Opinion on TT/Tri frame design

Hi People,

We do this alot with our wheels and frames for road but have never truly done it with our triathlon/ Tri frames. Here is a prototype drawing for our new TT/ Tri frame. The Prototype will first be done in titanium (hence the ovalised tubes). If all goes well, we will start production of these frames in aluminium. The jury is still out whether we go full Tri or a sort of road/ Tri hybrid (ala soloist)… yes yes I know this is a triathlon forum. The seatpost is reversible and can be used 73deg/ 78deg so it should be possible.
As always opinions will vary, but that’s the fun of a forum, hopefully we can keep it as civilised and on topic as possible. If the picture is unclear:

  1. BB30
  2. Internal routed cables on DT
  3. Rear brake at BB

http://www.bikesoul.com/gallery/albums/Misc/Fenix_2011.jpg

Let me know what you think.

Does titanium feel different than carbon. Softer, stiffer. Make one with a taller head tube. That would be nice

Cheers Rick

Hey Sean,

Toptube entry of cables? Is that possible? I’m guessing it’ll be hard…

What’s the clearance for wheels, especially the rear wheel? Can use one of the wider rims (esp the Zipp 404 firecrest rims)?

I’m more curious as what the current status is of your (off the shelf) carbon frame. When will it be avail, and at what cost?

http://www.bikesoul.com/gallery/albums/Misc/Soul_TTC_silver.jpg

I like the look of the frame adn think it is going to be a nice addition to the already growing frames. I think that a 2 cm. headtube gap on the frame would give it more versatility, especially with the low bar setups that alot of companies are now producing. Measuring the stack and reach and keeping it more along the lines of a Tri setup rather than a TT setup. This could also be done by lowering the B.B. drop to a 8 cm. drop, which for triathletes is generally not a bad thing because it does help with aerodynamics and also brings up the headtube in general. It will make it easier for an athlete to get there leg over the toptube in transition as well. Pedal scrape is usually not a problem because of the nature of a TT and or a Tri where there are generally not huge packs and taking an apex of a turn is generally a long sweeping process. Triathletes are generally; not all, going to a much shorter crank to get the overturn easier and to “bring up” their cadence. Also, a replacable dropout setup would be nice, due to all the packing and shipping and then reassembling of bikes travelling to IM races. It never is fun to tell an athlete that the race they have trained and awaited all year is now not doable on their current frame because of a dropout issue. Dropouts get beat up by triathletes from putting them in certain trainers (Cervelos and I think Kurt Kinetic which rub on the top of the der.). Also I know that it may be more of a logistical nightmare to have it produced in carbon, but feel like it would be lighter and have a better sell value. With all of the welds and the shaping of the aluminum would probably lead to a frame around I guess four plus or minus pounds. Also the tooling and hydroforming of the tubes not to forget the number of welds going into the frame especially on the downtube add up and also the seat stay life with the quick turn to flare them out to meet the 130 mm. spec may prove to be a weak spot in the aluminum configuration. It is possible to take it to a welder such as Russ Denny who welds and fabricates other aluminum manufacturers frames is great, will still have certain limitations with ensuring non- frame failures either due to fatigue or complexity of welds overlapping here and their. The internal cable routing would also be much easier to have done in the carbon counterpart with the running through the frame in an easier manner and less flex on the housing itself. I do not know why someone also has not redesigned a fork and hub combination to incorporate an internal cable to a smaller drum hub which would clean up the front end and also get rid of the front brake being an issue either due to aero, and or getting sticky from gu s and or from sweat coming down and clogging up the bushins of the front brake. I also know that there are a thousand and one different ways to implement things so take what I think lightly, someone may have a better way of achieving certain things here or there. Feel free to contact back and let me know what you think. We could also talk over the phone if you like.

Does titanium feel different than carbon. Softer, stiffer. Make one with a taller head tube. That would be nice

Cheers Rick

Hi Rick,

Many many threads on this topic alone. I’m a little biased as all my own bikes are titanium. RE Headtube heights, well, you can go higher but not lower, so a lower HT is always more flexible.

