u/ridwanakf

I understand that tax or deduction situations are tricky and don't have one formula to rule them all.

But is there like a rule of thumb way to estimate what will be your THP from the listed salary (which I assume will be gross salary)?

Hi! I'm doing a custom Ti build and trying to settle one thing in my head: tube butting and profiling.

In steel it seems standard on nice frames (Ritchey Logic, Fairlight triple-butted, etc.), and from what I gather it's not just about weight. Thinner middles, thicker ends, supposedly a livelier/springier ride.

Does the same hold for titanium? Ti runs different diameters and a different modulus, so I'm not sure the steel logic carries over.

A few questions for people who've actually ridden it:

1. Butted vs straight-gauge Ti, similar geometry -- could you actually feel a difference, or is it spec-sheet only?
2. If you paid the butting upcharge, was it worth it or would you spend it elsewhere?
3. Does ovalizing or changing tube diameters noticeably change how a Ti frame rides?

For context: relaxed endurance/light touring, ~70kg, comfort over weight. Trying to figure out if this is a real decision or a rabbit hole I'm overthinking.

First-hand experience appreciated, especially from anyone who's owned a few Ti frames. Thanks in advance!

Hey all,

I've put a deposit down with Waltly for a custom titanium gravel frameset and just received the first design drawing. I'd love a sanity check from people who actually know frame design — I'm a rider, not a designer, so I want to make sure I haven't missed anything obvious or asked for something dumb.

My starting point was the Curve GXR4 "Kevin," size SM — I gave Waltly (Amy) that geometry as the base to replicate. I picked it specifically because its geometry is built around relaxed, long-distance endurance riding, touring, and bikepacking, which is exactly what I want this bike for: an all-rounder for 100 km+ audax-style rides, light touring, and general daily riding. I love long adventure rides but I'm not a racer — I'd rather take it slow, and my #1 priority is relaxed geometry. After a lot of research this frame kept coming up as a great fit for that brief.

Since the whole thing is custom anyway, though, it feels like a missed opportunity to just clone it 1:1. The GXR4 is a proven design so I don't want to reinvent the wheel — I'm more interested in whether there are specific, sensible refinements worth making for my body and use case. Unfortunately I haven't had a professional bike fit, so I'm working with what I can measure myself. For reference: height 172cm, cycling inseam 80cm. But if it's too much guesswork, then please feel free to focus on the frame building side of things only

Here's everything I asked Amy for and what they confirmed:

Frame

• Custom Ti gravel frameset, GXR4 (Kevin) SM geometry as the base, 3AL/2.5V titanium
• 42/52mm tapered head tube
• 700C × 50mm tire clearance
• T47 85.5mm bottom bracket
• UDH rear dropout
• 31.8mm seat clamp, 27.2mm seatpost
• Flat mount brakes (160/180mm)
• External cable routing
• Custom yoke on the chainstay
• Rack + fender mounts, top tube mounts, 5× M5 mounts under the down tube (for cable guides)

Build-specific changes I requested

• Running a 1x wireless groupset (starting with the new wireless GRX Di2 RX717, later upgrading to SRAM Rival XPLR), so:
  • Remove the drive-side chainstay cable guide (keeping the non-drive side for the brake hose)
  • Remove any front derailleur mounts/ports
  • No dropper post — remove any dropper-related ports (running a rigid 27.2mm post)
• Carbon fork (semi-internal routing — brake hose enters the fork leg externally, not through the headset)

What I've found so far comparing the drawing to the original Kevin (things I'm planning to raise with Waltly, but want a second opinion on first):

• There seem to be two M5 mounts on the seat stay near the UDH in the drawing. What scenario would actually need two mounts there? The original Kevin only uses one M5 mount in that spot, so I'm not sure why the drawing has two.
• On the original Kevin the seat stays look more shaped/curved (I don't know what this type is called), whereas the drawing has them straight. Would it be possible to match the original's curved seat stays, and are there any downsides to making them curved rather than straight (ride feel, strength, cost)?
• Could the top tube be ovalized? Are there any disadvantages to doing that?

Questions:

1. Given my use case (100 km+ endurance, light touring, daily riding) and my note about shoulder fatigue / preferring a less aggressive position, what — if anything — would you change from the stock GXR4 SM geometry? I've wondered about a slightly taller stack / more relaxed front end for long-day comfort, chainstay length for loaded stability, BB drop, etc. Or is the GXR4 already dialled enough that I should leave it alone?
2. Anything I'm forgetting to remove/add given the 1x wireless + rigid post setup? (Did I correctly kill all the FD/dropper provisions?)
3. Anything else I miss?

For reference, here's the original Curve GXR4: https://www.curvecycling.com/products/gxr-aka-kevin-frameset

Thank you in advance!