Bike Building..

The Northern Monkey

there are 2 parts now worrying me.

1) Crown Race - My headset has been fitted already and i just have to fit the crown race to the forks and cut the steerer. I've had a crown race swapped over onto another set of forks before, should that be ok or does it require fitting professionally with specific tools?

2) Bottom Bracket - i was going to fit this myself, but after reading threads about facing and ensuring that the bearings are correctly positioned i'm thinking i'm going to get the wheels on and wheel the bike down to my LBS for it fitting. How much would it cost for BB facing and fitment? or would i be ok doing it myself?

Taa
B

p.s. anyone used Action Bikes? they reputable?

David Lund

1. you can get a specific pipe like tool which you push the race on with or just bash it down CAREFULLY with a screwdriver or a bit of wood and a hammer.
I usualy just use a hacksaw to cut the steertube or you can get a large pipe cutter from a hardware shop.

2. If you want to face the BB, go to a bike shop and they should do it for you or you can buy a facing kit but there rediculously expencive! if your not too bothered about it id buy a bb tool and put it on yourself, cheeper and you can use it again anytime you need to fit anything. Not sure about the cost of facing as iv never had the BB done myself.
Dave

The Northern Monkey

Ah k cheers dave

Whats the benefits of facing the BB? Does it just ensure that the bearings sit flush and in alignment, therfore increasing life and reducing wear? is it advised to do it on a new frame?

-liam-

I was told that you don't need to face the shell on a new bike unless the faces are obviously damaged.

Part of the manufacturing process of turning the shell, prior to welding to the main frame would be to face the shell up when turning/screwcutting the rest of the component.

David Lund

Im not sure about on a new frame but people seem to do it, possibly as the new paint may have built up on it and needs to be shaved off.
Exactly what you said about the bearings and also helps it fit perfectly so you dont get so much crap getting in. Is there anyone who has dont it? Im not realy the person to ask from experience lol.
Dave

The Northern Monkey

Fair enough.. as my BB/cranks cost me £145 i want to get it right

-liam- that was my thinking...new bike should already be faced to an extent as its new, but as dave said, there could be a paint overlap... i'll inspect it closely

stumpyjon

It's a 10 min job for your LBS to face and fit a bottom bracket, mine did mine for free whilst I was buying (alot) of other stuff. Same goes for fitting the crown race.

spongtastic

Been thinking about this for a while now and I'm not sure that a BB shell needs to be faced as the bearings take their reference from the BB thread, not the shell itself. If the thread isn't alligned this would cause problems, but nothing else should.

Having passed this theory past an engineer who designs parts for nuclear power stations he seem to be of the same opinion.

stumpyjon

Maybe if you tighten up the external cup too much and the BB faces aren't parallel you could distort the bearing cup?

spongtastic

don't think so as you'd strip the thread before that happens and the plastic rings that shimano etc use would make this even more unlikely.
The only problem I can see is if there is far too much paint which could affect axle length and therefore shifting, but you could get the same problem with too much taken off the shell.

topsey_turvey

Never had a BB faced yet, and never had problems because of it. That's in over 20 years of bike building. If you are really worried you could carefully scrape the paint off, but all BBs are cut from a length of steel tube with precision cutters, so faces will be parrallel once cut; unless you've some some hookey frame builder they should remain so.

Buy the tool, do it yourself - slowly, and you've learned a skill that you will use time and again. Remember one side is right hand, and the other is left hand thread. Good BBs will have arrows to show which way to turn.

If you are using HTII don't overtighten the preload, or you'll knacker your bearings in double quick time.

wysiwyg

Facing and chasing should be around £15. Once its done its done, would seem a shame not to make sure theyre parallel. Cos should you have a BB fail prematurely, first thing anyone is going to ask is was the BB faced correctly.

snotty badger

If there was no need to face the frames then it wouldn't be mentioned!

For the sake of £10-15 I'd have it done.

Anonymous

it is a tiny ammount of material which is removed. it is pretty much just the paint. the shell should be square enough just from the manufacturing process, also, if it was that big a deal, every bike from the factory would be faced

ive never worried about it personally and have never had any real bb problems but there is enough written about it to make me wonder.

definatley take the advice about the preload, dont tighten it up too much or your bb will wear super quick, the reason the shimano tool is just a plastic hand turned key type of affair is because it doesnt take much torque to preload the bearings.