[Cadent]

Gentlefolk;

Really newbie question, because although I have taken off front wheels, I have not taken off a back wheel yet.

In the TdF, I watched the back wheel swapped out in 5 seconds, and I couldn't figure out how this was done...what kept the rear derailleur from clunking on the ground?

How does the rear end work? Does the gear cassette rotate splines on the axle to provide the propulsion? And how DO you take off the back wheel without the derailleur going "clunk"?

Thx!

Don

 

[BruceG1]

The derailleur is bolted on to the frame of the bike.

 

[Cadent]

<duh>...I was looking for the attachment point on my bike and I couldn't see it... so I assumed the derailleur was supported by the axle. Have to look closer at my bike...

So the derailleur is bolted to the frame, the gears send power to the hub, the hub sends power to a splined axle, and things go round and round?

 

[milkbaby]

Typically on a road bike your RD will be bolted to a replaceable hanger that is bolted to your frame. That way when you crash or get the RD into your spokes, it rips off or messes up the hanger which you just replace instead of part of the frame (hopefully).

You probably have a freehub equipped rear wheel. The cassette (the group of cogs in back) slides onto splines on the freehub body. Inside the freehub are spring-activated pawls or a star-shaped pawl that grabs on pedaling in the forward direction but just slips when pedaling backwards. If you stop pedaling and then start again, you may notice a slight hesitation before your pedal stroke meets resistance, and that's because there is a little bit of distance before the pawls catch on to turn your wheel...

Check this out for pics:
http://www.parktool.com/repair/readhowto.asp?id=45

 

[Cadent]

Thanks, Milk... you have my system nailed...yes, its a freewheeling hub..I was just concerned about what to do with the rear derailleur when I would be fixing the inevitable flat. I kinda assumed that everything would somehow stay in place and all I had to do was pull the axle and the wheel would come off..but I have assumed simple tasks before.

(Ask me about repairing VWs sometime....)

 

[Kerry Irons]

Try this at home

I kinda assumed that everything would somehow stay in place and all I had to do was pull the axle and the wheel would come off..but I have assumed simple tasks before.

Just curious, but is there something preventing you from just trying this on your bike? It will become immediately obvious how things work.

 

[Mr. Versatile]

Good advice from previous posters. I would suggest one more thing. Before removing or reinstalling the rear wheel shift gears to the smallest cog on the rear. It'll make the change much easier.

 

[Opus51569]

If you'd rather see it done first...let your fingers do the walking to YouTube. There are a number of videos that show you the process for removing/reinstalling the rear wheel. Might be worth checking out.

 

[Cadent]

Just curious, but is there something preventing you from just trying this on your bike? It will become immediately obvious how things work.

I have found that in my personal experience, reassembly is NOT the reverse of disassembly.... in short, while I am a whiz at taking things apart, reassembling the component parts into a functional whole tends to be an exercise in random reassociation.

So, I like to have an idea of what I am encountering before I start taking stuff apart.

(It took me about 90 minutes to reasemble a Ruger MK II... but in my defense, it usually takes everyone about 90 minutes to reasemble a Ruger MK II....)

Anyway, I have an older Univega MTB that I think will be my project bike for tearing into and seeing how it works. It has been slipping gears for some time now -- would probl. help if I replaced the 15 yr old rusted cabling....

 

[e39540is]

Thanks, Milk... you have my system nailed...yes, its a freewheeling hub..I was just concerned about what to do with the rear derailleur when I would be fixing the inevitable flat. I kinda assumed that everything would somehow stay in place and all I had to do was pull the axle and the wheel would come off..but I have assumed simple tasks before.

(Ask me about repairing VWs sometime....)

This is not like a motorcycle, you do not need to pull the axle out. If you have a quick release, just release it, and the wheel will come out intact, and the derailleur will stay on the frame. If you have nuts, just loosen them enough to pull the wheel out.

 

[Cadent]

This is not like a motorcycle, you do not need to pull the axle out. If you have a quick release, just release it, and the wheel will come out intact, and the derailleur will stay on the frame. If you have nuts, just loosen them enough to pull the wheel out.

OOOHHhhhh...hmmm.... really gotta play with this before I need to. The "owners manual" that came with the bike was useless. It explained all the legal limitations of Raleigh but never got around to explaining how to adjust anything.

 

[milkbaby]

If you'd rather see it done first...let your fingers do the walking to YouTube. There are a number of videos that show you the process for removing/reinstalling the rear wheel. Might be worth checking out.

+1... You definitely want to try this at home and figure it out before you really need to out on the road! You may get stuck out there with no bicyclists riding by to help you out, and it'll be a lot easier to do if you did it before.

 

[Hooben]

Sometimes seeing is believing....

 

[perttime]

Taking the wheel off really is that easy. Putting it back takes a bit more care so you don't get tangled in the chain. On some bikes I have to pull back on the derailer to get enough space to get the wheel in the dropouts.

On bikes with fat tires, the brakes may get in the way, and need to be opened up to allow the tyre to pass through.