bikethis

Hello there, hopefully someone can help me out. I recently converted my hardtail MTB into a singlespeed. I'm using a 42T chainring with a 14T rear sprocket. The frame has vertical dropouts so I am using a Surly Singleator chain tensioner to tension my chain, all though it's not really working.

Basically, if I am to take a link out of my chain right now, it's too short and won't reconnect so that's not an option.

I also can't tension the chain by pushing the tensioner upwards anymore as it's hitting the frame, meaning the chain is on and does work but it's incredibly loose and keeps falling off the rear sprocket after a while. (the cable ties are there because the Singleator is actually not so good of a product and kept losing tension after I would bunny hop).

Lastly, pulling the chain down instead of pushing it up results in an undesirbale chain skip if I crank the pedals too hard, so I'd definitely prefer to push up.

So I am a bit stuck now, does anyone have any suggestions? I'm even considering just buying a horizontal dropout hardtail frame but am struggling to find any that are cheap.

I have a DMR tensioner on the way which doesn't utilise a spring so hopefully the results may be a little bit better.

bikethis

ceelint

Looks like you should be able to remove a couple links. Just loosen the tensioner, reattach chain and re-tension

79pmooney

If you are running an 1//8" chain you can get a half link to dial in length to the nearest 1/2". (Easy to find. Any bike shop that does much with fix gears or Ace Hardware probably has one. (I bought an industrial one from Ace? True Value? 10 years ago. Completely compatible with 1/8" chain. A little bulkier so look to make sure the hardware doesn't contact anything. Haven't looked but online should be even easier.)

The half link is a hybrid, outer link at one and, then plates that bend in to the inner link and roller. Around $5. Neat things to have on hand. there are also chains made up entirely of half links. KMC makes one and I believe Izumi does also. Never used one. I think they cost appreciably more but you could buy one and have half links for this and your next few lifetimes.

c_m_shooter

Go a tooth or 2 bigger on the rear gear. It looks like there is enough slack to remove a link though....

samkl 

Looks like you have the chain routing wrong. It should go on the underside of the tensioner not over the top. Then adjust the tensioner so it takes up the slack.

79pmooney

There are two ways to run tensioners. Like an old single pulley derailleur or like one's finger pushing into a too slack fix gear chain. The derailleur one is the better known and all I knew about until I saw this yesterday but if you google Surly tensioner you will see examples of what the OP is attempting,

The OP's approach gives far more wrap and so will be much more secure against the chain slipping and a knee hitting the HB hard. Also it becomes easy to supplement the spring with a stronger elastic. (At the expense of a slower wheel change.)

c_m_shooter

The Singulator work better in the push up mode. I added another spring to mine to keep it from skipping off road, the same issue the op cured with zip ties. I didn't use zip ties because mine is on a dingle speed and gets switched between gears regularly.

samkl 

Huh, I had no idea.

bikethis

Update:

Issue fixed by switching to the DMR tensioner. I believe the problem actually pertains to Surly, or more specifically, spring loaded tensioners in general. They simply lose their tension after hitting a bump or jumping something; in my experience at least.

I tried pulling the Surly down long before I cable tied it to the chainstay and it created an undesirable chain skip if I were to crank the pedals too hard.

Edit: and yes... I tensioned the spring with an 18mm cone wrench as instructed by the Singleators manual.

Regardless, problem solved.