please check your rims

[hellosunshine]

because my front wheel collapsed on me,twang!bang and the rim came apart on a silver slivver,result of worn winter wheels- was lucky was uphill,but DO CHECK YOUR RIMS TONIGHT!im used to checking brakes/gears etc in winter,but rims i never thought of.

[DebW]

Can you post a picture of the collapsed rim? Rim type? Number of spokes? Single or double wall? How many years of use did the rim have? Did it fail on the sidewall from brake friction or at the spoke eyelets? I've only seen one collapsed rim, and it was quite old.

[Eden]

What a coincidence - I blew up a rim last Friday! We've had a fairly nasty winter around here (at least for the area.....) so there have been several times when road crews put sand on the roads and none of it has been cleaned up. Its been particularly punishing on the old rain bike even though I clean it off every time I go out in the wet - you may as well be using sand paper and rubbing compound to brake with! I was noticing the rims were looking worn and I even took them down to the shop a couple weeks ago and he thought I had about 6 months left in them.......

Well - luckily enough I was on a trainer at the time it went (it was the rear for me), unluckily I was in the middle of my VO2max test..... when about 1/4 of my rear rim when flying across the room, accompanied by a rather loud bang. Also fortunately for me I had just recieved my new rims that I got off of Ebay about 3 days earlier - cause my rainbike takes 650's and I didn't have any spares before that.

I can't post any photos since its already at the shop being rebuilt, but I can tell you it was a Velocity Deep V, 28 spokes and it was the braking surface of the rim that failed. It folded right over everywhere that it didn't completely blow out on one side. I don't know how old the rims were, though I don't think more than a few years if that - they had been on a used TT bike that I purchased last summer from a triathelete (and you just don't do a lot of heavy braking when you are doing tri's) and they were in pretty good condition then. When I took it down to the shop he thought one of the brake pads must have worn to the metal, but I know that never happened - in any case they are cartridge pads so they don't have a metal post or a bolt to stick out in the middle.

[RoadRaven]

Thanks for this reminder

I hardly ever glance at my rims, though I almost always run my hand over each tyre and always lean on the tires to see if they need more air... won't take much to look at the rims as well!

[Velobambina]

Question from a dummy: how can you tell if your rims are going bad?

[DebW]

This is something you never saw 30 years ago, but now rims are lighter and tire pressures are higher, so I can see where they'd fail that way. Yet another advantage of sew-ups - sew-up rims don't take air pressure stress from the tires/tubes. If one failed, the rim sidewall could collapse by 1/2" but the tire would stay in place and remain fully inflated.

eden or hellosunshine, did you notice the rim expanding (maybe the brakes needing to be loosened) before the rim failed?

[Eden]

Hmmmm hard to say - I had just cleaned the bike really well the day before and changed the brake pads since they were very worn. After I changed the pads I certainly did need to adjust them, but I usually do since I adjust them in as the pads wear. I never even braked with the new pads as I wasn't allowed to ride before the VO2 and we opened the brakes completely when we put it on the trainer.
The day before my rim failed had been a particularly gritty day. It wasn't raining, but it was damp outside so all of the sand that was out on the roads still was sticking to the bikes in a lovely gritty slurry. It would have been better if it had actually been raining since then at least then the grit would have been getting washed away.
I did a little poking around on the internet. It looks like I'm not alone with having a Deep V fail suddenly and catastrophicaly. The theory that's thrown up mostly is that since the walls of the rims are taller than most that they don't have to wear as much to collapse (plus apparently deep V's are pretty thin too). I had just filled the tires the night before also. Since I'm little I generally go with about 100/110psi, even though the tires are rated to 120, but because I was having the test and its better to have the tires very solid when you are on a computrainer (less slippage I think) I did actually put 120psi in them, which may have also contributed. When the tire heated on the trainer - bam! - now I get teased by my coach about my awesome rim destroying power (I was up to a whole 190 watts when it went.....)

[hellosunshine]

eden or hellosunshine, did you notice the rim expanding (maybe the brakes needing to be loosened) before the rim failed?[/QUOTE]



soz for a late reply-been without internet since feb 13th.......no!i dont think i did,next bottom bracket and back wheel bearings have gone.


internet back on,so things are looking brighter (my firewall had blocked internet explorer-ive a nasty feeling i pressed the wqrong button installing my ipod,so am now going cold turkey thinking of continuing my ipod.off subject etc etc.)