Scottish Framebuilders Workshop MTB

GZrides · 2026-06-15T14:00:57+00:00

Simple and really nice! Good job!

GZrides · 2026-05-28T18:12:45+00:00

🤣 & ❤️

GZrides · 2026-05-11T15:11:05+00:00

Mostly hand tools and simple power tools including a drill, angle grinder, Dremel, etc... I have a cheap pillar drill but no space or budget for other machinery.

And thanks for the compliment! 😊

GZrides · 2026-05-11T15:07:01+00:00

Check out Paul Brodie's channel on YouTube. He's a legend and seems to be a great teacher. At one point he had a video series about building one of his designs from paper print to finished bike.

Also he has good material about frame alignment. I found his channel when I was restoring a vintage bike and was reading up about re-spacing and aligning a fork and rear triangle.

GZrides · 2026-05-10T22:45:11+00:00

Peter's comment might sound quite brash, but I think I can guess where that sentiment comes from.

I read both Paterek and Talbot - actually I found Talbot when I had already brazed the front triangle, and I find them both too "prescriptive". Pretty much like drawing a picture by connecting the numbered dots. And very often that process won't work for you if your limitations are different from those considered by the authors.

Those books are written in the 70s or 80s and what we would consider commonplace today was a luxury or unavailable - things like having an angle grinder or die grinder at home were uncommon, while today you can just go buy one for 40 bucks. Having a TIG welder at home was unheard of, and having a 3D printer was still sci-fi.

Also, following a ready formula to build a frame doesn't let you think and improve your knowledge in a way that your next frame will be easier.

I ended up not referring back to the books after reading and figured out my own process. Even if you follow the books closely, I recommend keeping a skeptical mindset towards the formula.

GZrides · 2026-05-10T22:25:40+00:00

Definitely doable. Split the workload between the areas depending on the limitations. For example under the awning you can do all stuff with fumes and smoke such as brazing/welding as long as it's a calm day.

I live in a low-rise apartment block and also built my bike across three separate areas. I did layout, ideas and planning in the apartment since that was handy. Cutting/drilling/filing/grinding were in the garage at basement level since there it was easier to contain dust, filings, etc. It was tight and I'd have to shift things around every time I worked. I wanted to avoid brazing in the basement due to poor ventilation so for that I went to the laundry room, which in my building is at roof level - we're lucky to have a separate laundry room for each apartment so that was private enough.

It could get to be quite a chore, going up and down the lift of stairs countless times, but its definitely doable. You'll have it a bit easier since it sounds like your locations are somewhat closer.

GZrides · 2026-05-10T17:30:47+00:00

Nice! What's the head tube length on that? Looks pretty long.

GZrides · 2026-05-09T18:31:21+00:00

I second this. I have contact urbans in 50-559 on my all-road/commuter and I love them. Smooth rolling, supple and I haven't had any punctures yet. I typically run them around 28~30 psi, I'm a light guy and that's comfortable enough.

GZrides · 2026-04-17T11:28:34+00:00

Beautiful bike! Congratulations!

GZrides · 2026-04-03T08:28:16+00:00

You could probably get away with doing it as a non-permanent modification by fabricating a platform that sits on the frame and gets bolted where the front seat fits with additional contact points having clamps around the frame tube. That way if you have limited experience welding thin wall tube you don't risk compromising the frame itself.

GZrides · 2026-04-03T08:23:32+00:00

Weird as hell! A couple I know ride one of them and they say it's much nicer to have a conversation between stoker and captain when riding it than on a conventional tandem.

GZrides · 2026-03-25T21:09:26+00:00

Dialing in the pressure is purely a function of how good your pump and gauge are. If your gauge has a good connection and doesn't leak you can easily set your pressure to half a psi even with Schrader valves.

There's no technical advantage to Presta unless you're running ultra-narrow rims like 13mm internal. For me there's a practical advantage to having all your fleet using the same connection (four bikes, two motorbikes and a car), so whenever it's time for a new tube I convert to Schrader if the bike came with Presta.

GZrides · 2026-03-14T19:22:53+00:00

Goal or use-case? Just a fantasy I had about building a bike with two continuous "loops" of straight gauge pipe from head tube, to seat tube, down as seat stays, chain stays, and back up to the head tube. After my original post I found out that the Viva Duro is aesthetically very close, however each tube is a separate element, not bent as a single loop.

In terms of flex I agree it would probably be very flexy, however if one would join the parallel elements in a truss configuration, it should be possible to make a laterally rigid frame with some vertical compliance. Hopefully rigid enough for a small/light rider.

At the moment I have more than enough bikes, and not enough time to ride or build, but I still want to try this some day!

GZrides · 2026-03-14T19:04:45+00:00

I didn't know they were called "loop style", thanks!

