samtaylor1

I am 6'7"- 275 lbs and I need help choosing a bike. I was doing a lot of single track with my Turner 5-Spot sasquatch size (that is what they call their biggest size) until I fell off and shattered my hand and lost my two front teeth. Now I am selling it, as I don't have what it takes to get back on, and want to replace it with a cycle cross bike. Couple questions: other then components and some nubby tires what SHOULD be the difference between a road bike and a cyclocross bike? Also for between 3300-4000 (whole bike) what cyco cross bike would you recommend (companies that either customer or make bikes my size only). Currently I ride a 66 cm custom Paul Taylor road bike.

ZenNMotion

Two words: Leonard Zinn

He's a custom framebuilder who specializes in large frames for big guys. He's a monster himself. Super quality (too big for me to ride, but I've seen a beautiful custom cross bike he built for a 6'5" friend) and knows how to build to fit someone like you. Zinn is also the author of the bible on MTB repair and maintenance, and has a repair and technical advice column in VeloNews- he's a tech geek as well. In short (pun not intended), he's your guy. His site is mostly about MTBs but he does cross and road as well.
https://www.zinncycles.com/

The main differences between a road bike and a cross bike-
More frame and fork clearance for wider tires
Slightly higher Bottom Bracket height for clearance over barriers and tight turns
Longer chainstays (tire clearance and more compliance for bumpy tracks)
Slightly different geometry than roadbikes- cross geometry designed for slower speeds, tighter turns, traction on steep uphills- but there is no consensus on what this should be- different builders do different things. Some are more like roadbikes, some designed to ride more like MTBs. Matter of preference and where/how you ride.
Lower gearing (often just subsituting the large chainring for something like a 46-48t)
Heavier gauge tubing (sometimes, not always)
Sturdier fork- but can feel harsh on the road over long distances
Canti, V, or disk brakes for riding in mud
Cable stops are mounted on top of the top tube, or inside the top tube to allow you to shoulder the bike without interferance with the cables. Some cross bikes have cable routing for the front derailleur that avoids going underneath the bottom bracket to protect from mud. These bikes need a top-pull front derailleur (FWIW I prefer a traditional road derailleur/routing, but ask someone who races in Oregon for another opinion...)
Reversed brake levers (Left=Rear) for dismounting (assuming you hop off on the left) without doing endo's

darkmother

You're definately in custom size territory. I'd look at a beefy custom frame, with 135mm rear spacing (MTB standard). This will make building wheels that will hold up a lot easier. I spec'd this on my custom cross frame, and I am very happy with the result. Personally, I'd look at a steel fork, like maybe a Kona project 2, as well.

Cross bikes need a really bulletproff wheelset b/c they don't have big squishy tires to protect the rims. I'd consider 36 hole, handbuilt wheels to be manditory for you. Slightly beefier rims may be a good idea, something around 500 gr with steel eyelets is a good move.

As far as differences from a road frame, there aren't all that many. Cross bikes are generally stronger, and have more tire clearance. As a result, the chainstays are longer, and the bottom bracket height may be slightly higher. Some cross bikes may have a more relaxed headtube angle, but this isn't always the case. I would shoot for a slightly lower standover height (drop the top tube a little) for more clearance in the rough stuff.

I had Habanero build my custom cross, and I am very happy with it. Mark Hickey was beyond helpful, and very knowledgable. He made sure I got exactly what I wanted, and the bike fits perfectly. Couldn't be happier with the bike.

Good luck with your build up!

ZenNMotion

Habanero's are really nice, no-nonsense affordable Ti bikes. But I'm not sure that Ti would be the best choice for a rider that needs such a large frame, as Ti tubing (at least the common round straight gauge that Habanero uses) may be a bit flexy. You could certainly design a Ti bike that would be appropriate, but probably not in the common, (relatively) affordable straight gauge stuff. More choices in oversized diamters in steel. For a bike for myself, at 150/ 5'10" I'd love a Habanero myself, but I'm not so sure for such a tall guy- Anyway, I'm not a builder/expert, so worth asking about anyway. For cross wheels, 36h 700c WTB speedmaster rims, 14 or 14/15 gauge spokes on some good hubs like White Industry, or Phil Woods would be my choice- the more expensive hubs for strength at the hub flanges for a heavy rider- not necessary for us wee mortals. The speedmaster rims are the bomb for big dudes and rough riders. Don't get talked into paired spoke, or low spoke-count (28 or lower) bullsh** wheels. Meaning no Bontragers, Cane Creeks, Ksyriums, Shimanos and the like, especially for off-road or cyclocross riding. I'll get flamed for that one, but I'm sticking to it! Stay with strong, traditional, easily trued and repaired wheels (by you in your garage or your LBS without a hassle).

darkmother

I don't think that is nessasarily true. Out of interest, I calculated the bending and torsional stiffness of a typical striaght guage 1.5" OD Ti downtube, and compared it to an aluminum tube of the same mass in a typical diameter (escapes me at the moment....maybe 2.0" OD?) The Ti tube is significantly stiffer in both bending and torsion. Now, of course, there are other things that influence frame stiffness than just tube diameter, but it is one of the most important aspects to consider.

I believe Ti has a reputation for being flexible, because early ti bikes were fabricated out of tubing diameters that were comparable to that of a traditional steel bike. Naturally, such a frame would be flexy compared to it's steel counterpart. Modern frames tend to use bigger diameter tubes-in fact, many people mistake my frame for an aluminum frame. It has 7/8" chainstays, 1.5" downtube, and 1.25" TT and ST. It is by far the most torsionally solid road bike I have ever riden. I weigh 205 lb, and I really mash the climbs.

