Is anyone aware of any frame designers that would assist with a custom design?

[Flying Trunk Monkey]

It seems the Chinese titanium build houses are pretty decent at building what you ask for. But what do you do if you don't know what you want? There are a few European outfits that specialize in the design work and then contract the manufacturing to the Chinese to build their custom designs. The issue with using them is that someone like Spanner Bikes wants the equivalent of $2200 USD plus whatever the shipping charges would be from the UK. Other outfits can do the same thing for significantly less so it seems that there is some money to be saved by dealing directly with the manufacturers.


I'm in a unique position of having engineering drawings for a custom design but I'd like to change some of the details on the front triangle (fork A-C and stem length mostly) and still maintain the same fit. Even on a a well planned Chiner budget a custom frame is still a big purchase for someone like me. I'm willing to pay some to make sure the fit is as good as possible but I'd also refer not to double the price of the frame just to get some experienced input.

Thoughts?

[gravity]

If you know your fit i.e. your preferred geo with stack, reach, STA, HTA, etc - your frame manufacturer can draw the frame for you. You can change and adjust until you approve the drawings. You’d be surprised the drawings is much more detailed than you can see from US or european builders.

[Flying Trunk Monkey]

"...your frame manufacturer can draw the frame for you. You can change and adjust until you approve the drawings. You’d be surprised the drawings is much more detailed than you can see from US or European builders."

The drawing I have is actually quite detailed, it obviously came from one of the build houses. Will the build house actually tweak an existing design as you stated?

Is there a way to tell what company might've done a particular design? I'm fairly certain it didn't come from Waltly/Xiamen but that's bout all I know.

The drawing I have is on the level of this (example only):

[ottoreni]

The drawing you posted looks like the drawings I have gotten from Chinese frame makers. 

They will customize the geometry to your liking.  I am fairly certain what I want, but on my last few frames, I have always gone thru at least three drawings. 

[Flying Trunk Monkey]

They will customize the geometry to your liking.  I am fairly certain what I want, but on my last few frames, I have always gone thru at least three drawings. 

That is very encouraging. The current design I have has the correct fit but... I've decided on a fork with a longer A-C and I'd like to shorten the planned stem from 90 to 35mm. Do you think it might be as easy as stating that this frame was designed to provide a fit with X spec components but I'd prefer to maintain the same final fit with Y components?  There are other significant design changes to the printed design I have but I already have pictures of examples of those changes that have been implemented in other finished design so I wouldn't think that they would cause an issue.

It sounds like you have been through the process at least a few times. Who all have you dealt with? Were you satisfied with your experience? Who would you recommend going with currently?

[bxcc]

I have two Waltly frames.

I ordered a gravel frame in 2021 and it's been perfect with only one minor complaint and it was self induced. If I was to order another one, I'd add 15mm to the head tube height. But that's on me for not knowing exactly what I was looking for as this was my first drop bar bike.

In 2020, I ordered a hardtail mountain bike frame to run as a single speed. This one is having an ongoing issue that's about to get the frame thrown in the dumpster. When I went through the details with Amy, I asked for a 31.6 seatpost. Most seat tubes are bit oversized to allow the post to fit correctly. Generally, .1mm or less. On the drawing, they had it listed as a 31.75mm bore. I asked if it could be 31.65mm and I was assured that this is how they do all of their 31.6mm frames. I've tried multiple seatposts with and without beer can shims and I still can't get rid of the creaking. Any change I make to clamp torque or seat height will help but it's only temporary. By the time I get done a 2 hour ride, it's back and extremely annoying. Now circling back to my gravel frame, I ordered it with a 30.9 post and it's been silent. No bore was listed on the drawing but the post is not nearly as sloppy as it is in my single speed frame.

[Flying Trunk Monkey]

This one is having an ongoing issue that's about to get the frame thrown in the dumpster. When I went through the details with Amy, I asked for a 31.6 seatpost. Most seat tubes are bit oversized to allow the post to fit correctly. Generally, .1mm or less. On the drawing, they had it listed as a 31.75mm bore. I asked if it could be 31.65mm and I was assured that this is how they do all of their 31.6mm frames. I've tried multiple seatposts with and without beer can shims and I still can't get rid of the creaking.

Thanks for sharing, I had a look at my current design and can see exactly what you are talking about unfortunately. I vaguely recall reading about the same issue while Googling a while back. Seems to be a known issue. I wonder why they are still spec'ing them this way. My understanding is that the most seat tubes are reamed to final finished ID so this shouldn't be an issue if limitations on manufactured stock dimensions.

From your experience I think it might be worth demanding that the manufactured spec in 31.7. The difference between 31.70 and 31.75 is only .002" and that isn't much at all.

If you can in fact use a beer can as a shim with a 31.6 post I wouldn't be surprised if your actual tube is a fair amount greater than 31.75.

[bxcc]

Ideally, I'd like to see 31.65mm for the bore. I'll have to take some actual measurements to confirm.

A beer can shim fits about when wrapped about 330 degrees around the BikeYoke dropper post. When I tried the bontrager fixed post, I had to trim the shim to only wrap about 180 degrees around the post before it would fit. So the BikeYoke post is definitely a bit smaller than others which doesn't help. Either way, all 3 posts that I've tried will fall into the hole with just gravity.

Keep us posted on what they do for you. I'm debating about getting another one built and might just stick with 30.9.

[Icyseanfitz]

Have you tried running a 31.6 to 30.9 plastic shim (AliExpress) and run a 30.9 dropper, might get rid of it and save the frame.

[bxcc]

Have you tried running a 31.6 to 30.9 plastic shim (AliExpress) and run a 30.9 dropper, might get rid of it and save the frame.

I haven't. But a plastic shim just might work. I'll definitely give that a try before giving up. Thanks.

[em_reeze]

I have a Waltly ti frame with a 31.6 mm seat post that is also bored at 31.75 mm. It creaks really bad as well. I wish I had ordered a 30.9 mm seat post not but I wanted to run a 31.6 mm dropper on this frame. Keep us updated if you find anything that stops the creaking.

[tripleDot]

One of my Waltly Ti is also 31.6mm seatpost with a 31.75mm bore. I have a Tito titanium seatpost on it with no problem. I also have a Waltly Ti with 27.2mm seatpost with 27.35mm bore, and the CarbonSpeed cf seatpost fits with no problem. And just recently received my 3rd Waltly Ti frame. Haven't built it yet but the KS 27.2mm dropper post fits pretty snug in the 27.35mm bore. I will update when it's built. I still have some parts & components in transit.

@Flying Trunk Monkey, I can only speak for Amy of Waltly. I've only dealt with her, twice at that. I'm very satisfied with her service, got to say she's probably the most patient person I've transact with. She also seems to have ample knowledge with bike parts. I remember after I gave her the list of geometry figures, she asked me if I want them to adjust the head tube length in case I am considering a Chris King Inset 7 headset. I believe that is related to your X spec component & Y fit component. You'll just have to be specific, and she'll ask you if she didn't understand.