RADBMX.CO.UK
Technical & Reference Section => Tech and Restoration => Topic started by: oldschoolace on April 20, 2013, 01:49 PM
-
Starting to gather a few gems for my latest build, a Starway freemaster pro :smitten:
(http://i1182.photobucket.com/albums/x455/oldschoolace/Picture008-1.jpg)
(http://i1182.photobucket.com/albums/x455/oldschoolace/freemaster1.jpg)
I always like to try new things with my builds and after seeing a few Woody Itson trickstar roller cam brake builds on the museum i decided to have a go myself.... with an Oddy pitbull :D
The Woody's for reference
(http://i1110.photobucket.com/albums/h444/JARHEADJONES/CIMG9635.jpg)
(http://i1110.photobucket.com/albums/h444/JARHEADJONES/CIMG8946-1.jpg)
So the first issue is mounting the brake itself, as the pitbull is mounted with a traditional bolt the shaft inside the fork would have to straddle the bolt with enough clearance not to bind when in use.
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150234_zps767d5021.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150234_zps767d5021.jpg.html)
In order to keep the shaft plumb and running smooth i bought a linear bearing. The shaft is 12mm diameter and the bearing is 12mm internaly and 21mm externally. The forks were 21mm at the top and tapered to just under 20mm where the break is mounted for some reason. Luckily i had already bought a beefy drill bit for another stem little project ;) so it was staightforward to bore out the tube to the depth i needed for the bearing
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-20120616_zps1c087381.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-20120616_zps1c087381.jpg.html)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150357_zps42801653.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150357_zps42801653.jpg.html)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150421_zps77fdb691.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150421_zps77fdb691.jpg.html)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150557_zps8db231a6.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150557_zps8db231a6.jpg.html)
Next i made a little bracket out of a 50mm x 50mm piece of 2mm steel plate. Cut like a capital letter V and bent in the vice to mirror the pitbull wedge shape.
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150203_zps88d51991.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150203_zps88d51991.jpg.html)
The type of bearing i used is an extra long one, 57mm, the standard ones are 32mm i think but i wanted the extra length to help keep everything running smooth
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150132_zpscc45a97b.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150132_zpscc45a97b.jpg.html)
The shaft offered up to the plate and ground to the right angle
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15150315_zps8cefe3aa.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15150315_zps8cefe3aa.jpg.html)
I made a little jig to keep everything square whle the JB Weld went off ( Once i knew everything lined up with the brake the joint was cleaned up and welded properly)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-18103503_zps4f67d9ff.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-18103503_zps4f67d9ff.jpg.html)
Once the shaft was cut to length i welded a small penny washer to the top to act as a stop for the pear end of a cable ( the pear fits nicely inside the shaft )
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-20122607_zps44c087a0.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-20122607_zps44c087a0.jpg.html)
The final result looks alot cleaner without the cable and horrid plastic cable hanger that is stock with the pitbull
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15162530pit_zpsa13843e6.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15162530pit_zpsa13843e6.jpg.html)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-15162513_zps89ea3a2a.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-15162513_zps89ea3a2a.jpg.html)
The cable will run through a barrel end mounted in the pots bolt of a freestyle stem and a modified Oddysey Knarp will attach the cable to the brake lever.
Just need to strip the pitbull now for a fresh coat of white paint and give the little pulley wheels a spot of grease :daumenhoch:
Thanks for looking guys, Clint
-
Fair play Clint! Another top job mate! Nice work :daumenhoch:
-
The ingenuity of some of the people on here never cease to amaze me.
Very clever indeed Clint. :daumenhoch:
Adam
-
top skills...nice1 :daumenhoch:
-
Top work Clint,always outside the box but brilliant! :daumenhoch:
-
Cheers guys, pretty chuffed with the results :)
-
:shocked: that's boggled my mind clint.......
-
I'm currently doing this on my trick star. It's a slightly different design to yours but the principle is the same. You have done a nice job. :4_17_5:
-
sweet job bud :4_17_5:
-
Skills! :4_17_5:
-
Superb fella :coolsmiley:
-
I'm currently doing this on my trick star. It's a slightly different design to yours but the principle is the same. You have done a nice job. :4_17_5:
Are you thinking of bolting your bracket to the back of the wedge by any chance? The holes would lend themselves to this.
I decided against it as i think it would give you less clearance on the caliper frame and less travel for the pads. Adjusted properly though it should be fine :daumenhoch:
-
Skill's :4_17_5: :daumenhoch:
-
I'm currently doing this on my trick star. It's a slightly different design to yours but the principle is the same. You have done a nice job. :4_17_5:
Are you thinking of bolting your bracket to the back of the wedge by any chance? The holes would lend themselves to this.
I decided against it as i think it would give you less clearance on the caliper frame and less travel for the pads. Adjusted properly though it should be fine :daumenhoch:
my wedge and the lifting bar inside the forks are going to be one piece. just like the original hutch prototype. im also using the suntour roller cam brake with linear sprigs. it will look the same as the hutch picture you have posted above. :)
-
Sounds cool, looking forward to seeing it :daumenhoch:
-
I'm currently doing this on my trick star. It's a slightly different design to yours but the principle is the same. You have done a nice job. :4_17_5:
Are you thinking of bolting your bracket to the back of the wedge by any chance? The holes would lend themselves to this.
I decided against it as i think it would give you less clearance on the caliper frame and less travel for the pads. Adjusted properly though it should be fine :daumenhoch:
my wedge and the lifting bar inside the forks are going to be one piece. just like the original hutch prototype. im also using the suntour roller cam brake with linear sprigs. it will look the same as the hutch picture you have posted above. :)
If I use it 'sprig' ... its always linear :daumenhoch:
-
Excellent engineering!
-
Had a bit of time today for some fine tuning :)
Drilled and taped a couple of holes in the plate for some adjusting bolts
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-25170650_zps11068b33.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-25170650_zps11068b33.jpg.html)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-25170829_zps57d4074c.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-25170829_zps57d4074c.jpg.html)
(http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-25171830_zps26325fcd.jpg) (http://s1182.photobucket.com/user/oldschoolace/media/2013-04-25171830_zps26325fcd.jpg.html)
And a quick vid of the thing in action :coolsmiley:
Click on the pic :D
(http://i1182.photobucket.com/albums/x455/oldschoolace/th_2013-04-25172402_zps3049225b.jpg) (http://i1182.photobucket.com/albums/x455/oldschoolace/2013-04-25172402_zps3049225b.mp4)
-
Ingenious :4_17_5: top skills dude :daumenhoch: