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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Ian,

I'm looking at either an X-PR or V-PR with the following fit coordinates:

Pad X (back of pad): 500
Pad Y (top of pad): 585, I have to pedastal my left side to 635 because my left humerus is shorter)
Pad Width (outside-to-outside): 290
Saddle Setback: 15
Saddle Height (at 165 cranks): 767

I'm discovering I'm an outlier and I'm finding very ew bikes that I can fit. Can I get that long and low on one of those frames with the Aeria Ultimate setup at the front?
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Hello,
I was fitted for a 54 or 56 PRFive 2 Disc, but I could have gone either way. My fitter said that 54 was the best. I wanted to get a second opinion on this.

Height: 179 cm
Inseam: 85.9 cm

Saddle Height: 75.8 cm
BB Center to Saddle Tip: 2.5cm
Stack: 67.5 cm
Armrest Width: 33 cm
Saddle to Shifter: 86 cm
Reach: 47.5 cm

I believe I am in between on the stack size.

Thank you for your help!
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [DonutMan] [ In reply to ]
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Quote:
Hello,
I was fitted for a 54 or 56 PRFive 2 Disc, but I could have gone either way. My fitter said that 54 was the best. I wanted to get a second opinion on this.

Height: 179 cm
Inseam: 85.9 cm

Saddle Height: 75.8 cm
BB Center to Saddle Tip: 2.5cm
Stack: 67.5 cm
Armrest Width: 33 cm
Saddle to Shifter: 86 cm
Reach: 47.5 cm

I believe I am in between on the stack size.

Thank you for your help!

DonutMan,
I'm on a life-mission to keep things clear. Remember, a Mars Rovers crashed into the planet's surface a while back 'cuz some of the big brains at JPL where calculating critical stuff in mm while some others on the same project via inches. So, brining this all brining this back to our world here: Stack and Reach are terms used to describe a place on a bike frame (the top, center of the frame's head tube) while Pad Y and Pad X (and, here I'm even avoiding the term Pad Stack and Pad Reach ) are terms used to prescribe not just a frame size but also the front end confirguration to arrive there. Thank you for surviving my rant!!

So, plowing ahead with Pad Y of 675 and Pad X of 475... you sure can fit on a few sizes, and that's true for lots of folks on lots of tri bikes now-a-days due to sizing overlaps but, in your case, the 56 is a far better fit than the 54. For you the prescription is...

Quintana Roo PRfive2, size 56, with a 90mm stem set in the -17 position, with 20mm of spacer set between the bottom of the stem and the top of the head tube and then 5mm of aerobar pedestal. That puts you at a Pad Y of 676. The, to get to 475 of Pad X the pads should be set "arm rest offset at -3.25". I put that last bit in quotes becasue that's QR's terminology to identify that pad location, if I want to common lanugage it would be "one hole forward of dead-center".

I like this set up a lot for you because it offers a good range of movement in all directions. I would be deeply foolish to override your fitter because they've seen you in person and I'm here in the ether... my calculations put your Pad X within 5mm of your fitter. That warms my hart. My assumption of your Pad Y are far different (I'm thinkin' 640, your fitter has you at 675). There's only about 30 reasons why 675 is right and 640 is wrong and some of them are impossible to change. BUT.... just incase... I'll add this: short cranks 160ish would be great and getting you out of the wind a bit, and this bike set up as it is now will allow you to pull out 25mm and drop it lower if/when you need it.

Get back to me here anytime with questions.

Ian

Ian Murray
http://www.TriathlonTrainingSeries.com
I like the pursuit of mastery
Twitter - @TriCoachIan
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Thanks for the response. I asked to get a 165 crankset on the 54 so would that make it fit better than a 56?

I was also fitted for a 56 Cervelo P series. I know this is a QR thread but would the Cervelo be a better fit based off my info?
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [DonutMan] [ In reply to ]
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Did your fitter try 155mm cranks?
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [jimatbeyond] [ In reply to ]
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No, only 165.
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [DonutMan] [ In reply to ]
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Quote:
Thanks for the response. I asked to get a 165 crankset on the 54 so would that make it fit better than a 56?

Donutman,
The crank length doesn't really have a great effect on the size of bike or the front end coordinates. The crank length has an immediate effect on how comfortable you are at a lower arm pad elevation: long cranks require higher aerobars because the hip gets "pinched" at the top of the pedal circle if the pads are low. Generally, low pads are good - comfort can be found there, power can be found there, less drag is expected there. But we can't get very low if the crank arms are long. This is a hard truth for the aero position. It matters less in road, gravel, mtb, etc.

