Cross Spoke Rim. In Tollerance or Bent?

[crotchrocket]

I bought a spare set of GSA wheels with, tyres, brake discs etc. They look great, not a mark on them. But, after trying them out there was a slight wobble on the front end, like the tyre wasn't balanced properly (actually very similar to the time I had a dodgy front PR4 tyre). I noticed the front rim had about 1.5mm difference, measuring between the fork stancheon and the rim and spinning it around. Took it to bmw (for something else) and asked whether the cross spoke rims are 'true'. Mechanic said they all have a small tolerance and are not straight. So I'm thinking it's the tyre? But this evening got a video of my rims (knobbly tyre). And the new rim (road tyre) and you can see a dip or debt? In the rim. Not huge, but you can see the tyre dips down at the same point. Could this be the wobble? Or does the rim look in Tollerance?

Click for video

 

[JJH]

It's hard to say from the video. 1.5 mm is somthing I wouldn't worry about especially if a BMW mechanic says it's ok. I'd be more worried if any spokes were loose or responded differently when tapped with a screwdriver. I'd leave well enough alone. JJH

 

[crotchrocket]

Thanks for the reply, I wasn't too worried about the side to side movement but there appears to be a dip in the rim & tyre when you spin it. As these were pretty expensive, and sold as very good condition I just want to make sure they are OK ASAP, or send them back if they aren't to avoid any despite that I may have caused the damage (if there is any)

 

[JJH]

It's hard to call. If you feel that they were not as described and you payed top money for them you'd be right to be annoyed. If they are dooing the job for you leave it. How much did you pay? JJH

 

[Y7 JMM]

Oh the joy of spoked wheels!!
If you are that worried take it to a wheel re-builder?

 

[tanneman]

First check if the wheel is oval. To do so mark the spot where the run out starts and another where it ends. Correct me if I'm wrong but if the run out is a significant part of the circumference then I would say it is possibly oval. If so then reject the item. My front has a very slight bent in at one spoke due to a pothole. No issues with the balance or vibration from it.

Also check the wheel balance. The rear wheel might be out, it does have the effect of making the front feel as it is vibrating.

Check the front brake callipers are not binding. When is the last time the brakes got a clean or the pads have been checked?

Spoke wheels always have a bit of an offset therefore the tolerance is generous during manufacture. I do believe that the manual specifies the max offset.

 

[crotchrocket]

It's hard to call. If you feel that they were not as described and you payed top money for them you'd be right to be annoyed. If they are dooing the job for you leave it. How much did you pay? JJH

I felt I got a good deal, with new Anakee 3 tyres, all bearings discs, abs ring, spacers £985 delivered. But. I did ask if the rims were true, and the seller said they were. It's a breakers though, perhaps the bike was in an accident. It still could be the tyre. I have a spare front Anakee 3 I can try out.

 

[JJH]

I'd get the wheels balenced. Then see if that improves the suitation. If not then try the other tyre. Don't do everything at once or you will never know what fixed it. Check bearings while you are at it. Judging by what prices people ask I'd say you done ok. I've seen bare wheels advertised at that money. JJH

 

[RedRick Esq.]

I would try and have the offending wheel and tyre balanced and see what sort of weight is needed to do it. Any thing like a huge amount of weight would suggest that the wheel is not right

Now starts an argument of what is a huge weight to balance a wheel.

I would say 80 and above

 

[crotchrocket]

Thanks everyone. Tanneman, i'll do that this evening and check if its oval. good thinking!!

JJH and Redrick, thanks chaps, i'll put the wheels back on tonight, and take it to a tyre shop at lunch tomorrow to get the front and rear wheels balanced. If that doesn't sort it, i'll try my spare tyre. I post the question on the FB page too, and all answers came back with 'they're all like that' so I'm hopeful its the tyre. If swapping the tyres does cure it. I'll put my knobbly tyres on the new set, for off road. That way i know I've got road tyres on a 'better' set.

 

[tanneman]

The max weight for imbalance is 5 gram according to the manual. Meaning that you can have 5 grams under or over the weight needed to balance the wheel.

 

[crotchrocket]

Messaged the chap that sold them. Was very good about it and said he's happy to take them back for a full refund if i find the balancing doesn't sort it out. He said the bike they came off wasn't crashed.

 

[Neil W]

Take wheel to a tyre dealer, get them to pull the tyre off the rim and stick the wheel on the balance machine and run it up , any kinks or ovality in the rim will be obvious as you watch it spin down

The front rim on my old TC went out of true and I had www.devonwheelbuilding.com sort it ( if in doubt about BMW tolerances contact the owner Doug Richardson) ,after he had done my rim it was better than BMW can guarantee from new and never gave any further problems

 

[tanneman]

Keep that on your bookmarks because not many wheel builders around to do BMW spoked wheels I gather.

 

[Bounce]

Keep that on your bookmarks because not many wheel builders around to do BMW spoked wheels I gather.

Tis true indeed......I used Hagon in Essex & they were excellent....specialise in wheels & shocks

https://www.hagon-shocks.co.uk

 

[oldnfat]

As above, Hagon were good, got the throw down from 2.3mm to 0.3mm by some magic. I understand tolerance is 1.75mm. The other problem I had was that the wheel wasn't round....that one is also easy to measure and is usually the bigger problem in terms if ride.

 

[crotchrocket]

As above, Hagon were good, got the throw down from 2.3mm to 0.3mm by some magic. I understand tolerance is 1.75mm. The other problem I had was that the wheel wasn't round....that one is also easy to measure and is usually the bigger problem in terms if ride.

Out of interests did that give you any handling issues or wobbling?

 

[oldnfat]

Out of interests did that give you any handling issues or wobbling?

Well....yes and no. The wheel itself gave me no problems....however, what it did do according to my tyre guy was cause irregular wear on the tyre which did, especially when cornering as it had caused the tyre to flat spot around about a quarter of the tyre and caused cupping on the outer edges of the tread pattern in the same place. This was with Tourance EXPs. It got so badat first I thou I had a bad tyre and changed the front. Bike was then fine....until that tyre went the same way in about 2000 miles.

Hope this helps.