Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 11-01-12, 01:12 PM   #1
glopez
Newbie
Thread Starter
 
Join Date: Oct 2012
Bikes:
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
700cc to 26"??

i found a nice cyclocross bike on ebay and was wondering if i could change the wheels to 26" if i ever had to change or replace them.
would there be a problem, besides the v-brakes? would it work if i switched to disk brakes?
thanks!
-g
glopez is offline   Reply With Quote
Old 11-01-12, 01:20 PM   #2
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,870
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 229 Post(s)
WHY? N+1.. Don't like it as is?, sell it and Buy the Bike You want,

[ Or if this is another Pre worry, and you didn't win the Bid, stop ]

rather than do those changes .. it's a fool's mission.
fietsbob is offline   Reply With Quote
Old 11-01-12, 02:12 PM   #3
cplager
The Recumbent Quant
 
cplager's Avatar
 
Join Date: Jan 2012
Location: Norwalk, CT
Bikes: 2012 Cruzbike Sofrider, 2013 Cruzigami Mantis
Posts: 3,017
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by glopez View Post
i found a nice cyclocross bike on ebay and was wondering if i could change the wheels to 26" if i ever had to change or replace them.
would there be a problem, besides the v-brakes? would it work if i switched to disk brakes?
thanks!
-g
If you switched to disc brakes, you could go to 26" wheels, 20" wheels, whatever you wanted to. People do things like this on recumbent bicycles somewhat often. Without disk brakes, you just need to have brakes that would work.

Cheers,
Charles
cplager is offline   Reply With Quote
Old 11-01-12, 02:23 PM   #4
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Changing the wheel size may be possible but it is likely to change the handling of the bike, and result in increased pedal strike from a too-low bottom bracket.

What is wrong with the 700C wheels? 700C is the standard size for CX, touring, road bikes, hybrids, and 29ers. You have practically unlimited tire choice (limited mainly by the clearance in the frame and forks), and the bike will work as it was designed.

What are you hoping to accomplish with this change?

Also, what model of CX bike is it and does it have mounts on the frame and fork for disk brakes?
LarDasse74 is offline   Reply With Quote
Old 11-01-12, 02:25 PM   #5
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cplager View Post
If you switched to disc brakes, you could go to 26" wheels, 20" wheels, whatever you wanted to. People do things like this on recumbent bicycles somewhat often. Without disk brakes, you just need to have brakes that would work.

Cheers,
Charles
I very much doubt you could use 20" wheels on a bike designed for 700C... 26 inch wheels would possibly work OK, 24" would likely put the pedals very very close to the ground, and 20" you would only be able to pedal 60 degress at a time to 'ratchet' the bike forward. Brakes are not the only consideration.
LarDasse74 is offline   Reply With Quote
Old 11-01-12, 03:49 PM   #6
cplager
The Recumbent Quant
 
cplager's Avatar
 
Join Date: Jan 2012
Location: Norwalk, CT
Bikes: 2012 Cruzbike Sofrider, 2013 Cruzigami Mantis
Posts: 3,017
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
I very much doubt you could use 20" wheels on a bike designed for 700C... 26 inch wheels would possibly work OK, 24" would likely put the pedals very very close to the ground, and 20" you would only be able to pedal 60 degress at a time to 'ratchet' the bike forward. Brakes are not the only consideration.
You're right. I'm thinking of short wheel base recumbents where there's no problem with hitting the ground.

Cheers, Charles
cplager is offline   Reply With Quote
Old 11-01-12, 04:11 PM   #7
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,870
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 229 Post(s)
Drop the tail end several inches the head tube angle goes down too..
even on a recumbent.
fietsbob is offline   Reply With Quote
Old 11-01-12, 04:17 PM   #8
FastJake
Constant tinkerer
 
