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Re: Official Fit Assistance for Profile Design Bars [jimatbeyond] [ In reply to ]
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jimatbeyond wrote:
What is the crank arm length?

165mm

@cyclenutnz, what makes you think I need shorter cranks?

cyclenutnz wrote:
Sorry about that.
If you need a solution for 5 weeks time, then sure - get a 40mm longer stem, it will feel a lot better. But it will make the bike feel less stable, whether or not that is a problem is individual - some people don't care and others do.
What info were you given from the fit?

Below is a data handout I was given for my fit. The QR PRFour data is in the far right column. My pads are further forward than noted in the handout, as I moved them to try and get more reach.

The other two columns are before and after fits on my Canyon Endurace road bike (incorrectly labeled as Canyon Ultimate). The Endurace (size S) I purchased years ago without being measured by a fitter and it turned out to be too small. I brought it to a fitter (different than the QR) who put on a longer stem. I still suspect the bike is too small (reach). Anyway, I mention it because I suspect the new fitter based my QR measurements/recommendation on my Canyon.




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Re: Official Fit Assistance for Profile Design Bars [nanban_ronin] [ In reply to ]
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There is no reason why you couldn't try for example 100, 110, or 120 mm stem. If anything, I would guess that having that longer stem makes handling more stable, which isn't a bad thing especially in a tri/tt bike. Remember that 40 mm (more reach) is roughly equivalent to two frame sizes, so you have plenty of adjustability. That's the beauty of those non integrated cockpits...

(Fwiw I would try a 120 mm stem and if that's already too long, you'd anyway have the chance to move the armpads rearwards.)
Last edited by: qpae: Aug 1, 22 3:34
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Re: Official Fit Assistance for Profile Design Bars [qpae] [ In reply to ]
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qpae wrote:
If anything, I would guess that having that longer stem makes handling more stable,

You're confusing road handling, where a longer steering lever reduces the input required to make a manoeuvre
And tri handling, where putting more weight over the front wheel can make the bike feel unstable (again, rider dependent)
It's more likely on a small frame where there isn't much front centre to start with
The OP has compensated for not enough reach by moving the saddle back, so needs a lot more length in the cockpit - which could be addressed in the short term with a longer stem (and there is 7.5mm more reach on the armrests) but I wouldn't like to advise someone new to tri bikes to be finding a 140mm stem

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [nanban_ronin] [ In reply to ]
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I haven't had anyone your height prefer 165mm cranks or have better fit numbers (using motion capture) since I got a fit bike with adjustable cranks. I wrote on the topic in some detail here.

Your fitter sized the bike well with he information they had, the QR fitting document gives the coordinates shown (but their tool not graphical)

Your coordinates are middle of the reach range
The failing in this calculation is industry standard. No one calculates for the impact of tilt

Which pushes you right to the front of the reach range, just to hit the original target coordinates

So that explains part of the problem, the tools available to your fitter are inadequate

The other part of the problem is how you arrived at the position in the fit. This could be that the fitter didn't try stretching you out or you weren't able to provide useful feedback on different positions.

What you've done now is compensated for feeling cramped by shifting the saddle back to get more distance to the bars, but that cramped up up your hip, so you raised the bars to relieve that.

This is what happens if we add 40mm to your current pad x and keep pad y about the same as you've set it (not from fit data)

As mentioned - a 120mm stem would be a way to try out a longer position, but ideally a larger frame would be the nicer solution

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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cyclenutnz wrote:
qpae wrote:
If anything, I would guess that having that longer stem makes handling more stable,


You're confusing road handling, where a longer steering lever reduces the input required to make a manoeuvre
And tri handling, where putting more weight over the front wheel can make the bike feel unstable (again, rider dependent)

I'm perfectly aware of those two factors, and sure it can be that nanban_ronin's weight distribution will be too far forward with a longer stem, but as said, needs to test and just see how he feels on it.

Actually, in addition to maneuvering and weight distribution, there's a third factor to how stable you are/feel on the bike. (A bit difficult to explain without a picture, so hope the following makes sense.) When the reach is too small, the center of rotation (i.e. where elbows contact the pads) of your body might be too far back and you feel like you are falling over the bike. Moving the center of rotation forward (e.g. with a longer stem) should improve stability from this perspective and in addition provide nice support towards which your elbows can lean if you have bit of tilt in the bars/pads.

