Saturday, September 18, 2010

I'm a college "Drop Out" !!

This title is for Rachel who told me she loves puns on blog title entries. The last couple of days I've been spending time working on my drop outs. I love drop outs and I think some major style points can be gained in this department. I love it when the braze between the drop and chain stays/ seat stays look super crisp. Ive been trying to get mine looking legit but have had marginal success. They turned out much better then previous attempts but I have a long, long way to go.

I first started by cutting slots with a coping saw. If your good you can cut the slots at a slight angle so that your drops fit more parallel with the frame without having to bend them. Im not that adroit just yet and feel that I would be risking getting things out of whack by attempting that manuever so I just cut them straight.




The next step is to file the slots to fit the drop outs correctly. You want your drops to fit nice and snug so they're not moving all over the place when you braze. I used a file that closely matched the width of the drop outs to make them fit nice.




The next trick is to make sure that drops fit in the slots the same. I think I got it pretty close this time.
 Sorry about the shadow in the pic. I've got to improve my photography as well as my frame building.




Here's a drop out right after brazing it with brass. Working with brass is so much easier for me for some reason and I am much more confident with it then silver. I feel like I can really get in there with the torch and move things around where I want them. I tried to pull as much brass down into the seat stay as possible to get a solid braze.




After both drop outs were brazed and had soaked I began the clean up process. It's a little less scary then cleaning up the braze on the chain stays but I always expect to be one file stroke from finding a big gap or porosity in the braze. Luckily I ended up with some decent brazing and  not much excess brass had to be filed off.




In a perfect world I would have been able to braze the drops without getting any brass right above the top ends of the chainstays. But it happened and I felt like I would rather try to incorporate this mistake into the transition between drop out and chainstay instead of filling it out (since it happened on both dropouts). I think it will look fine after its painted but I really aspire to getting better transitions because they are aesthetically important to me.




The sharpie marks on the drop outs are indicating where my wheel will sit when the chain stays are in place in the bottom bracket. Hopefully by the next post I'll be brazing these guys into place and getting the wheel aligned nice and straight.


Monday, September 13, 2010

Seat Stay Caps

I think seat stay caps are a really important detail in making a bike look good. I personally like the caps nice and long and I really like it when they're made with inverted tubing.  Making the caps with inverted tubing is a little tricky but I think its well worth it in the end. You can get caps that plug into the ends of the seat stays and they're way easier and faster but I think making your own caps adds more of a personal touch to the frame. 

To make the caps I used a bench grinder to make an angle on the seat stays that was about 4.5cm long. Then I took a half round file that matched the circumference of the tubing I was going to use for the caps and filed a concave along the angle I cut.  I used left over head tube for the concave caps and made sure I filed the seat stays to except them as close as possible. I like using head tubing because its a little thicker and the extra material helps with shaping the cap. I brazed the caps on with brass and made sure I got plenty of fill along the edges. It looks like I went overboard with the brass but I just wanted to make sure I wouldn't have to come back and fill any holes or gaps.



The part I like best about making seat stay caps is watching them take form after you start filing them down. This is the third time I've made these type of caps and its been sort of nerve racking each time you go hacking away at these guys. But the more material I remove the less anxiety I have about screwing them up and they begin to work themselves out.




In the end they always look really sweet to me and I am glad that I put in the extra time and effort. On the next frame I would like to change it up and either try to have the caps wrap around the top of the top tube or maybe do some sort of fast back arrangement.


Saturday, September 11, 2010

Head Tube Clean up & Frame #2

Today I spent some time cleaning up the head tube lugs. Before I started this I went back in and filled some little gaps with silver. I hate going back and having to do this and it always gets the lugs even messier so that there is even more to clean up. I really want to get better at brazing so that I can bang it out perfect first time.


To get the lugs clean I use a couple different files, emery cloth and sometimes a dremel. It takes me way longer then I would like get it clean because there is a lot of excess silver on and around the lug. I'll work on these some more later on to get them exactly how I want but for now I'll move on to cleaning the seat lug and bottom bracket.

This is a pic of the second frame I built when it was almost finished. If you look close you can see some excess silver under the seat lug and on the seat stay cap I still needed to take care of. You can  also see very clearly my disorganized ghetto work bench.


I set this frame up with a bunch of random components I had laying around so its not to cohesive in that department. I wanted to see how well it rode before I invested in any parts or a paint job so I just put it together with what I had. It ended up feeling really good and I have been riding it pretty hard for the last couple weeks.



