Wheel Rim Wear

[townbikemark]

OK: so I've taken my Kettler Spirit to one of the few bikeshops that can service its 8 speed Nexus hub which is fine, but I'm told that the rims are dangerously worn on the front wheel and could collapse at any moment...

They phoned me up and I haven't collected it yet.

They quoted me a new one complete with dynamo hub for £124 which I shan't be taking up as I'm currently in between jobs. I plan to look in the classifieds, ebay etc - although having said that, ebay doesn't seem that good for single 700c wheels. At the moment anyway. The bike gets me about and I need it.

I bought it July last year and have used it mainly for utility; occasionally up to 30 miles in a day, usually less than 10 - I'd say in between 2000 and 3000 miles - and rarely exceeding 15 mph. Also, mostly in fair weather. I've kept the V-brakes reasonably well maintained, having replaced the blocks a few times and cleaning the wheels, including nylon scouring pads every now and again.

This level of wear seems to be premature - is it? Could the shop be wrong?

Thanks

[jb]

Sounds a bit early for the mileage you've been doing, on the other hand if you have replaced the blocks a few times then you are giving it some heavy use. Rims can be very thin these days unless they are specifically heavy-duty (which for your bike might be the case). Also check to see if you're rims have a wear indicator that will show up as a groove appearing on the braking surface if they are worn (conversely, some rims have a groove on when new which disappears when worn). There needs to be about 1mm of thickness left but measuring it is tricky without callipers.

[Vantage]

Wearing a rim out in under 3000 miles seems unlikely to me. I've had mavic rims in gloopy mountain biking last longer than that. Why are they quoting an entire wheel rather than just the rim and why so expensive? My lbs just built me a 36 plain gauge spoked 3N72B dyno hub to a Sputnik rim for £90. And he's a damn good mechanic at that.
Maybe it's just me, but I've a sneaking suspicion that your lbs is trying to take you for a ride.

[townbikemark]

Sounds a bit early for the mileage you've been doing, on the other hand if you have replaced the blocks a few times then you are giving it some heavy use. Rims can be very thin these days unless they are specifically heavy-duty (which for your bike might be the case). Also check to see if you're rims have a wear indicator that will show up as a groove appearing on the braking surface if they are worn (conversely, some rims have a groove on when new which disappears when worn). There needs to be about 1mm of thickness left but measuring it is tricky without callipers.

I don't think that I needed to TBH; I just thought I'd replace them instead of levelling them flat with the stanley knife - it's a messy job as it is and there's all the fiddling to get the levers equal; easier to use new blocks I thought (at the time).

[townbikemark]

Why are they quoting an entire wheel rather than just the rim

Thanks - that's a good question I wouldn't have thought to ask. I'll ask them...

[andrew_s]

The gauge to use for rim wear checking is the Iwanson gauge, generally about 5 or 6 pounds on eBay. A new rim or wheel should be ordered if it shows less than 1mm.

It's easy enough to put a new rim on an existing wheel, but it may not save you a lot.
You need either a new rim that matches your existing rim 's ERD, or a non-matching rim and a new set of spokes. A bike shop will almost always use new spokes anyway, as they won't use old spokes that they don't know the condition of because of guarantee work. If it's you doing the work, it's fine to re-use spokes provided they are still the right length and you haven't had any breakages.
The bike shop may have suggested a new wheel because a gear hub has non-standard length spokes which they would have to order in by the 100 spoke box.

Rim wear is very variable - I've worn rims out to the point of failure quicker than the tyre. I found that changing the brand of brake block to Koolstop ended my problems. Shimano blocks seemed very prone to getting bits of grit or glass embedded in them, which then scraped metal off the rim. If the blocks show metallic specks, they are bad. You can pick out the bits of grit, but I found I needed to do it on a more or less daily basis.

[Brucey]

I would suggest a second opinion is in order. Mind you, London is expensive....

A suggestion; if you have a Nexus 8 rear hub I'd suggest considering trading the V brakes for a roller brake at the back. Then you can use that for most braking purposes and take a lot of the wear out of both wheel rims, saving the front for when you really need to slow up in a hurry.

cheers

[breakwellmz]

OK: so I've taken my Kettler Spirit to one of the few bikeshops that can service its 8 speed Nexus hub which is fine, but I'm told that the rims are dangerously worn on the front wheel and could collapse at any moment...

They phoned me up and I haven't collected it yet.

They quoted me a new one complete with dynamo hub for £124 which I shan't be taking up as I'm currently in between jobs. I plan to look in the classifieds, ebay etc - although having said that, ebay doesn't seem that good for single 700c wheels. At the moment anyway. The bike gets me about and I need it.

I bought it July last year and have used it mainly for utility; occasionally up to 30 miles in a day, usually less than 10 - I'd say in between 2000 and 3000 miles - and rarely exceeding 15 mph. Also, mostly in fair weather. I've kept the V-brakes reasonably well maintained, having replaced the blocks a few times and cleaning the wheels, including nylon scouring pads every now and again.

This level of wear seems to be premature - is it? Could the shop be wrong?

