Forum search & shortcuts

chain tensioner or ...
 

[Closed] chain tensioner or magic ratio?

 aw
Posts: 0
Free Member
Topic starter
 
[#382020]

My chain came off spectacularly tonight on the way home from work. i was going fast downhill and I fell heavily on my knee against a rock grazing and bruising it quite badly. I am not sure what happened but I had to fix the tensioner in the dark and cycle home in pain 🙁

Is it better to have a chain tensioner or the 'magic ratio'

I tried to get the magic ratio on my cindercone SS convert but the chain soon stretched and then was too loose. When I tried to take a link out it was too tight hence the tensioner.

Or should I just give up and buy a shiny new SS specific bike/frame with slidey drop out 🙂

seriously I do have lots of maintenance problems with tensioners and get through them on a regular basis! This on a SS which should be maintenance light?


 
Posted : 11/03/2009 11:04 pm
Posts: 656
Free Member
 

If you're going to do the magic ratio thing, make sure you use a decent chain so it stretches less. 7 speed sram ones were good iirc.

My '97 cindercone worked spot on with 32-16 and a somewhat worn chain, so it is possible.


 
Posted : 11/03/2009 11:08 pm
 aw
Posts: 0
Free Member
Topic starter
 

I have a 97 cindercone 🙂

Yes I tried a good chain I thought but it still stretched...then I was trying to mix and match old and new chain or stretched and unstretched...


 
Posted : 11/03/2009 11:14 pm
 K.s
Posts: 0
Free Member
 

Have you tried halflink chains? These might be more precise as obviously you can take less of a link out when it stretches?
Just a thought


 
Posted : 11/03/2009 11:16 pm
Posts: 4405
Free Member
 

What tensioner are you using?

I found a Surly singulator to be fine for 'ages' of use


 
Posted : 11/03/2009 11:22 pm
Posts: 34
Free Member
 

My Rock Lobster Ti until this evening was running magic 34/16 with a KMC 8 spd chain, but as the chain wore (I've recently found out that 'stretch' is not the right terminology for what actually happens to it) it obviously got slacker. Sadly, not slack enough to whack a half link in, but I've now just put a 17T on the back, and I've got really good tension. Maybe that's the way around it?

The original cog was a proper SS cog with long teeth and the 17 is off an XT cassette I had lying around. I've not ridden it in anger yet, but I'm hoping that it'll a) give my knees a break for a bit and b) mean I can chop and change between ratios and keep the magic thing going without an ugly tensioner.

BTW: Rule No. 1 of cycling: singlespeed = less maintenance = complete fallacy!
🙂


 
Posted : 11/03/2009 11:29 pm
 aw
Posts: 0
Free Member
Topic starter
 

I am currently using the DMR tensioner


 
Posted : 11/03/2009 11:31 pm