musicman,
Something seems funky in these numbers to me and I want to double check before I prescribe the right PR4 for you. "Arm Pad Stack at 693" - seems possible. I would have guessed something closer to 577 but based on your pad drop and seat height this seems plausible.

"Arm Pad Reach: 382" and then "Arm Pad Reach BB: 693". This is the part that's got me confused, especially if your saddle set back is -17. I'm just hoping beyond hope that one of these numbers is a typo. Can you confirm and get back to me?

Ian

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

EP,

If you're after the PR4 or PR5 then... it's a 54cm with a 90mm stem, zero spacers under the stem and .5mm of aerobar pedestal with arm cups 1 hold forward of all-the-way-back.

If you're after the PR6 then...it's a 54cm with the 75mm stem and the stem bar clamp set in the low position + 20mm of arm pad pedestal. Use the front arm cup hole and orient the arm bracket forward.

Ian

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

Thanks Ian. I’ll keep you posted.

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"I drank what?!?!" - Socrates
Poor Swimmer. Weak Cyclist. Slow Runner.
TriDot Ambassador / Sacramento Triathlon Club

Your target position can be fairly closely matched on the 54 PR4

(PR4 is same geo as PR5, I just haven't added it as a separate name in my database yet)

5mm steerer spacer means one of these with no other spacers: https://speedandcomfort.com/.../copy-of-5mm-top-cap

Pad Row 11 means the 2nd most forward config

No need to worry about pad col as you're happy with width

Note that I modified your Pad XY to be to the rear of the pad

Basically you need the bars fully slammed and nearly all the way forward. You'll likely need new extensions if your bars came with T4C (definitely if they were cut) as the new generation ones are longer, a 400mm extension gives a max length of 376 (on x axis, so will be fine on diagonal).

Thank you, cyclenutz! I appreciate your help. The 400mm bar extenders makes sense to achieve the proper reach. I'm still not sure how I can lower the stack from 650 to 600. The current top cap appears to be 15mm (photo attached), so a new 5mm cap will lower the stack to 640mm. There are currently no spacers on the bars (photo attached), so it seems to be as slammed as it can go. I'm not sure how to achieve the final 40mm in drop with the AU bars. Thank you again for any assistance.

Greg

At this point I'm going to suggest that you remeasure the Pad Y. The only way I can see that setup being at 650 is if the frame isn't a 54.

Greg,

Couple of things...
1) cyclenutz (David Bowden, VelogicFit) is a master at this, a savant, brilliant! We're lucky to have him involved in this thread.
2) If you measure out and find that you're still down where you want to be.....I suggest you click on over to Cobb's Speed & Comfort page and order an ultra thin top cap: https://speedandcomfort.com/collections/top-caps

It'll look like this and you'll gain ~10mm:


Keep us posted, Ian

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

Yes, that was it. My measurements were way off. Thanks again!

Thank you, Ian. My poor measurement skills were to blame! It's where it needs to be.

Hi Ian,

I'm interested in the PRSix Disc. I'm 33 male and 6ft. My last Retul fit was in 2015, so I plan to get another in early 2020. I am a much stronger cyclist now. My next bike needs to fit a more aggressive position. I have been doing tri's for over 10 years and just cracked the top 10 of my AG in my last IM. Hoping for a AG podium in the coming years.

Saddle height: 812mm
Handlebar reach: 505mm
Handlebar drop: -124mm
saddle setback: -24mm
armpad reach: 436mm
armpad drop: -68mm
armpad sack: 725mm
armpad reach: 412mm

Thanks for the help!

flight<bird,

Don't know how I missed this. Terribly sorry.

I'm thinking your Pad Stack is ~651 and your Pad X is ~502. Now, let's take into account your desire for best bang for the buck. For me (fit snob) position is job one so we've got to nail that! We're going with rim brake to save a few doubloon and the groupo...well, that's up to you. What's nice about this prescription is that it applies to both the PRfive and the PRfour so you can choose.

Size 54 with the 110 stem, 10mm of spacer under stem and 5mm aerobar pedestal, use the 3rd from back bolt holes in the arm cups and screw them into the forward holes on the mounting bracket.

Let me know if you have more questions. Ian

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

Hello Ian,

Thanks so much for your help! I've been looking at the PRfour, do you know anyone in the Houston area who can help me out?

Thanks!

jgills,
Help out with purchase? It's probably Philip at Shama Cycles.
Help out with fit before you buy? That could be Philip too (waiting to hear back). I'm willing to help and can get pretty darn close with some info...

Do you have a tri bike now that fits well and if so - I want the Pad Stack and Pad Reach off of that (I can tell you how to measure at home).
Do you have a road bike at home now that fits well and if so - I want the seat height and your height and your inseam and let me work with that.

Let me know, Ian

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

I'm looking for help with a fit before I buy, but also purchasing if it works out and I like the bike. I do not have currently have a tri bike, I've done a couple longer events on road bike but I never had a proper fit performed with it. I don't necessarily know if the setup I have is the best fit, but I haven't had an issues on long rides. I'll give Shama a call and see if I can get in touch with Philip. I'm 5'-8.5" with a 30" inseam (I'll have to shoot over the seat height when I get home later).

Thanks again!
John

Hi Ian. I'm considering a PRfour Disc within the next several months. The default table seems to suggest a 54 or 56. My measurements are:


Overall Height (cm) 181.2
Inseam (cm) 88.5
Torso Length (cm) 59.0
Overall Arm Length (cm) 187.0
Shoulder Width (cm) 41.5

Much appreciated!

