface of what’s out his back door.
In good newb fashion, I started the ride off strong. I was trying to take a picture (right hand) of the trail and scenery while keeping up with him and the trail dove left. Being that I only had the front brake to use (left hand), I tried to feather it to make the turn but instead flipped off the side of the trail. Camera, bike, and I were ok and luckily there was no poison oak at the spot I landed. After some readjustment of the seat and bars we were off again. For some reason I was bragging how cool the Knard 29plus tire platform is and how ‘i haven’t flatted yet and run 8psi!’ I then went on about how I don’t “need” suspension with the fat tires especially because it’s not rocky here compared to Colorado. (This is where I think we changed routes for some reason.) So what happens next of course is that I front flat after a rocky section. It was the slowest pinch flat i’ve ever had since I could ride it for awhile, but I did have to take my foot out of my mouth. We made it the rest of the way unharmed but bringing only two water bottles and it being over 80 degrees out trying to follow a local on his trails I was pretty wrecked.

A few days later I met with a friend of a friend from Truckee (whom i’ve actually ridden once with before on Mt. Tam years ago) who was down here for work. We tried to hook up this winter to go fatbiking but it just didn’t happen unfortunately. For this ride, he was riding a 6″ travel Santa Cruz Nomad and I was on my hardtail 29er with a 100mm fork. I had him on the uphills but man he was hard to keep up with going down the Culvert Trail and Confluence. Even with the new work on Culvert (it’s pretty smooth and bermy now instead of fast and rocky) I barely kept up. Stopping for pictures didn’t help but at least I stopped to shoot this time!

Riding with these guys made me feel like there’s hope yet for this new homeland. Even if there’s nobody (as far as I can tell) in the town I can ride with, the Auburn, Truckee, and Nevada City areas have great riding communities to patch into and offer endless miles of trails to explore.

Yes there are rocks in California

Most of it was smooth singletrack like this

Sputnik chainstay mitering fixture – SOLD

THIS ITEM HAS BEEN SOLD AS OF 4/30/13

I bought this chainstay mitering fixture in 2011 for approx. $800 total with:

• 3 sets of tubing blocks size = 2 of the 30×16 (one square and one with rounded corners) and one 26×18. ($200). The newer rounded corner 30/16 fit better than the squared edge blocks for MTB s-bend stays like True Temper (HSBENDCS1) and Dedacciai. The 26×18 fits the single bend True Temper chainstays (HOX4CS). (Was $100 extra for each tube block set.)

• Hooded/Wright/Breezer dropout blocks, and tab-style dropout blocks. (was $100 additional for the 2nd style of dropout blocks.)

• Custom tapped angle plate for use on a vertical milling machine. (was an extra $55 for this.)
  

This is the older version of this fixture, the new version is seen here. It’s in excellent shape. I used it to miter 16 sets of chainstays. The only modification is that I drilled and tapped M5 holes for 170mm axle spacing.

I would like to sell everything for $550 plus shipping. Thanks for looking.

MTMF on the horizontal

The Anvil main (all, actually) tube mitering fixture barely fits on my horizontal mill.  Mostly the 5×20″ table is pretty tiny for an 8″ rotary table (rotab) which is what the MTMF requires.  I have the rotab attached in the center t-slot but really i should have fabricated an extension plate so I’d be able to use the full Y-axis.  But because the knee/Z-axis is somewhat limited (15″) I could barely center the fixture with the spindle as it was.  To help this effort, Anvil fabricated me a special adapter plate for my rotary table that is thinner (3/4″) than the stock adapter plate (~1″).  Even this little bit of difference helped.  The adapter plate also came with slots instead of single holes to attach it to the rotary table so you can tram the plate’s rail to the spindle axis like seen in the photos.  The reason? Anvil makes their adapter plates for Phase 2 rotary tables and I have a Yuasa type that has the t-slots about 19 degrees offset/different than the Phase 2 table.  So when I had the stock adapter plate the rotary table read 119 degrees when it was perpendicular to the spindle instead of 90 degrees.  With the new plate I was able to set it right at zero (or 90) with the rail perpendicular to the spindle.  Makes it mush simpler to set the miter angles this way! It sounds like Anvil now offers this type of plate as an option for the MTMF because not everyone will have the same type of rotab.

