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Is it worth it to get my cross bike built for really WIDE tires?(18 posts)

Is it worth it to get my cross bike built for really WIDE tires?SJT
Mar 19, 2003 2:37 PM
My builder hasn't started cutting the tubes for my custom steel CX bike so I can still renig on some of the details I asked for. Right now I'm still debating if I want to have him build it to accomodate some of the larger 700c tires such as 44mm tires, or "skinny" 29"er tires. I own a couple of mountain 26" mountain bikes and thought it might be cool to try wide tires on the crosser and take it on some of the rougher trails, but the more I hear that a cross bike *is* not a mountain bike and won't handle as well in the rough stuff, the more I see it might be a waste. One problem with going with a rear triangle that can accomodate 44mm tires is that I will need to go with a long spindle BB, at least that is what I think will be the solution. I plan on discussing this point with my builder, just curious to people's thoughts here on the issue of running wider tires (>40mm) on a cross bike. Thanks.
re: Is it worth it to get my cross bike built for really WIDE tiatpjunkie
Mar 19, 2003 5:06 PM
IMHO No! 38's will fit most standard cx bike frames (some euro frames excluded) and after riding 30's and such for race season, my 38's feel HUGE. learn to ride the rigid bike with narrow tires, your MTB handling skills will thank you for it.
re: Is it worth it to get my cross bike built for really WIDE tiSJT
Mar 20, 2003 7:39 AM
Maybe it's my mountain bike bias that I'm always thinking wider tires=better. Not that I run really wide tires on my hardtails (2.2" is probably the widest I have), but I've always felt more in control whenever I went up to a wider tire. I'll need to have a talk with my builder to see what he recommends. Thanks for your comments.
-Steve
A couple of thoughts...Steve_O
Mar 20, 2003 6:37 AM
One potential issue that I would ask your builder about is the effect of wider chainstay potentially causing chainsuck or chainline issues.

Wide chainstays can get really close to the rings on your cranks. If you want to run a triple ring setup you'd probably need to space the crankset out even more. To do this you'd need a longer BB spindle and, depending on if you are looking at running a road or MTB BB, you might have a tough time finding the right BB. Beyond all that, if your a real technoweenie kind of guy, Q-factor issues get involved as the cranks get spaced out more...

As for the wider tires, I think ATPJunkie is right in that you'd be surprised on what you can do on 35c - 38c tires. Here is an example of some Kenda Cross Supremes 700 x 35c that I just picked up. These big meats should be able to handle a lot of terrain and give me traction in loose, sandy stuff...

Final Note - If you still have your heart set on wide tires your builder should take a look at the specs on the Strong Frames Overlander...http://www.strongframes.com/frames/overlander/
This frame seems to kind of match what you are looking for...
A couple of thoughts...SJT
Mar 20, 2003 7:37 AM
I'll be talking this issue over with my builder in the next few days. He's made cross frames to accomodate >40mm tires (I've seen the pictures) so I know he can do it correctly. The whole BB spacing is a concern of mine though. It might be tougher to spin if the pedals are farther apart.

So is 38mm generally the largest most people go in a CX race? I'm new to cross and I'm learning something every day. 38mm=roughly 1.5", so it would be like running a 1.5" tire on my mtn. bike. The narrowest tire I've ever run on my mountain bike though is 1.75" which is ~44mm. That is why I told my builder to make the frame to accomodate 44 or 45mm tires which are mostly marketed towards the 29"er crowd. 29" bikes seem to be gradually getting more popular and I wanted to be able to run some of the newer tires that might come out for them. I figured I could run such wide tires (for cross) with low air pressure to give me a nice comfy ride on the singletrack. That along with disc brakes, top mounted brake levers, and a wide (46mm) Salsa Bell Lap bar, I'd be set for some nice semi-technical singletrack. This bike is meant to be a jack-of-all-trades...master of none kind of bike. The cross bike category is what it is mostly designed for, but it will be used on and off-road. I just don't want to jeopardize my on-road riding (which is what it will be used the most) for the singletrack riding. If designing for 44mm tires makes too much of a compromise I will quickly change the design to no more than 38mm with fenders.

