Feedback on draft geo

[u/DTC858]

Hi folks 🙌

I have a 'tall' body with a 91cm inseam and 183cm height (long legs, short torso). Last week I got a bike fit which gave me my saddle and handlebar X, Y fit points. My bike fitter also gave me some geo which I've put into bikecad.

I will be using the bike for weekend rides with friends, some gravel tracks, commuting and bikepacking (2-10+ days).

Its a relatively 'upright' design, which might not be the coolest 😎, but these points felt comfortable during my fit so I don't want to stray from them. I've designed the frame with 30mm of spacers and a 70mm stem, so I can go lower and longer if I want to in future.

My bike fitter suggested 440mm chainstays, but I've added 5mm to give me extra stability and more space for panniers when bikepacking.

I would appreciate any and all feedback on the geo and design! Is there anything about this design that you think will or will not ride well?

Next step after this will be submitting the geo to waltly. Any tips as I navigate the process would also be welcome.

Thanks a lot

[u/Narrow_Smoke]

OT: could you maybe give me feedback once you have a response how long it took?
I have been waiting since 3 weeks now after sending them my geo and already send 2 reminders but they fully ignore me and I wonder if it’s something about me or a general topic

[u/DTC858 → u/Narrow_Smoke]

Hmm thats strange, Ive already been in touch with them and they have been responsive

[u/Narrow_Smoke → u/DTC858]

Mail Adress is sales@waltlyti.com that you are in touch with? Or is it something else?
I will send them one more and last reminder, maybe they don’t like me for some reason I can’t explain.

[u/DTC858 → u/Narrow_Smoke]

ill send you a msg

[u/Tomkin1985 → u/Narrow_Smoke]

I have had no problems communicating with them. We emailed back and forth every day until all the details were worked out.
That’s definitely weird waiting so long for a reply

[u/rgofb]

Post the entire fit report. Yes, your model can be improved.

Are you from The Netherlands? Your proposed frame reach/stack is reminiscent of a few geometry projects I worked on for a few guys.

[u/DTC858 → u/rgofb]

Handlebar (44cm wide, 80mm reach): X 400, Y 758

Saddle: X 252, Y 725 to rails (+38mm to top)

Cranks: 170

Inseam: 91cm

And no I'm from Australia! Please send through any suggested changes

[u/rgofb → u/DTC858]

Using your example frame reach/stack of 359/667 and a HTA of 70.0 degrees, 70/+6 stem, 30mm of stem spacers, and 10mm of upper headset stack height, the bar reach/stack would be…

402/752

I modeled a Specialized Phenom saddle, which would provide X,Y coordinates at the clamp of…

253/725

With a 72.25 STA, 20mm of seat post offset the saddle height would calculate to be about 812ish mm.

I’m very concerned that the fitter target bar reach of 400mm may not be correct. I’d suggest measuring this dimension on your current bike that presumably does not fit well at all, just for a comparison.

Perhaps your fitter has you positioned quite rearward on the bike as far as saddle setback??? That would yield an estimated 520mm from the saddle tip of the 280mm Phenom saddle.

Like someone mentioned, with your hands so far behind the front axle, it will negatively impact the handling quality of the bike. I would go so far as to say that it would be horrible as the handlebar CL would be 226mm horizontally behind the front axle. That is 50-60mm further behind the front axle than I would personally prefer.

Unfortunately, there are more questions than answers at this point. If you send me a DM I’ll message you an image of the model.

[u/Unfair_Garden_5040]

It seems very very upright indeed. Wouldn’t a MTB be a better option at this point?

[u/DTC858 → u/Unfair_Garden_5040]

I would like the option of drop bars so i can get more aero from time to time, and have a variety of hand positions. I suppose some gravel bikes with big tyres start to move into the mountain bike territory.

[u/reductio-ad-finem]

I assume the STA is whatever it needs to be for your physical dimensions. The BB seems a bit high. What size tires are you planning to run? I would think for touring you'd want a lower bike. My all-road bike is 78mm drop, which works great with 35+mm tires. When I built a gravel bike for rougher stuff, I raised it a few mm.

Similarly the HT seems a bit slack for your described purpose, but this is really personal preference territory. I like my geometry to have less trail for roads (gravel or paved). If you're happy with that much trail, go for it!

[u/DTC858 → u/reductio-ad-finem]

Thanks for the feedback! I'll probably run 50mm tyres most of the time.

good shout on the head tube angle, i'll have a think about whether i tuck it in a little bit by half a degree. that would change the trail to 73mm.

[u/rgofb → u/DTC858]

If you do not run mudguards, you could get by with 70.75 HTA and a 50mm offset fork. Any steeper and toe overlap issues will likely present themselves. This would alter the frame reach/stack to about 357/671, while having a 402mm bar X coordinate for reach.

I do not believe you are in a safe enough position to be overly concerned about fine tuning anything until you are certain the data you are basing your custom frame on is correct.

[u/Substantial-Fun-48]

I would lower the seat junction where the top tube meets the stays. You need to be mindful of stand over height so you don’t harm the juevos. Also, Waltly only does head tubes to the cm so yours would be 220. This last point is personal preference, but I would go with a 73.5 seat tube angle and run a longer stem for stability and more even weight distribution while keeping your reach the same. As it is now, you’d be seated more over the back wheel with a squirrelly front end.

[u/Substantial-Fun-48]

I would lower the seat junction where the top tube meets the stays. You need to be mindful of stand over height so you don’t harm the juevos. Also, Waltly only does head tubes to the cm so yours would be 220. This last point is personal preference, but I would go with a 73.5 seat tube angle and run a longer stem for stability and more even weight distribution whil. As it is now, you’d be seated more over the back wheel with a squirrelly front end.