Chain skipping a tooth on a new chainset, chain and sprocket. Help?!

Ok, you guys are probably gonna hate this set up, but its my first SS on a vertical dropout mountain bike frame.
Problem I'm having is that under any real pressure the chain skips a tooth (at least I assume its the chain and not my new hub), but my chainline is mm spot on.
Have tried reversing spring tension on chain tensioner, so its pulling the chain up (instead of down away from chainstay) so it wraps more round the sprocket, which helped a little but still skipped and so I changed the sprocket to a better quality one, to no avail.
The sprocket, chain, hub, chainring, cranks and BB are all new and installed properly (I think) and its all 9 speed compatible.

Spec; Shimano SLX M665 double and bash chainset with the inner removed and original 36t ring (so far), SRAM PC991 chain, standard single jockey chain tensioner, Gusset 15t sprocket.

When I contacted the manufacturer of the first sprocket, they suggested that it might be the chainring. As its not designed for SS use, could this be the issue? Or maybe its the SRAM powerlink? I cannot work this out and its really starting to piss me off having spent 3 months saving and building this bike to not be able to ride it! GRRRR!!!

Any suggestions?!

Is it a sticky link in the chain? turn the cranks and watch the chain and see if it is anything other than smooth. Also have a real close look at each link from above and make sure the sideplates are all ok, a bent one, or one coming away will be fairly obvious.
Check the powerlink too, of it hasn't locked into place properly it might be the problem but if have have applied real pressure it should be OK.
If it isn't the chain then it must either be the chainring (look for a bent tooth) or the hub, is this a sprocket on a freehub? Is it tight? are there enough spacers to hold it on tightly? Of course I assume the chain is tight enough with the tensioner.

Had looked at the chain, but gave it a better check of each links vertical and horizontal movement and its fine, full oiled and free moving with no kinks.
The hub freewheel is a standard geared version, with spacers and sprocket. Sprocket is pretty tight in there and looks as straight as it can be.
Had the spring wound damn tight on the tensioner pulling up before and it was still slipping.
Chainring is brand new, and has less than 1mm horizontal movement, which I'm pretty sure the chain would take up the slack of. Want to replace with a 40-42t SS ring anyway, so will see if that helps.
Apart from that, am pretty much at a lose as to what it could be!

Is it slipping over the chainring or the sprocket? Sorry if I missed something in the OP.

A SS ring will have taller teeth. Also I found finding a chain tensioner that actually worked something of a minefield when my 29er was SS.

Is it slipping over the chainring or the sprocket? Sorry if I missed something in the OP.

A SS ring will have taller teeth. Also I found finding a chain tensioner that actually worked something of a minefield when my 29er was SS.

Tbh, while riding it (the only way of getting enough pressure to make it slip), its kinda hard to tell whats slipping. But after replacing the sprocket, I'm kinda sure it ain't that.
After staring at this bloody thing upside down turning the pedals for a couple of hours I'm starting to agree with you on both accounts dude. Hpefully a larger SS chainring will help. Any recommendations for chain tensioners?

I had a no brand thing working eventually. Probably somewhere like Superstar would have one of those basic ones cheap. I had to run the chain pretty short to get good tension so I replaced the jockey wheel (the original one on the tensioner had play in it and was just a bit shit).

I've not used them but Yess now make a bb mounted tensioner that looks great. Like I said I haven't used it yet.

The tensioner I've got on there at the mo is a single sealed bearing jockey tensioner from Superstar. Hoping that a larger SS chainring and smaller sprocket will give me a tight enough chain to sort it. If not, will try a BB chain tensioner too.

Highly frustrating.

this sort of thing is common if your using an old chain on a new sprocket but your not so i'm a bit stumped.

Is the sprocket from a 9 speed cassette? If so did you put it on the right way around? Or could you try a different one from that cassette?

This isn't a cheap solution but you could maybe try using a bigger ring and a bigger sprocket so that the chain has more teeth to grip but you have the same ratio.