 After I took it on a couple decent rides (10-20 miles) I was confident that it wasn't going to explode under me or anything crazy. I even ended up taking it to NYC last weekend and doing like 60 + miles  around the city and over the G.W. bridge to Jersey.  I think I'm going to ride it around a bit more and then hook it up with a paint job if she still treating me right. Maybe I'll even invest in a matching wheel set and brakes.

Wednesday, September 8, 2010

Brazing the Front Triangle

I did a really bad job documenting the brazing of the front triangle but hopefully next time I'll take more time and take pictures of the whole process. This is a picture of the frame after I had tacked the HT and ST lugs and was checking the alignment before I tacked the bottom bracket. I don't have a real alignment table right now so I've been using this big ass piece of granite counter top. I figured it was level enough to get a decent measurement off since they shave these things pretty flat.  I use a digital height gauge and 1-2-3 blocks in conjunction with the flat surface to check how my alignment looks after each tack.


The basic process I went through to braze up the front triangle this time was:

1. Drilled and pinned all the lugs in multiple places with 4d finishing nails.
2. Fluxed up the lugs really good with white Stay-Silv
3. Made sure the alignment on the HT and DT were as good as I could get them and then I tacked them with sliver
4. Checked the alignment after the braze then moved on to the HT/TT connection and checked alignment and brazed
5. Same process was done with ST lug connections
6. Final alignment check was done and then I tacked the bottom bracket in place.
7. After everything had been tacked I checked alignment again then re-fluxed the lugs and brazed them completely.
8. I let the frame cool down then soaked all the joints in warm water.

The process to align and braze the frame was my attempt to follow Richard Sachs method which he so graciously posted online recently. It seemed to really work well for me and I was able to get the frame pretty straight this time. There is definitely a lot of room for improvement on my part and so here is a list of the things that didn't go so well for me.

1. I definitely need to work on my brazing technique. The tacks I made were really difficult for me and ended up pretty messy in some places.  The final brazes went much better but I still need to work on getting the shorelines properly worked out. After I soaked the joints there were a couple of gaps in the shorelines that I'm going to have to go back in and refill.

2. Even though multiple alignment checks were made at each phase of brazing the frame did not come out as aligned as I would like.

3. I need to be more careful when shaping the lugs to fit my set of angles. There were some gappy spots from reshaping the lug that I thought would fill in fine but when it came down to it I had trouble filling them and pulling the silver to the shore line. Next time I need to make sure everything fits perfect before I braze.

The next step will be to clean up all the lugs with files and 40 grit emery cloth, go back in and fill the little gaps with silver and think a lot more about how I can improve on building up the front triangle.

Sunday, August 29, 2010

H20 Bosses & Buttermilk Baby

I got out the old torch and did a little brazing for the first time in a few weeks. I'm definitely out of practice but it felt good to move the flame around even if it was for just for a few minutes. I ended up having the torch way to hot and burned the flux way quick so I had to soak the tube and start over. The second try I got the torch right and the braze went smoothly.



 Here's a shot of the bosses after they've been soaked and cleaned up.




I also did some mountain biking this weekend and took a couple photos while I was out on the trail.




If you've biked Buttermilk east to west in Richmond, VA a few time then you can probably recognize this little root section. It's really unassuming but this little clump of roots is seriously one of the hardest obstacles on the trail. It's just one of those things that if you don't hit that perfect line you fail. It sucks because you can go out feeling great thinking your going to have a no foot down run of the trail and this little "shit root" comes up right in the beginning and takes you out. But if you manage to get passed this thing no problems then I feel like you have a 75% better chance of crushing the rest of the trail.

About half way through Buttermilk, right before that steep as bridge thing, you can stop and turn around and there is this bad ass climb. It's super steep and I hardly ever make it but I always try.



This picture really doesn't do it justice. It's a really short climb but it's super steep at the top and you really have to dig in to have any hope of getting up the last crest. Its also really fun to ride back down because you end up going so fast and then you follow that up by bombing down the wood plank thing. Fucking awesome. Kudos to all the dudes who volunteer and people at James River Park System who maintain this trail system. It might be one of my favorite things in Richmond.

Friday, August 27, 2010

Miters: How good is good enough?

Cutting miters is sort of fun but when its comes to making them perfect it can be a little frustrating. I feel like its important when trying to build a well aligned, solid frame to start off with the best miters you can possible achieve. I think most frame builders out there worth their salt have the same opinion. It just makes sense. From what I've ascertained the mitered tube should make as much contact with the parent tube as possible while still achieving the desired angle. You need nice tight miters because when your brazing the silver will have a hard time filling any big gaps in the miter and this could create a void in the braze. A good miter also acts as a support for the whole bike structure. If there is a big enough gap in the miter the tubing could possibly shift while you're riding and cause a crack. Thirdly, having good miters is the first step toward having good alignment in general.

