Is it just me or has my chain thread been removed?

[ipswichcycler]

I measured the distance away from seat post to centre of chain a do added half seat post diameter and I think it is 4.2 + 1.5cm so 5.7

If I want to get to 54 mm should I loosen the bottom bracket and slide it over? The BB currently lines up with the edges of the frame on both sides ??

[mickeg]

If you are off only 3mm, that will not affect chain life enough to worry about it.  Don't try to make any adjustment.

I noted before that mine is off by about 5mm and that is intentional on my part.  I ordered a bottom bracket with a shorter spindle than I needed because I wanted my width of pedals to be similar to my other bikes.  That is why I say mine is off intentionally.

I do not see your old thread either, I suspect  it is part of web site maintenance, it will probably reappear later.

[ipswichcycler]

Also wanted to say thanks to everyone for the advice it is much appreciated

[Andre Jute]

Resist the temptation to start messing around with spanners. These rough and ready measuring methods are merely used to ascertain that your installation is in the ballpark. They could easily be one or two or even three millimetres off, so the most likely case, considering that your bike was built by Thorn and you haven't told us anything about you making any lateral adjustments, is that your chainline is either spot on 54mm or no more than 1mm either side of it. Spannering on it is as likely to make it worse as to make it better.

In short, it now seems unlikely that chainline angle is responsible for eating a KMC X1 in only 1300m.

If you can afford another X1 in 1300m, it seems to me the smartest thing you can do is nothing. Ride the bike and see what happens with the new chain. If it makes a decent mileage, some external factor (sea mists at Nairn?) was responsible for the abnormal wear. If it doesn't make decent mileage, perhaps that demonstrates that you're hard on chains (I am too; at one time I used to trash a chain every thousand miles). But it isn't worth making a big mechanical investigation -- and certainly not major disassemblies to fit spacers behind bottom bracket fasteners -- until you have more routine experience with the bike.

***

The one thing that you could do, which in your case is likely to be worthwhile to a greater extent than for almost everyone else on this conference because you start from such a low mileage per chain, is to fit a Hebie Chainglider.

[ipswichcycler]

I've since bough a new kmc X1 and two kmc x8 so I think I shall see how I get on for a while. 

[mickeg]

I do not know if the K8 and K1 use the same connector link, they might not.  So, try to avoid mixing parts.  KMC uses two different connector links for 8 speed chains.  (I learned that the hard way, which means I know more trivia about KMC chains than I ever wanted to know.)  More info here:

http://kmcchain.us/connectortype/8-speed-below-ml/

Good luck with your chain issues.

[Danneaux]

KMC uses two different connector links for 8 speed chains.  (I learned that the hard way,...

<nods vigorously> I got caught out by this as well, mickeg. It might not seem like it, but that little variation in width can make a huge difference in how easily the connector slides together.

Best,

Dan.

[Andre Jute]

I bought a packet of each kind of KMC X8 quick link just to see. It makes a difference too to how well (silently) the chain runs in the Chainglider; check the Hebie literature for chain thickness spec. I threw out the "wrong" KMC quicklinks to avoid ever fitting them accidentally.

Notice that, unlike some others, the KMC X8 quicklinks are reusable, so you don't need more than one spare, and there are two in a pack, so two packs will do most of us. (Why would you need four? Well, sometimes you cut a chain too short, and then you need two quicklinks per chain, and you still need a spare, that's three, but they're sold only as packs of two, hence four is the magic number if you're just switching over to the X8 or its single-speed and theoretically cheaper sibling the Z8.) Or buy one pack and save the quicklinks from worn chains for spares.

Andre Jute

[mickeg]

I sometimes use a 36T chainring, other times a 44T chainring.  So, I have two quick links in my chain when using the 44T, only one when using the 36T.