Wrong rims?

[MattHB]

GF and I have a specialized crosstrail each, same model (v-brake 2011) from same shop, same time.

A weird thing is that when we got them the braking area on the rims was painted black. As I've now done some miles this is no longer the case and the rims are heavily scored from the standard brake blocks that had bits of metal in them. The other weird thing is that where the rims formed when the 2 sides come together there is a ridge, which is obviously bad for a block wizzing past.

Did we have the rims for the disc version fitted? The hubs are normal non disc hubs, no carriers are on them for any rotors.

Im going back to the LBS Saturday with the bikes so they can look, but I wouldn't mind knowing before hand what the deal is.

Am I also right in thinking that on proper v-brake rims the braking area is likely to be of a tougher material than one not designed for them?

Cheers.

 

[PpPete]

You need to clean any bits of metal and grit out of the brake blocks! They are not part of the brake block, they are picked up as you go along.
Ridge where rim is joined? = cheap wheels.
Tougher material on brake track than on rest of rim? No chance.

 

[lukesdad]

Rim brake rims are machined so, yes the rims you have are not for rim brakes, the only exception being ceramics which your rims are not but your blocks may well be. What are the hubs like ? got any pics ?

 

[lukesdad]

sorry just re read standard hubs you say ?

 

[Zoiders]

The last few years with Specialized has shown a marked dip in quality control and not just with mid range bikes.

It does sound like it's the wrong wheelset, someone could have even plugged a disc wheelset in there by accident at the shop, they could have been shipped to the dealer that way, what beggers belief though is that the dealer did not pick up on the issue at the point of sale.

 

[fossyant]

Not all rims are machined. Cheap wheels are often painted (anodised), even on the braking surface.

 

[Zoiders]

If Spesh are doing that then they have fallen a long way from what they used to be.

A Cross-Trail is not a cheap BSO with a throw away wheelset.

 

[Smut Pedaller]

Generally a disc specific rim will not even have a flat braking surface, normal rims will have a flat braking surface as well as being slightly thicker there for wear. Rims are either pinned or welded together normally, a pinned joint still leaves a very small visible joint like you have described which is not usually a problem as they are usually flush.

 

[lukesdad]

Not all rims are machined. Cheap wheels are often painted (anodised), even on the braking surface.

They d have to be very cheap ! even cheap kids bikes are machined ,and the anodised wheels ive come across have been machined before anodising hmm.

 

[MattHB]

Cool thanks for all the info. I'm disappointed that they seem to have put cheap stock on, I shall see how I get on making big loud noises!

 

[threefingerjoe]

I don't know if the machined/non-machined controversy is still raging, but I believe there are still high-end rims that aren't machined. I'm told that machined rims break in the brake blocks faster, without squeeling, but I've had machined rims that squeeled and non-machined rims that didn't. I've also heard that a machined rim can have thinner spots where the wheel is joined, resulting in a weak spot.

Anyone else?

 

[MattHB]

I don't mind having non machined rims, but surely they should stay black and not grind (and they really are) down?

 

[youngoldbloke]

Not unusual to have a slight ridge at the pinned join. My Aksiums had enough of a step to be noticeable when braking, but almost undetectable by eye. If you don't remove shards from the blocks they will wear down the rim, and unless the rim is black all the way through (!) the black surface will be removed. Alloy rims wear out - sooner, or later.

 

[snailracer]

They d have to be very cheap ! even cheap kids bikes are machined ,and the anodised wheels ive come across have been machined before anodising hmm.

Machining and anodizing add cost but do not improve the braking or durability of alu rims. They are done purely for aesthetics - which might be why you can find them on kids bikes and "fancy" wheels. More expensive and better-looking does not mean better quality.

 

[mickle]

Rim brake rims are machined so, blah blah blah

Wrong. Some rim brake rims are machined, but not all.