Custom titanium frame questions...

Discuss light weight issues concerning road bikes & parts.
pdlpsher1
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by pdlpsher1

A custom builder won’t be able to duplicate the tubing on this Litespeed. They lack the specific tooling to create these complex shapes. Perhaps you already know it but the Vortex is built from welded 6/4 Ti sheets. These complex tube shapes can only be done from a sheet. The tubing is not butted but it’s probably very thin cause the tubes’ cross sections are so large. Your best option is probably look for a used Vortex. Lynskey also has some bikes made from welded 6/4 Ti sheets. They do look a bit industrial and perhaps way too stiff for anyone except a Clydesdale.


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by Weenie


pdlpsher1
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by pdlpsher1

Nixster wrote:A good challenge!
I don't like the weight although that's not the biggest deal. The front end is a little high and the steering a little slow, mainly because the cstays are around 10mm longer than I would like at 425mm.
Mainly it's a feeling that it's over built and not the most elegant engineering solution, although I still like it. Also despite having long stays the brake bridge restricts clearance so it won't take guards/ fenders with wider tyres.
I can deal with all those points and include a few other details by going custom.
I’m going to be in the minority camp to say this but there’s little benefit to a short chainstay. Short chainstay is an old school tradition and unfortunately too many old school traditions are still around. After riding my Ti bike with 425mm chainstays I cannot go back to my racing carbon bike. There’s no comparison. The racing bike has poor stability and a lack of confidence above 40mph. I descend faster on the Ti bike with the touring geometry because when I’m confident I can push the bike much closer to the limit. I highly suggest that you stick to 425mm.


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ebsilon
Posts: 133
Joined: Fri Aug 12, 2005 12:36 pm
Location: Denmark

by ebsilon

Berzin1 wrote:
Tue Jun 19, 2018 12:57 am
These are the photos of the frame that got me intrigued about a custom ti frame. It is a Litespeed Vortex, but I have no idea what year.

The tube shapes are what I like the most, except for the head tube. I think it would look better with an hourglass design, but that's just me.

Image

Image
Hello Berzin1 Image

It is a 2004 and 2005

Image

Ciaooooo

PS the best looking Ti fram ever!!!!
Speed of Lite

DJT21
Posts: 214
Joined: Sun Mar 27, 2011 7:35 pm

by DJT21

pdlpsher1 wrote:
Tue Jun 19, 2018 7:49 am
Nixster wrote:A good challenge!
I don't like the weight although that's not the biggest deal. The front end is a little high and the steering a little slow, mainly because the cstays are around 10mm longer than I would like at 425mm.
Mainly it's a feeling that it's over built and not the most elegant engineering solution, although I still like it. Also despite having long stays the brake bridge restricts clearance so it won't take guards/ fenders with wider tyres.
I can deal with all those points and include a few other details by going custom.
I’m going to be in the minority camp to say this but there’s little benefit to a short chainstay. Short chainstay is an old school tradition and unfortunately too many old school traditions are still around. After riding my Ti bike with 425mm chainstays I cannot go back to my racing carbon bike. There’s no comparison. The racing bike has poor stability and a lack of confidence above 40mph. I descend faster on the Ti bike with the touring geometry because when I’m confident I can push the bike much closer to the limit. I highly suggest that you stick to 425mm.


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It's unlikely that the feeling between the two bikes is JUST down to the chainstay length.

pdlpsher1
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by pdlpsher1

ebsilon wrote:
Tue Jun 19, 2018 8:58 am
PS the best looking Ti fram ever!!!!
Nice looking bike. Any idea on the weight of the bare frame? Just curious.

pdlpsher1
Posts: 1680
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

DJT21 wrote:
Tue Jun 19, 2018 9:37 pm
It's unlikely that the feeling between the two bikes is JUST down to the chainstay length.
You are correct. It's just that someone mentioned he wanted shorter chainstays and I wanted to emphasize not going that route. The benefits of longer chainstays are numerous, including but not limited to wider tire clearance, less cross-chaining, and easier wheel removal. And due to the ample tire clearance I asked my builder to not dimple the chainstays which is typically done on shorter chainstays. Undimpled chainstays are stronger and will cancel out the lost stiffness due to the longer chainstays.
Last edited by pdlpsher1 on Tue Jun 19, 2018 10:34 pm, edited 1 time in total.

RyanH
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by RyanH

pdlpsher1 wrote:
Tue Jun 19, 2018 7:49 am
I’m going to be in the minority camp to say this but there’s little benefit to a short chainstay. Short chainstay is an old school tradition and unfortunately too many old school traditions are still around. After riding my Ti bike with 425mm chainstays I cannot go back to my racing carbon bike. There’s no comparison. The racing bike has poor stability and a lack of confidence above 40mph. I descend faster on the Ti bike with the touring geometry because when I’m confident I can push the bike much closer to the limit. I highly suggest that you stick to 425mm.
I had 415mm CS on the Crumpton and on a tight twisty descent like Tuna Canyon I averaged 28mph on my Litespeed vs 25.5mph on the Crumpton. Tight turns at 20mph were a struggle. Also, if you look at most race oriented disc brake bikes today, they're now doing ~405mm CS length despite being below Shimano's recommendation. Considering that most disc brake bikes abided by the 415mm CS minimum in the beginning and then manufacturers recently started shortening, they must have determined there's a handling benefit to shorter CS that they couldn't get out of 415mm stays.