Thanks for your comments. I've checked out the Overlander, cool bike, not keen on the paint job though. My bike will however be painted by Strong.
-Steve
A pic of what I had in mind...SJT
Mar 20, 2003 7:50 AM
Here's a picture I found on this website or mtbr.com of a Srong cross frame with really big meats on it...this is kind of what I originally had in mind for my bike for singletrack.

wow! that's a nice looking bikelaffeaux
Mar 20, 2003 10:35 AM
I'd need the bars higher, but otherwise that looks great!
Ditto on the Kenda Kross SupremesDale Brigham
Mar 21, 2003 8:43 AM
Those are the weapon of choice on my Jake when it's singletrack time. Kenda also makes the Kwick (a Speed-Max clone) in a 700c X 35 that I have mounted on a wheelset, but have yet to ride. The Kross Supreme and the Continental Twister 700c X 37 are the two biggest 700c tires I have ridden, and they both work great off-road.

In my experience, its more the limits of (low) gearing and pilot error (my incompetence) that stops my Jake on tough trails, not overly-narrow tire cross-section. In other words, I don't think tires wider than 35 mm or so would help me out much, and their extra traction and rim protection would be offset by their extra rotating mass and concommitant decrease in maneuverability. Just my 2 cents!

Dale
Umm ... maybe.GlowBoy
Mar 20, 2003 1:03 PM
There is a little benefit in terms of ride quality and off-road capability in running a tire as wide as 44mm (as you can on a Surly) but I'd give you two strong caveats.

First of all, 44mm is still far narrower, in terms of how the tires will actually perform, than ordinary mountain bike tires, which are 50-54 mm. Even with a 45mm tire up front at 40 psi, my 'cross bike doesn't even come close to handling fast rough terrain as well as my (non-suspension) mountain bike. As you mentioned, no matter what you do it will not really be a mountain bike anyway.

Second, there are darn few tires made in the 44mm range. As far as I know, your only options are the 42mm Ritchey ZED, the 44mm WTB MutanoRaptor and the 45mm Panaracer Smoke (no longer made but may still be found at some shops). I haven't tried the Ritchey, which may actually be a decent tire and I'm considering trying it. The WTB is notoriously bad in wet conditions. The Panaracer, which I've tried up front on my 'crosser, has great grip and decent cush but abominable rolling resistance.

All the really good tires are either true 29"er tires or are in the 32-38mm range, because there are bikes out there that fit them. By the way, I sometimes run that Kenda Kross Supreme that Steve_O showed in his post. It gets a little squirmy on hard surfaces, but in real off-road conditions it's absolutely amazing what the tire can do. And its rolling resistance, while high for a 'cross tire, is still far lower than the 45mm Panaracer.

Bottom line: given the compromises you may have to make (longer wheelbase, flexier curved chainstays, and/or increased chainsuck risk) to make a frame accomodate the wider tires, I'd say it's probably not worth it unless you decide you want to build up a true 29"er frame. That last option would result in other compromises, but I should add that I am actually planning on doing that myself in a year or two, so I have a bike that can run my choice of 'cross or 29" tires depending on conditions.

- Dan
good feedback...Steve_O
Mar 20, 2003 2:48 PM
Your right about the difficulty of finding those midrange tires (40c - 45c). I also appreciate the feedback on the Kenda's as I haven't mounted them to try them out yet...

One other thought that I had for SJT on the big tire issue is that cross bikes are notorious for toe overlap. putting a bigger tire worsens the situation. Assuming that he wants big tires to do what his mountain bike does (singletrack, twisty trails) then the overlap might also be more noticible as he's steering away... That would be a concern to talk to the builder about...

Steve-O (so much to think about with a custom bike...)
good feedback...atpjunkie
Mar 20, 2003 6:52 PM
ps higher bars...wider tires....might as well build a 2-9er. I'm a big boy and not the smoothest of bike handlers and I still wouldn't run bigger than a 38. I'd just pull out my MTB. One thing about bigger tires feeling better, they do, but it's the narrower tire that will make you a better (and faster) rider. Skinnies, learn em, live em, love em.
Schwalbe makes a couple wide 700c'sJan Gerrit Klok
Mar 23, 2003 2:29 AM
Black Jack in 1.6 and 1.9, very agressive looking.
Fast Fred in 35 and 40 (just for fast hardpack I think)
Snow Stud 40
Big Apple 50 and 60 (43mm and 56mm real)
Marathon in 28, 32, 37, 40, 47 and 50 (most are smaller in real).

