[Rhubarb]

I am no expert at setting up a drive chain but I am able to get it pretty dialled. I have a Knolly Delerium and while I have noticed a reasonable amount of chain slap while descending I just recently noticed there was a fair bit of wear right at the rear pivot. I have tubing wrapped around the chain stay but I cant run it right over the pivot etc. I was wondering why it would be so bad right near the cassette so I pushed down on the chain above the chainstay and noticed it felt pretty slack.

I have set my chain to the recommended length and removing an additional link would probably be pushing the limit of the rear deraileur when in the highest gear on the cassette. I am running a medium XT deraileur and 32t front ring. With the chain in the highest gear the tension on the deraileur is obviously much better but this is not where I spend 95% of my time. The chain will obviously sit higher off the chainstay too.

There are 2 things I can identify:
The rear deraileur doesnt generate enough tension.
The Hope Pro 2 cassette has alot of movement between engament points.

I am not sure how to determine if I can run a short cage deraileur and I am not sure if my reasoning on the lack of engament points on the Hope hub has a contributing factor. Maybe the Hope springs also do not have enough tension.
I have already put some thought into trying a better hub. While I have been running Hopes for years I figured I woudl try something better to see what it would be like, Hope free hub bodies also notch real easy.

Anybody got some suggestions?

 

[big-ted]

The number of engagement points will be of negligible consequence. One thing with the pro 2 is that the main freehub seal can cause a lot of drag. I'd suggest pulling the hub apart and lubricating that seal with some thick chainlube and checking for free rotation upon reassembly.

Also, you are running a pretty small chainring for a DH bike, making the chain run low to the pivot. If you can, consider running a larger ring.

And yes. You can run a short cage deraileur. You only have one ring so the change in chain length across the gear range is almost certainly within the range of a short cage.

 

[Rhubarb]

This is not set up for pure DH. I was thinking that if I ran a 34t front ring I would sit higher up the casette and this would lift the chain and add tension from the deraileur. The trouble is this is my one bike and while I dont do alot of milage rides I can still make most climbs with a 32x32 setup. Winter is comming so the milage rides should increase therefor I cant really consider upping the front ring.

I cant compare the pro 2 to any other hub but it just seems like there is a lot of rotation and I was thinking that if there were more engagement points it would help to prevent the casette rotating and allowing the chain to "hang loose".

Milage rides start this week so I will pay attention to my gearing and determine if I can go to a 34t front ring. If not t hen I need to think about going to a short cage saint.

 

[FlipSide]

You are talking about the derailleur hitting the frame at the pivot? All shimano derailleur will do that on FSR frames.

The cure is to glue a 2mm thick piece of rubber on the derailleur where it hits the frame. Use a good glue like epoxy and it won't fall off.

 

[Gary]

also, removing any of the larger sprockets you don't ever use on a DH run, replacing with spacers, limiting the mech and shortening the chain appropriatly will leave you with much less chain to slap about i the first place.
I found fitting a tiny ziptie round the knuckle (next to the pivot stop) can stop old skool road mechs (105/Tiagra) from rotating far enough to slap the chainstays, the ziptie's so tiny it will eventually break, but once you've figured out where it needs to be it's a 2min job to replace with a new one. I don't know if the same can be done on older mtb mechs (no harm in trying), newer shadow mechs shouldn't hit the stays but I find them weak.
I always found older road mechs to have stiffer spring tension

 

[4130biker]

Is your chain worn? Lateral movement developing from wear can make them way noisier than a new chain.

 

[mtg]

3M Mastic Tape works wonders for quieting chain slap, and fits in places that you generally can't wrap with a tube. Check it out.

 

[jekyll991]

3M Mastic Tape works wonders for quieting chain slap, and fits in places that you generally can't wrap with a tube. Check it out.

The stuff doesn't last long at all though. After 3-4 runs the chain will eat through it. An old tube will work better.

 

[Scrub]

The stuff doesn't last long at all though. After 3-4 runs the chain will eat through it. An old tube will work better.

You must be doing it wrong, that tape last quite a long time unless your chain is directly riding on it.

Scotch 2228 Moisture Sealing Electrical Tape made by 3M is the stuff I use. Home Depot has it. And this:

http://www.pinkbike.com/news/World-Cup-Tech-Video-Setting-Chain-Tension-2011.html

 

[mtg]

The stuff doesn't last long at all though. After 3-4 runs the chain will eat through it. An old tube will work better.

My experience has been the opposite, after two years, I'm just now needing to replace it on my DH bike, and my trail bike Mastic tape is still going strong after the same period of time.

 

[NoUseForAName]

This is not set up for pure DH. I was thinking that if I ran a 34t front ring I would sit higher up the casette and this would lift the chain and add tension from the deraileur. The trouble is this is my one bike and while I dont do alot of milage rides I can still make most climbs with a 32x32 setup. Winter is comming so the milage rides should increase therefor I cant really consider upping the front ring.

I cant compare the pro 2 to any other hub but it just seems like there is a lot of rotation and I was thinking that if there were more engagement points it would help to prevent the casette rotating and allowing the chain to "hang loose".

Milage rides start this week so I will pay attention to my gearing and determine if I can go to a 34t front ring. If not t hen I need to think about going to a short cage saint.

So fit a 34t up front and get a 11-34t cassette...

Short cage - 1 chainring
Mid cage - 2 chainrings
Long cage - 3 chainrings.

If you are going to be buying a new der anyway, consider going 10 speed with an 11-36 cassette...

 

[Rhubarb]

I need to take a picture. I am not talking about the deraileur hitting the chainstay. I am talking abou the chain contacting the frame right at the rear pivot point. I have never had a chain do this so far back and usualy old tube on the chain stay is sufficient. It will not be so easy to wrap tubing where it needs to be and would look seriously fuggly. I am thinking the condition could be improved rather than masking it. I wanted a short cage XT but it never happened, just forgot about it cause the medium has been lasting and working really well. Now it seems I need to make some changes.

The Delerium is really dialled right now but I think it could do with some minor tweaks, this will be the first one. I will go with a short mech first.

 

[davec113]

freehub drag would be my guess, as big ted mentioned. The short cage rd can't hurt either, I just went 11-36 10 speed and it's nice on a 1x setup... went w sram x9 rd, and the cage has a lot of spring tension.

 

[Rhubarb]

If I have freehub drag I would be surprised. It runs smoothly to me but I have 2 wheelsets, one has a fair bit of milage and abuse and the other not, so I will compare. I will put grease in the older one since I am doing full maintenance this week.

 

[jasonvelocity]

I change my Mastic annually. It can last longer, but starts to turn into bubblegum.

 

[jekyll991]

I must not have used the right tape then. Whatever I used was just slightly thinner than a xc tube and like I said didn't last very long at all. Oh well.