Custom Titanium Options

[Jeff N.]

It always puzzles me how some custom Ti frame builders are limited with certain options. For example, some frame builders only offer 27.2 or 30.9 seat post sizes (Caletti, Firefly, No 22, Moots) while others offer 31.6 (Mosaic, Holland, et.al.). Same thing with internal rear brake cable routing. Seems to me that all these high-end builders could/should offer these and all options. What's the limiting factor? Thoughts?

[tuscanyswe]

If i recall correctly..

I was told by an upscale brand that 31.6 diameter tubing were not done in a large enough scale to a good enough quality so the they did not think it was a good option for use in seatposts.

Bs or not. I dunno .)

[eddief]

more inventory = more dead money.

Maybe the 80/20 rule applies?

[Ken Robb]

How much experience is required for a builder to become really skilled with a type/size material and/or technique? Some custom builders may want to stick with the things they have mastered and they may not feel that offering buyers more options won't improve the final product.

SOME (not all) builders may feel that offering many options is part of the mystique that leads people to order custom frames even if the builder knows some of the options won't improve the final product. Surely some very good builders tell customers something like "just tell me how you want the bike to perform and leave the design details to me."

[sandyrs]

I see no reason a builder who has plenty of business should feel compelled to offer options they don't consider worthwhile, either for the rider or for themselves.

[Black Dog]

Originally Posted by tuscanyswe

If i recall correctly..

I was told by an upscale brand that 31.6 diameter tubing were not done in a large enough scale to a good enough quality so the they did not think it was a good option for use in seatposts.

Bs or not. I dunno .)

Hmmmm... Litespeed does 31.6 in Ti. The OD is standard 34.9.

[tv_vt]

Don't know. Could also tie into their build philosophy.

I know Eriksen only does 27.2 ID seat tubes, or almost 'only'. Certainly doesn't hurt the ride at all.

Ti is for sure harder to work with than steel.

[zank]

Sizing the ID of a seat tube for a seat post is generally done in one of two ways. One way is to glue a composite shim and the other way is to weld in a thicker extension. Generally speaking with 34.9 mm seat tubes, the shim works well with 27.2 (nice because just about every post comes in 27.2) and the weld in works well with 31.6 (nice because you don't need to weld in a thicker extension to reduce to 27.2). Note that there are exceptions.

Not all builders want to add more heat to a tube than what is necessary and some builders feel very strongly about not wanting to pierce a tube. Any weld invites contamination and there is risk involved with expensive material. It's similar to the topic that pops up often about weld-in vs riv nut bottle mounts.

Each builder/company has their own philosophy and comfort level. Having observed and been a part of this niche for a long time, I can say that a lot of marketing speak has been written because a company doesn't want to do something. This is especially true about titanium.

[David Kirk]

So....is the idea that all builders should offer the same options?

dave

[Pegoready]

What bike are you planning next?

[Mark McM]

From a rider/owner perspective, what are the practical implications of 27.2mm vs. 30.9mm vs. 31.6mm seat post diameters?

[tommyrod74]

Originally Posted by Mark McM

From a rider/owner perspective, what are the practical implications of 27.2mm vs. 30.9mm vs. 31.6mm seat post diameters?

27.2 allows for more seatpost flex (especially given a lot of exposed seatpost and/or setback) and therefore more seated comfort. Maybe better for smaller/lighter riders.

Larger diameters allow for a stiffer seat tube and theoretically a stiffer frame - bigger interface with BB shell, top tube, etc. Maybe a plus for larger/more powerful riders. Also - easier to find dropper posts in 31.6.

Of course, there are other ways to build in stiffness or compliance.

[Clean39T]

Originally Posted by David Kirk

So....is the idea that all builders should offer the same options?



dave

Curious if you see any reason to do anything other than a 27.2? Is it just about being able to connect an OS TT?

Any reason a framebuilder couldn’t/wouldn’t be able to shim an OS tube to fit 27.2 off the bat?

The only thing I find annoying about my Ellis is the 30.6 post it requires. I think I’ll be able to find a way to shim it so I have more post options, but it sure would be nice to just slide something off the shelf in there (other than a god-forsaken Thomson..). That’s picking a fleck of sand off a giant pearl though - and I’m sure that Dave had a reason.

To answer, no, I don’t think all should be uniform. Not that anyone else could do what you do anyway...but I like seeing builders have touches that make them unique. Variety is the spice of life...except when it comes to seatposts and threaded B.B.s that is

[Clean39T]

Originally Posted by tommyrod74

27.2 allows for more seatpost flex (especially given a lot of exposed seatpost and/or setback) and therefore more seated comfort. Maybe better for smaller/lighter riders.



Larger diameters allow for a stiffer seat tube and theoretically a stiffer frame - bigger interface with BB shell, top tube, etc. Maybe a plus for larger/more powerful riders. Also - easier to find dropper posts in 31.6.



Of course, there are other ways to build in stiffness or compliance.

When it comes to stiffness, it isn’t just about size - it’s how you use it... amiright???

[vqdriver]

Originally Posted by Clean39T

The only thing I find annoying about my Ellis is the 30.6 post it requires.

oy, that'd be annoying for sure.
my time uses a 29.2 for some unknown reason