Sure a bigger frame would be a more optimal solution but I don't see any reason why not to try a longer stem meanwhile. Costs maybe 20-30$ and should be in stock in any bike shop.
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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cyclenutnz wrote:
I haven't had anyone your height prefer 165mm cranks or have better fit numbers (using motion capture) since I got a fit bike with adjustable cranks. I wrote on the topic in some detail here.

Thanks, cyclenutnz. That blog post was interesting, I wasn't aware of the advantage of smaller cranks. Although 140-150mm cranks sound shockingly short.

cyclenutnz wrote:
So that explains part of the problem, the tools available to your fitter are inadequate

The other part of the problem is how you arrived at the position in the fit. This could be that the fitter didn't try stretching you out or you weren't able to provide useful feedback on different positions.

My fitter's methodology was to first measure and fit me on my road bike, which I believe to be too small (I consulted no one when purchasing it). He then moved me to a fit bike and we carried over most of the same measurements. He also seemed to think I was really flexible and could hold an aggressive aero position (I can't touch my toes).

cyclenutnz wrote:
This is what happens if we add 40mm to your current pad x and keep pad y about the same as you've set it (not from fit data)

As mentioned - a 120mm stem would be a way to try out a longer position, but ideally a larger frame would be the nicer solution

I can't say I fully understand how these data and graphs work, but I do see a size 50 with a 120mm stem still has me at the edge of the dot grid and utilizes a lot of spacers.
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Re: Official Fit Assistance for Profile Design Bars [nanban_ronin] [ In reply to ]
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Road bike fit and flexibility don't have a lot to do with fit on a TT bike.
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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Hi Cyclenut,

I have a shiv tri disc and it’s a bit of a punish to angle the extensions but I have found a couple companies that make an angled spacer for the central stack.

Keen to understand the height rise on those snazzy new ASC43 extensions and the degree of tilt most people would go with if they’re looking for a higher hands position.

The angled spacers I’ve found come in 10, 15 or 20 degree options.

I’ve previously used a tririg bar with 115mm height rise and a 7 degree spacer under arm rests. That was comfortable but height rise from pads to top of extensions ends up being around 100mm and I figure I could go higher.
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Re: Official Fit Assistance for Profile Design Bars [Cookies] [ In reply to ]
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Hi Cookies

The rise on the 43ASC is intended to pair with a long armrest in full contact with the arm, it's not really going to work if you like to put your elbow on the pad and raise your hands up. You can see on the diagram I posted earlier in the thread that the rise is ~90mm (measured to centres)
Usually I find riders achieve good comfort and bracing with a 10-15deg angle.



That's a quick sketch of an armrest tilted 7deg with a 115mm rise extension for a fairly average length setup
You can see the equivalent rise if the extension had tilted with the pad would be 74mm
So if you can tilt the whole mono on your bike the 43ASC will give you ~16mm more rise than this example

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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cyclenutnz wrote:
As mentioned - a 120mm stem would be a way to try out a longer position, but ideally a larger frame would be the nicer solution

Hi Cyclenutnz, what size QR PRFour and stem would work better than my size 50 with a 120mm? I think you used a size 54 and 80mm stem in your analysis. I'm working towards exchanging my bike. Thanks!
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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Any chance the wing ultimate basebar will have a long stem version? I really like integrated stems, but they always seem to be short (90-100mm measuring to the center of the pad bolts)
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Re: Official Fit Assistance for Profile Design Bars [BigBoyND] [ In reply to ]
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BigBoyND wrote:
Any chance the wing ultimate basebar will have a long stem version? I really like integrated stems, but they always seem to be short (90-100mm measuring to the center of the pad bolts)

I'm afraid not. The fit window for that bar is middle of the range. The solution for extremes is the Wing20C+
Or wait a few years for the next generation bars and bikes

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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Sorry it took a while to get back to you.
I am on an old Cervelo P3C (2009) in size 61. Frame stack&reach is 564 / 454. My pad stack&reach is 648 / 553. I have played around with stems before.
It can be a bit tricky to get from top of headset to my pad position, but the really difficult bit is actually maximizing the distance between pads and end of extensions.
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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Slowman has written about the new extensions
https://www.slowtwitch.com/Products/Handlebars/Profile_Design_43ASC_Extensions_8436.html

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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They look really nice. Good work on these.
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Re: Official Fit Assistance for Profile Design Bars [nanban_ronin] [ In reply to ]
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nanban_ronin wrote:

Hi Cyclenutnz, what size QR PRFour and stem would work better than my size 50 with a 120mm? I think you used a size 54 and 80mm stem in your analysis. I'm working towards exchanging my bike. Thanks!