'dan - The sprocket is a wide based SS adapter sprocket that can only go on one way round on the HG freehub body and is already the second one of its type I've tried, the first being a 16t that was a little loose and I wasn't certain wasn't slightly elliptical, but it doesn't appear to have been that, or at least not totally.
Will be getting a 42-44t chainring soon as I have some cash spare anyway as a 36t is just too small.
Think, as you say, its just gonna be a case of experimenting with different combinations to get the right chain tension and grip.
So frustrating when I've got £1200 worth of bike, that I spent about 3 months scraping and saving to pay for parts and STILL can't ride the bloody thing!
Oh well, guess it all helps to stock up parts for any future projects! :P

Sounds as though the chain could have a stiff link as previously mentioned,check it again and again it may not be visible straight away.The size of your chainrings is fine,that shouldn't make a difference.

I would have to agree with dan.If it was me i would personally ditch the 9 speed chain and opt for something alittle wider like a standard width BMX chain and try that before anything else.

'dan - The sprocket is a wide based SS adapter sprocket that can only go on one way round on the HG freehub body and is already the second one of its type I've tried, the first being a 16t that was a little loose and I wasn't certain wasn't slightly elliptical, but it doesn't appear to have been that, or at least not totally.
Will be getting a 42-44t chainring soon as I have some cash spare anyway as a 36t is just too small.
Think, as you say, its just gonna be a case of experimenting with different combinations to get the right chain tension and grip.
So frustrating when I've got £1200 worth of bike, that I spent about 3 months scraping and saving to pay for parts and STILL can't ride the bloody thing!
Oh well, guess it all helps to stock up parts for any future projects! :P

in that case i'm stumped!

Sounds as though the chain could have a stiff link as previously mentioned,check it again and again it may not be visible straight away.The size of your chainrings is fine,that shouldn't make a difference.

I would have to agree with dan.If it was me i would personally ditch the 9 speed chain and opt for something alittle wider like a standard width BMX chain and try that before anything else.

Have checked the chain by hand for stiff links, not just eye and it seems fine.
Apart from obvious strength increase from a BMX style chain, are there any other real benefits?
I wanted to up the size of the chainring mainly to give me some better options ratio wise, as I'm gonna be spinning like a bitch when on the road! Plus, if there isn't quite enough chain tension, I reckon the Shimano chainring designed with shallow teeth, ramps and pins for smooth shifting might be a possible cause of probs... but woulda thought that would only affect things if the chain line was off and would make the chain come off the ring altogether, not just skip a tooth.
Thanks for the input guys, I'm pretty stumped on this myself and appreciate other minds on the problem!

Well you have done a thorough job of ruling out all the components bar the freehub, which is the only thing left. Best bet now is to try another wheel.
I haven't known freehubs to cause this sort of problem, but it seems to be the only thing it could be.
Where are you?

Gonna try new chainring before I rule out possibility of that entirely. Have taken everything off the freehub and checked as best I can for an elliptical rotation and couldn't see anything more than a possible 0.1-0.2mm deviation, but could be wrong on that, as you say, checked almost everything else out!
I is based in Ashford (surrey), right out south west of Heathrow.
Ordering a Renthal 42t ring from chainreactions now.

Right, FINALLY got the new chainring today. Couldn't get size I wanted through chainreactions so ended up getting FSA ring (that actually looks quite good) else where and next time will remember not too as it took a whole week! >_<
So, new sprocket, new SS chainring, perfect chain alignment and much better tension, BUT chain tensioner still bobbing up and down like mad indicating that something weren't right with freehub. Turns out that freehub body is slightly too small, leaving the sprockets I've tried too loose and therefore slightly off center.
Packed out the HG splines with very thin card so there's no movement, and voila! Sorted.
What a bloody merry go round that was.
Took it out for first proper ride today and apart from noisy (cheap and already slightly loose) chain tensioner and too short a stem, that I'll probably replace both of soon, rides lovely.

Avoid superstar hubs if I were you, or at least the Switch Evo. But apart from freehub body being minutely too small, everything else is fine. Lost 200g getting rid of heavier chainring and bash and it looks better. :D
Now it just needs the 100mm Thomson stem and a decent set of carbon forks and we're away!

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