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Question for the Fitting Gods.... help please!
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I know, I know, buy the bike that fits and get it fit by a pro - I am a believer. But... this situation requires a low dough solution.

I am trying to put a buddy (total tri newbie) on a tri bike for the least amount of cash. I have almost enough spare parts to build up a frame with a Shimano 600 grouppo - will need to get seatpost, pedals, aero bars & wheels (so if you have any of these you are looking to unoad cheap give a holler. The frame we are looking at is 650c).

Here's the issue - the best deal on a steep frame/fork (understanding the pros and cons, he wants to ride steep) is a compact Tsunami frame from Chucksbikes.com at $160. It has received positive remarks on this forum. The L has a 56cm Top tube and the M has a 53cm top tube and between three of us novice monday morning fitters, we are unsure which frame will work better. I figured with the collective knowledge on this forum would exponentially increase the accuracy of our decision.

My buddy is 6' 2" so i initially think the L should be closer to a reasonable fit, so..... I put him on my 53 Tequilo (I am 5' 10") and a Medium Giant OCR from accross the street to see how things looked. The OCR measures 55.5cm on top and has clip ons with the arm rest alllll the way back and the seat allll the way forward to shorten the cockpit. I understand that the OCR seat tube angle is slacker but if i am looking for fit on the reach, i don't think it matters for this purpose (please correct me if i am wrong on this. the head tube angles are apart by .5 degrees). The result is that The OCR still looked too long - especially if the arm rests were where they were supposd to be and the seat was not slammed all the way forward on the rails. The position on my QR looked about right.

A bit befuddled, we pulled out the trusty tape measure to measure proportions: 24.5 torso (same as mine at 5' 10" which is why my 53 QR looked better on him) 34.5 inseam. SO it seems that his lower body fits the L better but the upper body wants to M. The Tsunami frame is, however, a compact geometry so should we be concerned that the M would show too much seat post?

Any comments, guidance, suggestions, ideas etc. out there to help with the decision between M & L? Thanks!!

Disclaimer: neither me, my two tri neighbors, nor our 6' 2" buddy are FIST certified, nor are we a member of the vast left wing conspiracy known as the Tom Demerely Internet Stalking Club.

jg

Last edited by: greenjt: Dec 31, 03 11:04
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Re: Question for the Fitting Gods.... help please! [greenjt] [ In reply to ]
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He's 6'2" so you're definately into a large frame for the OCR or the Tsunami. I'm 5'10" and ride a medium TCR. I also have a 53 cm toptube length as my ideal on a tri bike.

To ballpark your theoretical frame size measure your friends inseam and multiply by .67. It gets more complicated than this because not all manufacturers measure their frames the same way. Some like Cervelo make compensation for their tri bikes so if you ride a given size road bike, their tri bikes are listed as the same size. But at least from here you could then go on the Cervelo site and look up the geometry of their tri bikes at your friend's size frame to get a good idea.

Setting up the OCR is not that hard. Learn the basics of bike fit on the Colorado Cyclist site they have a good explanation. Once there for tri events swap out the regular seat post for a neutral set back one. Bontranger is one company that makes these at a decent price, in fact I just sold one on ebay for twenty bucks. Push the seat asfar forward on the rails as possible. This gives you about 75/76 degrees which is as much as you want for a road geometry frame. Don't go to a forward seat post as it will throw the handling off too much IMO. For aero bars you want them to be shorter than he would ride on a tri geometry. Probably something like a Syntace C2 one size smaller than he would ride on a tri bike will work great.

I'm unfamiliar with the Tsunami frame but for a $160. for a genuine steep angle frame with carbon fork how can you go wrong? I am quite confident that he would probably need a large. The best thing to do is read over Slowman's articles on tri bike ft and then go to Tom Demerly's Michigan Bike Sports site and read his articles on fitting. Once you've got it set up post some photos here and a number of people will likely try to help out. Just be sure that you can still use 650 wheels on a large frame. A 6'2" guy should more likely be on 700's.
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Re: Question for the Fitting Gods.... help please! [cerveloguy] [ In reply to ]
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CVG - thanks for the feedback. The problem i have is that his torso seems to fit the M but the legs seem to fit the L (and no a custom frame is not an option here. So i guess the question is do we get the smaller frame and have a lot of seatpost but a good fit accross the top or get the larger frame with a zero setback and very short stem?

fyi... we were using the medium OCR as a fitting tool for comparison to the tsunami as the top tube is almost identical to the Large tsunami.

jg

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Re: Question for the Fitting Gods.... help please! [greenjt] [ In reply to ]
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Here's my suggestion.

I just an 04 TCR aero. I'm 5'8" and ride at a seat height of 72cm.

I set the bike up as per this site and Tom Demerly's. I took pictures of myself on the bike....drew in the line angles ( 90 degrees etc) and compared to pictures on Tom's site.

I even e-mailed them to slowman and he said it looked good.

In the end I have a 75 degree seat tube seat pushed forward ( about 77 drgrees) with syntace aero bars with bar end shifters on profile pursuit bars with all the spacers out.I have the 2 - 90 degree angles and proper leg extension. the bike feels Great.

Holding your picture up to Tom site really shows you what needs to be done when you can't get the help of a pro.

It's a Good life if you don't Weaken!
My Mom 1922-2004
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