54cm frame v 56cm

General cycling advice ( NOT technical ! )
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digitalgerry
Posts: 18
Joined: 5 Feb 2022, 11:35am

54cm frame v 56cm

Post by digitalgerry »

All
Feeling somewhat stupid, I recently bought a Cannondale S/H and have had a few problems feeling ‘right’ on the bike.

I went into my local bike store today and they saidI should have a 56cm. I double checked the sizing and i’m 5’10 which I believe looking at Cannondales chart is the upper end of 54”

The seat was too low and they’ve adjusted that but they say I must have a 56 frame. Interestingly they then suggested I look at their carbon range!

so what are peoples thoughts. I am prepping for a London to Paris ride and need everything in my favour but the wallet is about to have a heart attack if I need a new bike.
scottg
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Joined: 10 Jan 2008, 8:44pm
Location: Highland Heights Kentucky,, USA

Re: 54cm frame v 56cm

Post by scottg »

What is a Cannondale S/H ?
+++++++++++++++++++++++++
Deutsche Luftschiffahrts-AG
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Cugel
Posts: 5430
Joined: 13 Nov 2017, 11:14am

Re: 54cm frame v 56cm

Post by Cugel »

digitalgerry wrote: 2 Jul 2022, 9:23pm All
Feeling somewhat stupid, I recently bought a Cannondale S/H and have had a few problems feeling ‘right’ on the bike.

I went into my local bike store today and they saidI should have a 56cm. I double checked the sizing and i’m 5’10 which I believe looking at Cannondales chart is the upper end of 54”

The seat was too low and they’ve adjusted that but they say I must have a 56 frame. Interestingly they then suggested I look at their carbon range!

so what are peoples thoughts. I am prepping for a London to Paris ride and need everything in my favour but the wallet is about to have a heart attack if I need a new bike.
Manufacturers have, for a long while now, taken to measuring their frames in different ways. For example, some measure a vertical line from the BB to the top tube; some the same except to the virtual top tube rather than the actual sloping-down-towards-the-back top tube; some from the BB to the top of the seat tube; etc.. This makes it difficult to choose the right size.

If you can get at the actual physical bike as you buy it, a better method is to get astride the different sizes. If you can stand over the top tube without it squishing yer bits, that's a good start. If the bits-to-top tube distance is many centimetres, it's too small.

Personally I like to get a frame that I can just stand astride, but only just. This often makes it nominally one size too big, in theory, if its a modern frame with a down-sloping (towards the back) top tube. However, it also means that you'll have the seat post a bit lower, the head tube (and thus the bars) a bit higher and the frame a bit longer than the next size down. This means a more upright position (which suits me, an ole scrote) and perhaps also that the front of a pedalling shoe won't catch the front wheel if one does a slow-tight turn.

You can still get your reach right with a shorter stem; and your seat height right with less seat post sticking up.

But if you want to have a racy position (nose on the front wheel) you can buy a smaller frame, with a higher seat post height and shorter head tube/lower bars (with a longer stem, if necessary) tipping you forward more.

Cugel
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slowster
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Re: 54cm frame v 56cm

Post by slowster »

If at all possible post a video clip of you riding the bike viewed side on, and failing that a still photograph or two. Posters on here will then be able to provide a better response.

In the meantime I suggest you read the article linked below on bike set up, which will help you understand the factors involved in bike fit, and especially how to determine saddle height and setback. The article was written by one of the main members of this forum, 531colin.

https://wheel-easy.org.uk/wp-content/up ... -2017a.pdf

Seat tube length does not influence saddle height or set back, i.e. as long as you have enough leeway to raise or lower the saddle to get the right height for you. It is likely that you can achieve the right position on more than one size of any given bike model, and the choice then of which is 'correct' may be a personal one, i.e. a preference for the feel of how the bike in one size handles compared with the next size up with a 10mm longer top tube and 10mm shorter stem (both give the same reach), or even just an aesthetic preference for the look of the smaller or larger size.
digitalgerry
Posts: 18
Joined: 5 Feb 2022, 11:35am

Re: 54cm frame v 56cm

Post by digitalgerry »

scottg wrote: 2 Jul 2022, 9:38pm What is a Cannondale S/H ?
A second hand (but in excellent condition) almost new.
Dingdong
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Joined: 22 Apr 2022, 4:59pm

Re: 54cm frame v 56cm

Post by Dingdong »

I've had a few Cannondales over the years, they are my go to frame for a commuter bike or winter bike, as the geometry is really nice and they are a very comfortable bike to ride, and beer ruggedly built unlike most harsh ride aluminium frames.

I'm roughly the same height as you, and if this is a sloping geometry frame, I'd say a 54cm (a medium in Cannondale sizing) is just about perfect. I have a CAAD 5 frame and it fits like a glove. Of course every frame is different (I'm talking about manufacturers, not this frame specifically) and a new fit always seems weird at first, but I guarantee you'll get used to it and come to love your Cannondale!
Jules59
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Joined: 16 Jan 2019, 2:34pm

Re: 54cm frame v 56cm

Post by Jules59 »

In truth buying a bike without riding it can be fraught with problems as is taking the advice from some LBS staff, unfortunately.
I've learnt a lot since buying my LARGE (55cm) Boardman Carbon road bike in 2013 having been told it looked "just right" by Halfords staff.
I'm 178cm (5'10").
Over the years I tried various changes to the saddle and stem and despite these alterations, shoulder pain gradually became worse on longer rides over 30 miles.
I recently bought a new bike and the manufacturer website suggested I required a 56cm bike, but only just.
I tried a 54cm bike in the shop and it was obvious that the 56cm was too big. It felt so much nicer than my old bike. Its amazing how just a few cm can make such a difference. I can now do 50+ miles with no shoulder pain.

Also I was advised that if you are between sizes then go for the smaller. Several forums have confirmed this too.
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TrevA
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Re: 54cm frame v 56cm

Post by TrevA »

I normally ride a 58cm (I’m 6ft 2 in) but after breaking my frame I borrowed my son in law’s 54cm Cannondale Caad 8. It fitted fine but was a bit low at the front. I just flipped the stem, so that it was pointing up a bit, and the position was perfect.
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Jamesh
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Joined: 2 Jan 2017, 5:56pm

Re: 54cm frame v 56cm

Post by Jamesh »

I'd take a 56 over a 54cm frame ...

I don't like being crunched up on the bike....

Others like the sporty feel of a smaller frame.

Is only 20mm difference so easily to change stem etc.
Jdsk
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Re: 54cm frame v 56cm

Post by Jdsk »

Is this the same bike on which your foot pointed out? How's that going?
viewtopic.php?t=151547

Thanks

Jonathan
digitalgerry
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Joined: 5 Feb 2022, 11:35am

Re: 54cm frame v 56cm

Post by digitalgerry »

slowster wrote: 2 Jul 2022, 9:47pm If at all possible post a video clip of you riding the bike viewed side on, and failing that a still photograph or two. Posters on here will then be able to provide answers
Thank you here’s not the best picture but you’ll bet to see my position of straight leg.
Thanks to all in advance
[img]
Jdsk
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Re: 54cm frame v 56cm

Post by Jdsk »

The image isn't showing.

Jonathan
digitalgerry
Posts: 18
Joined: 5 Feb 2022, 11:35am

Re: 54cm frame v 56cm

Post by digitalgerry »

Cannot get it in
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