Hey Sean,

Toptube entry of cables? Is that possible? I’m guessing it’ll be hard…

What’s the clearance for wheels, especially the rear wheel? Can use one of the wider rims (esp the Zipp 404 firecrest rims)?

It makes things too difficult to get cable entry on the TT especially for ti and alloy frames. The DT becomes a complication of different shapes and the routing isn’t clean. More than ample clearance for wheels at the moment.

i’m kind of more curious as what the current status is of your (off the shelf) carbon frame. when will it be avail., and at what cost?

Well, that thread kinda came and went and didn’t have much interest in there. We have eventually ordered some frames and will probably sell them at RRP of around USD1000.

Any photos of the actual frame? Post those and I think you will see quite a bit more interest. So if someone in the usa wanted to order one of the carbon frame/fork with your color scheme, how could we see a pic, see the specs, see the sizes, see the geometry, get more detailed info, etc.? Also, since it is ‘off the shelf’, may I ask which manufacturer produces it?

I like the look of the frame adn think it is going to be a nice addition to the already growing frames. I think that a 2 cm. headtube gap on the frame would give it more versatility, especially with the low bar setups that alot of companies are now producing. Measuring the stack and reach and keeping it more along the lines of a Tri setup rather than a TT setup. This could also be done by lowering the B.B. drop to a 8 cm. drop, which for triathletes is generally not a bad thing because it does help with aerodynamics and also brings up the headtube in general. It will make it easier for an athlete to get there leg over the toptube in transition as well. Pedal scrape is usually not a problem because of the nature of a TT and or a Tri where there are generally not huge packs and taking an apex of a turn is generally a long sweeping process. Triathletes are generally; not all, going to a much shorter crank to get the overturn easier and to “bring up” their cadence.

Well, right now the geometry has not been firmed up. As stated at the beginning, this may well just end up being a road/ TT frame as the majority of the market is in the road segment for us. It will still make a very affordable Tri bike but I’m not sure there is such a need.

Also, a replacable dropout setup would be nice, due to all the packing and shipping and then reassembling of bikes travelling to IM races. It never is fun to tell an athlete that the race they have trained and awaited all year is now not doable on their current frame because of a dropout issue. Dropouts get beat up by triathletes from putting them in certain trainers (Cervelos and I think Kurt Kinetic which rub on the top of the der.).

The alloy version will probably have one, but the ti version will not.

Also I know that it may be more of a logistical nightmare to have it produced in carbon, but feel like it would be lighter and have a better sell value. With all of the welds and the shaping of the aluminum would probably lead to a frame around I guess four plus or minus pounds. Also the tooling and hydroforming of the tubes not to forget the number of welds going into the frame especially on the downtube add up and also the seat stay life with the quick turn to flare them out to meet the 130 mm. spec may prove to be a weak spot in the aluminum configuration.

It’s actually probably easier to make it out of carbon but the design will be remarkably different if done so. There is actually no hydroforming done to the tubes, the DT will not have many welds actually, in fact only at the HT and BB. The ST/SS cluster may be a concern but we will see how it goes with the ti version first. We have done such a bend with our road frame SS and there hasn’t been any adverse effects. We may straighten it if we find it too complicated to bend.

It is possible to take it to a welder such as Russ Denny who welds and fabricates other aluminum manufacturers frames is great, will still have certain limitations with ensuring non- frame failures either due to fatigue or complexity of welds overlapping here and their. The internal cable routing would also be much easier to have done in the carbon counterpart with the running through the frame in an easier manner and less flex on the housing itself.

There will not be many overlapping welds, only at the BB junctions and SS/ST. However we believe it will be fine. The way it’s designed now, the internal cable routing will be no different between alloy and carbon. As I said earlier, it will be alot different if we did it in carbon as we would probably enter through the TT or HT directly.

