Hello,

I am working on gathering materials for a track bike build for actual use on a velodrome. I am having some issues with determining exactly which materials I am needing. For example, I have found the following set up from Nova and would need to pick up track dropouts.
April Spc A NOVA OS ROAD LIGHT TUBESET with LUGS & BB SHELL :: MONTHLY SPECIALS** :: Nova Cycles Supply Inc.

However, my issue is with geometry because I will need to raise my BB up to not have pedal strike. I will ride at Giordana which is a 250m and my first session on the track with a rental bike I went sliding to the bottom of the track. Since this is a first bike build I am not that concerned with a "perfect" fit as I do plan to make others in the future. I would like the bike to be near neutral, but a little more on the twitchy side (I am a sprinter). I have done a bit of looking around in the other forums as to what the "ideal" geometry should look like, but not many address the actual construction on the bike. The following link is to a general overview.

Urban Velo #3 - Bicycle Culture on the Skids

MY QUESTION: With buying a set like from Nova, will I be able to get a track frame geometry from it? The concern is that the angle of the lugs will not be adequate.

FWIW, I do have an Oxyacetylene set up and have been brazing furniture for a little bit.

Thanks,

Lugs generally have some room for variance in angles.

I don't know your frame building skill set, but I think some concern should be about whipping out a frame, and taking it out and racing on it. Potential for hurting yourself/ others. There are countless mistakes a first-time builder can potentially make. I have been building for many years. Not trying to be snobby but even good builders make mistakes on their first attempts. I also recommend not building your own fork--a major liability.

Brain25 and I have rather different experiences it seems. Given proper brazing I see no issues with making one's own fork. Actually the set up and alignment is the greater issue with most home made forks I've had to deal with.

As to the frame design and the lug angles- the first step is to design the frame and see what the angles are then see what lugs and shells are available in what angles. The cast sockets can usually be tweaked a couple of degrees with little problem. Beyond that more aggressive socket mods are required but still doable. Perhaps not the best first frame method...

I would strongly consider looking at fillet brazing if the angles get too far from the shells and lugs options. Also I would suggest using bronze for any modded sockets. Bronze is far stronger across the gaps that poor fitting tubes have in tweaked sockets. Andy.

Google and download rattlecad and play around with the angles that you need. In general, standard lugs should be fine but the more you "customize" the geo the more you need to see the frame drawn out to see if it will work.

Hey thanks all! I probably should go that route of determining ideal geometry first and then look at the lugs to make sure they work. My concern about fillet brazing is the strength issue because of it being apparently easier (less likely to fail) to make a solid bond with lugs. The other thing Andy brings up is to use bronze, but I am under the impression that the gaps are pretty tight where the tubes fit into the lugs and seems to be too tight for the bronze to flow very well. Or am I wrong?

As far as safety is concerned, I will be riding it solo for a little bit before doing anything mass start. I also already have a fork I was planning on using.

The millions of bronze brazed AND LUGGED frames might disagree with the suggestion that bronze can't be used with best results in a socket. It's all about the prep and the skill of the brazer. Actually the concerns about silver filler loosing it's strength with gaps beyond .005" is a greater one. With bent angles but no added interior build up then reaming/grinding back to the new angle and spec diameter THERE WILL BE GAPS.

As to a filleted joint not being solid just talk to the thousands of tandem riders who ride them. Or the early mountain bikes made by Ritchey and others, or the motorcycle frames, or...

Now the skill of the builder comes into play with any type of joint. It's just that to alter lug angles and do a good job with silver means that the skill lever goes up significantly. Andy.

I guess my basic question on that regard was that I was planning on going the route of a lugged frame because I read that there is a lower likelihood of failure because of the larger surface area for the filler to adhere to. This is going to be a first bike build for me so I want to make sure that I set myself up for success. I just know that silver flows into smaller gaps better. Now, this leads into a totally separate question that brings me back to the beginning as to whether I should be looking at building a frame with fillet joints rather than lugs - there would be a much lower cost involved. I was actually unaware that people use bronze for lugs which makes me happy because of the much lower cost of filler material. I am aware that my tubes would have to be cut much better. My skills brazing are pretty decent; I have done a fair amount of furniture work and no one has broken anything I have built while using it.

The bike itself would be built more geared toward the sprint events - match, keirin, etc. My background is as a track and field sprinter and olympic weightlifter so anything over 5 minutes and I'm dropping. But for geometry, I'm aiming for neutral because of my relative inexperience on the track.

All decent builders will say that your mitering and tube set up needs to be the same regardless of joining method. Using lugs to compensate for poor mitering isn't right. (Not that many factory frames don't do this). The problem with silver is that the socket fit up needs to be much closer. Silver will contract as it cools. Large gaps and voids (as in a pressed lug at the crotches or a highly angle changed lug done poorly) might actually get filled (not that you'll know this...) but as they cool the interior of the silver will contract outward and the interior will suffer cracks. Sure given enough surface elsewhere these cracks and weak spots might not matter. But why accept a standard that has flaws?

When I started out silver was considered the bar to achieve. Miters, lug prep, temp control, cleanliness all needed to be at a higher level then with bronze. But over the years as my frame designs drifted from easily available lug angled ones (it was the "24"" front wheel of my first wife's bikes that started this) I saw more gaps and decided to use a filler which tolerates these gaps better. In time I further decided that a well brazed bronze filler frame had all the same performance as a silvered frame did but with a greater insurance of joint integrity when things weren't just right. At some point I wanted to venture into filleted joints so I did, of course using bronze. My cost went down (not that this is an issue for me) especially when considering the amount of practice I sometimes do before starting another frame. I have suffered a couple of frame failures and at least one wouldn't have happened if I had used bronze for the braze on.

So I have ended up with fillet and bronze as my current preference. I only use silver in certain places. Some braze ones, the Stainless Steel stuff (not that I do much of that lately) being pretty much all. Andy.