We're proceeding under the assumption that your Pad Y/X is 675/475. If we're talking about what bike and what size fits you...simply meets your position, hard stop. There are many bikes, many sizes. For example you can get those nubmers out of a QR PRfive in size 52, 54, 56, 58.5. I went to the next step in my thinking which included...
  • 675 seems to high to me, I suspect you'll ride lower in the future.
  • I never like to put someone in a corner fo the bike's capabilities and getting 675mm of Pad Y out of a 54cm QR PRfive is an extreme corner of it's capabilities.

That script I extended to you in the above post, the 56 with the 90mm stem, -17, +20mm, +5mm - that results in a Pad Y of 676 and a Pad X of 475... .AND.. it gives your room to move up, down, fore, aft.

Lastly, that other bike you asked about has an official fit thread here on ST, you can post there too. I'd like to share my criteria for buying a bike:
1) Does it fit and fit well in the middle of a range so you can move in the future?
2) Group Set & Price: I want Di2 or Ui2* and I want sexy wheels, and I want a fair price for all that (*Ultegra Di2)
3) Color: never ride a bike you think it ugly
4) Availability: this is kinda new, it's a post Covid thing, How long do you I have to wait?


Ian

Ian Murray
http://www.TriathlonTrainingSeries.com
I like the pursuit of mastery
Twitter - @TriCoachIan
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Dear Mr. Murray,

The PRfive2 sizes I can find at Brazilian QR dealer are 56 and 54.
Your assistance on selecting the right frame size for me would be enormously appreciated.
The following are my specs:

height: 1.89m
inseam: 89.5cm
saddle height: 82cm

Regards from Brazil
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [Rodrigo Azeredo] [ In reply to ]
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Quote:
Dear Mr. Murray,

The PRfive2 sizes I can find at Brazilian QR dealer are 56 and 54.
Your assistance on selecting the right frame size for me would be enormously appreciated.
The following are my specs:

height: 1.89m
inseam: 89.5cm
saddle height: 82cm

Regards from Brazil

Rodrigo,
Thanks for writing. You've got pretty long legs for your height and I'd guess your Pad Y to be around 670 and your Pad X to be ~500.

Both sizes will work but the 56 is preferable. The best set up is #1 and then nearly best is #2.
  1. QR PRfive2 size 56 with a 110 stem in the -17 degree position with 10mm spacer under stem and 5mm pedestal under aerobars. Then mount arm pads 1 hole forward of center. That yeilds a Pad Y/X of 672/505
  2. QR PRfive2 size 56 with a 90mm stem in the -17 degree position with a 10mm spacere under stem and 10mm under aerobar. Then push arm pads out one hole short of 100% forward. That yeilds 672/500

Ian

Ian Murray
http://www.TriathlonTrainingSeries.com
I like the pursuit of mastery
Twitter - @TriCoachIan
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Mr. Murray,
I greatly appreciate your help!
My best regards,
Rodrigo
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [AKCrafty] [ In reply to ]
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Quote:
Ian,

I'm looking at either an X-PR or V-PR with the following fit coordinates:

Pad X (back of pad): 500
Pad Y (top of pad): 585, I have to pedastal my left side to 635 because my left humerus is shorter)
Pad Width (outside-to-outside): 290
Saddle Setback: 15
Saddle Height (at 165 cranks): 767

I'm discovering I'm an outlier and I'm finding very ew bikes that I can fit. Can I get that long and low on one of those frames with the Aeria Ultimate setup at the front?

AKCrafty,
Sorry I missed this one. You provide a solid challenge with the two Pad Ys... It won't happen on the V-PR with either arm pads options

As to the QR X-PR... if you got a 52 (and this is with Aeria Ultimate) you could run a 110stem with the "stem stack" at zero* and with 50mm of aerobar pedistal under one arm and zero under the other you'd arrive at your Pad Ys of 585-635. *That "stem stack" thing refers to this: the stem has a clam shell within the base bar clamp and you can put both sides of the clam shell atop the base bar and that pushes the base bar as low as it'll go. Then, to get your Pad X, mount the pads forward one hole shy of the max and you'll have 501.

Ian

Ian Murray
http://www.TriathlonTrainingSeries.com
I like the pursuit of mastery
Twitter - @TriCoachIan
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Hi, I am looking @ a 2018 QR PR6. It is a 52cm. My BMC road bike is a 51. I am 5'7 1/2"; inseam 30.5"; my road bike seat height is 28.5" from BB and 36" from center of pedal. I have never had a tri bike before or been measured for X, Y, and Z. The QR site indicates 50 or 52 for 5'7", and 52 for someone 5'8". I am trying to confirm if the 52 is right for me, and if I get it maybe a good plan would be to take it to a fitter to dial in seat height, bars, pads, and crank. Do you have any thoughts on this? Thanks.
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [allblacks] [ In reply to ]
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I would recommend getting a proper fit before buying a bike.
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [allblacks] [ In reply to ]
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Hi, I am looking @ a 2018 QR PR6. It is a 52cm. My BMC road bike is a 51. I am 5'7 1/2"; inseam 30.5"; my road bike seat height is 28.5" from BB and 36" from center of pedal. I have never had a tri bike before or been measured for X, Y, and Z. The QR site indicates 50 or 52 for 5'7", and 52 for someone 5'8". I am trying to confirm if the 52 is right for me, and if I get it maybe a good plan would be to take it to a fitter to dial in seat height, bars, pads, and crank. Do you have any thoughts on this? Thanks.

