Thanks a ton - now the hard part.... trying to decide which color scheme I like the best...

Blue! Blue! Blue! Blue!

I really like blue.

Hi Ian,

I am considering purchasing a PRSIX2 Disc and would love to get some feedback from you on sizing/fit. I currently ride a 54cm Cannondale Slice, I am 5'7" tall, more legs than torso. I have a 30 inch inseam. My pad X is 395mm and pad Y is 620mm, my saddle height is 735mm.Thanks for your assistance! Kim Ruble

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Kim Ruble

Kim,
All perfect info, thank you!
For a Quintana Roo PRsix2... your position can happen on two different sizes, the 48 and the 50. I'm gonna detail both so you have all the info you need and I'd like to share my opinion.

Size 48 with the 75mm stem, the base bar clamped in the high position (this just puts the two clam shell pieces under the base bar in the clamp) + 40mm of pedestal. The arm cup bracket will need to be mounted rearward and then the arm cup itself will be mounted in the mid-front hole. All this yields a Pad Y of 620 and a Pad X of 390. If you move the arm cup to mount in the middle then it's 405.

Size 50 with the 75mm stem, the base bar clamped in the high position + 20mm of pedestal. The arm cup bracket will need to be mounted rearward and the arm cup screwed in using the mid-front hole. The result is Pad Y of 620 and Pad X of 400

Now for the Op-ed: If you had just written in with your height, inseam, seat height... I would have suspected your Pad Y to be 605 (so we're very close there) and your Pad X to be much longer at 430ish. There could be many reason why we have disparity. My initial thoughts would about the saddle - where it's mounted on the rails (it's back, I'd like is slid forward). It could be where you're sitting on that saddle (you're back, I'd like you forward). It could be comfort of that saddle (your back for comfort, we need a saddle that allows you to sit near or on the nose of it and be comfy there). It could be about crank length (you're on something longer than 160 and I want them to be 160 or 155). My point of this is if you move into a position that I suspect would be better (more comfort or the same comfort - and/or more power or the same power - and/or slipperier through the wind) both of these bikes will allow you to progress your numbers in the direction I'm thinkin with all the same hardware.

Get back to me where with questions or comments.

Ian

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

Ian,

Wow, you know your stuff! Yes, my saddle is back just about as far as it can go. I will have to experiment with a more forward position. Unless, I did my Pad x measurement wrong, how does being more forward change the pad x? I used the BB to center of arm pad horizontally for my 395. Changing the seat doesn't change this, no? My nose to extension is 760mm, that number would definitely change. I tried to include a photo of me on the bike, but can't get the resolution low enough to include it.

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Kim Ruble

 

Kim,
Sorry about the duplicated sentence in quotes up there... there must be something wrong with the editing software on the site :)

Okay, this is GREAT!!! When (not if, but when) you slide your saddle forward on the rails it'll take your whole body position forward on the bike. So the entire front end will need to move forward- the arm pads will need to go forward, the aerobars will need to go forward. There's one thing you could do to your current bike that will move everything all at once and that would be a longer stem. You're riding a 54...it's a mortal bike.. stems are aplenty and pretty inexpensive for that bike - if you move your seat forward, put on a stem that was 20mm loner and then tweaked the pads/extension out a bit you'd probably find the position I'm talking about. AND THERE'S ANOTHER THING...when you move forward like we're talking about you can very often go lower at the same time and still be comfortable (always top priority to me), still be powerful (maybe even more), and you'll be out of the wind a bit more.

All of this is just chatter about altering the position on your current bike - you're clearly ready for a new bike so don't put too much time and effort into changing this position - rather - order the new QR as prescribed in previous post. Set the seat height at 735, position the saddle farther forward that were you have it now and then move the pads and aero extensions farther out by 20mm minimum and maybe a bit more. The prescription I wrote will make this easy, the bike will go there - it'll just be a matter of screwing the arm cups in a more forward hole, sliding the extensions out a bit.

Lastly, QR has shown the ability to install cranks of the length you want when ordering. Ask for 155s. If they balk then get 160s - if you have to settle at 165s okay but nothing longer.

Ian

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

Hi Ian...

I just had a fitting done. I was hoping to get a sense of the ideal QR tri bike type and size

Stack: 574mm from BB to head tube top
Reach: 450 from BB to back of pad
Saddle height 771 mm
Seat Tube angle 79 deg

180 cm tall
inseam about 84 cm.

I have a pile of other extraneous numbers, so let me know if you need anything else

thanks!!
HS

HS,
The critical numbers for me (or anyone really) to prescribe a bike is Pad X (Pad Reach) and you've given that here with 450mm to the back of the pad. I'd like Pad Y (aka Pad Stack) and I'm betting that number is in the neighborhood of 635-660. It's measured from the BB to the top of the pad.

If you can get me that I'll get back to you right away.

Ian

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

Hi Ian,

It comes in at a 648 on my current bike, which I'm very comfortable with.
Thanks for getting back to me, I really appreciate it.