FastJake's Avatar
 
Join Date: May 2010
Location: Madison, Wisconsin
Bikes:
Posts: 7,574
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
V-brakes? No. Disc brakes, it would work but what are you trying to accomplish? As stated a smaller overall tire height will change the handling and make the BB lower.
FastJake is offline   Reply With Quote
Old 11-01-12, 04:33 PM   #9
cale
Senior Member
 
cale's Avatar
 
Join Date: Oct 2004
Location: Seattle
Bikes: Kuota Ksano. Litespeed T5 gravel - brilliant!
Posts: 3,250
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
A 26" wheel sporting a 1.75" tire has an axle height of only ~.5" difference to a 700c wheel sporting a 28mm tire. These sort of difference aren't significant enough to impact handling. It's about the same as moving from a 23mm to a 35mm tire on a 700c wheel assuming you had the brake and frame clearances.
cale is offline   Reply With Quote
Old 11-01-12, 04:55 PM   #10
Airburst
Senior Member
 
Join Date: Oct 2009
Location: England, currently dividing my time between university in Guildford and home just outside Reading
Bikes: Too many to list here!
Posts: 1,921
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
I very much doubt you could use 20" wheels on a bike designed for 700C...
Don't be so sure - I managed to put 20" wheels on a 26" wheel bike recently - I did have to use very short cranks, but it worked. Don't even ask how I did the brakes, it'll scare people.
Airburst is offline   Reply With Quote
Old 11-01-12, 05:08 PM   #11
Lexi01
Senior Member
 
Lexi01's Avatar
 
Join Date: May 2011
Location: Geelong, Australia
Bikes: Cannondale Supersix Hi-Mod / Scott Spark 930 / Scott Sportster 20 / Jamis Allegro 2.0
Posts: 659
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Airburst View Post
Don't be so sure - I managed to put 20" wheels on a 26" wheel bike recently - I did have to use very short cranks, but it worked. Don't even ask how I did the brakes, it'll scare people.
How did you do the brakes?
Lexi01 is offline   Reply With Quote
Old 11-01-12, 05:09 PM   #12
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,870
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 229 Post(s)
yea but that 559 -47 tire wont fit in a CX frame,

made for a 622-32 tire, particularly the fork.

fool's errand ..

go get a hundred yard spool of waterline while you are at it.

Last edited by fietsbob; 11-02-12 at 11:01 AM.
fietsbob is offline   Reply With Quote
Old 11-01-12, 05:21 PM   #13
AlphaDogg
I let the dogs out
 
AlphaDogg's Avatar
 
Join Date: Apr 2011
Location: Boulder, CO
Bikes: 2011 Fuji Roubaix 1.0, 2003 Ti Merlin Solis, & 1994 Raleigh MT200
Posts: 1,934
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by fietsbob View Post
Drop the tail end several inches the head tube angle goes down too..
even on a recumbent.
The angle doesn't change if you're lowering the rear and the front equal amounts. Maybe I misunderstood what you said?
AlphaDogg is offline   Reply With Quote
Old 11-01-12, 05:22 PM   #14
Airburst
Senior Member
 
Join Date: Oct 2009
Location: England, currently dividing my time between university in Guildford and home just outside Reading
Bikes: Too many to list here!
Posts: 1,921
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Lexi01 View Post
How did you do the brakes?
Sections of an old rim - I mitred them to fit across the fork blades and seatstays in the same kind of way that kickstands do, drilled out a spoke hole on each one to admit the centre bolts on the brakes, then bolted them in place with the centre bolts. The brakes are BMX sidepulls, but the levers are absolutely massive, so I can pull them by the ends and the braking's OK. The bits of rim stick out a couple of centimetres each side, so I put duct tape on them to reduce the chance of them killing me if I ever crash the bike. I need to do something less bodged when I next get the chance, I might cut the canti bosses off and move them down to the right height if I can borrow a stick welder.

I don't feel too bad about cutting and welding on the frame, it's a BSO that was donated to the co-op, and it's severely rusted. It was in the "scrap pile" when I found it. The 20" conversion was mainly to see if I could. It works, and who the heck's gonna steal it?
Airburst is offline   Reply With Quote
Old 11-01-12, 07:32 PM   #15
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Bikes: Several, mostly not name brands.
Posts: 16,373
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 63 Post(s)
Quote:
Originally Posted by Airburst View Post
Don't be so sure - I managed to put 20" wheels on a 26" wheel bike recently - I did have to use very short cranks, but it worked. Don't even ask how I did the brakes, it'll scare people.
Quote:
Originally Posted by Lexi01 View Post
How did you do the brakes?
I'm thinking "Ted Shred"
JohnDThompson is offline   Reply With Quote
Old 11-02-12, 07:30 AM   #16
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by Airburst View Post
Don't be so sure - I managed to put 20" wheels on a 26" wheel bike recently - I did have to use very short cranks, but it worked. Don't even ask how I did the brakes, it'll scare people.
The question that immediately pops to mind is not 'how,' but 'why?'
LarDasse74 is offline   Reply With Quote
Old 11-02-12, 07:49 AM   #17
cplager
The Recumbent Quant
 
