My New Mid School Bmx Frame and other bits the build begins

[AceFto]

Hi guys sorry not been on here for a good few days
Excuse the rubber thingies they are lights lol had them on at
Night today





I made a video of me riding and you can hear the crank crekaing I'm sure you will know exactly what is happening trying to upload it to Photobucket but it's not happening

[oldtired]

if its noisy then somthing is moving, most probably the arms ,

thin smear of grease on the splines and tighten up the crank end and pinch  bolts, to seat the arms properly,    plenty of grease in the bb bearings,  check for play in the bb and adjust if needed,  forged arms will make noise if not tightened up , more so with new sets like yours

    sounds odd but sometimes the same noise can come from the stem  , it sounds like the crank/bb area as it only does it whilst riding ,   may not be this in your case but it's worth checking  ,  agian thin smear of grease between the wedge and quill and tighten up the bolt well usually sorts this 

just out of interest (nagging little voice in my head)   is the chainwheel on the outside of the axle flange?   ie you can take the arm and chainwheel  off without removing the bottom bracket ? 

[AceFto]

 Hi guys sorry for not replying sooner have missed a few posts

I've got the pegs on for show will not be doing any stunts in a hurry
Is it better to take the nut of and screw the peg all the way to the frame ?

I will need to get some grease and grease the splines don't think they have much grease on them
And go over everything and tighten it,

The arm has no bolt going through the chain ring as soon as you take the arm off chain ring slips off due to it not being bolted in as chain ring slides into the hole and then u just tighten the arm

Also my little cousin has a 9 tooth rear cassette and a 30t chain ring and says his bike is quicker and can keep on paddling unlike mine which will not paddle at a certain speed

What's the benefit off having a smaller sprocket and rear cassette

Will be riding to work on it later it's all nice and clean polished up

Cheers

[oldtired]

post up a pic of the chainring side of the cranks as you have them fitted ,

it's sounding like you have the bottom bracket assembled incorrectly

     it's just odd that you needed a top hat washer , usually they are not needed on loosball bb, just been nagging at me since you posted up the chainring issue,

as to gearing ,   ( front gear first rear second)   i assume you are running 44t up front and 16t on the back , which is pretty much standard bmx , you may have 17 or 18 on the back if so dropping to 16 will improve things (shoten the chain to suit)


 small or new school gearing ,  usually it's a 25/9 which is near enough equal to 44/16  or a 28/9 which is like a 45/16

usuall gearing   is     old school        44/16    or   45/16
                             new school      25/9      or   28/9
 

new school  28/10 is also near enough   44/16 ,     there are lots of other combinations that produce similar ratios ,   

all relates to how hard it is to pedal a  harder gear will be slower/harder  to get going but will give you more speed for less crank rotation, once your rolling,       it gets complicated going into anymore detail than that 

if your little cousin i running 30/9  he must have legs like Popeye 

   

[AceFto]

Hi thanks for explaining I've attached the pictures for you
Halfords put the bearings in for me as I was having trouble getting them in and even they had trouble
But the splines might need greasing as they don't have that much on them















Is this gap normal ?

[oldtired]

thought so  you have put the bottom bracket together wrong!    and is potentially dangerous !  you have the bottom bracket fitted backwards!!! take it apart now!!


sorry to be abrupt  , i thought this was the problem to begin with ,        easily done with components you are not familiar with and tbh i have seen this done before i'll dig one out and post up pics of how it should go together 

bottom bracket,       if you need pics of one in a frame lmk i'll put it in a frame, if you put it together correctly the chainring will not come off without taking the bottom bracket apart , the drive arm can be removed ,you will not need the top hat washer,   

 you must have problems with chain alighnment too?  the chainring may be a little loose on the axle  as it it already damaged a little, however if you tighten up the race nut well (nut with big notches) it should not be to bad don't forget the big washer or the chainring will hit the bb cups, first pic.

did you get a fitting instruction sheet with the cranks ? 

driveside  chainring side







non drive side



turn the axle round this should be on the drive side, (pic below)

[oldtired]

Right , tbh i replied based on the pictures , i didn't read the text, i opologise for stating this is something you have done 

if the mods find this unaceptable then please delete but the following needs to be said


go back to halfords and tell the bloke who put it together he's a fooking muggy c**t (  swear filter no doubt worked here)


   not much winds me up tbh, but fook me!!!!  they are suposed to be professional mechanics , what they have done is potentially life threatening , as you said you ride this work ,     every one on Rad is all to aware of the tragic events that can occour by simply falling off on the road 

       ffs 




go in and tell them ,ring them up,  they may have made the same mistake on other bikes , possibly childrens bikes

