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.

Hondo6

If you haven't see them previously, you might find these pages from the late Sheldon Brown helpful:

https://www.sheldonbrown.com/singlespeed.html

https://www.sheldonbrown.com/no-derailers.html

You might also want to use an enclosed cam skewer if you're running single speed with vertical dropouts. They clamp much more firmly when properly installed than the open cam style.

Bike Gremlin

Are the chain and the (rear) sprocket new?
Where does the skipping occur when you pedal hard - at the rear, or at the front?

Basically, my line of thought is to make sure the sprocket and the chain are new (not worn) and try then with that chain tensioner that pushes the chain downwards.

If that fails, try with a Shimano Alfine chain tensioner (Amazon affiliate link).

dedhed

Zip ties tell me something is wrong with your installation.

​​​​​​https://surlybikes.com/uploads/downl...structions.pdf

Hondo6

Hmm. Looks like you might have something there, dedhead.

OP: looks like you installed your current chain tensioner in "push up" mode. You might want to try the "push down" mode instead. That may allow it to work properly with your configuration. The link dedhed posted tells you how to change the tensioner from one mode to the other.

andrewclaus

Try a half-link.

bikethis

Hey, both are brand spanking new. The skipping completely stops when I push the chain up.

bikethis

Yep, I did mention that the zipties are used because the product is garbage. I've had 2 springs snap on me because they can't hold the tension. Others online have joked about the Surly only working after cable tying it to their frames which unironically is the solution.

Hondo6

You haven't explicitly stated whether or not you've tried the "push down" configuration. Have you?

I ask because the manufacturer (Surly) specifically notes in their installation instructions that some specific user configurations may require either the "push up" or "push down" configuration to work properly. (Their instructions also say that you have to reverse the spring in order to use the "push up" configuration, because the product is shipped in the "push down" configuration. I'm going to assume you did that.)

If you haven't tried the product in both configurations, you don't really have a good reason to call the product "garbage". And so far, you haven't stated whether or not you've tried both.

bboy314

Im curious about this too, though it does seem like the OP states they tried this and it caused chain skip. I imagine it would work better with a cog with more teeth, but then the chainring would need to be swapped to retain the current gearing (which to me seems too high anyway, especially if the bike is being used for trail riding).

bikethis

Not to be condescending but reread the original post please if you're going to attempt to answer. I've already stated that both configurations don't work.

"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."

"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."

bikethis

I adore this ratio. It works best for my strength and since I'm mainly riding urban areas with the occasional subpar trail where I live, it works great.

70sSanO

A tensioner should function like a rear derailleur cage, but obviously without chain wrap.

I’m guessing a more traditional position is to push down the chain.

John

Edit added. Technically you could slap on your old rear derailleur and lock it in the proper alignment using the high limit screw. If the limit screw won’t move it enough, use a few inches of shifter or road brake cable going through the RD barrel adjuster.

Hondo6

Actually, the OP states they tried something that worked in push down mode and had excessive skipping. While that may have been the OP's Surly Singleator, he doesn't state this fact outright. It could have been a different chain tensioner.

Hondo6

Not to be condescending, but perhaps you should re-read my last comment above. And no, your original post did not explicitly state that you've tried your existing Surly Singleator in push-down mode.

The last sentence of your original post indicates you have tried some form of chain tensioner that works in a push-down fashion and found the results unacceptable. However, you did not explicitly state whether or not that was done using your existing Surly Singleator. For all we know, that could have been a different chain tensioner you tried previously that worked only in a push-down mode. That's why I asked the question.

Does your original post imply you tried it with the Surly product? Perhaps. But until you tell us you did, we don't know; we're assuming.

Assume: ass-u-me. It's generally if not always best to ask the questions necessary to confirm assumptions.

Finding out precisely what has and has not been tried previously is pretty much step 1 in troubleshooting any problem. That's all I was attempting to do above.

Hopefully someone can help you figure out how to fix your problem.

bikethis

I mean yeah dude.. it's going to be the same tensioner otherwise I would have stated. Props for the essay though

Hondo6

Really? How do we know that?

Oh, I know - we're supposed to magically know that's what happened without being told. Or, in other words: we're supposed to assume that's the case.

The concept of "verifying an assumption to make sure you are correct" shouldn't be that hard to grasp.

Done on this thread. Good luck.

urbanknight

Sounds like the product is garbage if it only works when it's zip-tied all the way against the frame. I would try the half link suggestion mentioned above, and if that doesn't work find a better tensioner. There are other ones out there.

Bike Gremlin

In that case, I'd try with a chain tensioner that is designed to push the chain up, like the afore-mentioned Shimano's model.

base2 

I'm probably being a big dummy but, the Surly Singleator needs the proper spring for the mode it is in.

Push up spring for pushing up.
Pull down spring for pulling down.
The wrong spring will cause it to work terrible.

Lastly, are you using the 18mm cone wrench to load the spring?

Your problem seems unusual. Even so, a half-link has been recommended & would do a world of good.

Also, a 48, 16 would also be identical in every way except chain length to your 42,14. So, there is that.

tFUnK

Use a 16t or larger cog. Use a cog without shift ramps. User the tensioner in push down mode.

bikethis

Hey so yeah. Guess I'll clarify. First off, yes, I was tensioning the spring with an 18mm cone wrench. The Singleator ships with the pull down spring fitted, which I tried and the chain skipping kept occuring. The spring then eventually snapped on me so I ordered a replacement spring and continued to pull it down to which, low and behold, the spring snapped on me again for the second time.

Fortunately, the Singleator also ships with a seperate push up spring. So I dissasembled my Singleator and armed it with the push up spring, tensioned it with the 18mm wrench to which it appeared to tension fine but after riding the bike for less than an hour, the Singleator would drop the tension, meaning that I would have to then re tension the thing; obviously undesirable and had nearly led me to fall off the bike twice!

THIS IS THE REASON THE CABLES TIES ARE THERE. By cable tying it the Singleator does not lose the tension, but of course it looks, and is, terrible.

UPDATE:

The entire problem is fixed by using a DMR STS tensioner. One WITHOUT a spring. See image below.

I'm lead to believe that the Singleators spring loaded tensioning approach is the reason behind the product performing horrendously for me. Who knows though, I'm just one guy so maybe I got a defective one? For £60 however I was expecting much better. The DMR tensioner cost me £17.99 and after a 3 hour ride today, it appears to be a much more reliable bit of kit.