cplager's Avatar
 
Join Date: Jan 2012
Location: Norwalk, CT
Bikes: 2012 Cruzbike Sofrider, 2013 Cruzigami Mantis
Posts: 3,017
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
What are you hoping to accomplish with this change?
I am curious about this as well.

I'm pretty sure you can probably change to 26" wheels. If you tell us why you want to switch, I think you'll get better advice.

Cheers,
Charles
cplager is offline   Reply With Quote
Old 11-02-12, 09:30 AM   #18
cale
Senior Member
 
cale's Avatar
 
Join Date: Oct 2004
Location: Seattle
Bikes: Kuota Ksano. Litespeed T5 gravel - brilliant!
Posts: 3,250
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Possibly the OPer doesn't want his reasons debated. I'm not sure I'd want that either.
cale is offline   Reply With Quote
Old 11-02-12, 10:12 AM   #19
cplager
The Recumbent Quant
 
cplager's Avatar
 
Join Date: Jan 2012
Location: Norwalk, CT
Bikes: 2012 Cruzbike Sofrider, 2013 Cruzigami Mantis
Posts: 3,017
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by cale View Post
Possibly the OPer doesn't want his reasons debated. I'm not sure I'd want that either.
You're quite possibly right. That being said, I really am just curious. I already live on the dark side (ride a recumbent) and am quite open to people doing non-standard things with bicycles.

Cheers,
Charles
cplager is offline   Reply With Quote
Old 11-02-12, 10:59 AM   #20
Airburst
Senior Member
 
Join Date: Oct 2009
Location: England, currently dividing my time between university in Guildford and home just outside Reading
Bikes: Too many to list here!
Posts: 1,921
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LarDasse74 View Post
The question that immediately pops to mind is not 'how,' but 'why?'
The short answer is "why not?"

The slightly longer answer is "it was a slow day at the co-op"
Airburst is offline   Reply With Quote
Old 11-02-12, 11:03 AM   #21
fietsbob 
coprolite
 
fietsbob's Avatar
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Bikes: 7
Posts: 18,870
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 229 Post(s)
Quote:
The angle doesn't change if you're lowering the rear and the front equal amounts. Maybe I misunderstood what you said?
Recumbents, predominantly, already have a small front wheel.
fietsbob is offline   Reply With Quote
Old 11-03-12, 12:08 PM   #22
Bat56
Senior Member
 
Bat56's Avatar
 
Join Date: May 2010
Location: St.Paul, MN
Bikes:
Posts: 1,732
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by glopez View Post
...if i could...would there be a problem...would it work...
Quote:
Originally Posted by cale View Post
Possibly the OPer doesn't want his reasons debated. I'm not sure I'd want that either.
Pretty sure OP wanted to know about potential problems and in order to answer that the reasons for the modification, or purpose of the modification is needed.
Bat56 is offline   Reply With Quote
Old 11-03-12, 12:08 PM   #23
LarDasse74
Guest
 
Join Date: Jul 2008
Location: Grid Reference, SK
Bikes: I never learned to ride a bike. It is my deepest shame.
Posts: 3,769
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by fietsbob View Post
Recumbents, predominantly, already have a small front wheel.

Even if the angles don't change, the amount of 'trail' will. Head angle is only relevant in that it works with fork rake and wheel diameter to produce trail.
LarDasse74 is offline   Reply With Quote
Old 11-03-12, 01:24 PM   #24
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Bikes: Rans Rockst (Retro rocket) Rans Enduro Sport (Retro racket) Catrike 559, Merin Bear Valley (beater bike).
Posts: 26,543
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 62 Post(s)
Quote:
Originally Posted by cale View Post
Possibly the OPer doesn't want his reasons debated. I'm not sure I'd want that either.
Does first and only post tell you anything?
Retro Grouch is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:52 AM.