Can somebody explain to me the difference in geometry, if any, between a road bike and a cyclocross bike? I know that the fork and frame usually have more clearance to accomodate wider tires, and that the brakes may be different including disc brakes which I understand and V?- pull or something which I don’t understand.
That said, can a standard road frame be used to build up a “cross” bike. I know it would work but what would the weaknesses vs. a made for “cross” frame be?
converting a road bike for 'cross use used to be the norm. 'course, that was when you could find “sport touring” bikes, with canti braze ons and clearance. still, if you go to thr races you will see a few guys riding old converted treks, or fuji’s, or whatnot.
for more modern road bikes you may need a fork for clearance, at least. ebay has cheap 'cross forks all the time, i got one for around 25 bucks. in the rear you can run a 27 mm vittoria tire ( the smallest available ) that will slip past most stays. the sidepull in back is really fine, slap a canti on yer new fork up front that you weasled out the back door of the LBS for free - the levers will work fine. the result will be a slightly raised front of the bike, so the effective head tube angle slacken a wee bit which is actually fine. you also raise the bb height a smidge, again fine. otherwise, you are good to go. maybe readjust yer stem/spacers, even a cheap ass new stem from someplace a little shorter, move the levers up a bit, ya know?
basically, the converted 'cross bike works like a bike. you pedal it, and it goes. lean it, and it turns. pick it up and run your sorry ass, and it goes over the barriers. 'cross races are on leaves and grass, and you are standing and hopping off and generally fixing to die anyway, so who cares if the handling is somehow sub-optimal? doesn’t matter a whit. in fact, you never know - my current converted 'crosser is a 1983 cannondale original road frame with a kinesis fork . . . . . that bike sucked so bad handling-wise new i think the conversion made it better. i rode the better part of a race last week on the wheel of a guy on a moots that probably cost more than a year at harvard and you know, the bike didn’t slow me down a bit. mind you, i’d take the moots, but 50 bucks vs 5000 ??
anyway, it works, and works well. it is the way everybody used to do it. cheap and fun.
It’s an old sport touring fuji that I am converting. 27" wheels made finding tires a pain, however a kindly slowtwitcher had some hanging in the the garage and TSRed them to me. I won’t be racing on it just some winte rriding.
well there you go. it is perfect as is. the new trend is to to sorta bring back the sport touring bike - see the trek pilot’s and spec roubaix. compared to the bulk of cheaper 'cross bikes your old fuji is likely gonna have a lower BB, longer stays, little more relaxed angles, and ride sweeter. bikes like that are what people search for. 700 c wheels would go on that dog and be fine, as well.
I ended up building up a 'cross bike from and old Sterling (phila.) frame. It was a laid back geometry, and a longish wheelbase and the chainstay bridge had to be moved closer to the BB for clearance. It had boltholes for panniers and shit, so I am sure it was touring specs. I ran Michelin 'cross tires, I think they were 700-27. Switched out the fork for one with braze-ons for the cantilevers, and a friend of mine brazed on rear ones for me. I think I could have gotten away with sidepulls in the back (long reach), like another post said. I also had a road frame (an old Bianchi) with Michelins on it, and sidepull brakes that I took as a spare bike for 'cross races. I would switch out during the race, ride it for the lap it took to clean up the race bike, and it did me just fine on all but the muddiest of courses (which ironically was when I would need it the most). I also ran the brake levers backwards, so the right lever was the front brake, and left was rear. I felt more comfortable dismounting this way, because my left hand stayed on the bars, while my right hand was on the top tube. Someone told me that was the “Italian” setup. Don’t know, it just worked for me.
In some circles that is referred to as the Italian system. Right hand front brake. Motocross riders use it too as they are used to the rt front brake setup. Not sure why the Italians do it that way, but probaly between 25-50 % of Italians do that. You don’t see it much more in cross as every one has the two brakes on the bar setup. G
When you’re dismounting and need to slow down you don’t want to lock up the front wheel.Rear braking from the left side allows you to drag the rear wheel and control the bike with one foot in the pedals as you step through and off the bike.
Cullen
700 c wheels would go on that dog and be fine, as well.
Just a bit of clarification, are 700s a little bigger or smaller than 27s, I know they both use the same tube.
700C are a wee mite smaller. if you use a bigger tire you will notice no difference at all, most likely. could be there will be a brake shoe reach issue, but you never know till you try. long reach sidepulls would be the answer, or if there are canti’s on there already no problem.
You can also use a mountain bike frame.Slap 700c wheels on and there is still plenty of room.Drop bars with a rise stem and this bike works fine.
Cullen
700C are a wee mite smaller (than 27’s) . if you use a bigger tire you will notice no difference at all, most likely. could be there will be a brake shoe reach issue, but you never know till you try. long reach sidepulls would be the answer, or if there are canti’s on there already no problem.
Lord… more internet forum misinformation. 700’s are sometimes referred to as 27’s. They are not different sizes!
Um, they are different. A 700c tire and a 27" tire are not the same. Many old touring bikes like folks are talking about converting have actual 27x1 tires. A 700c tire will not fit on that wheel.
uhhhhhhhhh, mojo. may wanna check this:
"Lord… more internet forum misinformation. 700’s are sometimes referred to as 27’s. They are not different sizes! "
dude they are definitely different sizes. FUNNY, with that bit about misinformation !! too funny. where did you get your info, don’t tell me the internet - i’m dying.
If you are not planning on racing and getting in a lot of mud then it sounds like the setup you are looking at will work just fine. You are talking more of a touring/commuting/weather-to-crappy-for-the-nice-bike type of bike than a true cross bike.
If you were looking at racing you would end up dealing with a million little details on equipment and techinique that are all mostly personal preference anyway, just like the millions of triathlon bike questions.
They are two differant sizes.Just like 26" and 650 are not the same.Inner tubes are interchangeable though.
Cullen
Um, they are different. A 700c tire and a 27" tire are not the same. Many old touring bikes like folks are talking about converting have actual 27x1 tires. A 700c tire will not fit on that wheel.
Uh… NO. Here… read and learn: http://www.sheldonbrown.com/tire_sizing.html
They are two differant sizes.Just like 26" and 650 are not the same.Inner tubes are interchangeable though.
Cullen
Nope… not on modern bikes. Formerly there were 26" wheels, but no longer. 650’s are sometimes referred to as 26".
uhhhhhhhhh, mojo. may wanna check this:
"Lord… more internet forum misinformation. 700’s are sometimes referred to as 27’s. They are not different sizes! "
dude they are definitely different sizes. FUNNY, with that bit about misinformation !! too funny. where did you get your info, don’t tell me the internet - i’m dying.
OK smartypants… think I’m wrong? Call any tire manufacturer. Better yet, go out and buy a 26" tire, 650 tire 27" tire and 700 tire. Huh? Aah… yeah, thought so. OK… now contact rim manufacturers and ask for a 26", 650, 27" and 700 rims. Yeah… see… know before you speak.
ok smarty pants…how come my 700 x 23 tire won’t fit on my old 27inch rim? i’ve tried… won’t fit.
an how come my 27x1 tire won’t fit on th 700 rim???i’ve tried…doesn’t fit.
*could that be because one is made for a 700 and one is for a 27inch???
they are slightly different sizes. not much, but differnt sizes…yes.
luke
you just proved yourself wrong!
from sheldonbrown.com
ISO Bead Seat Diameter Traditional Designations 635 mm 28 x 1 1/2 630 mm 27 x anything 622 mm 700 C