deda fang

alex100a

Hi,

I recently purchased a deda fang to try and prevent dropped chains however when I offered it up earlier I noticed it sits a good 20mm+ away from the N/W chainring and as such is not going to do anything.

Can anyone recommend any other product I could use? My old Trance does not have the mounts seen on later models, which most chain guides etc seem to fit to.

Regards

Alex

The Rookie

Crikey, what chainline are you running, a dog fang should reach easily!

Are you dropping chains? I've never dropped one with a narrow wide.

You can use a seat tube mounted chainguide (looks a bit like a front mech) but if your ring is that far out it may not reach anyway.

You can also get a BB mount (clamps behind the bottom bracket as you screw it into the shell) or if your Trance has a direct mount front mech you can get a direct mount that bolts in that location.

Examples
BB mount http://www.superstarcomponents.com/en/x ... nguide.htm
Seat Tube http://www.superstarcomponents.com/en/x ... keeper.htm (its known to be a bit fiddly to mount)
Direct http://www.superstarcomponents.com/en/x ... nguide.htm

Obviously there is lots of choice of manufacturer.

JGTR

Have you mounted your chain ring in the correct position? 20mm is a lot!

larkim

I thought fangs were mostly used by roadies on double / compacts?

keef66

larkim wrote:

I thought fangs were mostly used by roadies on double / compacts?

+2 I have them on both road bikes, one a double and one a triple. My Scott CR1 frameset came with one.

alex100a

The problem is that I purchased the bike already converted to single chain ring and as it all seemed to work ok (expect the chain jumping off on fun rocky decscents) I assumed it had been done properly but maybe not!?!?

Please see picture:



Sounds like I need to do some research so I can work out what, if anyhting is wrong, with the set up.

The Rookie

larkim wrote:

I thought fangs were mostly used by roadies on double / compacts?

My daughter had one on her 1x with a bash as chain retention (that was when NW rings were still priced as though made of unobtanium).
Did the job perfectly.

Inner guide rings and a bash outer also work very well if you have the clearance for an inner ring.

larkim

On reflection, I think we have one in our family's bikes - on a kids 24inch cheapo Rockrider. I think I thought its purposes was more to prevent a dropped chain falling in between the chainring and the frame and getting stuck (I've experienced this with kids bikes in the past) rather than to stop it falling off in the first place.

@alex - I think those who know their stuff might want to see a picture of the chainline to advise whether the single ring you've got on there is perhaps too far out-board, which would explain why the fang isn't getting anywhere near to reaching. A photo along the top of the chain taken from the front so you can see the alignment of the front chainring with the rear cassette.

cooldad

Is the chainring on the outside of the spider? Can't really see. If so move it inboard and the chainline might be better.

I can't see that little toothy thing reaching over all the suspension bits though, no matter where the sprocket is.

alex100a

Thanks for all the advice.

I've measured the chainline and its 60mm, which seems a lot after a quick google. The deda fang is actually 14mm off the edge of the chain (not 20).

pic looking down my chain with it on gear 4 of 10 on the rear cassette.



now i've taken the chainring off from the outside of the spider and positioned in inside, which has made 7mm of difference. Chainline is now 53mm and the deda is 7mm off the chain. pic below:



Is this possibly as close as I'm going to get it? I guess for the deda fang to work it needs to be no more and 2-3mm off the chain.

sorry for the huge pics! I'm not sure how to make them smaller using TinyPic.

The Rookie

Unless you have a boost rear the chainline should be 47.5 or 50, move the ring and your chains will last longer as well as the fang now possibly working.

JGTR

You can fit 3mm spacers which will bring chainline down to 50mm which would be better.

But as stated the fang is a chain catcher and not a chain guide.

alex100a

Thanks again guys for the advice. I'm on the case getting spacers and longer bolts to move the chainring inbound but it does look as though the deda fang is not going to help.

I've looked at chain guides (suggested by Rookie above) and can eliminate direct mounted ones. With regards the bottom bracket mounted version I assume this will push my chain line back out again? if so i'm thinking a seat tube mounted version might be best.

The superstar device seems to get rather mixed review (alot bad) so has anyone else used another make/model with any success?

Thanks again.
Alex

larkim

Better chainline alone might prevent dropped chains. Homemade chain guard mounted under the chainstay could be another cheap option to try before faffing around with BB mounted options?

https://www.youtube.com/watch?v=AS1jQ9qJ_uQ