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PostPosted: Sat Aug 18, 2012 10:17 am 
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Supposedly you should have 'two fingers' of stand over height, or an inch if you prefer, between the crown jewels and the top tube, but in reality you can have more than that. The more important factors in fit are seat tube, top tube, stem length, and saddle to bar drop. At 175 your cranks are ideal for someone around the 6' mark, but I'm 6'2" and seem to be able to ride cranks from 170-175 without much noticeable difference. Some people seem to have very specific preferences, and others don't. This too applies for what frame sizes one can ride on. At 6'2" I ride a 61c-t and a 59c-t with not much noticeable difference, except a bit more seatpost showing! The more you ride, the more bikes you try, you begin to learn what will or wont fit!


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PostPosted: Sat Aug 18, 2012 12:40 pm 
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Try a 56m frame first though. You may fit fine on it if you will accept a more upright position as the saddle to stem drop will be quite low, which suit some well.

My suggestion of a 52 cm frame comes the inseam measurements given and not his height. Please read my psoting and the OP repsones. The OP may have made a mistake on his inseam measurements but as I have not meant him/her I an't pass judgement on that!

The Le mond fit which takes your inseam (77cm) and multiplies it by 0.67 to give your C-T seat tube length.

77*0.67 = 52cm. It is just a starting point. Two customers who are 5ft 8" but have a 31-32" inside leg fitted on a 54cm compact frame and had the right position for them.

It all depend on the effective top tube length plus stem length and the positon you want to take up as too what frame size works best for you. The bar shape you choose make a big difference as well.

I would suspet 172.5mm cranks would be fine and so would 170mm cranks. 175 will also work if you knees are not sensitive. I ride 170 -177.5mm cranks and my knees don't complain.


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PostPosted: Sat Aug 18, 2012 6:18 pm 
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bm0p700f wrote:
Try a 56m frame first though. You may fit fine on it if you will accept a more upright position as the saddle to stem drop will be quite low, which suit some well.

My suggestion of a 52 cm frame comes the inseam measurements given and not his height. Please read my psoting and the OP repsones. The OP may have made a mistake on his inseam measurements but as I have not meant him/her I an't pass judgement on that!

The Le mond fit which takes your inseam (77cm) and multiplies it by 0.67 to give your C-T seat tube length.

77*0.67 = 52cm. It is just a starting point. Two customers who are 5ft 8" but have a 31-32" inside leg fitted on a 54cm compact frame and had the right position for them.

It all depend on the effective top tube length plus stem length and the positon you want to take up as too what frame size works best for you. The bar shape you choose make a big difference as well.

I would suspet 172.5mm cranks would be fine and so would 170mm cranks. 175 will also work if you knees are not sensitive. I ride 170 -177.5mm cranks and my knees don't complain.


The inseam given is almost certainly the trouser inseam, so I would not base anything on that measurement. This is a typical error of beginners. I have never met anybody the height of the OP with that short an inseam (it should be measured from the ground right up to the crown jewels) If this is indeed the case, a 52 cm frame would be insane. Likewise, if the OP is indeed a freak of nature and does have very short legs for his height, this will necessarily mean that he has a very long torso and therefore would likely want a longer top tube than would normally be found on a 52 cm frame.

As regards the complaints of sore back and neck, this is generally indicative of lack of suppleness of the rider, so it would normally be indicative of someone who still needs to put in some extra miles before feeling at home on a bike. This is why I suggested and continue to suggest, try a shorter stem, get some miles in and gain some suppleness. Learn from every bike that you own, before trying to change things. 58 cm C/C is NOT that outrageous. I don't think that any knowledgeable person would ever make it their first choice of size, but it is a plausible size for a beginning rider. As a comparison, I have a mate I ride with who is he too 5'11" and he rides a custom made 62 cm C/C frame with 54 cm C/C top tube. Granted he has very long legs, but the bike disappears under him and nobody would ever question the frame size when they see him riding, but when you see the bike leaning up against a building when at a rest while out on a group ride, nobody would guess that it is his frame.