I cut all my miters by hand by first using a hack saw for the rough cut. I get a little closer with a grinder and then I close in on the miter with a file. I do a series of checks as I get closer to the miter I want.


As I get toward the end of the miter I check to see if I have the right angle I'm going for. If that looks good I make sure that the sides of the miter are squared up.


The the third thing to do is to check the miter with the tube its going to mate up with. Some people say to have a really good miter you should be able to look at it and not see any light coming through the miter. Personally I would love to get one this close but it always seems like there is a tiny gap somewhere in mine. I'm working to close that gap though.


In the end I usually get my miters pretty damn close but never perfect. One of the things about miters that keeps causing me trouble is what to do with the sides that meet the outer most part of the parent tubes circumference. Is is better to continue up with the sides and then file the miter so it meets flush with the parent tube or do you file the sides flat and the tubing sits on the inner edge of the tube wall? Is that good enough?  Is the silver able to bridge that gap? When I think about the miter I can see how you could continue filing right up the edge of the tubing and how the tubes could mate perfectly. Though when it actually comes down to doing the miter I always seem to end up with a bit of flat edge on the top. This bothers me and I think I should do a couple practice miters where I go specifically for that flush fit.

After I cut all the miters as best I can I dry fit the tubing  in this sort of template/ sizing board thing I made. It's basically just a board with the drawings of the specs taped to it. Then I screwed some boards down onto the drawing to hold the frame in place.


I don't have a frame jig so this is sort of a way for me to check to see if the frame is matching up to my original drawing and specs. It also lets me see if the miters and angles are working. I wish I had a jig but I don't because they're expensive. I do subscribe to the idea that a good jig doesn't necessarily make a good a frame.  However I firmly believe that a good jig could make building an accurate and aligned frame much easier and faster.

You don't even have to start telling me how my current setup could lead to inaccuracies because I already know. But it does help to get an idea of how things are coming along and when I set the frame in it everything seemed to line up really well. Nothing seemed stressed and all the miters set well against each other. The next step is to fit the frame  up with the lugs.


I stuck on the lugs and things still seemed to to fit nicely. The only area that was a cause for concern was the lug connecting the DT and HT. The lugs seemed a bit stressed and kept trying to pull away from the HT.


You can see on the lower lug how the top is pulling away from the HT. When I dry fit the tubes that miter seemed fine which leads me to believe that maybe the lug itself is not completely accurate. It sucks that that miter is the one giving me trouble because the DT to HT connection is one most important miters. I think I'll try to reshape the lug a bit and see if that helps the situation. Other wise things seemed to feel pretty solid so I'll keep moving on with the build. The next step is to take care of some more prep and then take it to the "alignment table" and see what she says.

I drilled some 1/4 inch vent holes in the HT but all the 1/4 inch bits I had were really dull so it didn't go as smooth as I anticipated. I've read that you should put up to three 1/4 inch holes per lug but drilling out that much metal sort of freaks me out so I'll stick to two for now. 



 I went out and bought a new 1/4 inch bit and drilled some holes for the H2O bosses. Its amazing what a sharp bit can do for you. I'll braze on the little H20 bosses before I go any further with them frame.



The last thing I got to was pre-drilling hole the lugs for pins. I'm going to use 4d finishing nails and I drilled the holes out with a 5/64 bit.  The last frame I built I used masonry nails ground down to small pins. I thought they would work better because they already had a sort of taper on them and I figured this would grip the holes better. It took way to long to prep them though and I am just going to give regular old finishing nails a try this time.










Tuesday, August 24, 2010

Lug Attention

Didn't get much done today but I did spend some time prepping the lugs. Basically I used a dremel, files and sand paper to grind out the inside of the lugs a bit so that the tubing would fit in nicely. You don't want the tubing sliding all over the place in the lug but you don't want to have to beat it in there with a hammer either. You need to have a nice, snug fit so that when you start to heat things up you get that capillary action going on and the silver fills the lug up completely . On the first two frames I used the cheap stamped lugs from Nova and it seemed like I had to grind all kinds of material out of them to get a good fit but these lugs were like butter to get right. I also spent some time cleaning up the outsides of the lug and filing the edges perpendicular where they meet the tubing. I really want to do a good job with the shorelines this time and paying some extra attention to the lugs might help with this. Plus I think it looks really sweet when the lug lines are really crisp. Hopefully I will get to start mitering the tubing in the next day or two.