I do not know why someone also has not redesigned a fork and hub combination to incorporate an internal cable to a smaller drum hub which would clean up the front end and also get rid of the front brake being an issue either due to aero, and or getting sticky from gu s and or from sweat coming down and clogging up the bushins of the front brake. I also know that there are a thousand and one different ways to implement things so take what I think lightly, someone may have a better way of achieving certain things here or there. Feel free to contact back and let me know what you think. We could also talk over the phone if you like.

Well, I think the answer is pretty obvious. Because no one has successfully sold a frameset that includes a wheelset. Sure, any form of system integration is possible and maybe looking at it from the standpoint of design would be an excellent one, BUT people want choices, they want to chose their wheels, brakes etc etc. We have looked at incorporating a new braking system built into the fork and frame, but ultimately cannot really justify the cost.

In regards to designing this frame, the idea was to come out with a relatively cost effective and efficient design. Sure we could have gone the whole nine yards and come out with something like a speed concept or a shiv etc etc, but we don’t have the marketing muscle to push such a design. The design shown here should be relatively cost effective and hopefully achieve some/ most of the concepts needed to make it as aero as possible.

Not sure if you’re looking at making it UCI legal, but there is a minimum 10mm width requirement on chain and seatstay sections for that, whereas you have 9mm shown.
There is a 1mm manufacturing tolerance on the UCI measurements, so if you are SURE you can make them no less than 9mm it should be OK in theory (I think), although maybe risky in practice.

I think the seat stays also need to meet the seat post no more than 160mm below the top of the toptube. That is a “constructed” limit from the UCI regs rather than an explicit one, but I think it holds.

Looks good, what price point are you going after? Do you have a target audience in mind?

To me, it looks like a Cervelo P3 from 5 years ago. Nothing wrong with that, in fact many people still praise them. I love mine.

I think where the rear brake usually is should look like the same area on the P4. Faired.

Soulbike,

I like a lot of what I see. I have been toying with the idea of a reasonably priced AL frame for Tri/TT.

My suggestions:

1: Look at the Trek Equinox 7: http://www.trekbikes.com/us/en/bikes/triathlon/equinox/equinox7/ and the detail for the headtube/internal routing. You would have to either have the extrusion made, or the headtube machined to except this style of routing/shape (I would even be happy to do the design work if needed). A hydroformed top tube with a tear drop shaped front profile could help to smooth the tube transitions between TT/HT and DT. I also encourage a drop in the DT to smooth the transition between the fork crown and DT.

2: I like the BB brake mounting, but a recessed/fairred brake would be better. I would also encourage you to try to use a center-pull brake design rather than the sidepull if possible. This could be achieved using a small skeg under the BB to route the brake housing/cables (ala the P2/3, GT edge, and BMC frames). A machined or stamped part to end cap the tube would help in frame fatigue testing.

3: I second the recommendation for replaceable dropouts. Perhaps something similar to the Fuji/Kestral 4000 shown at this years Giro?

4: double pass smooth welds to feather the transitions between tubes in the path of clean air.

5: Possible to twist the seatstays and attach in a horizontal plane similar to the method used on the DA/Shiv? (PM me and I can email you a model of what I am talking about.

6: good downtube/seatube profiles. Too many AL frames use off the shelf tubing that is merely elliptical, or tear drop in profile.

My six cents. :wink:

-Pete S.

Hi People,

We do this alot with our wheels and frames for road but have never truly done it with our triathlon/ Tri frames. Here is a prototype drawing for our new TT/ Tri frame. The Prototype will first be done in titanium (hence the ovalised tubes). If all goes well, we will start production of these frames in aluminium. The jury is still out whether we go full Tri or a sort of road/ Tri hybrid (ala soloist)… yes yes I know this is a triathlon forum. The seatpost is reversible and can be used 73deg/ 78deg so it should be possible.
As always opinions will vary, but that’s the fun of a forum, hopefully we can keep it as civilised and on topic as possible. If the picture is unclear:

  1. BB30
  2. Internal routed cables on DT
  3. Rear brake at BB

http://www.bikesoul.com/gallery/albums/Misc/Fenix_2011.jpg

Let me know what you think.