As I said earlier, try the shorter stem. If nothing else, the OP will be able to start to build up his own base of knowledge as to what he likes and does not like.


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PostPosted: Sat Aug 18, 2012 6:46 pm 
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Joined: Tue Aug 14, 2012 8:33 am
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Thanks for all the advice and support. I may well have measured wrongly but my torso is in fact long and is more or less equal in size to my legs. I am not that much of a beginner to road bikes but when i was more financially stable bought from a LBS. My last bike was a cannondale road bike which i unfortunately had to sell. That was a 56cm compact frame but we never managed to really get that comfortable because of torso length.

I have raised the stem on the Giant and that seems to have made a difference. I have decided to stick with it for a bit and put a shorter stem on it and recable it etc. My only worry is there is 2mm between the top bar and my crown jewels, but I should be ok unless I come off.

What diameter of quill stem should I be looking for - there seem to be different ones available. I will be going for an 80mm length.

J


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PostPosted: Sat Aug 18, 2012 8:26 pm 
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The diameter of a quill stem relates to the diameter of the handlebars, you just need to find out the clamp size of your handlebars and make sure you get a quill stem that matches. Planet X have tons of NOS quill stems, in lots of different lengths and clamp sizes, as does ebay, and this very forum.


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PostPosted: Sat Aug 18, 2012 8:32 pm 
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Also, when you say you've raised the stem, surely that makes the fit even worse, assuming the bike is already too big for you?

Or are you after more of a sit-up-and-beg affair?


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PostPosted: Sat Aug 18, 2012 8:56 pm 
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BITD frames were pretty much all the same size from different manufacturers 60cm frame from Raleigh was the same size as a 60cm frame from Viking and so on and so on.... You could almost get the size by standing against a wall and sticking a pencil under the crotch and taking it from there...

When I bought my 2011 bike I found sizes were all over the place, in particular the Cervelo's seemed very "long" and I was almost nose flat to the bars LOL

In the end I went for a 56cm Basso which in 1970 would have been for a 12 year old LOL

Back to the OP, It seems to big for you and I'd think about selling it and buying something you have tried :)

Shaun


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PostPosted: Sun Aug 19, 2012 11:38 am 
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I agree there maybe a mistake in the inseam but I cannot say for sure as I have not met the chap.

Normally for 5ft11 folk a 56/57cm frame is a good starting point. I suggest the OP visits a shop and gets measured up. Or visits this site to do the measurements properly to get a good starting point.

http://www.competitivecyclist.com/pdf/fit_details.pdf


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PostPosted: Sun Aug 19, 2012 8:14 pm 
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bm0p700f wrote:
I agree there maybe a mistake in the inseam but I cannot say for sure as I have not met the chap.

Normally for 5ft11 folk a 56/57cm frame is a good starting point. I suggest the OP visits a shop and gets measured up. Or visits this site to do the measurements properly to get a good starting point.

http://www.competitivecyclist.com/pdf/fit_details.pdf


I know the fellows who developed the competitive cyclist software and they have developed this for the fit, serious riders using modern frames and components that frequent the web-site. For these riders it is indeed very good. Wrenchscience.com also offers very good fitting software (but you need to sign in), perhaps better than competitive cyclist. Neither applies anywhere near as well to your average occasional rider or to vintage components (just one example: modern seatpins are far longer than vintage ones and frames are better able to withstand the use of these seatpins). It is therefore not recommended to use these softwares to size a vintage bike.

I agree wholeheartedly that a 56-57 cm C/C frame would be most common for somebody 5ft11. Back in the 70's, 80's and early 90's however, for most Asian manufacturers, the standard frame sizes that were offered jumped 2 inches between frame sizes: most frequently 19" (48.5 cm), 21"(53.5 cm), 23" (58 cm) and 25" (62.5 cm), which would mean that somebody 5ft11 would be sold a 58 cm C/C. Perhaps not ideal but very workable.

The OP has already stated that he has top tube clearance (even if somewhat limited), so my advice remains to try it with a shorter stem and if that does not work, then move on to the smaller frame.


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