HS

 

HS,
If you went with the QR PRsix (the super bike) your position could be achieved on several sizes but the 52 is the best. On the 52 you'd use a 90mm stem and the base bar captured in "mid clamp" (it's a clam shell, this means one half atop the base bar, one half below). 35mm of arm pad pedestal, the arm bracket oriented rearward and the arm cup mounted in the middle. This would put the pads at 645-450, if you preferred 650-450 then you'd do 40mm of pedestal rather than 35. With this size bike and hardware (90mm stem) you'd have room to move up-down-fore-aft quite a bit to find you're ultimate spot.

If you wanted the QR PRfive or four (the mortal bikes) the 'script would be...I like the 54cm bike better on this one: 90mm stem set in the -17deg position, 10mm of spacer under the stem and 5mm of pedestal. Then the arm cups mounted one hole closer to you than center. The result of that is 647-453 and you have lots of room to tweak up-down-fore-aft to find the perfect spot.

On it's face a 52/54 sounds a bit odd for someone your height but the method that QR uses to measure their bikes (the exact Stack of the frame) is the smartest, it just feels weird. If they called the 54 a "medium" and a 52 the "sm-med" we'd all be good with it in a sec.

Get back to me here if you have more questions.

Ian

PS. QR's pretty good about swapping out bits so take the order opportunity to get the crank length you want/need (165 max)

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

wow.. this is awesome and I'm so glad I asked.
My current bike is an old Giant Trinity size 54 and it has worked well. I had recently questioned this based on my height, but your feedback makes a lot of sense.

Thanks very much for this. As the other posters have said.. I just have to decide on a colour scheme now!

Hi Ian,
I am looking into a QR PRsix2 and the bike shop has recommended a 50cm frame based on measurements i have given.

Due to COVID i can't get a proper fit nearby at the moment. They would do a fit and adjustment when i pick it up... however, clearly the frame size can't be adjusted.

I am 170cm tall (c5ft7) with a 82-83cm inseam so quite long legs and short torso, although quite flexible. They are adamant that a 50cm would be a better fit than the 52 to allow for a shorter reach and the pad height can be increased to avoid being overly stretched out. I plan to race mainly Standard distance and 70.3.

The thing that worries me is whether the frame will be too low on the base bars vs my saddle height to be comfortable/controllable when i do need to come out of the aerobars, or even would i be at the max saddle height on the 50cm.

On my road bike i ride a Specialized Venge (2019) in 54cm. I have a 90cm stem and about 1.5cm of spacers and a 77cm saddle height with 165 cranks. When i bought that i was fitted and they actually sized me up from the 52cm due to longer legs to avoid the front end being too low.

Any guidance would be appreciated.

Hi Ian, I'm looking at the PRfive. Rider height 5'7" (170cm). I was fit on the ISM PN 1.0 saddle.

Arm Pad Reach (BB): 442
Arm Pad Stack (BB): 620
Arm Pad Drop (saddle to pad top): -89
Saddle Height: 723
Saddle Setback: -3
Grip Angle: 22d
Arm Pad Width: 232

Thanks!

LeonFer,
You've provided a lot of good info here. Thank you for that. Based on your details I think your Pad Y is roughly 600 and Pad X is about 455. For the QR PRsix you could fit on three different sizes: 48, 50, and 52. The 52 I can toss out right away because 600 is the absolutely lowest that bike goes and I don't want you painted into that corner.

The 50 fits you very well. The details are these...
The stem holds the base bar with a clamshell clamp and if you put both bits on top then you need 20mm of arm pad pedestal. Put one on top and one below and then you need 10mm of pedestal. Put both on bottom and then you use no spacer. I give you these options as you mentioned the time when you're riding on the pursuit bars (the bull horns, the base bar) how you worry about the "drop" to the hand position while on the brakes. The max difference between the arm pads and the pursuits is only 20mm - that's not very much.
Now, about the cockpit distance or the Pad X of the position... this bike has three different stems: 75mm, 90mm, 110mm. Pad X of 455. The 75mm stem requires you to mount the pads almost to the extreme: bracket forward and armrest hole mid-rear. If you do the 90mm stem then you've got the bracket forward and arm-rest hold middle. If you do the 110 stem then bracket is rearword and armrest hole is middle.

I think you should get the size 50 with a 110stem and put the clam shell one on top and one below with 10mm of pedestal.

As I type this I have no idea what max seat height is on this bike (PRsix size 50). Let me get back to you here tomorrow.

Ian

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

Ian,
First, thanks for doing this for the community.

I'm looking at PRsix2 bike. Below are my rough measurements from my 2014 Trek SC medium. Overall, I'm pretty with my fit but could get a little more aggressive. I also, currently ride 170mm cranks. I am around 170cm tall with about 81-82cm inseam If I mis-measured something, please let me know.

saddle setback: -35mm
Pad Y: 410mm (measured from BB center to back of pad)
Pad X: 620mm (measured from BB center to top of pad)
Saddle height: 747mm (measured from BB center straight up vertically to top of saddle.)


Looking at the chart, I could fit on a 50 or 52. I would like to know the pros/cons of either from your perspective.

