Self Build - Clicking From Bottom Bracket?

sdavies13

Hi all.

Decided to start commuting into work so bought the bits and built a suitable bike, however it has a clicking coming from the bottom bracket area.

Clicking only happens on the down stroke and sounds similar to a mis-aligned derailleur, thing is I built it around a Shimano Alfine 11 geared hub and the frame has an eccentric BB so there is nothing to be misaligned!

I tried replacing the Shimano 110mm bottom bracket with a Token 103mm believing my problem was due to chain alignment but just had my first ride since the swap and the clicking is still there!

Any ideas or suggestions?

Really want to get the setup perfect before I actually start commuting with it.

Thanks.

nicklouse

pedals.

does it happen seated or standing?

check the cable adjustment as well.

sdavies13

Only noticed the clicking when seated, but haven't done much riding standing yet.

Alignment, it is slightly off by a couple of mm. Already realigned once so will do so again. Interestingly I didn't initially notice the clicking after fitting the new BB but once I had been through the lower gears a couple of times it seemed to come back so suppose the changer cable slipping could cause this...

Colleague who's into cycling thinks it might be the chain. It is a half linked BMX chain. Are chains directional?

I might just split the chain then put it on the other way around and see if it makes any difference. Any input on how much play I should have in the chain? Suppose I have about 5-8mm play there but could tighten it up.

No idea if it helps but it clicks twice on the right side down stroke but only clicks once on the left side down stroke. These are per revolution.

Most annoying thing is this is the first time I have built a bike and having this problem has knocked my confidence in my building abilities. Makes me wary of the 12 mile commute each way.

nicklouse

not really.

get the bike vertical and look down the chain for alignment.

1/2" vertical half way down one run of chain.

most likely cranks/bb/pedals.

if it was the chain it is unlikely to be a repeatable noise 2 on one side and one on the other.

sdavies13

Nick,

Thanks for the advice. I will upend the bike at the weekend and have a proper look at the chain's alignment.

Odd how the clicking only occurs when peddling. If I just rotate the peddles by hand nothing occurs.

Also odd how the clicking went away after replacing the BB but then came back after a few gear changes (sounds like it is coming from the BB so doubt anything to do with the rear hub). Think the clicking didn't occur initially until after I had been up the road changed gears a few times so perhaps something is giving.

Am wondering if could be the eccentric insert but that is machined from aluminium and is in there pretty tight so doubtful there's any give. Once I have it upended I will check the eccentrics lock bolts and make sure they are all tight and that there's no play on any of them.

Cheers again.

el_presidente

When I had this it was the front derailleur cable end hitting the crank once every revolution.

sdavies13

Well I would never have thought it was that...

With the bike upended and "peddling" it although I couldn't hear any clicking I could "feel" a click roughly similar to what I was hearing. Checking things out looks likes some of the rivets on the chain are longer than the rest!

Now am in a quandry. See if I can source some shorter rivets to replace them with or remove the plastic chain guards on the Alfine hub.

Anyone aware of any problems I might have if I remove the plastic chain guards from either side of the hub's cog?

Cheers.