In UCI cross racing, 35mm is the maximum allowed, so not too strange that we see so few tires much wider than that, and still trail ready.
Sure a 45mm real tre is more sutable for extreme offroad than a 35mm, but the 700c mountainbike feeling only starts above that.
Now with the developments in 29", cross trail riders will benefit. Already tires are being marketed that are sub-600g and over 50mm real. 54mm 570g coming up soon. On a cross-specific frame, it's most often easier to put a fatty up front than in the rear, and that's also where you need the most cornering grip. Forks are available that won't upset geometry too much, while offering breathing room for 50mm tires. A WTB Motoraptor barely fits a Surly Cross-Check fork, the better Kenda front tire may fit as well.
For rear tires most people are limited in they tire size, but you having a new one built have options. Try to find a 29" mtb that will fit any tire, and see how you feel on various size rear tires, to figure out how important clearance will be for you.
This is what I have done.Allroads
Mar 20, 2003 9:11 PM
I have a 'cross bike that was built as more of an all-around type bike and I asked for it to be able to fit 42mm tires. I ended up with a bike that accepts 52's (just barely).One drawback is that I have to run an mtb crankset because of the chainstay flare but this is ok. The bike probably isn't is nimble as some of the racing frames out there but it runs really well on trails. If you do want to run 52's you will need chainstay width and length (something like 435mm at the least) or the curved seat tube thing I have seen on some frames. Even then I had to switch front deraillers because the really big tires hit. One other thing...My frame has a low bottom bracket which makes it very smooth on the road and stable off road...I just don't pedal through corners.

AR
consider a full on 29erbike_rider81
Mar 24, 2003 4:00 PM
if you check the 29er board at mtbr, there is a guy 242baram, something like that he posts all the time. he got a 29er sycip that he runs cross and road tires on as well. he really likes it. i personaly have a planetx that i normally run 40's on and ride it offroad all the time and have a blast(note; i have also passed mtbrs dh while on the 40's). truthfully i really like the faster road/cross geometry offroad, more than the limited 29er geometry that i have ridden. skinny tires are alot of fun offroad, but i do wonder what it would be like to have 45 wtbs on there or bigger. just make sure you can run a 52T ring nomatter what you do. i doubt this helped too much but bikes are just too fun and the possiblities for their charateristics are too broad. too bad you can't buty one of each. good luck
52t ring? 11t cog, 100rpm, that's...39+mph!!Jan Gerrit Klok
Mar 26, 2003 11:22 AM
How many tail wind or downhill grade do you typically encounter on the typical cross ride?
Making room for the 52t ring AND fatties, automatically forces a builder to keep the rear pretty long.
I just got back from a tailwind, record-time commute, and never came close to even using the 44/12 biggest gear of my 29" bike. A 52t ring, I don't even need that for crit racing, 48/12 suffices, and I'm hardly a spinner.
52 sure works great with road derailers and chain wear is great, but please explain for what type of riding a 52t is so badly needed, especially on a fatties equipped bike.

I really wonder what a 29"-ready cross bike would be like. Curved seatstays might allow an extra short chainstay, especially if you don't need a front derailer. BB height could be made to be 27cm on skinnies, 28cm with 30mm tires and 30cm on 29" fatties, just ideal for the corresponding types of riding! Should you be okay with using just a 40-42t outer ring, short BB and 11-32 cassette, than tire clearance would not be an issue at all, nomatter how short you want your chainstays. Though mind you, shorter is not always better.

Happy trails,

J
SureHoopes of glory
Mar 27, 2003 4:18 AM
Why deny yourself the option? You don't have to run them, but you'll be able to if you want. Downsides? Miniscule weight penalty and er...ummm...none.
downsides....atpjunkie
Mar 27, 2003 7:19 PM
never get used and smaller ring would provide more 'real time' gear choices. I ran a 48x36 with an 11-30 8 sp. on one of my cx rigs this race season. I think I used the 48 x 11 (maybe only the 12), in one race this year. There aren't long enough flats or downhills in most cx races to warrant it and if you can pedal a 52x 11 downhill offroad on 700x 30's your bike handling skills must be better than most pro downhillers. Pull a 52 out for road use in the off season but it has no place in the dirt.
Eh?Hoopes of glory
Apr 3, 2003 5:22 AM
I think you may be on the wrong thread here??