Hope you don’t mind if I put several (possibly daft) singlespeed questions in one thread please?

I’m just about to take delivery of some new wheels – Hope Pro II Trials / SS rear hub and they’re going on my vertical dropout Rock Lobster Team Ti.

That’s currently magic geared with a 34T chainring and a 17T screw on sprocket, so I can’t re-use the latter on the new wheels. I could get a 17T rear cog and put that on, and run the existing chain and chainring, or I do have a choice of chain ring / cog options in the parts bin. The 2:1 ration does seem to suit me around here though.

Questions are:

1: I’m using a KMC chain and like the ease of how it joins. It’s a 3/32ths width, but can I run an 1/8th” width on a regular chainring without any problems?

2: Do chains stretch to a point, like gear cables do, and then stop stretching or will they continue to wear and therefore stretch? I think I know the answer but it would be good to hear.

3: Do 1/8th” chains stretch any less than 3/32ths” or is it much of a muchness? It’s just that if I can get a chain that resists stretching I can keep magic gearing the bike. I just worry that the status quo will not remain as the bits get older and more worn – in fact it’s sagging just a touch anyway now, which can’t be good for it.

4: I’ve got external bottom brackets on all my bikes, but there must be something better – is it worth me looking at a Middleburn singlespeed crank with a square taper BB? I’ve just about had my fill of the short lifespan of these BBs, but so saying…

…I’m still waiting on a solution to be available on the Eccentric Bottom Bracket in a regular shell vein. The American Forward Components one is currently out of stock as he’s not got bits for it that he needs, and I’m waiting on a STW advertiser bike shop to eventually do the deal with Excentriker for theirs – again, I think they have stock problems in Germany. Either way, they’re over £100 each anyway, so I could do without the expense…

OK – you can go now! Thanks for reading this far. Stop yawning at the back.

1. Yes, but why would you want to
2. As far as I know, they continue to “stretch” or at least will keep wearing until the wear the rings more quickly too
3. Don’t think so. BTW I keep having to adjust the dropouts on my SS every few rides to keep chain tension
4. Square taper works for me £25 2nd hand Race Face cranks and £15 Shimano Un54 – only got 11 months out of my last BB after much racing and riding

Not sure about your best chain tension solution. Worth looking into converting your hub into a QR one (easy to do) if you like quick wheel removal…

1. Not much problem using a 1/8 on 3/32 sprockets, buy not much point either unless you want mud clearance. Heavier and noisier.

2. Chains don’t stretch, the links wear which gives that impression. You may get some “stretch” initially from the lubricant being squeezed out off the links. You can lessen this by hanging the chain up with a weight attached before use, but it’s too much faff for me.

3. The larger surface area of a 1/8 bearing would suggest that it would wear less, but I have never noticed this in practice.

4. Middleburns and square taper BBs have been reliable for me.

Okay – so let’s say I go for a Middleburn / square taper setup (or similar). I really don’t want to put a chain tensioner on, I’m not getting ENO eccentric hubs and I’ve got vertical dropouts.

I possess half links, but what, if anything, can I do other than muck about with sprocket / chainring rations to get it to magic gear . . . forever? Or am I just being totally daft?

Does this look like a good deal? If so, then what sq taper BB to go with it?

Okay – so let’s say I go for a Middleburn / square taper setup (or similar). I really don’t want to put a chain tensioner on, I’m not getting ENO eccentric hubs and I’ve got vertical dropouts.

I possess half links, but what, if anything, can I do other than muck about with sprocket / chainring rations to get it to magic gear . . . forever? Or am I just being totally daft?

Erm – I think that’s why they invented horizontal/sliding dropouts/EBB ~ from what I can work out Magic ratio is only a short term solution 🙁

I’ve a spesh rockhopper I use for SS, same sort of setup with a dmr revolver ss hub and vertical dropouts. Being honest, I don’t like having a tensioner on, but needs must unless you want to replace the chain pretty frequently.

Without the tensioner, I run a 38:16 ratio which seems to be a magic ratio on the frame. I use KMC bmx chains, as they seem to take the longest to ‘stretch’, but once they do I stick the tensioner on until it starts wearing more and then replace.

Like you, I’d love a neat eccentric solution, but can’t stretch to a WI rear hub or eccentric bb. I like the frame, so I’m not in a crazy rush to replace it with something with horizontal dropouts. What I’ve got works well.

Half links wear too, they can be useful to get a magic ration to start off with, but its not that fine an adjustment. If you’re not getting a amgic ratio easily, move on and either get a tensioner or a new frame! It looks pretty, but you don’t notice that much difference riding.

I’ve got a straighforward square taper bb with hollowtech cranks, they came on the bike years ago and show no signs of tiring.

Heres some useful info

Decide which ratio you want to run, dont try and go for a magic ratio

Get a KMC or Sram 7/8 speed chain, these work with the following half link: http://www.alansbmx.com/product_info.php?products_id=4266

Now set your ss up. You may not need the half link and it may work straight off. If it does great. When it stretches, install the half link. Like wise, if you install the half link first, then remove it when it stretches.

You should be able to get it right like this.

If the worst comes to the worst and you have to tension it, get one of the gusset or on one tensioners with the plastic rollers. These tension upwards and provide a better chain wrap around the rear cog, thus preventing a skipping gear. With the half link installed, your chain shouldnt be too slack so you cant tension upwards