I had a fuji d6 that I loved and fit well.
It was the the large (58cm)
Stack - 52.4 (and 35mm of spacers)
Reach - 44.5
Stem - 110mm
Now I’m getting the Norcom Straight. Which size would work better for me? (I do not have the ability to get fit on the bike ahead of time.)
NS 55cm:
Stack - 54
Reach - 43.5
Stem - 110mm
NS 57cm:
Stack - 56.5
Reach - 44.9
Stem - 110mm
Seems like I might not be able to get low enough on the NS 57…?
So should I get the 55cm?
Thanks for the help!
If these are the only two options, I think the 57 is a better fit.
The NS55 is 1 cm shorter on the reach. If you use a 120 stem to make up the difference, you’ll (at least slightly) be overweighting the front wheel. This will impact how the bike handles.
The NS57 with no spacers and the same stem, will add 6mm of stack to your current position. This may be ok or you may be able to hit your current position by changing the bars, or by replacing the stem.
hth
Thanks for the feedback!
So 10mm extra stem length is going to “over weight” the front wheel?
I’d say you’re better off on the 55.
Interesting… I had always heard you can always make a smaller bike bigger, but you can’t make a big bike smaller (within reason). That’s why I’m nervous. Thanks again for the input guys.
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So 10mm extra stem length is going to “over weight” the front wheel?
Yes James, I do. 1cm, only a slight change. And it does depend on how steep the OP rides. But, 110 is pretty long already for a tri bike. 120 is definitely pushing it.
I made the same change on my large Transition. The difference was surprising.
To the OP, I think a bike with more read and less stack would be a better choice.
The NS55 is 1 cm shorter on the reach.
**No it isn’t! **That is the problem I have with the reach term as defined. It is measured at the stack height… so if two frames have different stack, you have to adjust the reach term to compare the actual reach.
Since he uses 35mm of spacers the actual reach on his Fuji is 44.5-0.33.5= 43.5cm, and the actual stack is 52.4+.953.5= 55.7cm.
On the NS 55 at the same stack of 55.7cm (which would be 1.8cm of spacers), the reach is 43.5-0.3*1.8= 43.0cm
On the NS 57 at the same stack of 55.7cm (which would be -0.9cm of spacers), oops… well lets just say the reach is 44.9, and stack is **.8cm **higher.
So the 55 gives him a half cm less reach at the same stack. The 57 has too much stack to get as low as he currently is and would require a shorter (by 1-2cm) stem to acheive similar reach.
If the OP has any aspirations of getting lower on the bike, the 55 is definitely the way to go. If he’d rather go higher, then the 57.
Nice :o ) great post
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So, the adjustment is based on the head tube angle? Thanks, I should have thought of that.
Yes… for the sake of comparing frames I think it would be best to list reach at some arbitrary fixed stack height that corresponds to the lower part of the headtube. Then the reach number would always tell you which frame was “longest” and by how much.
So it sounds like 55cm is pretty firm. Thanks guys!!
That depends on whether or not you are interested in making any changes to your position… usually for aero reasons.