[Closed] Single Speed Orange Five: Terrible Idea?

Depending on the size of front ring, you may need more than a singulator type tensioner - perhaps a short cage roadie mech locked in position with some longer limit screws.

Initially looking at 32 x 20 on 29in wheels, using potentially the Paul Melvin tensioner which does look more mech-like.

Out of interest, why would the chainring size determine the tensioner needed?

Presumably it has some impact on chain growth as the rear suspension compresses

With different chainring sizes there'd be a difference in the distance between the pivot and the chain line. That affects the amount of chain growth / shrinkage. THe closer the chain path to the pivot the smaller the effect.

Does the shock have a good lockout?

as above, your choice of tensioner will depend on chain growth through the travel. If you set it up just disconnect the shock and cycle the swingarm up and down fully to make sure the chain doesnt bind up.

With a good lockout on the shock it should be ok. (no less horrible than a single speed ever is)
With an ineffective damper i imagine it would be wildly unpleasent.

Do it. Report back.

EDIT: If it were me, i would see if i could fit the tensioner at the bottom bracket. combine an old "roller" chain guide and a sprung tensioner, some how, to give it a clean looking back end.

Edit 2:

Use/Try this: https://crucialbmxshop.com/yess-etr-b-chain-device

Alfine tensioners work fine on a 4" full suss, so I can't see 5" being a problem. Basically a pivotless mech

OK, so potentially not a disaster waiting to happen then...a clean back end is very desirable (ooh err missus!) but it's got to work ultimately!

Shock is a Cane Creek DB Air so plenty of adjustability, but I'm no expert of set up so I got it to how I like it and then haven't touched it since! I keep it completely open all the time at the moment and it doesn't bob too much.

Chain growth is something I'd heard about but not researched much, I assume the path of travel for the rear wheel isn't a constant distance from the BB?

not unless the pivot IS the BB. (as on the DMR bolt, iirc)
Might get longer, might get shorter, might get longer at the bottom and then shorter at the top of the stroke. Unhook the shock at the swing arm end and give it a waggle up and down, see what the mech does to compensate. (thouht it wont be much i dont think)

Does the DB air have a compression switch? It doesnt bob too much at the moment, but do you stand up and crank it up every climb in 32:16?

TBH the easiest way to try it out is to just not change gear for a ride! find a ratio you like and see if you can do it. can you beast it up the climbs and tolerate not being able to pedal on the flats or descents

Guy at uni used to run his stinky single speed. He rode mostly downhill, pushed the ups but never got chucked off his bike by his gears crunching, never knocked a mech off and got good at holding his speed/staying off the brakes. Infact add that to the "bike you wish were made" thread.
Single speed DH bikes.

I ran quite a few SS full suspension bikes and after many frames and tensioners realised I was just as well running gears once I'd finished "simplifying" my bike.

Worth experimenting all the same.

I'm going with yes, terrible idea. Aside from the chain growth, which is probably a lot on a 5 depending on vintage, when people singlespeed they tend to stand up and heave on the pedals, and this is the worst way to ride a FS bike. It'd bounce all over the place. I used to do that on hardtails and then when I got FS bikes I stopped doing it cos I hated the pogo stick effect. And yes, whilst well set up bikes don't bob under normal pedalling, if you bounce up and down on the pedals like that they are bound to. Unless it's a Specialized Brain type affair.

I'm sure some weirdo 😉 is going to come along and tell me they ride a SS with ninety nine inches of travel and it's not as bad as you think...

not unless the pivot IS the BB. (as on the DMR bolt, iirc)

Also Kona Aa no?

In simplified terms, the chain tension when you pedal reduces the amount of pedal bob because the upper run of chain has to get longer as the bike goes through the rear travel. The rear sprocket size has a small effect on the anti-squat but the front chainring size has a large effect. You can reduce the pedal bob by running a smaller chainring but this will increase the chain growth.

Orange have moved their pivots up and down over the years but their best bikes usually have the pivot in line with where the chain meets the chain ring. Where the pivot is higher the suspension extends under pedalling, when it’s lower it squishes under pedalling.

In simplified terms, the chain tension when you pedal reduces the amount of pedal bob

Yes but there will still be loads because of the huge weight transfer. I have ridden a 5 and climbing out of the saddle was always rubbish as on any FS bike.

Even on a Kona Cowan with its concentric pivot it was bouncy. It's was a fun experiment but did not last long before I switched back to hard tail SS.

Kona Aa no?

They really should have made a bike called that.

Have you ever seen a filing cabinet with only one drawer...

@molgrips, my particular vintage is 2016 Alpine Five (29er).

I quite fancy giving it a go, I have cogs and spacers here. Reading through the comments though I realise I do tend to climb in the saddle on the Five, whereas I'm usually an out-of-the-saddle guy on my other bikes. I've never thought much about that but I guess it's to do with the squish. Might have a play around and try a steep-ish climb on a single gear out of the saddle and see how bad it is...

Interesting reading about the chain growth piece though, appreciate the insights!

Further evidence for Irn Bru to have been the only orange thing that should be allowed to be made from girders.

So, I had a brief mooch around gurning up some hills in a far too hard a gear, and I’m happy that the suspension is supportive enough to handle the singlespeed conversion, so I’m going to go for it!

I have the prerequisite spacers and cogs to choose from, but first question will be relating to chain tension I think, and whether I can get away without a tensioner but not needing the chain too slack. Playtime in the garage ahead tonight.

Watch this space - might even chuck the dropper too for a while for even further reduced clutter…

I singlespeeded my Hemlock but at 100mm travel. It rode better than I expected and I quite liked it but I was under no illusions it was "a good idea". More prone to mashing with a longer travel frame (although I'd have a go anyway, just for the hell of it) and I'd be very surprised if it worked well without some sort of sprung tensioning device with any frame that doesn't pivot around the BB. I used an old short cage clutch mech.

I have the prerequisite spacers and cogs to choose from, but first question will be relating to chain tension I think, and whether I can get away without a tensioner but not needing the chain too slack. Playtime in the garage ahead tonight.

I'm putting my bets on "nope". Can imagine it being a baggy mess everywhere other than at full compression, when you're highly unlikely to be pedalling anyway. You're also pinning your hopes on the chain just-so-happening to be the right length when you've got nothing to fine tune it with

If I remember correctly my (geared) Alpine 160 rode better when the pivot was in line with the chain/chain ring. I assume this will carry over to SS.
You could try using an old short cage or Road mech as a tensioner. Or NSMB had something recent about SS from Andrew Major.

So, an update:

The Orange is now single speed. I ummed and ahhed about the chain tensioner but couldn't bring myself to stump up £50+ for a Paul Melvin, but came across a basic single jockey wheel sprung tensioner on eBay for £5, so I bought it.

It arrived yesterday and I tentatively fitted it without too much hope, using a spare chain and a 20t cog. Signs were all good so I went for it, fitted it all up properly, hoiked the cassette, cable and shifter off and had a quick play on the drive.

Compressing through the travel was all fine and it pedalled well enough so called it done and put it away.

Well, the sun is out today so I took it out for a quick lunchtime loop up a steep-ish bridlepath onto the moor and then back down a little rocky/muddy descent. It's surprisingly good! Pedalled well, and didn't bob too much - but I did put the forks into 'pedal' as opposed to leaving them open as they were moving more than the rear was. Was also noticeably quieter, which was nice. Although it meant I could hear my dropper post rattling, so that was annoying.

More feedback to come after a few more miles and a few more hills.

POIDH.

Gizza pic