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Disadvantage of a bigger road bike?


Saudiq
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Hi All,

 

I'm contemplating purchasing a 54 road bike with the top tube being 54.8cm however, when I did the ergofit bike setup it has my top tube has 53.7cm.

 

My question is, how would this disadvantage me if any? If I used a shorter stem would this compensate enough for it? My height is 173 which according to the sizing chart means I have to ride a 54? :unsure:

 

Please let me know.

Edited by Saudiq
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Dude, 10mm (or rather to put it into persepective = 1cm) is not going to make that much of a difference. If you are concerned, do as AndreZA said and put a stem that is 90mm instead of 100mm.

 

Not really a train smash man. Enjoy the new bike when you get it :thumbup:

 

 

Edit: Discovered a typo

Edited by Tiny K
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It's unlikely you will find a 54cm bike with a top tube as short as 53,7cm. Perhaps you should be looking at a size 52. Anyway, my top tube is 2cm bigger than it should be. I put on a shorter stem too and it does help.

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Hi All,

 

I'm contemplating purchasing a 54 road bike with the top tube being 54.8cm however, when I did the ergofit bike setup it has my top tube has 53.7cm.

 

My question is, how would this disadvantage me if any? If I used a shorter stem would this compensate enough for it? My height is 173 which according to the sizing chart means I have to ride a 54? :unsure:

 

Please let me know.

 

Why go for Ergo Fit then?

 

I used to use a Large Scott....and then I went to buy a medium Fondriest with a top tube of 55.7.....according to ergofit I need a 55.7 which was spot on, then your stem gets added to that according to the measurements the program gives as your flexibility, etc. Speak to Renay Groustra, he did my ErgoMax setup, he will be able to explain better to you and since he is a pro mountainbiker I am sure he knows what he talks about.

 

Rather get a frame that fits you as mentioned by ErgoFit....your whole setup is worked out according to that system.

 

If you want I can send you his number?

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Don't most fitmnent programmes measure your total reach rather than your top tube length.?

This should then allow you to some leeway i.e. top tube + stem = reach.

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I'm contemplating purchasing a 54 road bike with the top tube being 54.8cm however, when I did the ergofit bike setup it has my top tube has 53.7cm.

 

I am curious as to which frames these are? The 54.8cm is probably being sold as a 55cm right? And the 53.7cm you have now probably a 54cm?

 

You are measuring centre to centre?

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Not a big deal. Just get a stem that's 10mm shorter. As long as it is not 80mm or shorter.

You've got me a bit concerned about the "not 80mm or shorter" part. I'm using a 70 stem on a 56 frame, used to have a 90 but find the 70 more comfortable. Makes me think I should perhaps be riding a 54 with a longer stem instead of a 56 with a short stem?

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I am curious as to which frames these are? The 54.8cm is probably being sold as a 55cm right? And the 53.7cm you have now probably a 54cm?

 

You are measuring centre to centre?

No......

 

Road bike sizes are normally quoted using the Seat Tube length. So, if he is talking of a size 54, then the seat tube, from the centre of the top tube to the centre of the bb is 54 cm. Top tubes are normally longer than the seat tube. That is why the top tube is 54.8 on the size 54 bike.

 

Also remember, because the seat tube is at an angle, the higher your seat post, the further away you are from the bars.

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No......

 

Road bike sizes are normally quoted using the Seat Tube length. So, if he is talking of a size 54, then the seat tube, from the centre of the top tube to the centre of the bb is 54 cm. Top tubes are normally longer than the seat tube. That is why the top tube is 54.8 on the size 54 bike.

 

Also remember, because the seat tube is at an angle, the higher your seat post, the further away you are from the bars.

 

Not entirely, that depends on the manufacturer, that is why I am asking which frames these are?

Some use top tube and some use seat tube measurements.

 

Mine say 57.5cm and that is exactly how long the top tube is.

 

when buying a bike top-tube length is the most important factor.

Seat tube is quite easily corrected with a seat post. Not much you can do about a top tube bar a cm or two with a stem.

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And with compact frames, the seat tube measurement helps you nothing at all.

 

You need a vertical top tube measurement.

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You've got me a bit concerned about the "not 80mm or shorter" part. I'm using a 70 stem on a 56 frame, used to have a 90 but find the 70 more comfortable. Makes me think I should perhaps be riding a 54 with a longer stem instead of a 56 with a short stem?

 

Again, depends on the top tube. I would go for 54cm with a 90mm stem but will how far will your seatpost stick out? If you are one of those people with long legs and short torso, you can stick with what you have. Otherwise you sit with a bike with a 400mm seatpost sticking out of your frame.

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You need a vertical top tube measurement.

Even better, find the geometry charts. In my case, most of the bikes with the right top tube have a head tube that is too short, forcing me to use a ridiculous number of steerer spacers.

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You need a vertical top tube measurement.

 

Do you mean horisontal?

 

I am with you on everything else. Most of the Euro manufacturers measure seat tube, but the US guys seem to meausre seat tubes - there are exception though.

I still dont get De Rosa measurements - a size 46 is about equal to 58 in ther brands if I understand correctly?

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Do you mean horisontal?

 

I am with you on everything else. Most of the Euro manufacturers measure seat tube, but the US guys seem to meausre seat tubes - there are exception though.

I still dont get De Rosa measurements - a size 46 is about equal to 58 in ther brands if I understand correctly?

 

Ja I mean horizontal, but what is the word (help the afrikaaner out here)

You have to draw in imaginary line because the top tube is sloped?

 

Know what I mean?

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