Whats bent?

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1/27/2018 9:46 PM
Edited Date/Time: 1/27/2018 9:54 PM

Hey all new here on the BMX side been on VitalMX forever. im an old dude who started riding again recently. My kid rides as well and ive been going out and riding with him hes good im old.... Anyway A few weeks back he landed kinda low in the bowl at Hoffmans and his bike started poppin on the chain and i thought damn he bent a sprocket. Bought a new sprocket put it on still bent.... Thought well crap guess ill buy him new cranks, got him a set of Fit Indent 24mm. Installed them and still bent..... Is the actual BB on the frame bent? here is a video

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I can assure you 110% the sprocket is straight the spindle is straight and the crank arms are straight they are all brand new taken out of the box tonight. The frame is a Free Agent Telum complete. Ive been slowly upgrading his parts on it to good parts whenever he breaks something. Is time for a new Frame? If he really bent that im gonna be honest im kinda proud.....
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1/27/2018 10:47 PM
Edited Date/Time: 1/27/2018 10:49 PM

Are your spacers in? Can you link to YouTube so we can see, that's a tiny imbedded video dude? Is it just me or do those two chainstay tubes look a lil off coming out the bb. Did he twist the rear end while landed. Its a free agent so its completely foldable as a bike wink

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1/27/2018 10:58 PM
Edited Date/Time: 1/27/2018 10:58 PM

Here is the full link straight to Youtube ">


Thanks for looking it might be bent in the rear ill check it out. All the spacers are in as well. Thanks for looking.
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1/27/2018 11:03 PM

Hard to say. The obvious answer would be bottom bracket. But you'd need both bearings and the tube spacer to all be pissed the same way. Did you tighten the sprocket bolt before putting the cranks on? All spacers in the right places? It could just be that everything is straight, but put on a little pissed

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1/27/2018 11:18 PM

grumpySteve wrote:

Hard to say. The obvious answer would be bottom bracket. But you'd need both bearings and the tube spacer to all be pissed the ...more

He would have had to change the BB when he put the 24mm Indents on there. wink

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My Sunday Soundwave V3 Build
Insta: @p.gibbons

"You can't educate pork"
- grumpySteve

"Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!""
- Hunter S. Thompson

1/28/2018 12:32 AM

Yea it looks like the rear end is twisted, that wheel looks closer to one side than the other and one of those CS tubes from the back of the BB looks twisted... so nothing might be wrong with any of the bb or the cranks , could just be like when a car gets hit and its dog legs from frame damage... check that rear end.... lol

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1/28/2018 12:53 AM

It doesn't look like the frame is twisted from that angle to me. Pics looking straight down at the stays could confirm that. I reckon it's to do with deflection of the sprocket. Notice the sprocket is closer to the crank arm where the bolt is. Loosen the cranks, loosen the sprocket bolt, tighten the cranks nice and tight, then tighten the sprocket bolt. I think the sprocket is just sitting slightly pissed on the axle. Plus, if the frame was twisted, that wouldn't make the sprocket move like that

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1/28/2018 1:13 AM

grumpySteve wrote:

It doesn't look like the frame is twisted from that angle to me. Pics looking straight down at the stays could confirm that. I ...more

I saw the same thing.

Make sure there isn't a spacer between the crank arm and sprocket.

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1/28/2018 6:29 AM

Honestly mine isn't perfectly straight and I have a new frame, bb, spindle on the cranks an it's spline drive. Sometimes I just assume that the parts aren't all perfect and if it's not causing problems then I would just ride it until it does

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1/28/2018 7:38 AM

The old setup did the exact same thing. Im going to tear it apart and redo everything. If its still doing it then i think ill just get him a new frame. Thanks everyone for looking

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1/28/2018 9:56 AM
Edited Date/Time: 1/28/2018 9:57 AM

Yeah I don't think a twisted frame would cause that problem. It would be very noticeable, if it was bent that much. Do what Steve said, tighten the cranks first, then the sprocket bolt last.

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1/28/2018 9:58 AM

NateBrown62 wrote:

Honestly mine isn't perfectly straight and I have a new frame, bb, spindle on the cranks an it's spline drive. Sometimes I ...more

This is definitely a problem. I wouldn't want to ride my bike like that. A little wobble is one thing, but that's going to cause extreme tight and loose spots.

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1/28/2018 10:53 AM

ggallin422 wrote:

Yeah I don't think a twisted frame would cause that problem. It would be very noticeable, if it was bent that much. Do what ...more

Yeah if the frame or bb was distorted it would only deflect ones way but that's more like uneven spacing on the cones...i ride my chain pretty loose .just tight enough where it doesn't hit the dsg..i like slack a lot lol

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1/28/2018 11:48 AM

grumpySteve wrote:

It doesn't look like the frame is twisted from that angle to me. Pics looking straight down at the stays could confirm that. I ...more

I agree with Steve here. Really the only thing that looks "off" to me when rotating is the sprocket. If your frame was twisted, one of the entire sides of the crank arm/sprocket assembly would wobble towards the frame.

I would try to just put the cranks on and nevermind the sprocket. Rotate again and see if there's a wobble. If not, your sprocket is on a little crooked (or pissed, I like pissed)

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BMX over 30: Eat clean, Stretch, and Pray.

