Frame geometry...

[TimoWr]

I just bought a cheap Kinesis alu frame and fork, originally designed for a randonneur bike. I want to build a cyclocross bike with it but noticed that, compared to my roadbike, the wheelbase is much longer, including a more "lazy" Kinesis alu front fork (the "angle" of the headset tube, don't know the english word, and the fork stays).

Is this normal for a cross bike, or should it have angles and a wheelbase comparable to a roadbike?

Thanks in advance,
Timo

 

[TimoWr]

I just checked. My Kinesis cyclocross/trekking frame has a wheelbase (axle to axle) of 109cm (frame heigth is 60cm) Is this a common wheelbase for a cross bike?

 

[Caracal]

I think (that means I don't really know what I'm talking about) that the wheelbase of an average cross bike should be somewhere between the wheelbase of an average Mtb an the one of a road bike

 

[TimoWr]

Thanks Caracal

Manitou, what's the wheelbase and frame heigth of your Alan?

Thanks in advance,
Timo

 

[Caracal]

http://www.alan-bikeframes.com/italiano/misurecross.html

 

[TimoWr]

Thanks Caracal,

But the wheelbase isn't given on the Alan site. length A + length B does not make the wheelbase because it's not a straigth line.

Regards,
Timo

BTW, a cyclocross tip: there are several commercial companies whicch can hard anodize aluminium frames and parts. Last week I had my frame hard anodized in matt black, which means a scratch free "paintcoat" which does not add any weight.

 

[Caracal]

a * a + b * b = c * c

c = wheelbase

for N 16 (H= 580mm) that whould be

598mm * 598mm + 430mm * 430mm = c * c

542504 mm = c * c

c = 736,55 mm

Whould it work to calculate the wheelbase like this?

 

[Caracal]

BTW, a cyclocross tip: there are several commercial companies whicch can hard anodize aluminium frames and parts. Last week I had my frame hard anodized in matt black, which means a scratch free "paintcoat" which does not add any weight.

Take a look at this (Airborne Titanium Cross Frame):

http://www.airborne.net/eready/janette/store/pilots/ferguson.jpg

(Caution: The colors will make your eyes bleed )

 

[TimoWr]

Aaaargh, that bike is ugly!!!

Anyway, 73cm seems impossible to me as a wheelbase. It's usually at least 98cm.

Just my 2 cents,
Timo

 

[Snapcase]

Hi Timo,

my Surly Cross Check sports a wheelbase of 101,4 cm (at a 54 cm frame size); this seems to be quite a popular length. The 60 cm frame has a 104,7 cm wheelbase, by the way.

Head tube angle is 72 degrees, and the seat tube angle is 73 degrees on my bike, while the 60 cm frame comes with 72 degrees for both.

The Steelman Eurocross, for example, comes with very similar dimensions.

In short, the *really long * wheelbase and laid-back angles on your Kinesis frame will result in a trusty and stable handling on fast descents while making it a a bit hard to corner on singletracks.

Hope this helps,
greetings,
Snapcase

 

[TimoWr]

Thanks Snapcase,

My bike is now "under construction" Hope to post some photos soon.

The parts allready bought:

- Kinesis 7005 alu frame and fork (black anodized)
- Cane Creek ahead set (black)
- Ritchey Pro stem (oversized)
- Ritchey Pro steer (oversized)
- Ritchey Pro seatpost
- Flite Genuine Gel saddle (black)
- Spooky cantis (black)
- Spooky singlespeed chain guards (black alu)

I will use my old but trusty Spinery Rev-X wheels with a 12-25 cassette. I still have to buy Shimano Ultegra brake levers (STI for the rear, normal SLR in front because of the singlespeed front blade), rear derailleur, bottom bracket, etc.

Any comments, hints or tips?

Regards,
Timo

p.s.: if you want to reply in German, no problem. I can read it all. I'm just not good at writing it

 

[Snapcase]

Hi Timo,

I would strongly recommend you get a pair of those additional brake levers (made by Empella or Tektro). They do not only allow braking from the more relaxed upper handlebar position, but do also give you the possibility to adjust brake cables very easily.

If you want to ride a single chainring, be sure it is suited for the terrain you want to ride.

Greetings,
Snapcase

 

[TimoWr]

I know, Spooky makes those handles too. But I doubt I'll need them because I usually ride with my hands on top of the levers at all times. With 42t in front and 12-25t. in the rear I can handle most terrain. Most terrain here is flat and fast, hence the lack of additional brake levers.

Regards,
Timo