Pull down or push up?

[bolzenanker]

What's put you off the Jockeys ones Donnie?

[Knowledge]

Remember, when considering pull up or push down, you are adjusting on the slack side of the chain. The chain will be tight at the bottom as the front sprocket pulls the chain around with the direction of the crank.

I know this is obvious to most people, but some don't think about it. However, it makes me think that it doesn't make much difference if you push up or pull down, just that pull down allows you to fit a one-size-fits-all chain (well, almost).

[Donnie]

What's put you off the Jockeys ones Donnie?

Mainly the design of the slot where you fix it to the casing. ie its one long slot fixed with the counter sunk screws, therefore it's technically splaying the slot outwards.

I know I know, it's not likely to affect it at all and any outward pressure will be minimal I'd guess but its just enough to put me off, whereas the RT one still uses the countersunk screws but in a hole thats not able to splay.

I guess that the jockey one is designed in a one piece way so that the slot allows you to move the whole tensioner up and down for chain adjustment, whereas the RT one is adjusted on the actual block the chain runs on.

Oh, then there's the buy one get one free aspect of the RT one, whether you run it as push up or pull down, once it's time to replace it, you simply undo the 2 bolts and turn the chain block upside down and use the unworn side. Simple yet brilliant idea.

[bolzenanker]

Fair points, well put. I might try one on my next engine. I think they are fairly new and weren't available for my last engine build.

[HxPaul]

I'm using a spring loaded self adjusting chain guide from Armandos in Sheffield.There has been a thread on this site and on the LCGB site decrying the use of this chain guide,but I have used this for a year now without a problem.The only thing I would say is,you must use quality sprockets and most important you must use a good quality chain,I use an Iwis chain.I took the chaincase cover off recently to check everything and it was all in perfect order.

[Donnie]

Cant find the thread you are referring to so googled the one you are talking of and yeah, no way I would fit that personally.

[dave411]

I think an adjustable guide is a good idea,but having seen this one,I will leave it.I think you have been lucky so far,the engineering gone into it leaves alot to be desired.If I were you,I would change it ASAP.Only my opinion,so dont take it to heart.

[Donnie]

Pretty much sums my thoughts up there. I did a bit of googling and it appears that it's a copy of one MBDevelopments were going to produce some years ago which looks a hell of a lot better.

Even then I'm not a fan of a self adjusting one personally.

[HxPaul]

I think an adjustable guide is a good idea,but having seen this one,I will leave it.I think you have been lucky so far,the engineering gone into it leaves alot to be desired.If I were you,I would change it ASAP.Only my opinion,so dont take it to heart.

Can you expand on that.As I say I've been using the chain guide for about 12 months without a problem,but if there is a problem with it that I cant see I'd like to know before I have any trouble.

[rosscla]

IMHO the chain is not supposed to be under tension, either pull up or push down I'd expect there to be the same amount of free play / slack. The original type is described as a 'guide' not a tensioner. The bottom is tight as that's the drive

Anything with a spring places actual tension on the chain and surely must increase wear. Additionally how is the spring secured inside the casing? I've some seen pictures of something similar where the top of the spring was simply resting round one of the studs that holds the gear change block down, not very secure.