Ian,

I am looking to purchase at QR XPR and am wondering the correct size. I am riding a 54 cm Cannondale Slice (2005 Aluminum), but I am worried it is too small because of how low the bars seem to have to be compared to my seat height (and my recent Trek experience see my post below), and back fatigue/pain (I have no back problems otherwise) at even an Olympic race, so I would rather fit based on my personal measurements. I don't fully trust fit coordinates as they are on the smaller frame.

Using the formula method, I am 176cm tall, my inseam is 86cm, and my seat height is 78 cm.

What is the QR size for me?

Thank you!

Hi Ian,

I had initially posted a question about which bike to choose on a new thread last week. Thanks for your input there along which many others, I am ready to move forward with the XPR. I am debating buying the Tri Rig Alpha or 43 asc extension for the front end and building it up with my fitter. Would you recommend buying the full bike now or buying the frame and adding pieces afterwards.

Seat Height: 797
Pad X/Pad Reach: 510/555
Pad y/Pad Stack: 680
Height 6'2"
Inseam 33" or 84 cm (to the floor, not ankle)
Crank length 160 mm (I seemed to like this one most)

Quote:
Ian,

I am looking to purchase at QR XPR and am wondering the correct size. I am riding a 54 cm Cannondale Slice (2005 Aluminum), but I am worried it is too small because of how low the bars seem to have to be compared to my seat height (and my recent Trek experience see my post below), and back fatigue/pain (I have no back problems otherwise) at even an Olympic race, so I would rather fit based on my personal measurements. I don't fully trust fit coordinates as they are on the smaller frame.

Using the formula method, I am 176cm tall, my inseam is 86cm, and my seat height is 78 cm.

What is the QR size for me?

Thank you!
Rob,
I get that you are weary and I can easily see how/why you've ended up on a bike where the whole frontend (base bar, arm pads, aero extensions) was too low. You've got long legs for your height and that demands that the set-up is "short and tall" (as opposed to long and low) so the pads need to come up and back to meet you. You can still be crazy fast in that position, and, as you've noted, comfort is critical.

I'd guess your Pad Y to be around 650 and your Pad X to be ~430. You should get an XPR size 54 - and get it with the Profile Design 1/Seventeen stem* (NOT the QR aerostem). Get the PD 1/17 stem in 90mm length, set in the -17 degree position, with 15mm of spacer under the stem and another 15mm of aerobar pedestal, and then pads should be set -7cm of off set (which is 2 holes forward of max back).

Let's stay for a sec that my assumptions are off - not likely, I'm an expert in this and I've had years of practice with thousands of atheltes - but if I'm off a bit you'll be able to move the pads all over the universe: up 80mm higher and back 30mm closer WITH THE SAME 90MM STEM. You can also go a long longer (50mm) and lower (30mm) but that's less of a worry in this case. The reason the ranges is so great is that *this stem we're talkin' about can be flipped to a +17deg position and gain a ton of height. Also, this stem is inexpensive, they make it in lots of lengths and you can give this bike a ton of range in the snap of your fingers. Also, the bike will come with a bag of profile design spacers and bolts of differing length - this is the pedestal system to lift and lower the aerobars so you can get the frontend exactly where you need it.

Get back to me here if you have quesitons but I'm confident in this so order before the sale ends.

Ian

Ian,

So in my case, I know you are recommending the 54, which sounds like I will have to have a very tall front end relative to the frame top tube. And I'm fine with this and am not doubting your background, experience by any means. But, most size charts/finders seem to place me on a 56 (Cervelo, Trek, etc.) and I also know each bike is different. But I couldn't imagine raising the bars on my C'dale as it would be so high on the front relative to the top of the frame and probably pretty tippy. If I were to go with the 56, would it even be possible to achieve the fit with a lower total front end relative to the seat height? (Shorter stem, less spacer height, etc.)?

Thank you for your time.

Rob

Ian,

I have attached my fit on my Med Trek SC. We had to get a seatpost with set back, and raise the front end so high on this bike. This position was not super comfortable, and handling was not great as the front was so high. I did NOT get a pre-fit, which is what I should have done, and as I think I stated, I had to sell the bike. I do not have the fit coordinates of my Cannondale which is far more comfortable with handling and power, but just not great for longer/harder rides on my back (but it is much lower on the front), but I could measure if you think it's necessary for you to determine.

Yes, this is why I am weary, and just want to eventually be on the right bike...and this is why I am reaching out here to work on this process with experts.