1/29/2018 12:35 AM

Make sure there's no spacer between the sprocket and crank arm, you may also need to remove any paint from the axle boss of the crank arm that may be stopping the sprocket from sitting flush against it. It could just be a coincidence, old sprocket bent, new sprocket not sitting flush on the arm. A small washer between the sprocket and sprocket boss on the crank arm could help too

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1/29/2018 12:07 PM

Since i hate threads that never have a resolution at the end i wanted to update this.

I ended up pulling the cranks off my bike and putting them on this bike same thing. Put these New cranks on my bike and they worked perfect. Has to be something with the frame still no clue what but it has to be.....
I decided to just get him a new frame and in the end i was noticing the quality of the Eastern Shovelhead especially for a complete so i just ordered him a new bike and left the new cranks on my Hangman frame I kinda like em I've been wanting his bars for awhile too so I stole them too while i was at it....

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1/29/2018 12:15 PM

OKCIS wrote:

Since i hate threads that never have a resolution at the end i wanted to update this.

I ended up pulling the cranks off my ...more

Maybe the bearing just sit in the cups at an angle

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1/29/2018 1:35 PM

I think you should have got an aftermarket frame, since you said, you have been upgrading his current bike with aftermarket parts. Otherwise all those parts were just a waste. An aftermarket frame will also last 3x longer, but the shovelhead is a decent beginner complete. It just sounds like he is no longer in the beginning phases of riding. Just my 2 cents.

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1/29/2018 2:45 PM

ggallin422 wrote:

I think you should have got an aftermarket frame, since you said, you have been upgrading his current bike with aftermarket ...more

Sad thing is I think your 100% right but i kept looking at that bike and thought man thats a deal and if he doesnt like it he can take my bike and ill take the eastern. Ive got a brand new Fit hangman fully built bike that i just built around christmas. We will see but for the price i figured it was worth a shot.

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1/29/2018 10:34 PM

OKCIS wrote:

Since i hate threads that never have a resolution at the end i wanted to update this.

I ended up pulling the cranks off my ...more

NateBrown62 wrote:

Maybe the bearing just sit in the cups at an angle

Both bearings, and the tube spacer would all have to be at the same angle. Otherwise the axle won't go through the hole.

I personally don't think it's the frame still. The sprocket would still move parallel to the bb shell no matter how bad its bent.

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1/30/2018 9:20 AM

OKCIS wrote:

Since i hate threads that never have a resolution at the end i wanted to update this.

I ended up pulling the cranks off my ...more

NateBrown62 wrote:

Maybe the bearing just sit in the cups at an angle

grumpySteve wrote:

Both bearings, and the tube spacer would all have to be at the same angle. Otherwise the axle won't go through the hole.

I ...more

Not necessarily. I've shaved a little off of a tubespacer and cone washers before to get the spacing even on my cranks and I didn't make them level. It all went together fine but then my sprocket was at a very slight angle. Even 3 degrees is pretty noticeable on a 28t sprocket I ended up using a micrometer to check everything and the tube spacer and cone were both uneven less than 1mm

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1/30/2018 10:00 AM

The bearings are a very snug fit on the axle. If one of them is at an angle, the axle won't go through. Even if it does, the sprocket still won't be off axis if it's tightened to the crank arm properly. For this to have affect the bb shell would have to be machined pissed, with a pissed axle, and pissed bearings. All within the same tolerance.

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1/30/2018 1:34 PM

Im an engineer for a living so I will eventually figure this out once i have some time. I plan on putting a micrometer to everything and figuring out whats causing it. The one thing and only thing that makes me think its the frame is the exact same parts on another bike dont wobble its only when they are on this frame. However like Steve has said the tolerances on the bearing are tight if they were tilted the spline wouldn't go through.... One day ill get some time to sit down and go through it.

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1/30/2018 2:59 PM

OKCIS wrote:

Im an engineer for a living so I will eventually figure this out once i have some time. I plan on putting a micrometer to ...more

If you have access to a surface plate, rest the crank's spindle boss on the surface plate and try to rock it side to side in the spindle boss center to pedal boss center axis. If the spindle boss and pedal boss aren't in line, that would be your problem.

Have you tried putting a known good sprocket on and checking for the problem or have you tried to put this sprocket on your bike?

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My Sunday Soundwave V3 Build
Insta: @p.gibbons

"You can't educate pork"
- grumpySteve

"Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!""
- Hunter S. Thompson

1/30/2018 3:45 PM

OKCIS wrote:

Im an engineer for a living so I will eventually figure this out once i have some time. I plan on putting a micrometer to ...more

p1p1092 wrote:

If you have access to a surface plate, rest the crank's spindle boss on the surface plate and try to rock it side to side in ...more

He said the whole kit works fine on another frame

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1/30/2018 3:50 PM

OKCIS wrote:

Im an engineer for a living so I will eventually figure this out once i have some time. I plan on putting a micrometer to ...more

p1p1092 wrote:

If you have access to a surface plate, rest the crank's spindle boss on the surface plate and try to rock it side to side in ...more

Mishinn_Control wrote:

He said the whole kit works fine on another frame

It says he moved the cranks over, not necessarily the sprocket too(unless I missed something). wink

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My Sunday Soundwave V3 Build
Insta: @p.gibbons

"You can't educate pork"
- grumpySteve

"Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming "Wow! What a Ride!""
- Hunter S. Thompson

4/20/2019 8:12 PM

grumpySteve wrote:

It doesn't look like the frame is twisted from that angle to me. Pics looking straight down at the stays could confirm that. I ...more

I had the same problem this worked for me , incase anyone stumbles across this thread like i did

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They say the worlds your oyster, but man oysters aint for me.