Детский шоссейник ? Risky project: Vitus Kevlar-Carbon 9 Rahmen , conversion to 20"

Вроде как реально:

Начало здесь (схема-чертеж, размеры, прикидки)
продолжение здесь (начало разборки рамы, заднего треугольника)
получены компоненты Microshift
рама Vitus разобрана

Из картинок понятна задумка ?

This example is a late '80s early '90s Vitus Composite FCK 9, basically a 979 with a carbon/kevlar wrap.  The 9 stands for all nine tubes being carbon/kevlar - seat tubes are counted as four as the brake bridge splits them each one into two, see picture .

Real chart:  Vitus road for kinder (Reah edition)

Про склеить:

3M™ Scotch-Weld™ эпоксидный адгезив DP-490 – черный, тиксотропный двухкомпонентный эпоксидный адгезив, отверждаемый при комнатной температуре. Он разработан для приложений, требующих особо высокой прочности; демонстрирует отличные характеристики при соединении композитных материалов. Обладает высокой устойчивостью к воздействию высоких температур и окружающей среды.
Scotch-Weld DP-490 EPXTM Эпоксидный адгезив черный
Артикул: 2388 691.83 руб. http://www.gs-glass.ru/klei/75/good2388.htm

DP490 is a black, thixotropic, gap filling two component epoxy adhesive with particularly good application characteristics. It is designed for use where toughness and high strength are required.


Про трансмиссию:   вот что интересно

Versa VRS-8 Road Shifter
The Versa VRS-8 Road shifter is an STI-style (Shimano Total Integration) shifter designed specifically for the Shimano Alfine 8-speed and Nexus -speed internal hubs. The VRS-8 integrates shifting and braking into a single lever that is mounted onto drop-style road handlebars. The shifter uses independent up/down shifters for smooth precise shifting at any time - while pedaling, coasting, or even at a complete stop. The Versa lever set works exclusively with the Shimano Alfine 8 and Nexus 8 internal gear hubs, providing a wide range of gearing from a compact internal hub. With the Shimano 8-speed hubs, Versa-equipped bikes will have 95% of the gear range of a compact double chainring, and 92% of the range of a full triple chainring, but without any external derailleurs or chain tensioners. This enables Versa-equipped bikes to have a unique clean look, high efficiency, low weight and very low maintenance. They are perfect for everyday commuting, daily transportation or fun, fast road rides.

Old links to road for kids:
http://junior-road-bikes.tumblr.com/

http://www.islabikes.co.uk/bike_pages/reis.html
http://www.btwin.com/blog/blog-and-news/sports/on-road/btwin-range-road-2012-triban-junior/
http://www.eurobike.uk.com/details.aspx?p=177


Про выбор шатунов
Один автор в крупном издании всего несколько лет назад утверждал, что, после значительного объема тестов с участием многих разных велосипедистов, установлено: длина шатуна должна составлять 18.5% расстояния от вершины берцовой кости до пола. Вы найдете верх берцовой кости очень легко. Он на 5-6 дюймов ниже выступа таза и сдвигается назад, когда Вы поднимаете колено.


Каретка
Кареточные стаканы стандартизованы и бывают 68 мм. или 73 мм. для МТБ рам и 68 мм. или 70мм. для рам шоссейных велосипедов. В настоящее время наиболее распространённым является 68-миллиметровый стакан как для шоссейных так и МТБ рам. На современных МТБ рамах стакан приварен не симметрично: на 2,5 мм. смещён в левую сторону (противоположную от звёзд системы) это сделано для возможности крепления переднего переключателя E-type. Резьба в кареточном стакане бывает двух типов: BSA (B.C. 1.37″ x 24T) и Italy (M36 x 24T). Последний встречается крайне редко, как правило на старых шоссейных рамах. Стаканы длиной 70 мм. имеют итальянскую резьбу.

Вот фотки детских велов еще: http://www.flickr.com/photos/henryinamsterdam/8127756412/in/pool-17234755@N00/

А тут вообще классные примеры детских велов:

About KidBike

Особенно порадовали вот эти 

From here:
Here are a few tips on starting your Junior on their first road bike that worked for us:
1. Start on an uncrowded bike path or unused road  – The shifting and handling take time to get used to. They are better off without  too many people or cars around. I did find that having some people around was good because it taught him to hold his line which is a key when riding on the road.
2. Use a trainer – If they are into it then have them also practice shifting on the trainer. This is also a good place to practice with clipless pedals if they are going to get those.
3.Remain calm – The first time I road behind him on a descent it freaked me out. He was in control but I kept imagining what would happen if he crashed and kept wanting to yell “stop! slow down!” every 2 seconds. I figure this is only the beginning so I better learn to be comfortable with him at speed. Instead of yelling remind them before the decent of the dangers then ride up next to them and remind them again if you need. Shouting from behind may cause them to try and look behind them and then they will crash.

To memorize (from):

posted by Tyler (Editor) - August 18, 2012 - 5pm EST

Hot on the heels of Culprit’s aero disc/canti road bike comes his two kids and 650C aero road bikes specially designed for children and really, really short people.

The Culprit Junior One, above, is the kids’ bike and is spec’d and sized specifically for fast little tykes. The story of the bikes begins, as most things do, with an unmet need. We’ve seen several kids road bikes from custom builders, but trying to find a well spec’d performance road bike for children isn’t easy. One of Josh Colp’s (Culprit’s founder) friends was looking for a race-worthy bike for his son and couldn’t find it, despite also working in the industry.

The Junior One and 650 Junior Two are made of double butted 7005-series alloy with welds smoothed after manufacturing for an almost carbon-like appearance.

On top of a quality frame, a solid standard parts mix was used where size concerns weren’t an issue: Shimano 105 derailleur’s and cassette, a KMC X-10 chain and TRP 820 brakes.

The handmade Culprit aero carbon seatpost has a two position saddle mount to give the bike a longer life as your kid grows.

Frame size is one thing. Component spec presented a whole ‘nother set of challenges, and Culprit ended up making some of the components in-house. To accommodate the smaller hands and reach, a shallow drop 360mm wide, 26mm reach handlebar was used.

They custom made 140mm crankarms with a 105 BCD and 40/32 CNC’d chainrings.

Lastly, the Junior One gets handbuilt 20″ wheels with 30mm deep front and 40mm deep rear aero rims. Pricing, geometry and specs for both bikes at bottom of post. This oughtta give that $8,000+ Kirklee kid’s tri bike a run for its money!

The Junior Two gets 152mm crankarms with a 110 BCD 46/34 CNC chainrings on the Junior Two (below). The front derailleur mount has room to accommodate a standard compact gearing of 50/36.


Those weights in ‘merican are 17.4lbs and 17.74lbs respectively, making these lighter than most kids bikes out there. Pricing is $1,550 for the Junior One and $1,625 for the Junior Two. Both bikes come in gloss black with your choice of red, blue or yellow logos, and they come with a color-matched junior sized jersey.
Colp will be at both Eurobike and Interbike with this, his UCI-approved road racing bike and the disc/canti Croz Blade.

http://www.flickriver.com/groups/1061238@N25/pool/interesting/