My suggestions:

1: Look at the Trek Equinox 7: http://www.trekbikes.com/...on/equinox/equinox7/ and the detail for the headtube/internal routing. You would have to either have the extrusion made, or the headtube machined to except this style of routing/shape (I would even be happy to do the design work if needed). A hydroformed top tube with a tear drop shaped front profile could help to smooth the tube transitions between TT/HT and DT. I also encourage a drop in the DT to smooth the transition between the fork crown and DT.

Well, we may be able to do a similar design, basically it’s just 2 HT together. However it seems the equinox has full housing running inside the frame? Not sure whether that’s going to be a problem especially with the new shimano STIs which already have alot of friction through the mechanisms. Worth considering nonetheless and will definitely make routing through the TT much easier.

2: I like the BB brake mounting, but a recessed/fairred brake would be better. I would also encourage you to try to use a center-pull brake design rather than the sidepull if possible. This could be achieved using a small skeg under the BB to route the brake housing/cables (ala the P2/3, GT edge, and BMC frames). A machined or stamped part to end cap the tube would help in frame fatigue testing.

There aren’t many brakes available for this application. So it’s going to be just a matter of availability at this point. I don’t like the centre-pull brake design, it’s hard to centre.

3: I second the recommendation for replaceable dropouts. Perhaps something similar to the Fuji/Kestral 4000 shown at this years Giro?
no problem.

4: double pass smooth welds to feather the transitions between tubes in the path of clean air.

No problem

5: Possible to twist the seatstays and attach in a horizontal plane similar to the method used on the DA/Shiv? (PM me and I can email you a model of what I am talking about.

Well, it’s possible but in ti/ alloy it’s not very suitable due to stiffness issues. Also, with BB30, clearances are an issue if done horizontal.

6: good downtube/seatube profiles. Too many AL frames use off the shelf tubing that is merely elliptical, or tear drop in profile.

Impossible with ti but definitely with the alloy version.
So the question is still with the routing. If we went with a full cable housing for the shifter and brake inside the DT, it will make life alot easier and possibly a cleaner solution. However if it was without housing, the current design is still easier to accomplish.

Impossible with ti but definitely with the alloy version…

As long as we’re relying on Trek, what about a Kamm tail downtube?

Taking all the feedback we got, here is where we are at with this frame. Cable routing through TT and a cleaner ST clamp design.

http://www.bikesoul.com/gallery/albums/Misc/Fenix_2.jpg

hey sean -

I really like a lot of the stuff you do, and I hadn’t seen your TT/Tri design sketches until just now.
So far, the suggestions I have have been covered re: cable integration, HT height (lower is always better), BB30 (yes please), road/tt/tri position capable (I’d love one to take to stage races)…

looking good, I hope you get the word out here, and also on bikeforums about this when you get ready to make it happen… I’ll almost certainly give it a couple of hard looks - an expressly designed dual-purpose road/tt bike (other than an S1) would be wonderful.

Oh, one thought as a general thing - the “narrow and tall” section of the tri-bike market doesn’t have nearly as many options as the long-and-low geometry bikes. Most of the lesser known names in the industry seem to be copying cervelo/felt/kestrel’s geometric progression. Not as many designers seem to be designing bikes that fit like the slice/plasma/etc…
Yes, I’m biased, but as a super-flexible dude with a short torso, I’d love to see more options that are “narrow and tall.” That is actually the reason I didn’t end up going with the carbon bike you put out, the fit coords just didn’t seem like they’d hit me (or i totally mis-read the chart, also a possibility)

Hi guys,

It has been some time, I just wanted to update those whom have followed this thread, or have contributed. Here’s the raw frame pic from our factory. Just waiting for sandblasting… sorry for the massive picture, don’t have the time to resize it.

http://www.bikesoul.com/gallery/albums/Frame-Factory-Shots/IMG_8520.jpg

Very cool! If it were mine Im not even sure I would paint it. Kinda has a ww2 aircraft feel about it in raw aluminum =)

nice look - I’d love to hear more about it…

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