Sorry for the slow reply - I'd go up to the 54 as shown in the chart, I think your position will end up higher and longer than currently.
Obviously going to a fitter first didn't work out for you, which is unfortunate as you did everything right.
If you don't feel confident trying with a fitter again - you can post a fit critique request on the forum and get some useful feedback (I don't take part in those as I feel hamstrung without my 3D motion capture data)

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [bas2205] [ In reply to ]
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Would you mind posting a pic of your bike please?
When I plug your numbers into the calc I don't come up with needing risers, so I'd like some info in order to help



Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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cyclenutnz wrote:
nanban_ronin wrote:


Hi Cyclenutnz, what size QR PRFour and stem would work better than my size 50 with a 120mm? I think you used a size 54 and 80mm stem in your analysis. I'm working towards exchanging my bike. Thanks!


Sorry for the slow reply - I'd go up to the 54 as shown in the chart, I think your position will end up higher and longer than currently.
Obviously going to a fitter first didn't work out for you, which is unfortunate as you did everything right.
If you don't feel confident trying with a fitter again - you can post a fit critique request on the forum and get some useful feedback (I don't take part in those as I feel hamstrung without my 3D motion capture data)

No problem, I appreciate you getting back to me. I contacted QR and they are willing to swap my size 50 frame for a 54, so hopefully it works out. I spoke to my fitter; he stands by his recommendation and noted that I don't have a lot of seatpost sticking out on the size 50.
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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cyclenutnz wrote:
Slowman has written about the new extensions
https://www.slowtwitch.com/Products/Handlebars/Profile_Design_43ASC_Extensions_8436.html

I was particularly excited to see these in GTN's video. However, Dan's suggestion that watch wearers might have issues with the exetentions is a downer.
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Re: Official Fit Assistance for Profile Design Bars [nanban_ronin] [ In reply to ]
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That fin on the inside of the wrist isn't great for watch wearing


As for seatpost extension, from your video I get this


Which means your saddle needs to go up, if you then get 155mm cranks that's another 10mm. So the seatpost extension will be similar on the 54 to what you have now.
Most importantly - the bigger frame will give you the reach that you really need

Speedtheory | ST Interview
Last edited by: cyclenutnz: Aug 15, 22 19:55
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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Much appreciated! These are very helpful numbers to know!
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Re: Official Fit Assistance for Profile Design Bars [jn46] [ In reply to ]
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jn46 wrote:
GTN have just posted good coverage on youtube, skip to about 8mins in.

There are a lot of new goodies shown in this video - new stem with internal cable routing, new smaller bottle that connects to stem, integrated stem and wing ultimate bars. When are these items all planned for release to the public? You mentioned November for the 43ASC extensions, and now I see October now for the Wing 20C+ in the Slowtwitch ad. Is everything else coming out in October as well (new stem with internal cable routing, new smaller bottle that connects to stem, integrated stem and wing ultimate bars)?
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Re: Official Fit Assistance for Profile Design Bars [khanlon] [ In reply to ]
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khanlon wrote:
When are these items all planned for release to the public? You mentioned November for the 43ASC extensions,

That date still holds, but the supply is going to be even tighter than initially expected. Production has been hampered a little which will most impact retail channels and of the items going into the USA market, the majority are reserved for domestic bike brands.

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and now I see October now for the Wing 20C+ in the Slowtwitch ad.

Yes, that is shipping out soon hence the ad

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Is everything else coming out in October as well (new stem with internal cable routing, new smaller bottle that connects to stem, integrated stem and wing ultimate bars)?

Unfortunately no, production is still slow. I think most of those items are going to be the middle of next year at this point.

Speedtheory | ST Interview
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Re: Official Fit Assistance for Profile Design Bars [cyclenutnz] [ In reply to ]
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Thank you for the detailed response
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