OzVMX Forum
Marque Remarks => CZ => Topic started by: stump magnet on August 06, 2012, 06:08:45 am
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hi all, i would like to reduce the travel of the rear brake pedal so that i dont have to press it down so far to get the same braking effort, the reason i ask is i have to run the rear brake quite tight on the adjuster to get the short travel on the pedal i like and so it heats up and starts to bind (so i have to run it slack for me) but if i had more slack in the adjustment but still a short pedal travel then the brake would not bind so my question is what do i have to do to the pedal or the brake arm? do i lengthen or shorten the pedals pivot or the arms? i have a longer curved rear brake arm at my disposal but have not tried it, it must all be a question of leverage ratio's i supose? the bike is a 360 sidepipe, cheers
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Stumpy,I dont like a lot of travel either but you dont want the pads binding.On one of my bikes the brake rod goes through the ferrel (I think that's how you say it) then I have a couple of spacers probably about a cm or 2 long then the threaded nut,seems to work pretty well.On the other newer bike I have the usual arrangement,but have put a spring from the countershaft sprocket guard (homemade) to a hole in the brake pedal which keeps it up under your boot and gives a bit more progressive feel to the brake.Your brake actuator arm position can also be altered on the splined shaft which might help.All a bit fiddly,you gotta these old bikes :D
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Stump
What I run on all the CZ is a Go Kart pedal spring from the rear brake pivot arm back to the rear chain adj bolt gives you tension on the pedal and free play on the brake shoes no matter how much play up or down you like
Back in the day most CZ guys used old inner tube to do the same job
My ankle does not pivot either ;D
Cheers
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Thanks for the replys guys but the return of the pedal is not an issue, the issue is how can I get more movement out of the rear ar arm for the same or less movement of the pedal
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Stump
Does the brake have good stopping power can you lock the rear wheel without stomping on the pedal
Try the longer rear arm set to the rear of vertical on the brake plate arm
The std CZ brake is one of the best
Had a problem when I had the rear shoes rebonded with wrong type of lining ,Same as you , Rear after one lap red hot binding with no stopping at all pull the rear wheel after each race to rough the shoes up lasted about one lap stuffed around with pedal and rear arm angles nothing work untill the shoes were rebonded with correct lining now works with mild pedal pressure as my ankle only has 10% pivot so the shoes are just about touching the drum :-\
Cheers
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have played around with CAD (cardboard aided design ;D) and a longer pivot on the pedal would result in more movement of the brake arm, a longer brake arm requires more pedal movement, the shoes are standard CZ by the way and has great stopping power, i just like a light switch style brake pedal
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There is also a fair bit of flex in the brake rod which has to take up before they bite,so maybe a more rigid brake rod???have seen one with 90 degree bends rather than the curved bend to get around the shock.
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Possibly try running the rear lever pointing downwards with a straight brake rod, that's the set up I use although with an extended rear lever.
Also using a billet brake plate which takes out the flexing from the standard one
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Ok have sorted it, have made a billet back plate and new billet lever with the rod hole 20mm further up how do I post pics from smart phone?
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You'll need to use a hosting site like photobucket or flicker.
http://ozvmx.com/community/index.php?topic=17785.0
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You can send via iPhone to photobucket, obviously you have to have an account ( free ) and photobucket tells you how to do it.
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Possibly try running the rear lever pointing downwards with a straight brake rod, that's the set up I use although with an extended rear lever.
The brake rod should run parallel to the swingarm, either above or below
If the brake rod runs diagonally across the swingarm it will cause the brake pedal to move with suspension movement
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(http://pbckt.com/p7.uV8GLp) does this work?
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can't see any picture???
You can run your brake rod, parallel, above, below the swing-arm or anywhere you like, as long as where the brake rod meets the brake lever is where the swing-arm pivot bolt is. Right in the center of the bolt.
If it’s not, then the suspension movement will stuff it up. ( eg: if it pivots below the swing-arm, you land of a jump and it locks up the back wheel ).
If you want to get less movement at your brake lever, you need a shorter rear brake lever on the back hub.
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has this worked? (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/D2E6008C-orig.jpg)
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it worked! heres the rear back plate (note the slight nibble where i went right rather than left) (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/396FD79B-orig.jpg)
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finally all together with the chain guide that i also made from billet for the arm and bracket but used a modified universal guide block from MD racing (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/97498178-orig.jpg) recognise the pipe GMC?
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no stopping me now! heres the CR billet yokes (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/B251B4BC-orig.jpg)
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billet gas cap i made (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/C84DF04A-orig.jpg)
whole bike (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/548F3252-orig.jpg)
and my twinport (http://i68.photobucket.com/albums/i14/stumpmagnet1/Snapbucket/E9C3B887-orig.jpg)
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I'm not a big CZ lover but they are very nice looking bikes Stumpy ... congrats 8)
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You should have a ride Simo,you will be converted.Jeez Stumpy,you're a bit handy..let me know if you go into production :)
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You should have a ride Simo,you will be converted.Jeez Stumpy,you're a bit handy..let me know if you go into production :)
Okay next time we are out TARTing about I'll swap you the TM for the CZ .... My only fear is that you will be converted to TM power and not hand it back ;D
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cz's rule, you will not want to get back on the tm..... ;D
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i think i will have to give the girls a freshion up over the winter as they have been raced for the last three seasons and the paint etc is looking tired
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Are you talking about the bikes in the photos?...If those bikes are "tired",mine must be close to death ;)
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No comment about state of my bike, didn't even get a winter rebuild but the 20year old barums may have to go before the season starts again at the start of ocotber
Have a look at this shot of my bike at the start of last season to see what I did to get rid of the rod flex
(http://i788.photobucket.com/albums/yy166/tony27_photo/003-1.jpg)
Have added a chain guide from CZstuff & ohlins shocks since this shot as well as a tall seat