Chainring spacers

My chainline is out by 2.5mm. OK, so it's maybe not the end of the world, but it was playing on my mind. I decided to do something about the misalignment and spent Saturday night looking for a set of 2mm spacers on eBay. I'm such a party animal...

The spacers turned up this morning. Not that I was watching for them or anything, but I practically caught the packet before it hit the doormat. :-) Just so you know what I'm talking about, my chainring is on the inside of the spider. In theory, the spacers should move the ring closer to the frame and give me a nice straight chain. In practice, the spacers move the ring so far that it no longer rests on the little ledges of the spider. I hope that makes sense - the ring is sitting proud of the spider. Now I'm thinking that this isn't a good thing. This sort of arrangement would surely be subjecting the stack bolts to stress that they're not designed to take.

So chaps and chapettes, what do I do? 1mm spacers? New bottom bracket? Ride it as it is? Order a Langster? :-) I dunno. My head hurts. Advice gratefully received.

I'd go the different BB route.
Though a London Langster is a close second. You'll look so cool!

what is the size of the bottom bracket?? maybe get a shorter one.

different BB for sure but maybe try them, I asked at Brixton if i could do this and the guy said yup should be a possibility, although i wondered about the stress on the bolts too, but he didnt mention it and knew i was riding fixed. Give it a go before shelling out for a new BB i reckon, you'll soon know, they arent all gonna bust in one go if it is too much stress.

but a £10-15 BB won't break the bank. could also try spacing out the non-drive side of the BB, if you are able to move the cup inwards on the drive side.

On my old conversion I put some spacers on and the spider stood out off the ledge. The stress on the spacers and the bolts was too much and the whole crankset kicked the shit out of itself in one fell swoop.

Take caution.

31trum what is the size of the bottom bracket?? maybe get a shorter one.

D'you mean what length is it? Jeez, I just knew you were all going to suggest changing the bottom bracket. When I bought this bike, I was really clear in my head about what was going to stay and what was going to go: the frame, the crank and the wheels were all good. I've changed the saddle, the bars, the stem and the gearing. I polished the original seat post to within an inch of its life, and drilled the back of the fork for a brake with an allen bolt fitting. Now that doesn't sound like a lot, but I can assure you that it bloody well is! :-) By the time all the parts had been carefully selected - callipers, brake levers, a new chainring - autumn had turned into winter. Then you have to wait for all those parts to turn up. And then you have to get your hands on all the other little odds and ends you need to finish it off and make it work: bar tape, cable housing (that isn't black!), a halflink, shorter stack bolts... Yep, I've definitely spent more time tinkering with this machine than actually riding it. An out of the box, off the shelf Langster is starting to sound more and more appealing. :-)

The thought that was in my head a minute ago - the one that prompted the rant - was that I had wanted to steer clear of the bottom bracket from the start. It seems like a very direct route to a world of compatibility-fuelled pain. I'll have a wee read about it...

Nicholas On my old conversion I put some spacers on and the spider stood out off the ledge. The stress on the spacers and the bolts was too much and the whole crankset kicked the shit out of itself in one fell swoop.

Take caution.

heed this not and not my advice... as in my earlier advice.

...although you did say it was out 2.5mm and not a big deal. so if you havent dropped your chain yet then it might be just fine. i've ridden worse. and fitting bottom bracket aint that bad either. Just need the right tool/s and be gentle. but for fucks sake don't go to the box, don't prize that 'oh so easy' bike from its packaging. worries you may have, others call them challenges, you will like your bike better for it i assure you

... now all we need is for spezialized to market the 'challenge' a bike that fits no part.

Och, I'm not really going to get a Langster. I've already got two Specialized bikes and while I DO look cool on them, I don't think I need any more. :-)

Nicholas has put me right off the idea of chainring spacers. Now I've spent some time reading about BBs, they're not quite as scary as they were this morning. Maybe that's the way to go. I think I'll take advice from a real person (controversial!) in a real bike shop.

Times like these i find my LBS very helpful, they seem happy to pull the BB out measure it and find a suitable replacement, and trial fit it (run it in the frame, but not tightened up) to check alignment, all for the price of the BB.

Measure the length of your bb Eg if its 68mmx115mm tapered square fit, then to pull it in by approx 2mm, get a 111mm BB. Watch out for the two type of tapered square fit BBs (JIS or european).
Old corroded in BBs can be a PITA to remove. I usually end up clamping them in the vice and rotating the whole frame. You may be lucky and it may come out easily.
Change the BB, you know it makes sense!

If you're gonna change the BB, maybe consider going much narrower, so you can run the chainring on the outside of the spider, which will look way better and give you more efficient, Graham-Obree-styleee pedal spacing! Just watch that the cranks still clear the chainstays. I bought a new (shorter) Campy BB from Condor recently and they agreed to take it back or swap it if it tuned out it wasn't compatible with the rest of my set-up after I'd trial-fitted it at home, so ask your LBS if they'll do the same. Or if you don't have BB tools, ask them to do the trial-fit, like someone else suggested. They would probably fit the BB alone for free anyway - doesn't take much longer to slap on the chainset, wheel and chain to check the line...

fatbloke If you're gonna change the BB, maybe consider going much narrower, so you can run the chainring on the outside of the spider, which will look way better and give you more efficient, Graham-Obree-styleee pedal spacing!

Ooh, that's good. I want to be like Graeme Obree - just without the suicide attempts and manic depression. :-) Seriously, that's a good idea, though. I'll measure the chainline from the outside of the spider and see if it's viable.

I'm resolved to change it now, so I'll make a trip to my not-so-local bike shop when I get a chance. If I'm lucky enough to get free BB removal and measuring, I'll maybe buy the tools to put the replacement back myself. You can only measure spindle length when the BB is in your hand and out of the bike, right?

get yourself a vernier gauge, and you should be able to measure it fitted.

xroads get yourself a vernier gauge, and you should be able to measure it fitted.

Already got one. Do I measure between the outer edges of the crank arms?

You will need to take both the cranks off (crank extractor reqd.) and measure the external dimension of the bare BB spindle.
If you've got that far you might want to borrow the right tool to take the bottom bracket out and measurements will be written on it.
Then you might as well buy and fit the new bottom bracket. :-)

haha... fair enough. I'll post again when it's all sorted out. Expect this thread to disappear for a fortnight. :-) Thanks for the advice, folks.

fortnight?!
BB tools are expensive though - I have 'borrowed' a campag one for 2 months now! ..and I havent used it yet - its a once a year tool.

I have to psych myself up before I spend money. And now you've told me BB tools are pricey... This is going to take three weeks at least. :-P

BB tools aren't that expensive!
Do you know what type you need? I have one I can lend you if it's for a shimano BB.

Object17 BB tools aren't that expensive!
Do you know what type you need? I have one I can lend you if it's for a shimano BB.

That's very nice of you, but I'm going to need a Campag compatible tool to get the current BB out of the frame. And it's not like I'm local anyway.

I was only kidding about the cost. It'll be about £25 on tools at the very most. Finding the time to get it done is going to be a pain. Stuck at work from now until Monday, ten hours a day. I'd have done something about it yesterday, but Glasgow's two best bike repair shops are shut on Tuesdays. I've got no idea what that's all about.

10hrs a day, back in my day....... :p

Soweto888 Glasgow

It is a little far for me to ride :]
Sounds like a challange though...

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