Then, i found a nice slotting saw arbor in the box of goodies that came with the mill. It was made for the Brown & Sharpe #9 spindle so I just was able to load it right to the existing drawbar.  Super easy set up and the MTMF keeps the chainstay or seatstay in phase without any futzing.  Just load it, lock it down and slot.  Seriously, it’s easier and more accurate than the hacksaw method I was using previously.  I love how the horizontal serves it up on a plate right in front of your face whereas with a vertical mill you’re (or at least I was) ducking and tilting your head to try and see under the mill’s head to align the tube and see what’s going on.  At least for me, I prefer horizontals now for mitering that I have one, even a tiny one.

tramming step 1 to get it close…

then getting all exact n stuff

very close to perfect

centering the spindle to the fixture

No, didn’t attach the overhead support beam. It’s rigid enough for these cuts.

this came with the mill, first time used!

DT miter for ST at 45 degrees. Couldn’t do this on my vertical mill.

1st Frame Anniversary

Three years ago today I finished my first frame. I like to look back and see how far I’ve come and will hopefully continue to proceed.  Still way fewer bikes than I thought I’d have under my belt by now (on number 17), but with a major cross-country move and this not being my only ‘hobby’ I can’t complain.  Here are some photos of my first frame which is now hanging up in the shop.

hot!

if I had only used the pulser…

wouldn’t have mattered much…

Wishbone from Nova Cycles

Needed a beer after that welding

Ride 2 or 3

Facelift with some rattlecan Pumpkin Orange

Fatbike fork for Dynamo hub

This fork is for loaded dirt, snow &/or sand touring once attached to his Surly Necromancer frame. It’s got more braze-on’s than most touring frames! It’s got three bottle bosses on each leg for Salsa Anything cages or for water bottle cages in one of two positions (high/low). It’s got one bottle boss on the middle of each leg and a threaded nut in the lower steerer tube for a Salsa Minimalist Rack. It’s also got one bottle boss at the dropout just in case he wants to use another type of low-mount pannier for bringing more stuff, or a fender perhaps. The last thing this fork has is internal routing for SON (Dynamo) hub wiring which will connect to a Supernova E3 light at the fork’s crown (which doubles as the upper attachment for the Minimalist Rack).

The internal wiring is less complex than it sounds, I just made a hole in the lower inside leg, brazed on the seen cap to protect the wire as it comes out of the leg and goes down to the hub’s tongs. I fed some bailing wire from that exit hole up through the crown BEFORE brazing the sleeve to the lower leg of the fork which made it super easy to fish through the crown. This wire stayed in place for the brazing and then the powdercoating and then I used the wire to guide some derailleur cable-housing liner through the fork leg to serve as the path for the light’s wire. The plastic housing will also protect the wiring from the edges of the fork crown. The wire will momentarily poke out the bottom of the steerer and attach to the E3 light itself. Hopefully Scott will send some pics of it all set up!

It’s an interesting fork that he requested because he wanted clearance for 4.7″ tires on a Clown Shoe (100mm wide) rim. Most fatbike forks that run this sized tire have 135mm axle spacing or even 170mm. Since the SON hub and other Dynamo hubs don’t come in that width we made this fork with the normal 100mm axle spacing.

The fork is built pretty beefy. The crown pieces are 1.125 diameter x 0.058″ wall since they are so long compared to a regular segmented fork. The sleeves and legs are the normal setup, sleeves are the same as the crown pieces and the legs are 1″ diameter x 0.035″ wall. Paragon hooded dropouts and a modified Willits ISO disc tab and there you have it. The color he chose closely matches the text outline on the Necromancer frame but also makes it stand out a bit from a standard black fork.