Anyway, I'm not trying to push Ti, or Habanero on someone who doesn't want one, but I believe a lot of the supposed characteristics of various materials are largely myth. When I was looking around for a custom frame, originally I wanted steel, but I went for the Habby because looked so nice, and was actually much cheaper.

samtaylor1

Thanks a lot. I will check out those recommendations. Anyone ridden a Eurocross bike by Steelman?

Sam

darkmother

Never riden one, but Steelman makes some sweet looking bikes. I want one.

jimblairo

I'm 6'6" and weighted 265 this spring. I bought a Marinoni Fango Cross. The frame (64 cm. )was custom made for me from Zona tubing and the cost of the frame and carbon fork was only 900 cdn (720 U.S.) Nice paint job too.

I had a set of wheels built using A719 rims with XTR hubs and I run 700X32 on them.

Total cost of the bike including Ultegra 9 was 3200 Cdn. (2500 US).

darkmother

That's a good deal. Any pics of the frame?

ZenNMotion

You missed the point with all the calculations- what is needed is atypical oversized tubing (Al, Ti, Steel whatever...) that is not likely to be easily available without a lot of searching. Habanero builds good, but typical diameter Ti, at least what is presented on their website. What's needed is unusually large diameter stuff, easier to find in steel or Al than Ti for a reasonable cost. Maybe Hab can spec it from their sources in Asia, I don't know. But it won't be $700 cheap, and not the same basically stock animal that you ride- He needs a 66cm frame- that's huge. And so's the diff. between 205lbs and 275lbs. I have a couple of Ti road bikes myself, and they ride quite differently from each other despite being the same size. One has all round tubing, the other shaped oversize downtube and bent stays, slightly different geometry. Both are stiff enough (for me, in 56cm) but neither I would describe as "stiff"- whatever that means. Anyway, interesting project, how to fit the outliers?

prodigal son

I have a Steelman 525. This is a stock frame; he doesn't make them anymore. He only does custom sizes now. I am really happy with the frame. I am 210 lbs and wanted a strong frame. I would also look at Rock lobster, kelly, Soulcraft and IF.

SAB

Another great custom framebuilder is Stephen Bilenky at Bilenky Cycle Works (www.bilenky.com). He works in steel and is a true artist. There was a big spread on him in Bicycling magazine about 2-3 months ago where he made a bike for some huge guy. He did a retro-fit of BTC's on my cross bike and did a wonderful job.

darkmother

Respectfully, no I did not. What I was trying to express was that Ti frames are not the floppy noodles everyone thinks they are. My calculation just proved to me what I originally suspected. Anyway, I think you could make a nice servicable custom frame to fit the OP out of steel, aluminum or Ti without going to exotic tube diameters.

Bolo Grubb

It was in the may 2005 issue and the author was 6'7" if I remember right. Bilenky has a great rep.

deathintransit

Long term goal will be to get this puppy right here.

Hubba hubba.


Ti cyclocross frame. Mmmm.

Mr. Markets

Dude, I am not far off from you. I ride a Cannondale Cyclocross Disc. it will work for you no problem. The discs have great stopping power, the frame is beefy. My only complaints are no triple up front for the hills, and the lack of fork rake (yeah I know it is a CX bike) make hands free a little dicey.

try one you'll like it. save the custom dollars for when you drop a few and want that six13 or whatever...

ZenNMotion

A little off topic, but it's a measure called trail that makes front end handling "dicey" or "slow". Trail is measured by the distance between where your steering tube axis meets the ground, and where the vertical line that passes through the middle of your front dropout meets the ground. This vertical line always meets the ground BEHIND where the steering axis intersects the ground (unless you have a negative fork rake!). Therefore, MORE fork rake = LESS trail. So if you want your front end to have slower, less "dicey" steering then buy a fork with MORE rake than what you have. Yes, really. Just remember that some forks, especially straight forks have rake built in by offsetting the angle of the blades rather than curving them, so you have to include that when measuring fork rake. Most road and cross bikes have trail measures between 55 and 60 mm, really most commonly between 56 and 58. Obviously your bike handling is very sensitive to this measure, as it doesnt take much variation to noticeably change how your bike steers. A few mm's of rake, or a 1/2 degree of head tube angle difference = a big diff in how it feels. When you look at specs on a bike and you see a trail measurement, this is of course dependent on a combination of the head tube angle as well as the fork rake, so for a GIVEN trail measure, a fork with LESS rake will have quicker handling when compared to another bike with the same trail measure but with a fork with more rake. But if you are considering a new fork for your frame, then one with more rake will be more responsive than what you have, since your head tube angle doesnt change. In other words-

If 2 bikes have same trail, the one with more rake= less responsive
But if you want less responsive handling on your present bike then install a fork with less rake-

Here's a diagram for motorcycles, but it's the same measure on a bicycle
https://www.kennedyschopper.com/Trailchart.html

Confused? If you havent fallen asleep yet, heres the formula to calculate trail, you can use a scientific calculator, or a slide rule (huh, whats that?) or just paste it into Excel and substitute the parameters with your bike's numbers. Am I a geek or what?
Trail =(tire radius*COS(headtube angle*PI()/180)-rake)/SIN(head tube angle *PI()/180)

Mr. Markets

actually, thanks a lot for the more in depth discussion!

ZenNMotion

Oops, Dang! I got confused! The first part of this is correct, but the second is a goof. For slower steering, buy a fork with LESS rake, not more. Sorry. Sheesh-