[rodriguez]

  top advice

lesson 1 - Don't ever get halfords any work for you on any type of vehicle, nevermind a BMX, go to an independent local bike shop/garage that have properly trained mechanics, very few halfords do, they are mostly just young fellas who have a bit of experience working on mtbs, cars etc.

lesson 2 - Try to do the stuff yourself, have patience, research what you want to do and how you are going to do it, google, you tube and RADBMX are your friends here, you can learn how to do almost anything on a bicycle, especially a BMX using youtube and a few basic tools.

lesson 3 - Walk before you can run, maybe you should have started off with a BMX that was already built, took it apart and built it back up again a few times, changed bits out etc the way most of us learned back in the day before embarking on a build from scratch.

Maybe lesson 3 should have been lesson 1 bit late now but thought it was worth adding anyway.

[AceFto]

Most of the work I did myself and with help on here, only problem I was having I couldn't get the cups in and hence why I went to halfords
if I got the cups in I wouldn't have been in this situation

but you all on here are so helpful and it's much appreciated

will be taking the crank apart when I get in

[rodriguez]

Most of the work I did myself and with help on here, only problem I was having I couldn't get the cups in and hence why I went to halfords
if I got the cups in I wouldn't have been in this situation

but you all on here are so helpful and it's much appreciated

will be taking the crank apart when I get in

A loose ball 3 piece US bottom bracket is a pain in the ass I know where I'd put it   

Main thing is you've got there and you've learnt how to do the stuff yourself 

[oldtired]

   few pics that may help,      sometimes better than words as the method  can be a little crude 

used a small chainring just to make the pics a bit clearer

1 chainring on the large threaded side inside the flange (top hat washer not needed as the axle is the correct size on this side)





2 big washer



3 race seat,  at this point you can fit the drive arm to get the chainwheel bolt (peg in your case) in place,if it's a bolt don't tighten it down until the race seat is tight,   thin smear of grease on the splines,  nip up the pinch bolt a small amount so the arm holds on , tighten up fully the axle bolt to seat the arm then tighten up fully the pinch bolt , tighten up the race seat , use something in one of the large notches and hit it with a hammer to tighten it up ,there is a proper spanner for this but the hammer method works , just untill it stops moving after a good whack, this locks the chainwheel in place and stops it moveing (yout first issue solved)

 i've left the spacer of the chainwheel bolt so you can see the threads but this is the peg on your crank



bearings should be this way round in the cups , pack em with grease the more the better you can't put to much grease in



put axle through the bb and fit the non drive side

1 race seat



2 washer



3 lock nut



adjust the race seat so there is no sideway movement on the axle then tighten up the lock nut , you may find the axle will not move freely after you tighten up the lock nut, if this is the case undo it and undo the race seat about 1/8 of a turn , then tighten up the lock nut again and check to see if the axle is free, repeat as needed,  it should have a small amount of resistance to rotation but spin freely and smoothly with no sideways movement

fit the nondrive arm using the same method as the drive arm , pinch bolt enough to hold the arm on, full tighten the axle bolt , there should be a shoulder for it to butt up to and nipping up the pinch bolt a little stops the arm going over the shoulder , then tighten up the pinch bolt

should look like this if correct







(the nondrive axle bolt is missing of the pic  )

if you've got it right the cranks should spin nice and smooth with no noise and no sideways movement, there should be a very small amount of resistance when turning them by hand,     ride it a few hours then check for movement and adjust the non drive side nuts if needed ,and check the crank bolts, tighten as needed, you may have to do this a couple of times whilst the bb beds in properly but after a few times it should all stay tight

[workshyfop]

that is a "how to" of the highest order!!! 

[oldtired]

another little nag has just cropped up     the  frames built for 39/14 gearing , really hope  im wrong on this 

could be another spanner in the works after the bb fiddling 

[AceFto]

Went to Halfords this morning they still didn't get it right.
Spoke to Jim and he explained to me what I need to do
He went beyond his way

And in about 15 mins I had it sorted













Chainring is nice and solid hopefully no more clunking once again really appreciate it Jim 👍

[griff]

Jim's a good egg 

[oldtired]

   the second little nag of mine was unfounded thankfully , 

 just spotted a minor brake issue, but Ace is on the case and weilding his own spanners now 

[poorboyee]

wheres the barrel adjuster for seatube threaded insert, it makes life a lot easier to fine tune the brake