And yes, race bikes handle a tad twitchier and require a little more attention than touring bikes. There's nothing wrong with either. It just depends on what your expectations are and expected use case.

pdlpsher1
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by pdlpsher1

RyanH wrote:
Tue Jun 19, 2018 10:27 pm
I had 415mm CS on the Crumpton and on a tight twisty descent like Tuna Canyon I averaged 28mph on my Litespeed vs 25.5mph on the Crumpton. Tight turns at 20mph were a struggle. Also, if you look at most race oriented disc brake bikes today, they're now doing ~405mm CS length despite being below Shimano's recommendation. Considering that most disc brake bikes abided by the 415mm CS minimum in the beginning and then manufacturers recently started shortening, they must have determined there's a handling benefit to shorter CS that they couldn't get out of 415mm stays.

And yes, race bikes handle a tad twitchier and require a little more attention than touring bikes. There's nothing wrong with either. It just depends on what your expectations are and expected use case.
You are correct but I should point out the tradeoffs. A bike that is agile on slower speeds will lack stability and confidence at higher speeds, like above 30mph. My comment regarding handling was referring to high speed descents with sweeping turns. A lot of the canyon roads that I ride have 30mph corners, and for sure my 425mm is far superior at speeds above 30mph. Going 50mph on the new bike feels very stable, like a missle on autopilot. I get scared descending at 50mph on the old bike. So perhaps one needs to consider the type of roads that are anticipated.

Hexsense
Posts: 517
Joined: Wed Dec 30, 2015 12:41 am

by Hexsense

or probably just to make it weight less and being stiffer?

I don't know how much weight saving and stiffness gaining (and aero improvement?) can you gain from shrinking chainstay, but those specs (weight, stiffness and aero) can sell better to customer than factors like chain angle and rear end stability?

Another question: which bike will make a dip down hill 90 degree turn at 20mph easier?
longer chainstay for stability or shorter chainstay to make tight turn easier?
Or it doesn't really matter as front end geometry and angle far outweight the influence on the handling of the rear?

pdlpsher1
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by pdlpsher1

Hexsense wrote:
Tue Jun 19, 2018 10:46 pm
Or it doesn't really matter as front end geometry and angle far outweight the influence on the handling of the rear?
Good question. Perhaps a frame builder can comment. Most tourings geometries have both long chainstays and relaxed front handling. So it's hard to know what happens when you combine long chainstays with more aggressive front end geometries.

Nixster
Posts: 81
Joined: Wed Oct 04, 2017 3:30 pm

by Nixster

It was me on the 415 stays rather than the 425 of the Lynskey (or the 405 of the Supersix).
I'm sold on the longer stays just 425 is too long for me. Not many alpine descents round here so 415 is a middle ground.
I'd compare the Lynskey to a Cadillac. The Supersix is not twitchy but it is a sports car. What I want is a 911 :D
I want lighter, more agile, more refined in appearance and I suspect also a touch more compliant than the Lynskey's over sized tubes. It was intended as a winter bike and I think it will be great at that with fat tyres on.
The Supersix is a race bike and a great one which I am still not entirely reconciled to parting with but I have an itch to have something made which I have influenced and not just bought.
Have to say I am enjoying finding out about this stuff! OCD I know...
@ RyanH care to share the difference in tube sizes on your Litespeeds? :)

Nixster
Posts: 81
Joined: Wed Oct 04, 2017 3:30 pm

by Nixster

pdlpsher1 wrote:
Tue Jun 19, 2018 11:02 pm
Hexsense wrote:
Tue Jun 19, 2018 10:46 pm
Or it doesn't really matter as front end geometry and angle far outweight the influence on the handling of the rear?
Good question. Perhaps a frame builder can comment. Most tourings geometries have both long chainstays and relaxed front handling. So it's hard to know what happens when you combine long chainstays with more aggressive front end geometries.
Is it the case that both ends should reasonably agree?

RyanH
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by RyanH

Let me see if I have a minute tonight (and remember) to caliper them. They're all manipulated except the ST. I believe the TT and DT (maybe seat stays too) are bi-ovalized.

RyanH
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by RyanH

Regarding the front end and rear end relationship, I don't know definitively but the Crumpton was 59mm trail IIRC and the LS is 63mm. Based on that sample, I'd say that front end geo isn't enough to overcome rear end geo.

Also, wheels play a big role in perceived stability of bike at high speed. When I had the Mavic Cosmic Ultimates (2016 models) the bike felt like it was stabilising itself, it was weird. I did not notice a stability difference at 40+ mph between the Indy Fab, Crumpton and LS despite the LS having the edge on agility.

by Weenie


pdlpsher1
Posts: 1680
Joined: Thu Jul 19, 2012 6:09 pm
Location: CO

by pdlpsher1

415mm might be OK. My carbon bike has 405mm and I didn't like it. My builder's initial design has my Ti bike at 415mm. I requested him to increase it to 425mm because I wanted a smooth riding bike above everything else.

There's definitely a stigma on bike geometry. The opposite of tight handling is loose handling. The opposite of race handling is slow handling. Nobody wants a bike with loose and slow handling. So all marketing materials point to their bikes as having a tight and racy handling in order to sell more bikes. But what people often forget is that when it comes to bike design it's all about compromises. Each design has its pros and cons. The key is to find the right balance, not just buy what it sounds good from the marketing materials.

I should point out it's pointless to compare the trails between bikes from different makes. The trail is a function of the fork rake, the head angle, and the tire's outside circumferene. If you use a narrow tire the trail will decrease, and vice versa. My bike's trail is between 61mm to 63mm depending on what type of tire and rim I use. Since bike makers don't publish what tire circumference it used to calculate trail, it's not prudent to compare trails between different bikes made by different manufacturers. You can only compare different bikes within the same make.

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