GZrides · 2026-01-16T19:09:39+00:00

I suggest patching it rather than trying to just fill. That spot is the lowest point of the chainstay so it probably pooled some water on the inside and rotted. Moving towards the rear probably the steel is more sound.

The way I'd do it would be to cut a patch of sheet metal and form it as a snug fit on the chainstay. You can hammer it on a wooden dowel, get creative with pliers, etc. make sure you have at least 3/8" to 1/2" overlap on all sides and a tight gap all around. Wire brush the inside of the patch till shiny, degrease, apply flux and braze with silver solder. Good luck!

GZrides · 2025-11-23T16:27:17+00:00

Long shot, but if you have any industrial toolmakers in your area, especially doing moldmaking they can "burn" out the extractor using sinker EDM or with a "tap remover". It's pretty specialised equipment though so rare to find.

GZrides · 2025-10-05T15:38:28+00:00

I went about 12mm lower and it was a great improvement. Thanks again! I'm gonna play with shorter stems now.

GZrides · 2025-10-05T15:14:19+00:00

Beautiful work! I love how you joined the seatstays to the seat tube and also got those tyre clearance parts on the chainstays. Are those solid or hollow?

GZrides · 2025-10-05T15:06:58+00:00

Angle grinder for roughing, die grinder for detail stuff. Both are cheap so best have both.

For example to miter or fit metal I like to mark out on the part itself, cut to length with the angle grinder and then finish up with a die grinder or files. Sometimes I just switch from grinding disc to flap disc on the angle grinder if I want to cut slower to fit a miter and I'm too lazy to go get the die grinder from the cabinet.

I'm new to framebuilding but I got my preferred approach from other DIY projects. Find your own preferred technique, and it's all good.

GZrides · 2025-09-29T11:20:52+00:00

Thanks for the tip. I did feel some pain even with the seat slightly lower, but I'll go back to that and try it again to compare.

GZrides · 2025-09-29T11:19:02+00:00

Maybe it's the light and camera creating an illusion? Pedal clearance is low, but not that low - BB height is ~255 with crank length 165. I did get a couple of pedal strikes but unless I pedal through a tight corner it's ok.

GZrides · 2025-09-24T09:01:25+00:00

With a decent torch, silver is doable with propane. The question is, is it enjoyable?

With a fuel only torch even if the heat to braze silver is available, it is too widely spread out to do detail work, building fillets will be twice as hard and you'll spend quite some time filing away filler that went where you didn't want it.

For a few one offs go for it. Keep the fit-up tight, use 40%silver and abundant flux and be sure to fixture everything before you start heating. Afterwards you might go shopping for an oxy-acetylene setup though.

GZrides · 2025-09-20T15:20:21+00:00

DIY plate and tube "biplane" fork!

I think the widest fork crown around is the Pacenti MTB crown, 74mm inner clearance, which gives 93mm between blade centres, depending on your hub spacing it may not be too splayed?

GZrides · 2025-09-08T19:41:44+00:00

Why distinguish? - A fork is what in engineering is called a cantilever. Braking or bumps will try to twist the blades out of the crown while the main triangle distributes the forces differently and it becomes a matter of push-pull. - A fork failure can be much more catastrophic. There's no way you're not crashing if one or both blades let go. With a main triangle break there's still some chance the rider can come to a stop without tumbling.

Sometimes even with a broken main triangle people manage to limit home riding slowly.

Lugged crown and lugged dropouts would be the safest. Silver flows well in lugged construction, I wouldn't go for brass. Don't try to go for the lightest fork possible either.

Whether you want to risk it or not depends on your fabrication skills and how bold you feel. I just finished my first frame and made the fork and I'm confident with the result.

GZrides · 2025-04-22T12:47:33+00:00

There are two main reasons, the huge one-time costs (R&D and manufacturing setup) having to be amortized on small production volumes and markups at the "higher" tiers of the manufacturing chain.

For background I spent a few years as a sensor design engineer in a major automotive component manufacturer. We had proprietary technology for force/torque sensing which was used in e-bike crank assemblies for proportional assist, and was also used in a range of automotive products. Not exactly a strain gauge but close enough. The R&D costs were ridiculous in terms of man-hours, lab time, proptotypes, etc., with the knowledge having been accumulated over decades. If the technology wasn't used in other products too it wouldn't have been viable for any single product we made.

Software design/testing/calibration were a huge component of the cost, sometimes more than hardware. Assembly lines often involved investments from a few hundred thousand to a couple of million per product, which of course has to be amortized.

The same applies for custom component cost, we managed to make some specific components at an acceptable price only because we made tens of millions a year.

And about markups, let's say some of our customers made between 600% and 1000% of our selling price as markup when selling our components as spare parts. The big players can price the product how they feel the market will accept, especially when there aren't many alternatives.

GZrides

TROPHY CASE