I'm not seriously planning anything, but pottering around on my singlespeed with sprung tensioner, considering what frame would fit a Pike I have spare got me wondering about the best single speed tensioner options. A few friends have ordered Marino frames from Peru, for very reasonable money,which got me wondering.
If you knew what singlespeed ratio you liked, rather than ordering a frame with sliding dropouts, could you just order it with chain stays the right length for "your" ratio?
So a regular bolt through hub, throw it in and bingo bingo it's correctly tensioned.
Or is the effect of chain wear sufficient that it wouldnt work properly for long?
I reckon the chain would go baggy. I SSed an old Ti frame using an adjustable BB and that does need a tweak.
I’ve had various SSs and have always needed to retension the chain at various times. You could potentially get away with bodging half links in and out, but that seems like an awful amount of faff.
Yeah - the golden ratio lasts only as long as the chain has minimal stretch. You’ll need a lot of chains or an eccentrica BB.
I'd agree that it'll go slack and need adjusting.
I've had two custom singlespeed frames from Titan in China, the first I had sliding dropouts which have been been bombproof but for the second I just ordered it with normal dropouts and fitted an external eccentric bottom bracket - works a treat and looks very clean.
+ everyone else. Go as custom as you like, but get an ebb/edo.
Even with a pile of new chains, it still relies on Marino or whoever making it perfectly accurately....
Alfine tensioner. They just work.
Personally I'd but bother with a magic ratio, for the reasons above but also you will want to change gear at some point, maybe not on a commuter which literally does the same route every time, but at some point you will go somewhere hillier or flatter and what a more suitable gear, or to gear down for a much longer ride or carrying a load or whatever.
I like the sliding dropouts on my Pipedream Moxie - they deal with the chain tensioning as a SS and also allow you to adjust the feel of the bike via the chainsaw length (425-441mm). I’ve found I prefer it closer to 435 than at the shorter end.
It’s designed for 140-170mm forks but they also have the Sirius which is made for 100-130mm - similar angles and BB height, same rear end, a bit shorter reach and lower stack.
Yeah - the golden ratio lasts only as long as the chain has minimal stretch. You’ll need a lot of chains or an eccentrica BB.
Most of the stretch is in worn alloy components. Use a decent steel chainring and rear cog plus a proper singlespeed chain and you'll get considerable mileage out of it.
I go for Magic Ratio and no tensioner and it works perfectly well unless you have a bike with skinny laterally flexing chainstays.
I’d order it with a PF30 BB and fit a Rideworks EBB. I’d also get a splitter in the seat stay so it will run a lovely, silent, maintenance free belt!
On my old bike with sliding drop outs, I could be quite lazy with tension and as the chain stretched I would just let it go a bit baggy, as it would with a magic ratio. However the current bike has less clearance under the chain stay and a loose chain would start banging against it so maintaining tension becomes more bothersome until I got the belt. Now I only ever have to set it when I’ve refitted the belt after changing bearings etc.
EBB would get my vote. Keeps the clean look and simple to adjust.
This is what I ended up with.
https://www.sjscycles.co.uk/bottom-brackets/trickstuff-excentriker/
Bought 2nd hand (obviously 😂)
My mate ran a 'normal' frame with the 'magic ratio' using a succession of very used 11sp chains which were just the right length ... Until 3 chain explosions and some sore balls later, when he saw sense and got a frame with adjustable dropouts!
I've not used a EBB, but when I was looking to get a SS frame, I asked on the Singlespeed FB page ... Overwhelmingly (apart from a few exceptions) the advice from those who'd tried both was to get one with adjustable dropouts. I think EBBs can be a bit creaky/temperamental and less tolerant unless set up perfectly and with a good quality (expensive) EBB. Also, more of a faff to adjust.
My Moxie is so easy to adjust - which is just as well as I generally need to give it a small tweak every 2-3 rides. Using a 9sp chain and aluminium chainrings, I guess the wear is a bit faster than on a SS chain and steel cogs/chainrings. But also, I've been able to play around with gearing really easily, trying out 19/20/22t cogs using the same chain and just adjusting the dropouts.
Front tensioner like a Black Spire Stinger for me but swap out the roller for a jockey wheel, gives a nice neat, quite solution.
I built up an old Chameleon with EBB as a singlespeed "mountain bikers dirt jumper" years ago. It did a good job but was quite fiddly to adjust and a bit creaky. I'd rather just have something with good sliding dropouts and a built in tensioner screw - the Stanton ones look really nice.
Or just get a frame with iscg tabs on and use a stinger-style roller at the chainring end to take the slack out of the chain.
I've just fitted a new steel ring, sprocket and ss chain - it still needed retensioning after the first 2 rides.
I've never had much luck with ebbs. The various expanding / wedge ones always get stuck in mucky conditions as the design naturally leaves gaps that draw in silt through capillary action (same with Whyte wedge seat clamps).