Is QR even the best bike to achieve a good fit for me, or is there a better choice? (for instance the Cervelo Head Tube length is longer/taller at size 56).

One more thing if it matters/helps. I rode a 1990 QR Superform 55cm. This was my first bike, and all of my best times were on this and I remember it being much more comfortable for longer rides (i still have the frame). Based on my own measure, frame stack was approx. 50cm, and reach was 42, similar to my Cannondale, but the head tube length was 14cm and the Cannondale's is 11cm.

OK, I'll stop now :) Thank you again so much for all of the time on this.

Rob

Hello Ian, and thanks in advance,

I'm looking at building a X-PR as my first TT bike, and I'm hoping to get some sizing guidance based on the fitting I did on my gravel bike a few weeks ago.
My fitter mentioned that a size 54 should work for me, and that the Profile Design component on the bike are easy to fine tune to the right position. The only thing I'd prefer to have is the QR aero stem, just for aesthetics, but I know it may not work and the profile design one would fit me better.

Height: 179 cm
Inseam: 83.7 cm
Saddle height: 72.2 cm
Crank length I felt most comfortable with: 160mm

See the screenshots below from the report I received.
I'm pretty flexible overall, and could have a saddle-handlebar drop much lower than 48mm, but that is the limitation of my gravel bike.

Looking at an XPR, sadly without a current bike fit. However, 5-11" male, 33.5" inseam. Wondering if a size 54 I've found with the 90mm stem with the upgrade carbon bars they offer is likely to be an appropriate size. Willing to take a chance and get fit after the purchase as it's a solid deal.

Thanks for any advice!

Hello,

I am looking at an X-PR. I am 178 CM and a self-measured 80.64 inseam. I am currently riding a bike I suspect is too big for me (2015 cervelo P2 58 cm). Previous fitter was sort of able to make it work, but i'm not in love with the fit and would like to find something more appropriately sized.
QR website is recommending a 52 or 54. Would I be able to make a 56 work?

Catsup,
Based on your morphology I think your Pad Y is roughly 640 and your Pad X is in the nieghborhood of 465.

I think it's polite to answer directon questions... "Would I be able to make a 56 work?" Yes, but it's not optimal, in fact, you're be painted in a corner, it's probably too big. If you rode a size 56 XPR you'd need a 75mm stem in the -17 positon and slammed - that speaks to my assumption of 640 as a Pad Y and -17 slammed is code for "cannot go lower". This is rock bottom pad height and in the most extreme corner of the range on this size. The Pad X has some flexability in the 56 but the Y negates this as an option.

In preparation to deliver the optimal prescription it's important to note....the XPR can built with a "mortal" stem, and QR uses a Profile-Design 1/Seventeen that can be set in the +17 position or the -17 degree positon. QR smartly offers three sizes: 75, 90, or 110mm. OR QR's own design... "aero stem".

If you got the XPR with this mortal stem then the optimal size would be 54cm with a 90mm stem in the -17 position with 10mm of spacer under stem and 10mm of aerobar pedestal. The pads would be offset -4.75 which is nearly dead center in the fore/aft range. Lots of room to move up/down/fore/aft in the front end to find perfection.

if you wanted the XPR with QR's OEM aero stem.... Size 54, 90mm stem, 10mm of stem spacer* and 15mm fo aerobar pedestal, pads offset at -5.50 - all a great spot with room to move up/down/fore/aft. *QR's aero stem has two, clam shell type spacers where the base bar gets clamped in the stem you can one half atop the base bar and one half below the baser bar to arrive at your 10mm of stem spacer.

Ian

Hi Ian, just wanted to report back and thank you for the guidance.
I ordered and received the X-PR with the details you provided me with. Today I did a fit and your numbers were quite close to what we ended up having.
I went for a 70 km ride today, and couldn't be happier with the bike. Legs were pretty good after the ride, and I just need to fine tune the aerobars to be more comfortable and hold the position for longer (together withe strengthening and getting used to it).
Thanks again for the valuable work and time you put helping us here. 🙏

Hey Fitters,

I’m 6’3” with a longer torso and currently have used a 60 cm Kestrel Talon with clip on aero bars. I wear 34 length pants. I measured my current pad placement at pad Y at 73cm and Pad X at 52 cm. I have never been bike fitted and never had any discomfort over a 70.3 riding in aero.

I’d like to pull the trigger on an X-PR and don’t know if I should go with a 56 or 58.5? Also, am I correct in thinking that a local bike fit would be better than QR’s online fit service?