Thanks

LeonFer,

Circling back on max seat height on the 50cm QR. It's pretty darn close to 835mm.

Here's why I say "pretty close": the posts are 380mm long from end to rail clamp. They have a minimum insert of 95mm so that leaves ~285. The "height" of an ISM saddle (comes stock on that bike) is ~50mm. So we take the Stack of the bike 500mm + 285mm in post + 50mm in saddle height and we get 835. You might run a different saddle with a different height.

Ian

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

Hi Ian,

I' m looking for an PR Five Disc.
I' m 172cm with short legs. Inseam 76cm.

My settings on my current bike:
Saddle height: 67,5cm
Pad height: 92,5cm
Saddle-Pad: 49cm
Saddle setback: 0,5cm

Thanks for sharing your knowledge.
Marcus

Lou123,
This can happen on a couple different sizes but the best PRfive for you is a size 52. Don't freak out about that bike sounding small, QR sizes according to frame stack and while that makes a world a sense it's just odd sounding.

So, it's a 52 with a 90mm stem set up in the -17deg position, 10mm of spacer under stem and zero arm pad pedestal. Arm cups will either be 40mm or 47mm back - one results in a Pad X of 438 or 445.

It's a great set up. I love it when the aerobars and the pursuit position (the break levers) are similar in elevation for quick and easy moves from aero to a hand position needed for technical bits, descending, braking etc.

Ian

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

Hey Ian,
I'm sure your a very busy man. Just wanted to confirm my thoughts on a 52 with a 75mm stem.

Thanks,
Brian

Hi Ian,

Looking at getting my wife a PRFive or a PRFour.

Height: 156cm
Inseam: 75cm

She's currently using a Specialized Shiv XS which I think is not the perfect fit for her.
So I am not sure if the Reach and Stack on her Shiv will be a reliable measurement.

What size would you recommend?

Brian,
with a Pad Y of 620 and a Pad X of 410 (I'm pretty sure you switched 'em there). The 52 will work but you'll be too much in a corner on the Pad X - and if you wanted to be more "aggressive" (I'm assuming you mean lower) the bottom of the Pad Y on the 52 is 600 so you're too near to that as well.

I think the size 50 is a better bet. In the PRsix2 you'd be a 50.... with the steam/bar clamp in the mid position, and 30mm of arm pad pedestal. And then you'd use a 75mm stem with the arm pad bracket in the rearward position and the middle pad hole.

Ian

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

Marcus,
Based on your height and your morphology I think you Pad X is probably 465-475 and that's pretty close to what's reflected in the math of your saddle-pad & setback notes. However, pad height of 925mm... something's wrong there. Either I'm misunderstanding what that number is, you've mismeasured. I think you're Pad Y is more likely in the neighborhood of 600-620mm. I'm going to move forward prescribing a PRfive based on Pad Y of 610 and Pad X of 470.

This can work on a few sizes but I think the 50 works best with a 110 stem in the -17 degree position, slammed with 10mm of aerobar riser, and then pads offset -1.75. This prescription puts you at a Pad Y of 607 but you can go up to 641 with just more spacers and pedestal. You can also go down to 597. The 110 stem allows you to go as short as 409 and as long as 486. Of course this is a mortal bike so you can swap stems with easy to get a super wide ranges of positions with ease.

Get back to me here if you think I'm flawed in the Pad Y of 925mm or if you have other questions.

Ian

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

jeyps11_c,
I think her Pad Y is near to 560-575 and her Pad X is roughly 430. This prescription will be the same on either the PRfive or PRfour....

Her current bike worries me because she needs (deserves!) a low Pad Y and the Shiv is one of the tallest bikes made. I can't imagine she's in a position that even approaches optimal.

She's gonna need a 48cm QR, it's the smallest PRfour and PRfive made. She's going to have to put the stem in the -17 degree position, slam it, pull out all the pedestal under the aerobars and she'll still be at 576mm. I'd do the 90mm stem with arm rest offset -2.50 and that would give you 430.4 but there's lots of holes to go shorter & longer with the cockpit.

I have a couple of addendums on this... A) she should be riding 150mm cranks. When you order the bike have the discussion with the QR sales folk and see if they'll deliver on that - if not, get Shimano 165s from them when they shep, when the bike arrives pull those off and sell them as new, never ridden. Then go and buy a set of 155s from Cobb or Rotor. B) If I'm right and she has the ability to ride with a Pad Y of something below 575 you could get there 1 of 2 ways: 1) find a stem that points down lower than -17 degrees, or 2) leave the Profile Design base bar and do an "under mount" with the aerobars. That might be moot as she might prefer to ride at 575mm of Pad Y

Ian

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

Thanks as always for your detailed response.

Thank you Ian,

I'm a little bit sorry, that I just figured out, what pad x and y really are.

I just took the numbers from my last bike-fit. Obviously it was not pad-Y but measured from the ground. So you are right, my current setup hat a pad-Y of 635mm.
So I will go for a 50 frame.

As I'm now riding a 170mm crank, I would like to go for a shorter one.
Any recommodations? I think of 160mm. (inseam 76cm).

Thanks a lot, Marcus