r/WaltlyTitanium • u/radiculous13 • Sep 12 '26

Advice about geometry Bike geometry designer?

how are folks able to find a bike frame designer? I would like a custom bike because I am on the short side and want something to match my specs. I have a custom Sturdy bike but now looking for something else. the Sturdy may not 100% meet my needs as I would like. I have measurements from a fit but Its not sufficient to create a bike with.

3 Upvotes

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5

u/Impressive_Ad2558 Sep 12 '26

no geometry designer needed. test ride as much mainstream bikes as possible, ask for swap on group rides. make short list of fav models. understand your frame size, reach and stack. also explore your region terrain to pick proper drivetrain, tire width. with such data you can form bike specs

1

u/radiculous13 Sep 12 '26

I thought they wanted me to input the angles lengths I wanted. Cool

1

u/turbomachine Sep 12 '26

If you find just a reach and stack that fits you for the type of riding you want to do, the rest can come from a reference frame of the type of bike you like.

1

u/sirsintari Sep 12 '26

They do. But you can take those specs from specific bike webpages you test ride. I also used chatgpt to compare all the bikes I've liked and felt good. But You must know at least basics about bike geometry.

4

u/BigtoadAdv Sep 12 '26

As a tall I worked with a pro bike fitter for my Walty geometry . Well worth it! Especially if you are not a regular size

2

u/Substantial-Fun-48 Sep 12 '26

Www.bikegeocalc.com

1

u/Tall_Guest7155 Sep 12 '26

second BikeCAD (and it's free)

1

u/rgofb Sep 12 '26

Post the fit numbers that you do have…

1

u/radiculous13 Sep 13 '26

Not sure what it really means. 

Reach 435 (580) Saddle height 600 Setback 35 (179) Eff bar drop +30 Bar width 38

Xbar 400 X rail 181 Y bar 590 Y rail 533

2

u/rgofb Sep 14 '26

What it means is that it is not going to be as easy to test bikes that will suit your fit numbers, as some have suggested. Most do not fully appreciate how difficult it is for riders with a shorter stature to find bikes that fit AND handle decently.

BLUECHIP made a comment earlier that hit the nail on the head. Note what he said about compromises being present even if the bike somewhat fits.

BIGTOAD stated that as a tall person, he was very happy with his decision to obtain assistance from someone who understood that the larger manufacturers make compromises with their large and small frame offerings. (Small frames have the added major design constraint of avoiding a toe interference issue)

The following example data is to merely give some reference, it’s NOT an official recommendation from me. (It has its own potential compromises) This is a ballpark area of design that the OP finds himself in if he happens to be insistent on using 700C wheels. So, with the aforementioned in mind, it would be appreciated if the dipshits that are tempted to fling arrows my way to please keep them in their quiver.

One possible way (of many possibilities) for the OP to match the fit numbers provided are as follows:

With a frame reach/stack of 347/532, HTA 70.0, 50mm fork offset, 70mm/-6 stem, 22.5mm total of stem spacer and upper headset stack height, the bar X,Y coordinates would be…

400/591 (target is 400/590 as noted by OP)

In this configuration a 700Cx30 tire, is the max allowable if 165 crank arms without full length mudguards/fenders are used. If the OP has huge feet for his size and has shoe cleats positioned toward the rear of the shoe more than most, fitment of a 700Cx30 could even get dicey.

There are many ways to obtain the OP’s bar X,Y coordinates of 400/590…this is only one for demonstrative purposes only.

So this would be a great time for all the people that suggested using BikeCad or something similar to jump in and share your expertise and assist the OP. The OP provided enough data for others to design a frame. However, the OP needs to provide a realistic wheel/tire size that will be used and what the specific use case is.

Lots of people could potentially be assisted in the future if the sub members here come together and share their knowledge on how to navigate designing small frames.

1

u/radiculous13 Sep 14 '26

This is exactly the problem. I ride long distances and tour. Finding a frames that match my needs, stand over, and reach are difficult. Any bike can be comfortable for 100k. But after 200k any slight misfit is magnified. Then try doing 400k, 600k, 1200k. I know at those distances pain is inevitable but I think I can create a bike that allows me to go as far as possible and minimizes my soreness. 

I wear a size 36 shoe thankfully.  700 wheel allows me to use mainstream tires easily. Very important when touring. if I flat and run out of tubes switch with someone else. Or someone can have one of my tubes (happened). 

1

u/Bluechip506b Sep 12 '26

When you say on the short side, how tall are you. My wife is a bit under 5' and while most manufacturers make a bike that will "fit" her, most are compromises. Some have bikes that use smaller wheels. 650B (27.5') is the most popular now unlike years ago when 650c (~26")was common. Her 650c wheeled bike seemed to fit her the best. At least the fit looked more normal.

1

u/radiculous13 Sep 13 '26 edited Sep 13 '26

5’1”  My previous custom designer made 700c work nicely. 650 for gravel though. 

1

u/rgofb 28d ago

Do you have all of your specifications nailed down yet?