Newbie Question - How to change rear tire on BMX bike?

[[email protected]]

My son got a flat on the rear wheel of his BMX bike (20" tires). I see
that this is much different than my road bike. I took the nuts off the
rear axle, but it looks like I have to break the chain to remove the
wheel. Is that correct, or is there some trick I'm not seeing? There
is also a little collar of sorts over the right side of the rear axle
that has what looks like an adjustment screw of some sort. Anyway, I
don't want to mess up the bike so I'd thought it best to ask here
before undoing anything more.

 

[M-gineering]

[email protected] wrote:
> My son got a flat on the rear wheel of his BMX bike (20" tires). I see
> that this is much different than my road bike. I took the nuts off the
> rear axle, but it looks like I have to break the chain to remove the
> wheel. Is that correct, or is there some trick I'm not seeing? There
> is also a little collar of sorts over the right side of the rear axle
> that has what looks like an adjustment screw of some sort. Anyway, I
> don't want to mess up the bike so I'd thought it best to ask here
> before undoing anything more.
>
Unscrew the chain tension adjuster so that you can slide the wheel far
enough forward to derail the chain (at the chainwheel)

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

 

[dabac]

My son got a flat on the rear wheel of his BMX bike (20" tires). ... I took the nuts off the
rear axle, but it looks like I have to break the chain to remove the
wheel. Is that correct, or is there some trick I'm not seeing? There
is also a little collar of sorts over the right side of the rear axle
that has what looks like an adjustment screw of some sort.

That might be a chain tensioning screw. You need to loosen the axle nuts, and loosen the chain tension adjuster. This should make it possible to slide the wheel a little forward, giving you enough slack to lift the chain off the sprocket and the crank/chainring. That in turn should give you enough slack to move the chain out of the way and remove the wheel.

At reassembly, check that chain tension is OK before tightening the axle nuts.

 

[[email protected]]

On Feb 8, 2:58 am, dabac <[email protected]>
wrote:
> [email protected] Wrote:
>
> > My son got a flat on the rear wheel of his BMX bike (20" tires). ... I
> > took the nuts off the
> > rear axle, but it looks like I have to break the chain to remove the
> > wheel. Is that correct, or is there some trick I'm not seeing? There
> > is also a little collar of sorts over the right side of the rear axle
> > that has what looks like an adjustment screw of some sort.
>
> That might be a chain tensioning screw. You need to loosen the axle
> nuts, and loosen the chain tension adjuster. This should make it
> possible to slide the wheel a little forward, giving you enough slack
> to lift the chain off the sprocket and the crank/chainring. That in
> turn should give you enough slack to move the chain out of the way and
> remove the wheel.
>
> At reassembly, check that chain tension is OK before tightening the
> axle nuts.
>
> --
> dabac


Some chain tentioners won't loosen enough to allow the chain to come
off the chainwheel. Even when a tensioner would allow that, the guys
I rode with & I always chose a different method as to keep our
tensioners set where we like them.

If you remove the axle nut on the chain tensioner side completely, you
should be able to slide the tentioner off after the nut just like an
oversized rectangular washer. The wheel will then go forward,
allowing the chain to come off at the chainwheel. From there you can
remove the wheel & change the tire as usual. If you have not turned
the adjusting screw yet, wheel position on reassembly will be as
simple as putting the chain back on, sliding the tensioner into place,
centering the tire & tightening the axle nuts.

Dan

 

[A Muzi]

[email protected] wrote:
> My son got a flat on the rear wheel of his BMX bike (20" tires). I see
> that this is much different than my road bike. I took the nuts off the
> rear axle, but it looks like I have to break the chain to remove the
> wheel. Is that correct, or is there some trick I'm not seeing? There
> is also a little collar of sorts over the right side of the rear axle
> that has what looks like an adjustment screw of some sort. Anyway, I
> don't want to mess up the bike so I'd thought it best to ask here
> before undoing anything more.
>
Slack the chain adjuster on the frame end. Push the wheel forward and
drop the chain from the sprocket.

Open the caliper if there is one, usually by detaching the cable
connection ( fingers only) or on an older bike by removing one brake shoe.

Mark the tire, rim and valve stem so you can trace the leak back to its
cause.

Before installing the wheel get some lubricant on those axle threads.

Take care to adjust the chain tension properly, noting there are tight
and loose points throughout the chain rotation. It's easy to overtighten
a chain and do real damage. Here's a photo:
http://www.yellowjersey.org/chainchk.html
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971