Frame size, new bike fitting, questions

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jeffy
Posts: 1325
Joined: Sun Oct 05, 2014 11:51 pm

by jeffy

Stancke - what frame model and size are you riding now what size and angle of stem?

Normally i would say that aero bikes (and many other race bikes) have an aggressive fit.

But from that chart - the 54 is only 10mm longer and 1mm higher than a size Small Defy, and is almost identical to a CAAD 10 / Supersix size 54.

Personally i would always err on making a small bike bigger than a big bike small.

A longer stem within reason is always better.
The exception is when the Stack measurement is too low; and if the stack measurement is too low in your size the size up is more likely to be too long.

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tymon_tm
Posts: 3651
Joined: Tue Sep 05, 2006 4:35 pm

by tymon_tm

bungis wrote:Any tips on dealing with major arm length differences in terms of fitting?

One of my arms is approximately 6cm longer than the other, probably from playing so much baseball. I'm wondering if that's contributing to my weaving on the rollers.


I had a pal who's had similar issue (after an accident) and had a custom cockpit made - a stem with two clamps (one on top the other if i recall correctly) and bars basically cut in half - one side was ~2cm higher. it looked strange, and weighed like a ton, but he was able to ride pretty comfy with that setup
kkibbler wrote: WW remembers.

efeballi
Posts: 492
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by efeballi

^or fit two stems on top of each other, will weigh a metric ton, but could work.
If it were a minor discrepancy you could have tolerated it by mounting shifters asymmetrically and/or mounting the handlebars off center, but 6 cm is A LOT.


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airsky
Posts: 26
Joined: Wed Apr 01, 2015 9:42 am

by airsky

It's always recommended go for a professional bike fit before a getting a bike.

Our local bike shop careless about this all they wants is to sell the bike quickly
and earn your money beside the mark up rate is very high and prompt me to
shop on line for accessory.

cyclenutnz
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Joined: Tue Jul 18, 2006 5:18 am
Location: Cambridge, New Zealand
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by cyclenutnz

twoangstroms wrote:I'm not sure if this is on- or off-topic for this thread, but I'm getting really interested in gravel grind/that kind of rides and racing. After years of road, mountain, and track racing, coaches and pro fits have pretty much dialed me in there. But what should one keep in mind for gravel bikes??? Do I want a shorter top tube, higher stack, which what the now? For reference, my last team bike was a 54cm Felt F series (a tad on the large side for me, but the smaller size didn't have enough saddle setback, which is key for my proportionately long femurs).


You're going to end up with less reach for the same stack on most Gravel bikes as there is a general assumption that a tall position is required.
As an example
twoangstroms.PNG


Because of the slackened steering you're still going to end up with more front centre even with the 20mm less reach. So being shorter is not going to make the bike twitchy.
basically just find something that matches your position and the usual geometric features of Gravel category will take care of the rest.
In most cases I'd expect to need a longer stem for a gravel bike than a race bike, even if it is custom designed to have the same stack as the race bike.

racersir
Posts: 69
Joined: Wed Oct 10, 2012 6:41 pm

by racersir

Look for the stack and reach measurements there a couple of calculators online that really help

raudis4
Posts: 12
Joined: Mon May 11, 2015 11:14 pm

by raudis4

need some help guys. I currently ride a Kestrel Talon in 55cm and was thinking of getting a Velobuild R-016. I'm debating between the 52 and 54cm. which would you guys recommend? I'm very flexible and don't mind an aggressive fit. I'm 180cm with a 83cm inseam. I Have 63cm arms and 69cm trunk

Current 55cm Kestrel

Seat Tube, Center to Center 57.5
Top Tube, Center to Center 55.6
Head Tube 12.9
Seat Tube Angle 73.5°
Head Tube Angle 73.5°
Chain Stay 41.0
Bottom Bracket Height 26.4
Bottom Bracket Drop 71.0
Stand Over Height, at Top Tube Center 79.1
Fork Rake 43.0
Trail 55.3
Front Center 58.6
Reach 39.3
Stack 54.8

raudis4
Posts: 12
Joined: Mon May 11, 2015 11:14 pm

by raudis4

sorry it would let me link the geometry chart for the r-016

Image

I was thinking about going for the 52 so I can get that aggressive look. Not sure with my measurements though that it might be too much and the 54 would be a better all rounder that I can use on longer rides.

