Bizarre TCR sizing

Discuss light weight issues concerning road bikes & parts.
GT56
Posts: 571
Joined: Fri Jun 05, 2009 9:40 am
Location: Switzerland

by GT56

Ypsylon wrote:Have you taken any other measurements, other than HT and TT? The most plausible thing that comes to my mind is that they put a wrong label on a frame.


that would be my bet too

wingguy
Posts: 3527
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

Stoo wrote:HT and TT are the only measurements listed on the giant site.


They also provide wheelbase and standover. Measure the wheelbase, remeasure the TT. You're highly unlikely to have measured the HT wrong but remeasure that for luck anyway.

Occam's Razor says you've been sold a Large frame by mistake.

by Weenie


Valbrona
Posts: 1482
Joined: Fri Oct 28, 2011 3:25 am
Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

wingguy wrote:
Stoo wrote:Occam's Razor says you've been sold a Large frame by mistake.


That'll be it.

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743power
Shop Wrench
Posts: 745
Joined: Sat Nov 29, 2008 6:15 am
Location: Colorado

by 743power

I've had two m/l's one advanced and one ISP and have sold and worked on dozens of every size. Your ISP looks like a large. You can tell by where the top tube intersects the top of the rear tire. Or in the case of the large, doesn't intersect. Measuring the ISP frame is difficult so you may be measuring differently then giant.
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."

Stoo
Posts: 318
Joined: Thu May 23, 2013 9:22 am
Location: Warwick, UK

by Stoo

Yeah I reckon so too.

Wheelbase suggests a large also for the ISP frame.
'17 Giant Trinity Pro TT - DA9070 - Rotor 3D+ P2Max - Zipp 900T/HED Jet 9+
'16 Genesis Equilibrium - U6800 - FSA SRM - WH6800
'15 Cannondale Super Six Evo HM - DA9000- DA9000 SRM - CC40C
'13 Giant Trinity Composite - U6800 - QuarQ DZero

Coppi51
Posts: 53
Joined: Mon Aug 07, 2006 4:05 pm
Contact:

by Coppi51

If the head-tube is 185mm...it is definitely a Large sized frame. Giant does not currently make any custom carbon models (for geometry) outside of the geometry listed on their website. (Trust me, I know ;-))

The horizontal TT on that ISP frame you have will definitely be 585mm (provided the HT is 185). The end measuring point you have on the ISP will be slightly different from the Vector post centerline you have on the Advanced model.

Hope that helps!

sharkman
Posts: 1390
Joined: Fri Jun 25, 2004 8:32 pm
Location: the Netherlands

by sharkman

The 2012 isp sl looks a lot like mine which is an L with headtube 18.5. Toptube is hard to measure with giant since it's extremly sloping but but it will be horizontal 58.5 (as is mine)

Stoo
Posts: 318
Joined: Thu May 23, 2013 9:22 am
Location: Warwick, UK

by Stoo

I think you're all right and I'm a biff!
Measuring that TT on the ISP sure is awkward.

Now, as this is the case....

Can I achieve the same sizing(kind of) by using 15mm of spacers beneath the stem to achieve the same effective Head tube height, and a 15mm longer stem to achieve the same HT length?

Will that work? Or am I being silly?
'17 Giant Trinity Pro TT - DA9070 - Rotor 3D+ P2Max - Zipp 900T/HED Jet 9+
'16 Genesis Equilibrium - U6800 - FSA SRM - WH6800
'15 Cannondale Super Six Evo HM - DA9000- DA9000 SRM - CC40C
'13 Giant Trinity Composite - U6800 - QuarQ DZero

User avatar
naylor343
Posts: 114
Joined: Sat Aug 30, 2008 1:46 pm
Location: Ariege, Midi-Pyrenees

by naylor343

It's not quite that straight forward due to head tube and stem angles. You can confirm your changes using a calculator such as this one http://www.ttbikefit.com/stemcalc.html Some of these calculators may have there faults so it may be wise to search for others and confirm the calculations before ordering a new stem. There are plenty of them out there if you search.

Even better, if you are near a giant store, take the bike in, they should let you try stems if your going to buy one. Good luck.

Stoo
Posts: 318
Joined: Thu May 23, 2013 9:22 am
Location: Warwick, UK

by Stoo

I've got a few stems at the moment.

Head tube and seat tube angles are identical as Are the chain stay lengths so in theory it should work with saddle set at identical height and setbacks.

I'll probably have slightly different weight distribution and steering response due to wheel base differences but I think it'll be ok...?
'17 Giant Trinity Pro TT - DA9070 - Rotor 3D+ P2Max - Zipp 900T/HED Jet 9+
'16 Genesis Equilibrium - U6800 - FSA SRM - WH6800
'15 Cannondale Super Six Evo HM - DA9000- DA9000 SRM - CC40C
'13 Giant Trinity Composite - U6800 - QuarQ DZero

Stoo
Posts: 318
Joined: Thu May 23, 2013 9:22 am
Location: Warwick, UK

by Stoo

Just to close up on this.

The ISP was/is a large.
Advanced is a medium/large.

No big deal. I race on the ISP. Train on the advanced.

My fitter got identical contact points by using a 110mm stem and 10mm spacer on the large and a 120mm stem with 22.5mm of spacers on the ml.
'17 Giant Trinity Pro TT - DA9070 - Rotor 3D+ P2Max - Zipp 900T/HED Jet 9+
'16 Genesis Equilibrium - U6800 - FSA SRM - WH6800
'15 Cannondale Super Six Evo HM - DA9000- DA9000 SRM - CC40C
'13 Giant Trinity Composite - U6800 - QuarQ DZero

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