Cyclocross - brake question, 26" frame to 700c wheels...

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truvaine
09-05-08, 11:39 PM
hey all
i've got a wonderful steel mid 1990s Specialized mountain frame that is set up as a singlespeed right now. i'd love to make it a singly 'cross bike to add to my stable (1984 Trek 410cx, 2002 K2 Enemy, 2006 Redline Conquest, ... and some frames haha) and use it to commute and do some rail-trail stuff.
question is, i want to run 700cs (or 27s....) on it, but i cant find any information on running 700cs on a 26" mountain frame. what type of brakes would be available for this conversion? i know it would need to be longer arms, maybe even V-brakes.... i know of and am not willing/wanting to run 650s.
any suggestions would be greatly apprecaited!! :thumbup:
and an old pic of my 1984 Trek for fun :
c_m_shooter
09-06-08, 12:41 AM
Unless you run disks, the only way would be to cut off and reweld the cantilever bosses. Unless you have the tools and knowledge to do it yourself, it isn't worth it. Try measuring to see if a long reach caliper would work as a last resort.
If you can find a set of old school Onza brakes you can do it. They had a post that the brake pad moved on to adjust for wheel size.
You used to be able to get them on ebay, but I have not seen a set of them lately.
Here's a pair on ebay http://cgi.ebay.com/Onza-H-O-Brakes-for-either-Cyclocross-or-MTN-Bikes_W0QQitemZ120301659812QQihZ002QQcategoryZ27949QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Saddle Up
09-06-08, 08:06 AM
Mavic makes brake adaptors that do exactly what your looking for. They also make a set of wheels (Speed City)for the same application.
http://www.mavic.com/mtb/products/Brake-Caliper-Adjuster.323944.aspx
truvaine
09-06-08, 11:48 AM
awesome, thanks!!
ive been contemplating running a fixie rear wheel i have laying around, but that would be just too much fun (and illegal in some races, and dangerous, and and... :D )
if i could just get a rear brake that would probably be fine. wondering about disc, but then i'd have to weld disc mounts on and find a rear disc wheel...
truvaine
09-06-08, 11:55 AM
Mavic makes brake adaptors that do exactly what your looking for. They also make a set of wheels (Speed City)for the same application.
http://www.mavic.com/mtb/products/Br...er.323944.aspx (http://www.mavic.com/mtb/products/Brake-Caliper-Adjuster.323944.aspx)
interesting. so, i guess the question now is, which option? dont really have money for wheels, but the brakes or the brake adapters? we know the brake adapters would definately work; what about the brakes? are they a definate? (being unemployed right now) dont have the money to buy a few things to figure this out..
danke so much guys/gals
Before I even worried about brakes, I'd check the wheels. Get a set of wheels with the tires you're going to use and see if they fit the frame and forks. Then worry about brakes. I tried the same thing on a 1986 vintage Rockhopper and with 23C tires they hit the fork crown and rear bridge. So, for me brakes were a non issue. Good luck
truvaine
09-07-08, 08:57 AM
yup already checked! got the wheels and tires mounted already. plenty of clearance!
i spent an hour or so last night with some cardboard, ruler, and a marker, and i'm going to have my friend make some adapters like those Mavics. just have to figure out the brake bosses. i think i have some laying around, i'll probably just have a nut welded on so i can have replacable bosses... might do a small piece of pipe and tap the insidei :thumbup:
Fixed Up North
09-08-08, 01:54 PM
Many mountain bike frames have holes drilled in the fork and seat stay bridge that will accomodate a road caliper. I have been able to put road wheels on a mountain bike with long reach road brakes this way. Mud clearance is a bit of an issue, but that is going to be the case anyway with a make-shift bike like this.
truvaine
09-08-08, 02:46 PM
Many mountain bike frames have holes drilled in the fork and seat stay bridge that will accomodate a road caliper. I have been able to put road wheels on a mountain bike with long reach road brakes this way. Mud clearance is a bit of an issue, but that is going to be the case anyway with a make-shift bike like this.
yeah, sadly the Specialized i'm doing this with doesnt have that as an option.
IRT make-shift = haha, i know. im just doing it for fun for a beater. i have too many bikes as it goes, might as well complete another one that funtions and is semi original. i've got a 26" Cannondale F900 singly XC bike, full rigid that i ride now; just wanted another singly thats more of a road/trail/path bike *shrug* :p
crushkilldstroy
09-08-08, 11:14 PM
I've seen a super janky bike where the guy just drilled some holes further up on a set of v brakes and somehow miraculously mounted pads to that. It looked like it worked for him, but I wouldn't ever try it myself.
I would assume that those Mavic brake adaptors would work for what you're doing. I just hope that they wouldn't flex too badly.
truvaine
09-10-08, 07:11 PM
are you sure those brakes will work for 700c wheels on a 26" frame?
they end very soon, just realized haha
are you sure those brakes will work for 700c wheels on a 26" frame?
they end very soon, just realized haha
Yes, it's what I started with
justinb
09-10-08, 09:13 PM
There are other types of cantis with enough adjustability to run 700c on 26" frames. Avid Tri-Align and an early Tektro model come to mind. I can confirm that the tri-aligns work great.
Regarding the Mavic brake adapter, make sure of tire clearance. I think it may limit you to 30mm or so.
jitterymonkey
09-11-08, 12:13 AM
If you can find a set of old school Onza brakes you can do it. They had a post that the brake pad moved on to adjust for wheel size.
You used to be able to get them on ebay, but I have not seen a set of them lately.
Here's a pair on ebay
Thanks Keith, (when Ya gonna update that blog?)
Picked them up for my 650B'd Cross Check.:innocent:
Now I have to choose....Run a 650B or a 700c wheelset?
truvaine
09-15-08, 07:29 AM
jittery monkey.....................so i was bidding against you?
guess i'll have to find something else.
LOWCOOL187
12-03-08, 03:32 PM
http://www.paulcomp.com/frmbrakes.html
expensive, but looks like they are well made
Why not put road tires or slicks on the 26" wheels? Isn't that easier than screwing with the brakes? I used to run Specialized Nimbus tires on my old MTB. While not as fast a real roadbike it was a lot faster than knobbies.
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