allblacks,
I have very strong thoughts on this....
The absolute best way to buy a tri bike is to GET FIT FIRST. And this is one of those things where you either do it right or not at all: go to a fitter who checks off these three boxes: they are educated in tri fit, experienced in tri fit, and they MUST own a dynamic fit bike*. Then you do fit, pay them whatever they ask, give them all your money because you'll leave with your exact Pad Y and Pad X telling you what will fit and what wont. Have them prescribe this bike you're interested in and 3 others. And you'll have all your fit coordinates (seat height, set back, cockpit detials, etc. etc. etc). The fit is done, you were part of the process, it's perfect - and you don't even own the bike yet!!!

*the dynamic fit bike is a critical piece of tooling. It's expensive and committed fitters purchase them becuase you simply cannot nail, dead-on a prescriptive fit without one. There are only really 5 of 'em: Shimano, Guru DFU, Purely Custom, Exit, and Muve. You need to interview the fitter, quiz them about where they tri fit education came from (they need to say Slowtwitch, Guru, Retul), ask them which dynamic fit bike they use (they need to name of of the previous), and ask 'em how many tri fits they do.

What I'm about to do it good but not as good as the above. Imma take what you've given me (morphology) and what you've left out (you didn't mention some catastrophic accident that left half your vertebrae fused or some such extreme thing) and I'm going to plug that into a formula, season with experience as a long time fitter and bike fit instructor, and over 2 decades of coaching triathlon full time and shazam... I've got some info to share. Again, it's good, it's not as good as the above...

I think your Pad Y is in the neighborhood of 600mm and your Pad X is roughly 460mm. A 2018 Quintana Roo PRsix size 50 will fit you and here are the options (because there's a few ways to arrive at these numbers).
To get our Pad X of 460...
You need either the 90mm stem or the 110mm stem. 2018 was a near year for a proprietary QR stem and they only made three lengths: 75, 90, 110
If it's the 90mm stem the bracket that holds the arm pads needs to be set rearward and then use the rear armrest hole.
If it's the 110mm stem then bracket goes rearward and use the middle armrest hole
To get your Pad Y of 600...
The stem has this clam shell system inside the base bar clamp. You should put one half of the clam shell on top the base bar and the other half below so you're in the "middle" setting. Then you only need you only need 10mm of arm pad pedestal to get to 600. Now this is a Profile-Design aerobar so it's easy to find bits you need to dial to perfection (bits= spacers and screws).

Some other notes to consider for your first tri bike. You must have a saddle that allows you to sit, in comfort on the front half of the saddle (look at any an all profile view pics of anybody at Kona and you'll see a lot of saddle behind their bum). You should ride 160mm cranks at the longest and prolly 155s so find our how long the cranks are on that bike and if they are longer, work the price down as you're gonna want shorter cranks.

Ian

Ian Murray
http://www.TriathlonTrainingSeries.com
I like the pursuit of mastery
Twitter - @TriCoachIan
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [ianpeace] [ In reply to ]
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Dear Mr. Murray,

I'm not sure if my recently purchased PRFive2 has enough clearance for 28mm tires.
Your help on clarifying this point will be enormously appreciated.

Thank you,
Rodrigo
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Re: Official FIT ASSISTANCE for the Quintana Roo PR Tri Bikes [Rodrigo Azeredo] [ In reply to ]
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Quote:
Dear Mr. Murray,

I'm not sure if my recently purchased PRFive2 has enough clearance for 28mm tires.
Your help on clarifying this point will be enormously appreciated.


Rodrigo,
Typically, I keep this thread to fit related issues but, I have some knowledge and opinion about this subject so I feel confident answering. 25mm tires will work in any and all cases. If you have a carbon rim that's wide... say inner width of 20mm+ and you put a 28mm tire on there.. the width of the rim + the width of the tire + the rim flex when out of the saddle and putting down heavy power can result in some rubbing of the sidewall of the tire on the chain stays of the frame. If you've got a narrow rim or an alloy rim with lots of spokes that typically won't happen with a 28mm tire.

Ian

Ian Murray
http://www.TriathlonTrainingSeries.com
I like the pursuit of mastery
Twitter - @TriCoachIan
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