The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: steven m on November 25, 2012, 02:18:32 PM

Title: crack in rear wheel
Post by: steven m on November 25, 2012, 02:18:32 PM
Just discovered this nice crack in my rear wheel.  Great.  Looks like time for a new wheel unless it can be repaired.  Not sure how this happened as I have not been jumping any buses lately or doing smoking burnouts, ha ha ha.  Any suggestions for a reasonable repair?
Steve
Title: Re: crack in rear wheel
Post by: Bob_Roller on November 25, 2012, 02:43:04 PM
That's a first, never heard of anyone having a wheel crack, let alone like that .

If it were my bike, I'd stop drill the crack and keep an eye on it while looking for a replacement wheel .

This may have been the result of a manufacturing flaw when the wheel was made .
Title: Re: crack in rear wheel
Post by: tvrla on November 25, 2012, 02:48:37 PM
Yeah, it's probably a manufacturing flaw. But you know, these wheels aren't tempered or anything - they're made purposely soft so they don't shatter into itty bitty bits. I wouldn't worry about having a good welder fix it up. Be sure to clean all the paint or powder coat from the area first, though!

Looking at it some more, it doesn't make sense. If it was a crack, it would have started from the edge of that hole, but it doesn't. And it doesn't even appear to connect with the hole. I'm wondering if it's a sloppy job of finishing the wheel before paint. Check on the inside of the wheel to see if the crack is visible there. If not, it aint a crack!
Title: Re: crack in rear wheel
Post by: steven m on November 25, 2012, 03:22:02 PM
Wirespokes, you make a good point.  I'll pull the wheel and take a look.  If it is just bad paint coming up, I'll clean it up and repaint.
Steve





Title: Re: crack in rear wheel
Post by: Barry on November 25, 2012, 04:21:57 PM
Surely on the other side of that crack (or paint defect) will be the steel brake drum liner. If it really is a crack that will make inspection or repair difficult.

Snowflake wheel can have some paint/casting defects that can look like cracks but are not. Hope that's the case here.
Title: Re: crack in rear wheel
Post by: georgesgiralt on November 25, 2012, 04:40:17 PM
Hello !
I've heard about rear drum wheels developing cracks but never saw one.
As far as I can remember what I've been told,  they develop cracks when the inner steel lining gets out of spec. As it is not replaceable, time for a new wheel...
So you'd better take the wheel out and measure the liner to see if I'm right or wrong. Then a very close inspection by a specialist to see if it is actually a crack or a paint/finish defect...
Life is too short to risk it on a wheel ...
Title: Re: crack in rear wheel
Post by: DgM on November 26, 2012, 12:39:56 PM
Looks like a crack in metal, not paint.  Contact Mackie in Sierra Madre, CA, wheel guru - (626) 355-7058
Title: Re: crack in rear wheel
Post by: steven m on December 01, 2012, 04:28:52 PM
Took wheel to Mackie.  Casting flaw, not crack in wheel.  Wheel structurally sound.  Mentioned I was thinking of stripping the paint from my wheels, have them glass beaded and then clear coated.  He said the glass beading process would act like a shot peen and smooth out potential stress points, but also said to find a powder coater who will put a UV block in the clear coat to prevent yellowing over time.

I also learned a 3" block is needed under the center stand to remove the rear wheel when factory luggage racks are installed.  Learned the hard way...

Thanks to all for suggestions.

Steve
Title: Re: crack in rear wheel
Post by: Rob Valdez 79 R65 on December 01, 2012, 04:51:04 PM
I always had factory bag racks on my '79.
I would always tie the cross bar on the centerstand to the exhaust crossover, remove the front wheel and tip the bike forward onto the forks before removing the rear wheel.  (Don't leave it in that position with a full tank of gas)

I still had to deflate the rear tire before I could get it out between the final drive and the swingarm though.
Title: Re: crack in rear wheel
Post by: Air4Life on December 01, 2012, 05:42:11 PM
Blocked for height, and suspended for safety reasons.   I haven't tried any other way since this was my first attempt.

I think I will try other methods next time.
Title: Re: crack in rear wheel
Post by: steven m on December 01, 2012, 06:29:36 PM
Nice rig.  I just put a 3" high block of suitable size under the center stand.  Bike rotates onto the front wheel, triangulated, very stable.  Rear wheel can now move down enough to clear racks on way out.  Without the rear wheel the bike is front heavy and not going anywhere.  If I was going to do any serious work I would put the bike on jack stands and tie it down.