SJS do a small diameter eccentric if you only need a small range of adjustment.
My favourite is a Hope hub with female threaded axle and great big M10 bolts. Plus my own closed slot dropouts. If just running one ratio you can have very short slots and can get away with regular (not slotted) caliper mounts.
I’ve had no trouble with the Rideworks PF30 conversion. They clamp between the BB faces rather than expanding inside the shell, so less chance of creaking or ovalising the shell.
My Kona runs a magic ratio through use of a half link. Getting the wheel in is a just fit which you get away with as on old QR setup but don't know if it would be so easy to line up with a modern bolt thru.
Frame builders have worked out ways of including disc tabs on sliding dropouts now so no caliper alignment faff any more.
Not tried EBB as not as aesthically pleasing to me and in an area I see as prone to creaking and corrosion.
For full custom I would take spooky's idea further and go elevated chain stay to run a belt. The one on my daughter's bike was smooth and quiet.
Do it
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But elevated chain stays are normally too flexy for a belt so splittable dropouts or a split stay are normally used.
To all the EBB naysayers - honestly they work fine 🙂
I've got 3 types of SS frame and they all have their pros and cons...
1) Surly Krampus with horizontal dropouts - you need to use chaintugs as they do eventually slip, even putting a load of torque on a Hope 10mm bolt-in!
2) Pipedream Moxie with slidey dropouts - probably the most effective but the previous owner had rounded 2 of the bolts, so you need to be careful when tightening up.
3) Stooge Mk3 & Stooge Mk4 with EBBs - in over 6 years of use I've had the EBB on the Mk4 slip once, and I suspect that was user error as I'd just changed a chainring, and probably not done the bolts up tight enough. The Mk3 has never slipped and neither has creaked - I just use plenty of copperslip when fitting them.
I'm not that fit but quite heavy and horizontal dropouts and a chain tug on the drive side work for me. That's with steel cogs both ends and BMX chains.
Front tensioner like a Black Spire Stinger for me but swap out the roller for a jockey wheel, gives a nice neat, quite solution.
How do you manage that? I've tried it with two different DH chainguides and a variety of jockey wheels and it's always been really noisy.
I'd sort of assumed it was because it's all solidly bolted to the frame.
Works well and looks sort-of neat though, and easy to adjust as you get the angle right with a fresh chain then just adjust the jockey wheel in it's slot as it stretches.
To all the EBB naysayers - honestly they work fine
+1, never had an issue with the grub screw type on stooge/singular/Charge bikes.
The split BB shell Ti ones make me nervous but seem to work well too.
Salsa's alternator system is a good compromise between easy adjustment and it staying put. And in my mind it looks like it should be stiffer/stronger than horizontal sliding dropouts as it bolts up to the rear triangle, rather than being cantilevered off it?
The split BB shell Ti ones make me nervous but seem to work well too.
My Thorn tandem has a split shell type and that's been rock solid for years.
Back to the OP - I tried the magic ratio route on a Dialed Alpine many moons ago, it was fine for a couple of rides, but then the chain had stretched enough for it to keep coming off.
For tensioning a non-SS frame the Paul's Melvin is the most solid tensioner I've used (Rohloff ones are very similar and work well too) also makes changing the ratio a breeze too as the double jockey wheel set-up is similar to a rear mech
How do you manage that? I've tried it with two different DH chainguides and a variety of jockey wheels and it's always been really noisy.
I think as long as the jockey wheel isn't too close to the chainring and the chain isn't too tight it's fine. Well fine as in much quieter than the standard roller.
I have a SS frame (Genesis) and it's great. I also have eccentric BBs on two tandems. Less great and never an easy adjustment. For a clean look on vertical dropouts, I'd go for a White Industries ENO excentrib HUB. https://www.bikemonger.co.uk/white-industries-eno-disc-eccentric-single-speed-rear-hub-29486-p.asp?srsltid=AfmBOor_0_nRRZ0QbMb_Td4TjsoqmmOOca2I6a5yRT7pyvyRz-muD35x
Marino do a sliding dropout option, if you´re getting them to make you a frame, I´d just stump up the extra ($40USD) for that TBH, it also has an integrated hanger IIRC, so you could fit a gear dangler for special occasions if you ever wanted...
Yes you could size your stays to match your prefered ratio, but having the option to change ratio down the line makes far better sense (IMO).
I'd go for a White Industries ENO excentrib HUB. https://www.bikemonger.co.uk/white-industries-eno-disc-eccentric-single-speed-rear-hub-29486-p.asp?srsltid=AfmBOor_0_nRRZ0QbMb_Td4TjsoqmmOOca2I6a5yRT7pyvyRz-muD35x
I've got a brandnew one of them sitting around if anyone is interested. (I usually Magic Ratio now)