Rear Freewheel doesn't engage when pedaling

[Steve_C]

I just purchased a used Mongoose kid's bike with a BMX style body but a freewheel in the rear. It's only one speed so there is only one sprocket on the rear wheel obviously.

When you pedal the bike for the first time the freewheel does engage and propel the bike forward. However if you coast for a bit it will then take several complete revolutions for the rear sprocket to engage again in order to turn the rear wheel.

Did I buy a lemon or is there an easy way to fix this problem?

Thanks!

[Bill]

What you can do is take off the back wheel,lay the wheel on a angle with the freewheel facing on the upward side. Get a can of wd-40 spray a few shots into the crevis of the freewheel, turn the cog on the freewheel back and forth a few turns. Spray it again, turn it a couple times. If it still turns then the freewheel is junk.

You have two options
1. Remove the freewheel and put a new one on like this site shows... http://www.parktool.com/repair/readhowto.asp?id=46 . To get a new one you will need to count how many teeth are on the cog of the freewheel. Type in for example if there is 20 teeth then put in the search ,"20t bmx freewheel" . You can search on http://www.amazon.com or go to a local bike shop to get one.
1.a. Just take it in to a local bike shop and have them do the work.
2. Search the above for a new wheel with a cog that has the same number of teeth on the cog, or again go to a local bike shop and they might just have a used one laying around.

BMX bike are plentiful and really expandable and easy to rebuild/upgrade.

Whatever choice you make I wish you well,
Bill

P.S. If there are more questions please feel free to asked.

[Steve_C]

(06-20-2010, 06:41 AM)Bill Wrote:  What you can do is take off the back wheel,lay the wheel on a angle with the freewheel facing on the upward side. Get a can of wd-40 spray a few shots into the crevis of the freewheel, turn the cog on the freewheel back and forth a few turns. Spray it again, turn it a couple times. If it still turns then the freewheel is junk.

You have two options
1. Remove the freewheel and put a new one on like this site shows... http://www.parktool.com/repair/readhowto.asp?id=46 . To get a new one you will need to count how many teeth are on the cog of the freewheel. Type in for example if there is 20 teeth then put in the search ,"20t bmx freewheel" . You can search on http://www.amazon.com or go to a local bike shop to get one.
1.a. Just take it in to a local bike shop and have them do the work.
2. Search the above for a new wheel with a cog that has the same number of teeth on the cog, or again go to a local bike shop and they might just have a used one laying around.

BMX bike are plentiful and really expandable and easy to rebuild/upgrade.

Whatever choice you make I wish you well,
Bill

P.S. If there are more questions please feel free to asked.

---

Thanks for the tip, Bill. I'll try to WD40 trick first before I order a replacement part. I explain the situation to a bike mechanic today and he said it does indeed sound like the freewheel is shot.

I also didn't mention on my original post that when the bike is coasting you don't hear that normal ratchet sound the rear hub would make so that leads me to think it's shot.

I have plenty of bike tools but I don't have a freewheel remover. I'll check out the video you linked though and see how to do it.

I only paid $30 for a 2009 Mongoose (I'm sure it's one of the box store models though) so even if I have to replace the freewheel I think it's a good deal.