Urgent bike fit comparison help required....

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diegogarcia
Posts: 571
Joined: Sat Apr 24, 2010 7:31 pm

by diegogarcia

Hi all,

I am after some expert help and guidance on bike fit comparison and need help, as typically, I cannot see the wood for the trees.

I am looking at a Giant TCR Advanced Pro 1 as a purchase, as had a TCR on demo for a week and fast, lively, stiff and has all the caveats I look for in a bike. It is very good without breaking the bank and sold my evo so have funds in place. However, I am torn between two sizes.

Going back, my ideal fit was a 56cm Specialized Tarmac and I rode these bikes for years in SL2, SL3 and SL4 guise, but trying other bikes. However, nothing has worked quite as well fit wise than the S-works as felt 'dialled' in on the bike and could ride for 6-7 hours no problem. At the minute, I cannot ride Specialized for corperate reasons. Long story, but not relevant. But here is the rub, I am classically, between sizes, short leg, long body, 2.4 torso length and I do not know whether to commit to a medium, or medium large and typically, there are differing opinions in store even and a fit concludes one or the other would do it. But, I am drawn to the M/L with a 100mm stem to replace the 110mm stem and that would be it. For reference I run 165mm cranks as short legs long reach and in looking at the geo, the M/L compares to a 56cm Tarmac, geo here

http://www.giant-bicycles.com/en-gb/bik ... /#geometry

https://specialized.com/us/en/bike-arch ... eset/38007

The M/L is 0.5cm longer but offset by a slacker headtube (matching angle to seat which is negated by fore and aft to accom 165mm cranks) and taller head tube too 160 to 168mm and relevant spacers which I would keep in place, so to my mind, the closest fit is M/L. Reach is very similar - 39.8 compared to 39.5....

Can anyone cast an eye over it an offer and opinion as I cannot see the wood for the trees as been looking at geo for days. They both fit. Ultimately, I have always preferred a 'bigger' bike, I do not race, casual rider but I enjoy 3/3/4 hour blasts rather than long bimble days. I noticed that with the medium, the short cranks ramp the seat post up and make the drop more pronounced.

Thanks for any input, readily received. I wrote urgent help required as I want to make a decision, but I do not need to buy it today, so to speak.

Here is an image of my Tarmac fit over the gens.

Image

Image

Thanks, Diego.

BikeAnon
Posts: 399
Joined: Sun Mar 02, 2014 6:36 pm
Location: NY USA

by BikeAnon

Get the frame that gives you the head-tube size you want. That is the one insurmountable fixed size, if you want to go lower.

The rest can be dealt with via seatpost, seat rail, stem, and handlebar replacement/adjustment.

Going "long" or "short" on the stem (90, or 120, even 130) will not bother you at all.



In my non-pro-take-it-for-what-it's-worth opinion.... When stuck between sizes, always go smaller with the frame. Components can "grow" a bike, a bit better than they can shrink one.

by Weenie


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kramnnim
Posts: 44
Joined: Mon Aug 30, 2010 10:18 pm

by kramnnim

Get the M/L.

nlouthan
Posts: 188
Joined: Mon Jan 31, 2011 2:41 am
Location: SF Bay Area

by nlouthan

Both frames will work without any problems. If your fit is 100% set, then M/L. The medium will let you go lower if you can gain flexibility in the future. The M/L will be more aesthetically pleasing if you don't. The 3mm difference in reach is the difference between gloves or bare hands.

diegogarcia
Posts: 571
Joined: Sat Apr 24, 2010 7:31 pm

by diegogarcia

nlouthan wrote:Both frames will work without any problems. If your fit is 100% set, then M/L. The medium will let you go lower if you can gain flexibility in the future. The M/L will be more aesthetically pleasing if you don't. The 3mm difference in reach is the difference between gloves or bare hands.


Yes, as I suspected. I have however got into a 'happy' dispute with the shop as I am taller than I look, even to the point that we measured me thrice over and they were all amazed. I am between 5'9 - 5'10 and though the M/L is a 5'10 opening gambit, my upper reach and torso are that of someone this height, if not bigger. My height is in my body, not my legs and if I ride small, medium, medium large, large, I always accomodate my short inseam with 165mm as per electronic bike fit some time ago.

So, I think the ML is akin to the large Tarmac. Thanks. This is using data, fit and feel from a large tarmac which I was BG fitted for after staring at my data and my screen, I concluded this. After an experiment with an Evo I am def suited to comact geo.

Finally, I blame my Dad for my Cavendish legs. :mrgreen:

Magic. Thanks.

by Weenie


Visit starbike.com Online Retailer for HighEnd cycling components
Great Prices ✓    Broad Selection ✓    Worldwide Delivery ✓

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diegogarcia
Posts: 571
Joined: Sat Apr 24, 2010 7:31 pm

by diegogarcia

Thanks all, I went with caution and ended up buying a Cannondale Synapse with much shorter reach and higher stack and have a fit next week. Oddly, last Thursday I shaved 55 seconds on a Strava segment without even trying so it bodes well once dialled in. Slow and old now, 45 next time round....Synapse seemed like the right bike.

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