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bigfatty
Posts: 135
Joined: Sun Sep 28, 2014 11:53 am

by bigfatty

to add to the thread, I have a question about head tube angle.
I am normally a Medium think I can go with a size small frame as reach is similar and other measurements are also not too bad. I have even actually rode both S and M but not long enough to judge diffence in angle.Also the S had only a 90mm stem which felt a little short. So I feel with my usual 120mm stem, things will be good. However, the one measurement I am troubled with is the Head Tube Angle. On small it is 71.5 which is rather relaxed, so they say, for a road bike. is it really so different to, say, 72.75? I would like to hear experience. Further, on my current bike, which I assume is 73 degrees head angle, I find it very twitchy riding "no hands", so maybe at 71.5 this will be an improvement for me.
look forward to hearing your experience

cyclenutnz
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by cyclenutnz

@bigfatty
If you go from medium to small the front centre will likely stay the same which means same weight distribution. But the slacker HTA will mean a lot more trail which could be better or worse depending on what you like. That you find your bike twitchy with no hands is more likely to be your setup (saddle too far forward) than the frame.

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bigfatty
Posts: 135
Joined: Sun Sep 28, 2014 11:53 am

by bigfatty

kia ora señor cyclenutz,

regards seat being to far forward, I have it set so as it complies to the "Knee over pedal spindle" theory. Though, I see from https://hypercatcycling.wordpress.com/2 ... l-spindle/ that it is suggested I could place saddle up to 1cm back which I will give a try. Thanks for the pointer.

regards the HTA & "what you like", it seems cycling is so subjective and in reality, many times, there is or should be no discernable difference. This is what I am wondering with the HTA. is it just a number? looking at the Canyon Alu vs Canyon Carbon it seems the Small frames in carbon have a steeper angle so this may suggest that there is an actual discernable difference.

cyclenutnz
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by cyclenutnz

bigfatty wrote:regards the HTA & "what you like", it seems cycling is so subjective and in reality, many times, there is or should be no discernable difference. This is what I am wondering with the HTA. is it just a number? looking at the Canyon Alu vs Canyon Carbon it seems the Small frames in carbon have a steeper angle so this may suggest that there is an actual discernable difference.


Kia Ora

Looking at Canyons
canyon.PNG


You'll see that the tradeoff for the steeper HTA on the Carbon is a shorter front centre - leading to more weight on the front wheel and a higher degree of toe overlap.
On the plus side the Carbon has trail of 62 instead of the 68 for the alloy.
Personally I like trail to be 54-60 but I'm on L or XL bikes and there is plenty of room to have steep HTA there.
Designing the handling of small frames is always a compromise. If Canyon made different rake forks they'd be able to customise the handling per size better.
The only way to know what you like in terms of the HTA/rake/trail/front centre combo is to try different bikes (after 30+ I have a decent idea).

Nejmann
Posts: 635
Joined: Mon May 06, 2013 6:25 pm

by Nejmann

Hey guys need some help here :-)

I got this S-Sworks Tarmac Sl4. I'm 195 and my inseam is 91 cm. The bike is a 58. Normal my stem is pointing up, if i ride over 3 hours i get a little neck/top back pain if it isn't. The stem is 110mm. I got a bikefit at the dealer.

But my question is, should i go for a size 61 next time, and have my stem straigt or should i go for a 58 and maybe get a little bit more flexible/upwards stem? I did have to get the 400mm enve stem to get the saddle height as high as it is on a 58. (according to the bikefit, and it feels right)

Here is a picture of the bike:

http://s1293.photobucket.com/user/Nejmann/media/Cykel_zps9hp33no3.jpg.html

cyclemd2
Posts: 1
Joined: Thu Jun 04, 2015 5:41 pm

by cyclemd2

:P

54 choose

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outnumbered
Posts: 226
Joined: Wed Jun 14, 2006 9:59 pm
Location: Reading, UK

by outnumbered

Nejmann wrote:Hey guys need some help here :-)

I got this S-Sworks Tarmac Sl4. I'm 195 and my inseam is 91 cm. The bike is a 58. Normal my stem is pointing up, if i ride over 3 hours i get a little neck/top back pain if it isn't. The stem is 110mm. I got a bikefit at the dealer.

But my question is, should i go for a size 61 next time, and have my stem straigt or should i go for a 58 and maybe get a little bit more flexible/upwards stem? I did have to get the 400mm enve stem to get the saddle height as high as it is on a 58. (according to the bikefit, and it feels right)

Here is a picture of the bike:

http://s1293.photobucket.com/user/Nejmann/media/Cykel_zps9hp33no3.jpg.html


How much saddle/bar drop do you want ? That's a key parameter in picking the frame size. I'm 1.93 and I use a fairly relaxed setup with just 10-11cm drop. For me that works a lot better than the 14-15cm I had previously. It looks like you have quite a big drop, from the picture.

Obviously it depends a lot on your flexibility. You'd need to go for the 61cm to reduce drop, unless you want to have an outrageously upwards-pointy stem. 61cm will also have a longer TT, so you may need to move your saddle forward somewhat.

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