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https://connect.garmin.com/modern/profile/domingjm

Jgills,

Also call Cynthia Stewart at Bike Barn 713.522.8911. I just had an email exchange with her that tells me she's a top drawer fitter.

Ian

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

domingjm,
I'm gonna put your Pad Y at about 634 and your Pad X rear at about 450. And if those numbers are right (knowing your current saddle height on road or tri would help me be more certain) I think you should be on a 52cm PRfour with a 90mm stem in the -17 configuration, 5mm of spacer under the stem, and arm cups mounted one hole back of center and in the forward bracket holes.

You could get this done on a 54cm but you'd be up against the wall in terms of Pad Stack (lowest possible).

Ian

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

Awesome, thanks. Do you measure saddle height from the center of the cranks, along the seat tube? Please note that I prefer a pretty aggressive position.

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https://connect.garmin.com/modern/profile/domingjm

Center of bottom bracket (where cranks spin around) to the top of the saddle in the middle - just a straight line, ignore seat tube.

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

Ian,

Thanks so much for all of the assistance you Provide! It's very much appreciated and valued!

I'm coming from a 54cm Scott plasma 10 (the UCI legal 4 frameset). I had been on it for 4 years now and finding that It was putting me into a very quad dominant position and affecting my run off the bike. I've been re fit on my current set up and there is NO way that it is going to work. So here is what we came up with. I'm 5'11" with a 32.75 inch inseam. 175 lbs. One thing is the need to focus on keeping hips open as I'm just coming off FAI Cam impingement surgery (Where they shave your femur down), Micro fracturing and Torn hip Labrum repair surgery on top of Osteitis Pubis and multiple stress fractures of my pelvis. I'm quite flexible. Riding a Cobb Plus Saddle.


Pad Stack 659
Pad reach 426
Saddle Height 767
Saddle Setback 11
Saddle to Pad Drop 155
Saddle to Pad Reach 483
Grip reach 742
Grip drop 82
Grip angle 48
Arm pad to grip 347
BB to Grip 773
Arm pad Drop -100

I'm a distance guy. I'm OK at the game. I'm open to any and evey suggestion to get me to that finish line faster! Aero and comfortable enough to run a fast marathon off the bike!

Once again, THANK YOU!!

I'm looking at buying a PRfive, size 56cm, based on what I can make of their sizing. My current fit is on a 61cm Cervelo P3 with 165mm cranks.
Pad Y = 685mm
Pad X = 478mm (pad rear) or 529mm (pad middle)
Pad Z = 133mm (inside edge to inside edge)
Saddle Drop to Pad 84mm


My inseam is 925mm


Does the 56cm frame sound correct?

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I'm closer to the feathered end of the spear than the point.

mpkellyjunior,
There's some good info in here (beyond the numbers), thank you - the more I know the better I can prescribe. You're leggy and that makes the reach aspect of your fit short and it complicates things slightly. I fit lots of people built like this, I'm built like this so don't freak out when you, a guy who's 5'11", the frame size I'm about to lay down here (it's 'cause of your morphology and that 426)

If you get a QR PRsix (the super bike) it's a a size 50, with the 90mm stem, the stem clamp shell in the "high" position, 65mm of pedestal, arm rest in the middle hole with the bracket rearward.

If you get a QR PRfive or foure it's a size 52, with a 70mm stem in the -17 configuration, with 10mm of armrest riser, with armrests mounted one hole back from middle.

Now, with the hip focus - combined with 100m of drop - I want to suggest...nay, insist that you go with short cranks (155s). One option is that you call QR within your order and get a set of Rotor 155 cranks installed on that bike before ship. Later, if you l like you can get Rotor's new INspider powermeter worked into that.

I'm here if/when you have questions, comments.

Ian

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

David_Tris,

Well, it will work on the 56 and the 58.5. Let me 'scribe 'em both and we can discuss.

If it's the 56.... 90mm stem in the -17deg position, 5mm of armrest risers, 30mm of stem spacer height, and pads mounted one hole away from the saddle from the center hole.

If it's the 58.5... 90mm stem in the -17deg position, 5mm of armrest risers, zero stem spacer height, and pads mounted one hole back towards the saddle from the center hole.

this is a VERY tough call - both setups are excellent. For me there's one tiny aspect that tips me towards the 58.5 and it's that I like the stem slammed more than I like 30mm of spacer, 30mm of spacer is acceptable for sure but not my preference.

Thoughts?

Ian

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

Dude - 9:00pm and you're helping folks, you rock!

It's a used 56cm PR5, so this was more of a "I'm not limiting myself, am I" kind of question. My P3 has 10mm under the bar and another 20mm above, and I've got the DI2 junction hiding behind it. So I guess I'm used to not being slammed. I have a Torhans bento that covers that junction box and kind of hides the fact that it's not slammed. As long as I can get the reach I need, I could be OK with this spec. I've been on an undersized bike before, and do not want to be there again. FWIW I'm 64 and not as flexible as some *cough cough* younger riders.

Could I slam the base bar and add more spacers to the aero bars/pads and get the same fit?

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I'm closer to the feathered end of the spear than the point.

That's an option but for TT I'm fine with a big disparity between the basebar elevation and the aerobars - for Tri I like the base bar and the aerobars to be closer in height. You should go for with the 56, sounds like it's a great find!

Ian

PS. only 7pm in California.

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