Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Slightly longer v-brake arms..?

Notices
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.

Slightly longer v-brake arms..?

Old 03-31-16, 06:50 AM
  #1  
Senior Member
Thread Starter
 
Join Date: May 2007
Location: Montreal, Canada
Posts: 223

Bikes: Marinoni Piuma, Tricross Elite, Tricross Sport (*R.I.P), Mikado DeChamplain

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Slightly longer v-brake arms..?

Hello,

I have an oldish touring bike with dropbar STI shifters (old Shimano RSX index shifter) that is fitted with Tektro Mini-V brakes, the arm length is 80mm. I bought Schwable Marathons 35C thinking they would fit (has my winter Nokians 35C do fit) but the tire ends-up rubbing against the noodle hook.

I can turn the wheel by hand but it won't spin so its clearly not fitting. The Marathons are much taller..

As it is right now (other tire) the break pads are pretty close to the rim, and its fine. I get full stopping power at about 3/4 of the pull (front brake).

I was wondering, can I install 90mm arms V-brakes like Tektro RX6 or do I risk losing lots of stopping power? I feel gaining 10mm in height would be more than enough to clear the tire, right?
DunderXIII is offline  
Old 03-31-16, 07:18 AM
  #2  
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 644 Times in 365 Posts
You'll actually get more brake power because you'll have longer lever arms.

Unfortunately, you'll also need a bit more lever travel. It comes down to how closely you can adjust your brake pads to your rims. You'll need to balance is the space needed unhook your noodle when you remove and replace a wheel against when your brake lever bottoms against the handlebar. If you asked me to bet, I'd go with not gonna work.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.
Retro Grouch is offline  
Old 03-31-16, 07:30 AM
  #3  
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,167

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4239 Post(s)
Liked 3,976 Times in 2,363 Posts
I periodically service (and install) Travel Agents on bikes. While I never like additional stuff in the cable runs these cable travel manipulators work very well. They turn a mushy lever feel that bottoms out on the bar before real clamping power has been achieved into a solid lever feel which doesn't bottom out on the bar and yet still has good pad clearance to the rims. The version with barrel adjusters are the choice we stock. Andy.
Andrew R Stewart is offline  
Old 03-31-16, 07:32 AM
  #4  
Senior Member
 
Join Date: Aug 2005
Location: Pittsburgh, PA
Posts: 33,656

Bikes: '96 Litespeed Catalyst, '05 Litespeed Firenze, '06 Litespeed Tuscany, '20 Surly Midnight Special, All are 3x10. It is hilly around here!

Mentioned: 39 Post(s)
Tagged: 0 Thread(s)
Quoted: 2027 Post(s)
Likes: 0
Liked 1,099 Times in 745 Posts
Given the same brake levers and hand effort you will get 9/8 or 12% more brake "power" but require 12% more lever travel to apply the brakes at all. So, if you now have plenty of lever travel left after the brake pads hit the rims and are compressed under braking then the taller arms will work. As noted, you may not have enough slack to unhook the noodle to fix a flat so a barrel adjuster may have to be added to the brakes to gain the clearance.
HillRider is offline  
Old 03-31-16, 08:58 AM
  #5  
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 30,225

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 1572 Post(s)
Liked 644 Times in 365 Posts
Originally Posted by Andrew R Stewart
I periodically service (and install) Travel Agents on bikes. While I never like additional stuff in the cable runs these cable travel manipulators work very well. They turn a mushy lever feel that bottoms out on the bar before real clamping power has been achieved into a solid lever feel which doesn't bottom out on the bar and yet still has good pad clearance to the rims. The version with barrel adjusters are the choice we stock. Andy.
I have a good amount of experience with Travel Agents too. Pluses are they work and they are very reliable. Negatives are they look a little bit goofy and they cost extra. The first time that you set one up can be a bit of a trip. My advice is to do the back first so, if you fubar the cable, you can cut it short to use on the front.

If it was my bike I'd see if I could get the long arm linear pull brakes to work, by themselves, to my satisfaction. If not, the Travel Agents are a viable plan B.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.
Retro Grouch is offline  
Old 03-31-16, 09:26 AM
  #6  
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,359 Times in 865 Posts
Basic engineering of a simple Lever .

V brakes are a type 2 pivot-work-effort .. so is a wheelbarrow.. wheel-load-handles

type 1 the pivot is between work & effort .. L type cantilever fall in that niche..


Magura Hydraulic rim brakes fit on V brake Bosses . fluid pressure pushes the pads against the rim.




your current TRP 90 Mini V are that long from the pivot ..

You may be able to measure 9 cm from the post and see if its high enough..

their 84 was changed to match the latest cable pull from Shimano for Road brifters.

Last edited by fietsbob; 03-31-16 at 10:56 AM.
fietsbob is offline  
Old 03-31-16, 01:19 PM
  #7  
a77impala
 
a77impala's Avatar
 
Join Date: Oct 2005
Location: Central South Dakota
Posts: 1,519

Bikes: 04=LeMond Arravee, 08 LeMond Versailles, 92 Trek 970

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 28 Post(s)
Liked 13 Times in 8 Posts
I have converted a few mtn bikes to 700c wheels and tires. To get the V brakes to work I extended the brake arm with scratch built spacers. Because I had to place the pads very close to the rim I ground off the nipple on the noodle to about 1/8 inch. Still holds in place but can be released if need arises.
On my wife's bike I used Rapid fire shifter brakes, on mine I used Sora brifters, the other the long travel tektro RL520 levers.
a77impala is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bobbygllh
Bicycle Mechanics
9
06-19-18 10:09 AM
Rocket Mouse
Bicycle Mechanics
6
09-30-17 11:59 AM
topslop1
Bicycle Mechanics
11
03-31-16 08:44 AM
wheelinthai
Cyclocross and Gravelbiking (Recreational)
10
12-20-14 07:25 AM
dds11
Tandem Cycling
15
05-04-14 12:22 PM

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.