Transferring measurements between bikes

Discuss light weight issues concerning road bikes & parts.
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dgasmd
Posts: 1753
Joined: Sun Apr 15, 2007 5:10 am
Location: South Florida

by dgasmd

cyclingburd wrote:I started using a cheap laser level on a tripod. I adjust the position of the level until the vertical line is through the bottom bracket and horizontal is at the top of the saddle. Then measure between the laser lines and various points on the bike. For me the laser level is easier and more accurate than measuring from wall and floor.

Sent from my SM-T700 using Tapatalk
Can yup post a couple of pict of how you rigged his up? Not following entirely

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Giant DK
Posts: 1313
Joined: Mon Jan 23, 2006 3:03 pm
Location: Denmark

by Giant DK

Don’t use the nose tip as reference point for setback and “top” off saddle for saddle height unless you use the same saddle. Us a reference point. One of the first Retül fitter told me to use the point where the saddle is 100mm wide as reference point. Meassure to this point for both setback and saddle height.

Since I began to set up my bikes this way me fit has always been 99% perfect every time. The last mm you need to ajust on the road, as you also can’t meassure how much your saddle deflects.
Technical editor at Cykelmagasinet Denmark

My Simplon Pavo II

by Weenie


probertsqbe
Posts: 146
Joined: Fri Feb 22, 2013 1:27 pm

by probertsqbe

I purchased the abbey bike tool fit kit last year when it first came out. Great bit of kit, simple to use and accurate within a mm, which is good enough for me. Also it’s nice and portable so if you get a hire bike abroad it’s much easier to dial in your fit using this device.
Further details can be found here https://www.abbeybiketools.com/products ... 9515341962

Also there are some tips that I’ve picked up along the way which are documented well by Steve Hogg in this article below

https://www.stevehoggbikefitting.com/wp ... Method.pdf

Anyone can measure their key bike fit measurements, but in my experience it does take some skill and practice to get it accurate within a few millimetres.

Obviously not everyone is that fussy or would notice but if you’ve got several bikes then you really should have your fit dialled across all bikes as close as possible to your optimum fit (assuming you’ve had a bike fit)

avispa
Posts: 275
Joined: Tue Mar 11, 2008 2:36 am

by avispa

You can just get one of these:
https://carbonreparatie.nl/bikesettings
:D :mrgreen:

