2013 Specialized Langster - Chainline/Upgrade Questions

[PedallingNowhereSlowly]

Last night I picked up a 2013 Specialized Langster and although there's some signs of use and unsympathetic storage, it is in original condition with, AFAICT all the original parts including tyres.

It's in a black and grey colourway (I'll get some pics posted).

I'm looking at running it as a single speed for now, but suspect I need to look at the gearing. I don't think it's current 48 x 16 (78.8") is going to be low enough for some of the climbs I'll need to tackle with it.

Which brings me to my first question, chainline. I've measured it a few times and tried to get as accurate a measurement as possible. It looks to be 40mm at the chainring and 42-43mm (guessing 42.5 mm) at the sprocket. I was expecting it to be the same at both, but is most definitely isn't. On first inspection, the chainline looks to be straight, but looking again does suggest these measurements are somewhere near. I don't think it will present a problem, but I'm wondering if it has had the bottom bracket replaced with a slightly narrower one?

I'm also thinking about changing up the wheels at some point. The original wheels still have some meat left on the braking surfaces, judging by the wear indicator but not a huge amount. I'm guessing they are around 14mm internal width too, so thinking about trying to crowbar on some slightly wider rims and tyres - looks like there's enough clearance. What brands/retailers are good to look at these days for track hubs and wheel builds?

 

[palinurus]

Nice. I found 48 x 18 was a nice gear.
I imagine the chainline was originally closer than that- someone more knowledgeable will be along soon...

 

[fossyant]

Just to be aware, if running 'evens' on a sprocket and chainset, make sure you rotate the chain one link every so often. If you've not had any reason to take the chain off (e.g. puncture) the teeth wear to that particular link and can run really rough if you move the chain round 'too late'.

 

[PedallingNowhereSlowly]

I've started fettling this.

Swapped the pedals out and the alloy seatpost for a carbon one.
I've got some carbon bars in the spares box I'm tempted to throw on.

Front brake has the centering adjustment bolt rounded out. I've got some campag brakes in the spares box, so I'll dig them out and have a look.

The original tyres are still fitted and they are only 23mm wide. I've got some 28mm tyres which should in theory fit - but they come up at 30 mm so might be a bit of a stretch. I'll probably try them for size.

And I'm thinking about the wheels - they do have a some life left, the front one isn't that true and if I'm honest, I think my scepticism of cheap wheels entry level bikes tend to ship with is kicking in so I'm looking at replacement options. Especially knowing that a tyre of a given width will come up narrower on a slightly wider rim.

 

[PedallingNowhereSlowly]

Had another look at this today.

First job was to rotate around the seatpost clamp and properly torque it, having change the post for a carbon one during the last fettling session. Easy.

First thing to do was to tighten up the headset which seemed very loose. No issues there and the bearings look to be in good order. Whilst I was there, I noticed that the handlebar stem had an integral shim for further adjusting it's angle. I rotated this around from the -4° to the +4° position and put the stem back. Did some measuring up and decided to leave it that way. Came to re-fit the bars and found that the front brake outer cable was too short. Now added that to the list of things to buy. And some more bar tape too.

Come to think of it, if I've not got to re-tape the bars, maybe I should swap the alloy bars for the barely used carbon bars in the spares box? Or is that asking for trouble on a fixed wheel bike?

Anyway, moved on to trying the Continental Grand Prix 28mm tyres on this bike. I don't fancy riding that much on the 23mm tyres the bike has on it just now.

Started with the front wheel - and found something odd. On one side, 75% of the front rim still has the wear indicator visible. 25% does not. And that 25% is indeed worn down to 0.9mm. I've never seen a wheel worn like that - but I do have half an explanation. I'll come back to that.

With the current front rim a bit worse for wear, I remembered that I had a Mavic Kysrium front wheel of some description knocking around the garage. Checked the internal rim width - 13mm. Pushing my luck with 28mm tyres, maybe. Checked the internal width of the scrap rim. 14mm. I figured I was out of luck.

Anyway, I mount the 28mm tyre on the Kysrium rim anyway and fit it to the bike, just to see whether it all fits. And the good news is that it does, just. Clearance under the brake calliper is tight, but no clearance issues with the fork itself. I've tried bearing down on the front of the bike and thus far I've not made the calliper rub the rim. The other thing is, that the tyre looks okay on that rim. It measures up at just 26mm wide - I think that's close enough for me to at least try it out. I'm not planning on doing any fast cornering anytime soon.

The only other thing giving me pause for thought, is corrosion at the rear of the alloy front fork crown. I've read up and the suggestion is, that if it's nowhere near the bonding of the carbon fibre fork legs, it's probably okay. Obviously water has got under the paint, the alloy has corroded and the paint has flaked away. It seems fairly localised so I'm not going to worry about it too much just yet. May invest in a new set of forks further down the line if I get on with the bike.

Final job, for today, was changing the rear tyre and in the process checking out that rear rim. Well, I'm glad I did this before I rode the bike. As soon as I removed the rear tyre, it became evident that a very small area, barely half a mm thick around the circumference of the tyre wall, has been worn down to the cords. Flexing the tyre to remove it from the rim, in one place it just gave well and fell apart.

Plenty of clearance for the 28mm tyre at the back. May have accidentally on purpose flipped the back wheel so the chain is on the fixed sprocket.

After re-mounting the wheel and tensioning the chain, came to adjust those brakes. And here I notice the wheel is out of round. Which I think explains the uneven wear. The rim is less worn in some of the places I can reach with the gauge where the brake blocks have not been contacting the rim in the areas the wheel is elongated?

The rear wheel has the same issue as the front, btw. Just not to the same extent so it looks like it is safe and usable. Worn down to about 1.1 mm thick at the thinnest point, where I can measure it.