Roads, rough stuff, and Roubaix

I've been popping up in the new project thread for a while now, as and when I build a frame. To date they've been for me and family.

That changed a little while back, when a friend approached me to build him a bike for use on bad roads, cyclocross jaunts, and he wants to ride Roubaix next year. It's my first commercial commission, which I'm excited about, and has also been a spur for me to go ahead and book a slot exhibiting at Bespoked in 2016.

The build is in progress now. Columbus Zona tubing with Paragon Machine works disc dropouts, tapered CF fork. It'll work with CX or fat road tyres, and have mounting for mudguards too. Groupset is SRAM Force 1 hydraulic a 1x11 setup. So rather than being a 'pure' CX bike this is in that expanding niche of bikes built to cover a range of riding styles.

I'd like to take you through some of the thinking I've applied and techniques I've used during the design and build.

Here's the design sketch from BikeCAD.

And the frame parts laid out and ready to go.

Cheers!

So rather than being a 'pure' CX bike this is in that expanding niche of bikes built to cover a range of riding styles.

Basically road geometry with slightly longer chainstay and massive clearance for whatever new big lightweight tyres cropping up in the future?

Ooh, lookin forward to see how this turns out. Good luck with Bespoked. May pop down next year, if so, I'll come and say hello. Keep up the good work, love your build threads.

It depends on what you regard as massive clearances, really. It'll take 38mm tyres, and can run 35mm with mudguards with a decent amount of room. The clearances on forks seem to be more of a variable, ranging from 35mm to 40mm. I'm not getting into monster cross with this one!

I've made the TT more dropped than the traditional squarer CX bike style to expose a decent amount of seat post, the thinking being to allow it to do more work over rougher surfaces. Obviously the tyre pressures are going make a major contribution there.

100 mm headstock 52 top tube 47 seat and 420 stays was enough for me . Plus a whisky fork rather than enve as they dont do mudguard eyes.

I wanted to use the Whisky No7, I've put it on a previous build, but it's currently unavailable, with no restock ETA.

TRP should have their 12mm through axle eyleted CX fork in the country soon, and there's also the Enigma Ecroix fork.

The options are slowly expanding, but Whisky are a bit unreliable in their supply management, it seems.

I just saw your email re: stays Mike. I wasn't ignoring you, but my email got spamfested that week, really sorry. You got the sorted?

Also, kinesis CXD ~ whiskey 7.

Hiya, yeah got that sorted thank you. And thanks for the tip about the CXD, will definitely look at that as an option. Especially as for now everyone is out of stock of everything!

For my first few frames I hand cut all the tube mitres, mainly because I was learning how to file well. More recently I've started machine cutting the tubes, which is giving me some nice results, and overall is a fair bit faster.

Fortunately I have access to some nice fixtures that help keep everything centered and accurate. I'm using Starrett bi-metal hole saws, which work pretty well. They're available in lots of sizes so you can almost always get a really tight match on the mitres. There are other cutters on the market, but I've not had chance to try them out yet.

Tight mitres help in the build process, as they minimise movement during brazing. That results in a better alignment for the frame. It's also really good if you're TIG welding (which I do as well) as TIG doesn't tolerate gaps anywhere like as well as brazing, as the joint area is a lot smaller and the tube edges are liable to getting burnt back if they are exposed.

Good work!

Damn, that is tidy. Good work.

Just out of interest, if I was considering a crack at frame building, what does a framesets worth of tubing cost?
Cheers. Jon

Depending on what kind of tubing you go for. Give Ceeway a ring - from memory it's certainly possible to get tubes and lugs for <£150

Cheers will have a look at Ceeway.

Yeah, costs are very driven by tubing. A set of decent quality tubing, plus the head tube, BB, dropouts and braze ons would start at £150 - £200, you also need flux and brazing rod.

You can keep costs down by buying heavier, plain gauge 4130 tubing, which isn't a bad place to start. If you do want to have a try let me know, I have some practice lugs knocking about that I don't need.

Also, I was getting some practice in with TIG welding today. I have built a TIG frame, but it started to feel a lot more natural today. This is a joint on 1.3mm to 0.7mm tubing, using a stainless steel filler wire. Planning on building a through-axle CX bike for myself over the winter. Going to weld it, rather than braze.

Cheers. That's very good of you. Will get back in touch, probably in the new year.
Keep building, keep inspiring me and others.

Some more in-progress shots. First couple are details of the tacks, used to hold everything together while you braze the frame. The material is incorporated into the pool of molten brazing alloy as you work around the joint.

I always tack down the centreline of the frame, but I've also added a couple of extras on the side to help make things a bit more stable.

And then here are couple of the fillets post-brazing. The red marks are where I've decided to do a bit more tidying up. You can get a fillet that looks finished to the eye, but when you run your fingers over it you can feel small bumps and inconsistencies.

A relatively short head tube on this frame meant I had to integrate the top and down tube brazes, but I'm pretty pleased with the way they came out.

That is incredibly clean! Stellar work!

Very nice. You have a talent for it.

Check out coba for the higher tooth count, seem to last a fair bit longer than the starett, especially when passing around with harder steels.

jontea is right you do have a talent for it, fancy going into business?

incredible work!

subscribed!

Yeah, may well do that, I find that the Starett cutters can be a bit "grabby" especially if you're near an edge. Have you used the Strawberry or Academy Tools mitre cutters? They look a lot more robust, but are comparatively expensive..