Chainline Question

Had the frame checked by the billy of the hills and it's straight.

FSA Carbon Track Pro cranksets are from the factory bent?

Could you provide some backup before I take it to the man?

Ah, no not the same bike. Fuji Tracks have RPM, and the weird chainring. Yours is Track Pro I take it?

Ok, I searched and couldn't find the answer I was looking for so...

Finished my first bike, total noooob to all this but understand the basics. My chainline is out and its making a really irritating clicking noise which I want to get rid of. My front chainring is further out than my rear sprocket, but there isnt enough clearance to swap the ring onto the other side of the spider, and I don't want to buy another bottom bracket as there will be the same clearance problem (I think).

I know I can shift my hub by swapping the spacer then re-dishing, but that seems like a lot of work and don't want to fuck it up. So, is it possible to put a spacer between the hub and the sprocket the push the sprocket further towards the correct chainline? Where can I get one of these (if they exist)?

the cog is stationary, you can't adjust it, only a mm or so with a large thin washer.

you'll have to buy a shorter BB or swap the chainring round to the other side of the spider.
Thats the proper way of doing it.

read the "Chainline Adustement-Rear" (sic) section

http://www.sheldonbrown.com/chainline.html

I read that already, which is why it seems my only option is new BB or redishing. Lame.

My worry is that a shorter BB is going to give me clearance issues with the chainring and chain on the frame. Gotta be another way round it, surely?

No magic available here i'm afraid.

You could always go down a few teeth on the chainring and rear sprocket to avoid clearance issues on the inner ring. Ideally you would get a shorter BB with new crank (if necessary) that would clear the frame.

If your frame has very wide chain stays then you may have to re-space the rear hub (and potentially dish the rim) regardless, but I doubt this would be the case.

You can get away with a very thin/large washer between the sprocket and hub as stated, but it's a bit too much of a hack for my liking.

I had to do what Jono described for my first build- to get a correct chainline I ended up with a fixed version of Suntour's MicroDrive (one for the old folks), with 38X13.

The frame had massive chainstays though, so I expect you will not have to go that small.

Crimp the chainstay with a ball peen hammer so there is enough clearance for the ring to go on the inside of the spider. I have done this before and it works fine, just give it a good hefty whack.

I tried that just now on the S-Works.. the frame feels a bit funny.. any ideas?

??

I tried that just now on the S-Works.. the frame feels a bit funny.. any ideas?

Don't buy plastic bikes?

Or

Hit it harder?

It must still be damp from it's swim in the canal- try drying the chainstays with a blow-torch.

I'm going to go an hit it harder. ..

you can get chainring spacers from Hub Jub http://hubjub.co.uk/etc/etc.htm
Wouldn't bother though unless your chainline is out by <2mm

Right, I've measured my current BB at 107mm. The clearance problem getting a shorter one is actually the centre of the crank arm, which is about 3mm away from touching the BB shell now.
If I got a Sugino 103mm BB, is it risky running that close to the BB shell? If my measurements are even slightly out it's gonna scrape, or not tighten properly.

Does this mean getting some lower profile cranks as well?

Short BBs hold the crank arm slightly inside the BB shell of the frame itself (hard to explain, the outer edge of the BB is flush to the frame and then has a concave appearance sort of thing), there will be no wear/touching of the centre of the crank to the BB unless you're using some wacky/chunky MTB/BMX crank, etc.

Just the standard BLB cranks, reckon this'll be ok because I'll order a BB soon as poss.

yo tim, u didnt mention how far it's out of alignment (at least i didnt see it anywhere) but imo if it is <5mm putting a washer/spacer on the hub to push out the rear sprocket is the best/cheapest option.
larger misalignment than that i would go for a longer bb rather than a shorter one and switch the chain ring over on the spider.

Out of interest, anyone here running singlespeed/fixed on a mtb-spaced frame (135mm)? I'm doing a Pompino build with a singlespeed mtb flipflop hub. What's the general concensus on bb length?

Sigh... Here I am asking the same old questions on an ancient thread....

I've just built a bike, got a Miche rear hub (36.3mm chainline according to S.B.) and old Sugino Mighty Competition cranks with 46t chainring, it's on a 103mm BB and gives a lovely 43mm chainline running as close to the chainstays as I'd like. It all runs fine, there's no way the chain is going to come off, but to 'fix' this I'd need a concave chainring, a 98mm bb and some re-shaped chainstays.

Has anyone with a 68mm bb shell got a BB /combo for a 36.3mm chainline ? From Sheldon's list quite a lot of track hubs have this line (Dura-Ace, Campagnolo, Surly etc), but most of where people state actual chainline distance in the transmission db they have 44-46mm.

I am missing something? Should I move some spacers and re-dish the wheel with the hub off-centre? Or should I stop fussy and just enjoy riding my bike?

36.3mm is really narrow.

A Miche Primato hubs is about 42mm. Is that what you have?

miro_o,
I just went to check. I am talking out of my arse. Yes it is about 42mm, my chainline is near perfect. I am an idiot.
I fitted new bb yesterday and must have had wonky eyes, then looked up the hub on Sheldon and got confused. Sheldon's measurements are centre to shoulder, not to sprocket.

doh!

Sorry, just glad a didn't start a whole new thread for this.

It's ok.

You had a chainline confidence crisis.