some info about compression release

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Sianelle

Guest
alaska van posted something that was interesting: http://www.motoredbikes.com/showpost.php?p=78386&postcount=8

Yup, coaster brake in the rear only. you mainly use the compression release to start and stop. Remember this is 1906, no traffic, no stop signs, you just got on your bike and rode non-stop to your destination, at about 15-20 mph avoiding chickens, dogs, and horses. This direct drive method was used for a long time, even after everyone else had clutches and three speed transmssions a light weight motorcycle named Servi-cycle had no clutch from 1935 to 1940 or so.
A compression release is a brilliant device and it's a shame that they don't put them on motorcycles anymore. A quick flick of the release lever and the resultant 'bang' down the exhaust pipe is teeeerrrific for getting rid of a pursuing dog. I'm hunting for the model of Villiers cylinder barrel that's fitted with a compression release for my own retro motor-bicycle replica. Not that I get chased by dogs much, but the main reason is that I prefer to have a compression release over a clutch or using non period brakes.
 
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antique-rider

Guest
I'm hunting for the model of Villiers cylinder barrel that's fitted with a compression release for my own retro motor-bicycle replica.
Sianelle, I've seen compression release kits on ebay, they fit a 14mm sparkplug hole. it could be machined into the head.


.....Bob
 
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ibdennyak

Guest
what's that little button for

A compression release is a brilliant device and it's a shame that they don't put them on motorcycles anymore. A quick flick of the release lever and the resultant 'bang' down the exhaust pipe is teeeerrrific for getting rid of a pursuing dog. I'm hunting for the model of Villiers cylinder barrel that's fitted with a compression release for my own retro motor-bicycle replica. Not that I get chased by dogs much, but the main reason is that I prefer to have a compression release over a clutch or using non period brakes.
Many larger chainsaws have them too. Local Stihl shop had them for me.
 
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Sianelle

Guest
Well that's something I didn't know :confused: Thanks ibdennyak and antique-rider :D
 
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ibdennyak

Guest
compression release

Actually, I should be thanking you for the idea. (the satisfying bang) Most dogs reaction to my bikes seems to cause them to lift one of there legs. Might be nice to perform a bit of behavior modification. :D

Denny
 
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gone_fishin

Guest
obviously, i don't have the heart to throw good info away, so i made a topic out of this misplaced stuff. we'd appreciate a bit more help... :)

a few clicks for you saves many for the staff :cool:

btw-i AM interested in the contemporary applications, if any...and wonder if it's still a benefit with the modern motoredbike? beyond that neat boom for the dog, that is ;)
 
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Sianelle

Guest
I'm sorry, - it's just that it's all soooooo exciting and interesting and I sometimes forget the rules (blush).....
 
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OldPete

Guest
On 2 smoker dirt bikes of the 1960s and 1970s a compression release was fantastic for down hill braking when the hills were steep and/or covered with loose gravel. A compression release gives a stuttering type of braking and the tire has time to regain traction.
Many dirt bike engines came with two spark plug ports, one to the side of the chamber and one dead center. Using the center spark plug gave the best performance.
Because strokers of that period tended to foul plugs, a spare could be carried off center and just the plug lead needed changing over. Some bikes went as far as having two ignition systems that chould be selected from a bar mounted switch (DKW).
Aftermarket compression releases were common "back in the day" and the off-center spark plug port was used for installation. Using a 2 stroke's compression release, releases unburned hydrocarbons into the atmosphere.
However...A compression release is valuable for push or pedal starting a reluctant engine.
 
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gone_fishin

Guest
it's all soooooo exciting and interesting and I sometimes bend the rules...wutuyugunudo, eh? :rolleyes:

btw-azkronic, drimpact, & srdavo do this sorta stuff day in
and out, & ne'er a complaint (to you)...

thanks, amigo's :cool::cool::cool:

pete...i translate "no" to contemporary benefits on compression release (?) thankee, too :)

sianelle...
I'm hunting for the model of Villiers cylinder barrel that's fitted with a compression release for my own retro motor-bicycle replica.
keep us posted? :)
 
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OldPete

Guest
Current large displacement, kick start, dirt-bike 2 strokes have compression releases to aid in cold starting. The engine must be slightly past TDC, then kick started.

The Robin Subaru 35 (33.5cc) has a decompressor built into the camshaft to ease pull starting it.
 
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