Hi everyone,
Up until now, we've mostly kept our heads down in the factory making parts—rims, hubs, spokes, rim tape, and tubes. We spend our days running tests, fixing whatever breaks, and shipping orders, so we haven't really taken the time to write about the engineering side of what we do.
Lately though, reading through threads on here, we realized a lot of the questions you guys debate are the exact same things we argue about in the workshop—why a profile is shaped a certain way, what a spec sheet leaves out, or whether the changes between two frame generations actually make a difference on the road. Since we already have the calipers, test rigs, and piles of cut-up or broken samples lying around the shop, we figured it makes sense to start sharing what we find.
Starting today, we're going to post one in-depth technical write-up every Wednesday right here in this thread.
A few ground rules for these posts:
Every number comes with a source: Whether it's from a published geometry chart, a vendor spec sheet, or our own calipers on the bench, we'll tell you where it came from.
No guessing: If we're estimating or extrapolating something, we'll say so upfront.
We'll be honest about blind spots: There's plenty we can't measure or isolate in our shop, and we won't pretend otherwise.
No sales pitches: Some weeks we'll dissect other brands' frames or components; other weeks we'll look at the internals of our own wheels. Either way, we're keeping marketing out of it.
Where to find everything
Every Wednesday I'll post a summary and the key takeaways here. Because forum posts get clunky when there are too many tables and raw data charts, the full write-ups will also go up on our own forum, where it's easier to archive data and track corrections:
👉 https://forum.tagoola.cn/
Open for suggestions...
What should we talk about next?
If there's a specific topic, design trend, or technical question you want us to dig into, drop a reply below. If enough people are curious about the same thing, we'll bump it up the list. And if you think we got something wrong in our analysis or numbers, please call it out—hearing from riders who actually put miles on this stuff is a big reason we're doing this.
Smooth ride smooth vibe.
The SL9 geometry chart looks almost identical to the SL8's. So we put a tape on both frames to see what actually changed. Short version: the fit didn't change, the carbon did.
1. Geometry: one size changed, and the steering didn't.
Six of the seven sizes match the SL8 to the mm. On the 54, the head angle went 73° → 72.5° and fork offset went 44 → 47 mm. Those two cancel out: trail stays at ~58 mm, and the front wheel sits ~3 mm further forward. If your SL8 fit is dialled, the same size SL9 carries over.
2. The fork is the biggest change.
The SL9 fork legs are bigger at every point we measured, up to +17% near the crown.
3. Material moved to where the loads are.
The top tube is now front-heavy (+9% at the head tube, −10% at the seat tube), and the lower head tube junction lost 17.5%.
What we couldn't measure: wall thickness, stiffness, and anything aero. It's also one frame of each, and our SL9 is a 52 against a 54 SL8, so read the trends, not the decimals.
The full write-up has all 5 charts, the measurement tables, and the SL9 vs Seka Spear sizing comparison: https://forum.tagoola.cn/d/6-same-geometry-different-bike-how-to-read-a-frame-update
How is the frameset you introduced about a month ago coming along... what stage is the development at?
Any photos available yet?