Chains The great Half Link obscurity

Discussion in 'Transmission / Drivetrain' started by Hello Moto!, Mar 29, 2016.

  1. Hello Moto!

    Hello Moto! Active Member

    So I have been searching fruitlessly for information on the half link or half lock available for 415 motorized bike chains. Well, here's the situation.

    I just need to take out a little bit of slack to fine tune my drive chain to sync up with the pedal drive chain. I've been fartin around trying to get it optimal on both sides and it just isn't 100%. The drive side has just a bit to much slack in my opinion. I have had no problems with the chain jumping or falling off but I would really like it to be a bit tighter.

    So I see these half links or half locks. I'm thinkin yeah that might work but don't have the info! What makes me nervous about the looks of these buggers is the little cotter pin that holds the roller pin in the link. This looks like it could cause some problems like jamming up inside the sprocket housing in the engine.

    The idea of using one of these to take just a bit of slack out of the chain sounds great but I just don't know much about adding one into an existing 415 chain. Can you connect it to the master link or do you need to put it somewhere else in the chain? And what about that hazardous looking little cotter pin on the half link?

    If someone could just shine a little light on this I would appreciate it! I mean I'm sure I could figure it out hands on but thought I'd see if I could get a little info before I start wrestlin with it. I am equipped with a chain breaker! lol. I also have an aftermarket chain tensioner that mounts to the engine over the sprocket housing. ( if you need to know )

    Thanks in advance for anyone who takes the time to read this![​IMG]

  2. butre

    butre Well-Known Member

    you replace the master link with the half link. the cotter pin is fine, it's just there to keep the pin from moving side to side which it has no tendency to do
  3. HeadSmess

    HeadSmess Well-Known Member

    never bothered using a half-link by itself as such, and they arent meant to be much good for high load positions due to the bent side plates, always a bit "agricultural".
    but at the same time, my favourite chain to use was HD bmx chain, comprised entirely of half-links...

    there is a difference between HD chain and regular industrial stuff...
  4. crassius

    crassius Well-Known Member

    1/2 link is OK to use - one bends the ends of the cotter pin all the way back so they won't snag - NOTE sometimes a bit of grinding/filing is needed as there are diffs in 415 and the heavy duty versions of 415
  5. bluegoatwoods

    bluegoatwoods Well-Known Member

    I used a half-link once on a 415 chain. When the chain snapped, it was the half-link that did it. So it would seem to have been the weak link.

    Right now I'm using one on a 41 chain. It seems to be holding up.

    I'm not exactly fond of half-links. Or you could say that I don't trust them completely. But I'll use one when that's what it takes to get proper chain tension. That's pretty important and I'll make some sacrifices for it.
  6. Hello Moto!

    Hello Moto! Active Member

    Thanks for the info and advice guys. I appreciate it. This is all good to know before the link gets here in the mail lol. I feel a little more confident now.
  7. Hello Moto!

    Hello Moto! Active Member

    Well I did get it today in the mail. I recently changed rear wheel with a smaller coaster sprocket and now the tension on the engine drive side is suitable but the pedal drive side is way to slack. I am confident now that the engine drive side is exactly where it needs to be in tension and in a far enough back position on the rear axle mount. It is right where I want it to be so I decided to save the 415 half link should I need it later and put a half link on the pedal drive side. To me this works out ok and makes more sense to me anyways so I'm kinda glad I changed the wheel and this new situation presented itself to me lol. If I am going to have a possibly weaker link, I would rather have it on the side under much less stress. I mean the pedal side is my only brake but It still, in my opinion, is the better option. So thanks again for the info on the half link. I'll let you know how this goes. I'll get them synced up yet!