Thanks

Primarily the front then?
I think they`re taking the pee!
Ask them what thickness it/they are down to, and why they can`t just replace the rim.

I use one of these-

http://www.ebay.co.uk/itm/IWANSON-gauge ... 0163452%26

[Mick F]

I had a thread on here some time back asking about the "half-life" of rims with respect to wear.
viewtopic.php?f=5&t=80303
Quite a bit of reading to do.

[jb]

I would suggest a second opinion is in order. Mind you, London is expensive....

A suggestion; if you have a Nexus 8 rear hub I'd suggest considering trading the V brakes for a roller brake at the back. Then you can use that for most braking purposes and take a lot of the wear out of both wheel rims, saving the front for when you really need to slow up in a hurry.

cheers

Yes, this is good advice providing you get the nexus roller brake as the cheaper ones are rubbish. They are heavy though.

[The fat commuter]

Primarily the front then?

I'm a bit mystified by the fact that it's the front rims that are worn too.

My bike's only done just over 1200 miles and I've been through about four sets of rear brake blocks but am on the second set of front ones. I only replaced the front set as it was part of a beginner's bike maintenance class.

How many times have you replaced the front brake blocks? Did they have loads of metal embedded into the surface? What sort of cycling do you do? I mainly use my bike for commuting but if I cycle home the same way that I cycle in then half of my ride is downhill. Something like 700 feet of descent in two and a half miles. If in traffic, I could be using my brakes for most of my journey into work - but this is mainly my back brake. Is your ride very hilly or in heavy traffic?

[cycle tramp]

I would suggest a second opinion is in order. Mind you, London is expensive....

A suggestion; if you have a Nexus 8 rear hub I'd suggest considering trading the V brakes for a roller brake at the back. Then you can use that for most braking purposes and take a lot of the wear out of both wheel rims, saving the front for when you really need to slow up in a hurry.

cheers

Yes, this is good advice providing you get the nexus roller brake as the cheaper ones are rubbish. They are heavy though.

i've recently installed a roller brake to the rear, and i would recommend getting a more expensive model.. i purchased a shimano IM55 (i think) and it feels like an indifferently set up cantilever brake...it will stop you, and possibly faster than you think, but in the back of your mind you can't help feeling that if it was a cantilever brake then changing the brake pads, or a change in the angle of the straddle wire would make it sharper and snappier. i guess i should use compressionless brake outers (or even an avid flak jacket tube) but even then theres a little bit of bend in the metal plate on the roller brake that holds the cable adjuster, when you pull the brake on hard (perhaps anti-skid technology?)

After i had purchased the roller brake, it became clear that i should have done a little more investigation (instead of just pointing and saying 'i'll have that one') and purchased the more expensive IM77 or even the IM80..... which i may be doing at some point in time. (i say some point, because if found a thread from a different forum that suggested that if properly treated that the brake can last for some thirty thousand miles. Although the author failed to mention the topography of the area he rode in... and i can't find that thread again. Sorry). However, having fitted it, i'm now in the process of attempting to wear the blooming thing out, which means that the roller brake handles all my 'planned breaking' duties, and as such i'm relying on the front rim brake less...

..although the little voice in the back of my head, does suggest that what i really really need is a nice 90mm drum brake at the front...

[townbikemark]

Primarily the front then?

I'm a bit mystified by the fact that it's the front rims that are worn too.

My bike's only done just over 1200 miles and I've been through about four sets of rear brake blocks but am on the second set of front ones. I only replaced the front set as it was part of a beginner's bike maintenance class.

How many times have you replaced the front brake blocks? Did they have loads of metal embedded into the surface? What sort of cycling do you do? I mainly use my bike for commuting but if I cycle home the same way that I cycle in then half of my ride is downhill. Something like 700 feet of descent in two and a half miles. If in traffic, I could be using my brakes for most of my journey into work - but this is mainly my back brake. Is your ride very hilly or in heavy traffic?

Assuming this was addressed to me: I'm not sure TBH how many times I've replaced the front block - it might be 2 or 3. Don't think I've seen anything embedded in the blocks - just a bit of uneven wear that I might cut down with a stanley or replace. It was just me thinking I was being diligent and proactive with bike maintenance...As to the type of cycling, very much short distances, less than 10 miles each day and I rarely break 15 mph. I do have a couple of baskets on the back that I load up quite regularly with shopping or gym gear - the gym is roughly 3 miles away.

[townbikemark]

An update: collected it today. Charged me £25 for the service instead of £28, which is good...

Got a second opinion from Evans in Reading, the front rims are indeed worn - quite concave...

Oh, and the £124 quoted wasn't for a new wheel...it was just for the rim!

Think I'll swap the front wheel from my other Kettler as a short term solution.

[Brucey]

....Oh, and the £124 quoted wasn't for a new wheel...it was just for the rim! .

Blimey.

Time you learnt how to build wheels, I reckon.

BTW concavity can be the sign of a rim on the way out but it isn't an infallible indicator; some rims are slightly concave when new. Hence thickness measurement is normally a more reliable indicator.

cheers