RADBMX.CO.UK
Technical & Reference Section => Tech and Restoration => Topic started by: southern andy on July 21, 2010, 08:34 PM
-
Bit of help needed please...
Fitted some cranks last weekend to my bike and all went smoothly till i took the bike for a small ride. I then noticed that the Non drive side bearing cup was starting to come out from the bottom bracket.
I thought it may be the spacer inside the bottom bracket being slightly too long. So tonight as i had a bit of time i thought i'd put the shorter one in.
Eventually worked out the tool and removed the non drive side, replaced the slightly shorter spacer to inside the bottom bracket and proceeded to refit the crank.
Job done after a lot of swearing so took it for a ride.
Looked down and it's started pulling out of the bottom bracket of the frame again. :tickedoff:
Any one have a slight clue as to what's happening.
I hate cranks, always have done and always will do.
You can see where it protrudes from the BB by about 1mm here in the piccy.
(http://www.radbmx.co.uk/archive/albums/p191/carpcrazyox/bb.jpg)
-
Have you got enough spacers on it? Maybe the bolt isn't clamping against the arm but just clamping against the axle? Is there any sideways play in it? Never had the BB cups work out
-
There is a very small bit of play, hardly anything though.
That's all my spacers used that it came with.
-
I'm a BMX novice but I do know one thing.....if you have enough spacers and no play it's impossible for the cup to come out.
-
What can you see if you take both crank retaining bolts out, Is the axle all the way to the end of the splined part of the boss. If it is put another spacer/washer on it.
BB shells and axles come in various lengths. Hope that makes sense.
If not PM me your number and I'll give you a call.
-
PM me your addy mate and I'll put some spacers in the post for you........sounds like the crank isn't clamping to the bolt, the bolts are just clamping to the axle, think of it like a headset, you need a small amount for the bolt to clamp to.
-
Hi Gary, i'll have another look tomorrow evening mate and see what's happening then. :daumenhoch:
-
the non drive side bolt looks to be sticking way out and the spacer washers don't look tight against each other,so i'd say down to spacing.
-
Ok cheers chaps, Rob PM on the way mate.
-
Just going to hijack your thread andy whilst we are on about crankage... I have a redline flight crank with a dk us bb on my bike at the moment, can i put my profile crank on that bike using that same bb or do I need a dedicated profile bb?
Matt
-
your spacer in the frame inbetween the bearings is a shade to long
run as is ,,it will be fine
-
your spacer in the frame inbetween the bearings is a shade to long
run as is ,,it will be fine
I thought that so i put the short one in, can i run it without a spacer ?????????
Just going to hijack your thread andy whilst we are on about crankage... I have a redline flight crank with a dk us bb on my bike at the moment, can i put my profile crank on that bike using that same bb or do I need a dedicated profile bb?
Matt
Any US BB should work Matt but then what do i know about cranks. :LolLolLolLol: should be fine to use mate.
-
Just going to hijack your thread andy whilst we are on about crankage... I have a redline flight crank with a dk us bb on my bike at the moment, can i put my profile crank on that bike using that same bb or do I need a dedicated profile bb?
Matt
It will be fine mate, both cranks use 19mm axle so the DK BB is fine :daumenhoch:
-
Cheers andy, just spoken to James(voivod) and he reckons it will work and he is in the know so its spanners out time...
Matt
-
your spacer in the frame inbetween the bearings is a shade to long
run as is ,,it will be fine
I thought that so i put the short one in, can i run it without a spacer ?????????
Just going to hijack your thread andy whilst we are on about crankage... I have a redline flight crank with a dk us bb on my bike at the moment, can i put my profile crank on that bike using that same bb or do I need a dedicated profile bb?
Matt
Any US BB should work Matt but then what do i know about cranks. :LolLolLolLol: should be fine to use mate.
if you don't use the spacer,it will side load the bearings and will run tighter than a ducks ass!
-
Ok cheers Hutchman. :daumenhoch: I'll give it another bash tomorrow.
-
Just going to hijack your thread andy whilst we are on about crankage... I have a redline flight crank with a dk us bb on my bike at the moment, can i put my profile crank on that bike using that same bb or do I need a dedicated profile bb?
Matt
Some Redline cranks have 20mm axle's.
-
Andy, if you've not got it sorted, bring it to the big green gazeeeeeeebo workshop at MK bud and we'll have you up and running in no time. I have a billion spacers for Flights - mush have had a dozen of the fookas in my time :daumenhoch:
Spen
-
Profiles now fitted, all spaced up nicely but does a profile crank not need the axle nut locking up as if I try to do that it keeps pushing the crank arm further up the axle tightening the bearings?
Matt
-
Profiles now fitted, all spaced up nicely but does a profile crank not need the axle nut locking up as if I try to do that it keeps pushing the crank arm further up the axle tightening the bearings?
Matt
(http://profileeurope.co.uk/wp/wp-content/uploads/2007/09/crankdia.gif)
the spacer tube on the spindle should enable you to tighten up, if fitted correctly. :daumenhoch:
-
Im guessing the tube spacer has slipped slightly then as it was fine with the flight crank fitted. Need to go get the profile crank removal tool tommorow and get the arm back off.
Matt
-
I think i've done mine aswell, i've added two more spacers (wrong colour though) to the non drive arm and it's now all tight. I've taken it for a spin around the block and the bearings seem to be staying in.
Chipped a small bit of chrome off though :tickedoff: :tickedoff: not happy, it was the profile tools fault. :'(
-
Are the Profile's new, I just bought a new set of profile's unopened in the box, Unwrapped them and 2 spots of chrome missing by axle boss. Could see the copper colour underneath. Spoke to my LBS where they came from, They got me 2 new arms. And said it has been known.