VeloAngle
Posts: 3
Joined: Tue Dec 11, 2018 6:13 pm

by VeloAngle

In full disclosure I’m Dave Archer, the developer of VeloAngle mentioned earlier in this thread. A bit late to the discussion - evidence of my limited marketing skills. Two points came up that I’d like to comment on. First was where/how to reference saddle location – specifically whether the saddle tip should be involved. Second was the bigger question of whether developing a $200+ tool is solving the problem nobody had.
Regarding saddle measurement, I’m in full agreement the tip is a non-functional reference, however it is one that is regularly used by both fitters and some enthusiasts for “saddle setback”. VeloAngle’s saddle adapter (pictured below) contacts the tip so that a saddle setback measurement can be produced, but it is not the reference for saddle measurement. The reference point is user-defined by sliding the adapter to the desired location, whether a given distance from the front or rear, or at a particular saddle width. The scale is provided so that the reference point can easily be found and repeated. It is also a platform on which to place VeloAngle for a tilt measurement based on the area of rider contact. Because the adapter contacts the saddle surface, it avoids avoiding “eyeballing” the reference location. The same positive location method is also used at the BB and handlebar.
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The question of whether spending $200 - $300 dollars to do what nominally can be accomplished with things found in the garage is a matter of personal opinion. However, most people wouldn’t call us Weenies models of fiscal responsibility with our rather liberal $/gram rationalizations. The best option for measuring and transferring bike setup is dependent on how each person prioritizes the three main parameters; cost, convenience and accuracy. VeloAngle has a big cost disadvange to household tools. Relative convenience is method-dependent and highly debatable. However, accuracy is quantitative by nature, so something we can explore.
There are two components of getting an “accurate” measurement, illustrated by shooting at a target. A tight cluster away from the bullseye is repeatable/precise but not accurate. A loose cluster centered around the bullseye is accurate but not repeatable. This is an important distinction because accuracy and repeatability errors tend to come from different sources. Generally the greater the number of steps it takes to achieve a measurement, the worse the repeatability. So although bubble level/tape measure/plumb bob measurements will tend to center on the desired locations, taking the same measurements multiple times from start-to-finish is likely to reveal variation. On the other hand, highly repeatable tools can be inaccurate, usually due to setup error. While VeloAngle’s direct point-to-point method defines the relative position of two points in one step, if its digital inclinometer is not zeroed to tire contact on a bike that’s not level it will consistently give inaccurate measurements.
The other big problem is not locating the point of interest directly. Saddle location is usually determined by placing a scale between your eye and the saddle. If the line from your eye to the saddle is not parallel to the saddle surface, an error known as parallax will result. Also, any time you lay a scale (or the line of a cross-laser) up to the BB, saddle, handlebar, etc the reference point (the center or edge of the feature) is being estimated rather than positively located.
I understand that that even after spilling all this digital ink most of you will still be perfectly happy with what’s in the garage. Given that reality, I’d like to forward my suggestion on how to go about doing it. After all, VeloAngle came about because I wasn’t satisfied with all my various homebrew efforts. I’d suggest ditching the wall when taking horizontal (X) measurements. Even though you have a bubble level, you are fighting gravity to use it horizontally. Lay a metal meter-stick on the floor centered under the BB (use 500 mm as zero). Then use your level to measure vertically (Y) down to the meter-stick. The difference between the location on the stick and 500 is the X value. You will need to prevent the bike from moving away from the 500 mm reference. The Centering Band we offer ($9), primarily for centering the handlebars, will also serve this function. A homemade alternate can be created by punching holes in a rubber strap and passing them through the stem.
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As I said, I’m not a marketing genius but I am interested in your questions and comments.
Dave

wintershade
Posts: 242
Joined: Mon Apr 16, 2018 7:12 pm
Location: San Francisco, CA

by wintershade

HI Dave -- I actually kind of want to buy your VeloAngle. It's looks great. I'm just not convinced I'd 1) be able to figure out how to use it, and 2) I'd kind of want output that I could send to a custom builder for example, and have them be able to make sense of it -- kind of like I can with my Retul sheets. Am I missing something?

VeloAngle
Posts: 3
Joined: Tue Dec 11, 2018 6:13 pm

by VeloAngle

Winter:
While a Retul output includes a number of body metrics that VeloAngle doesn't touch, I made sure the bike measurements output in the Veloangle's app are consistent with Retul, which is in turn largely consistent with other fitting systems. For example while VeloAngle measures directly in length and angle (polar coordinates), the app coverts all measurement to the more common X-Y coordinates, and also has a utility to convert existing X-Y measurements to polar so you can use VeloAngle to match existing Retul (or other) output.
This is an area I find interesting. We use length and angles to describe frame handling characteristics, and proper body position on the bike, but we retain the old gravity-based X-Y system to define the position of the bikes contact points. Also length and angle is more scalable and can be more informative. For example, the impression of a 90 mm handlebar drop is quite different on a 54 mm frame than on a 61 mm frame. However a 10 degree drop has more universal meaning.
Recognizing that the approach is different, we have both printed instructions:https://www.veloangle.com/downloads/ and instructional YouTube videos:.https://www.veloangle.com/blog/category/usage-tips/
Please contact me and I’d be glad to answer any other questions you might have: https://www.veloangle.com/contacts/

wintershade
Posts: 242
Joined: Mon Apr 16, 2018 7:12 pm
Location: San Francisco, CA

by wintershade

Thanks for answering my questions Dave. I just ordered the VeloAngle. I'm excited to try it out with a couple new bikes on the way.

VeloAngle
Posts: 3
Joined: Tue Dec 11, 2018 6:13 pm

by VeloAngle

Thanks for your belief in it Winter. It will ship tomorrow. Dave

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