i have just replaced the wheels on my 2017 Anthem having broken 2 Giant carbon rims. Setup was tubeless, NobbyNic 2.25 on 650B wheel at around 26-28 psi. I am around 12.5 stone, so probably 13 plus in riding kit, and riding largely xc natural stuff. Rim width was 21mm. Riding is firmly wheels on ground stuff..
new wheels are Hope XC Pro 4s, so 19.5mm rim, same tyres, tubeless.
I am wondering whether I am running a bit low on pressures, and did that contribute to busting the rims (on fairly innocuous features - fast compressions through a dried up river bed for the last one, and I think a not that heavy water bar landing for the first), or was it just crap light race wheels. The Hopes are 32h vs Giant at 28 I think, and a bit heavier, and sturdier.
any thoughts ? I reckon from reading other threads that my pressures were about right....
Riding is firmly wheels on ground stuff..
a not that heavy water bar landing
If your wheels are firmly on the ground, what did you land from?
^^^^ ok, they were in the air momentarily to clear a trail obstacle !
Tbh I just think those giant rims are shite.
I just think those giant rims are shite.
Think so too.
thanks, you are reaffirming my opinion about the Giant rims. I grudged replacing the first one after a year of light use, back in March, so when the new one cracked 10 days ago it was time for a change back to trusty Hope's !
as an aside, the Hope's went up tubeless first time last night and are holding fine today. 2 wraps of Stans 21mm, some soapy water on the beads, pop with a Schwalbe booster, crack a bead, sealant in, pop again with booster, core in, top up with pump. I was expecting to have some problems so was very pleasantly surprised !
I reckon those pressures are at the lower end of what I might run, I'd probably up it to 25/30 front/rear for rocky stuff in the dry, down to 20/25 for if things are slidy and not too rocky (or I can pick a line).
I haven't put any dents in any of my alu rims in about 15 years, you know how I ride although I have started using Procore on the hardtail recently, and previously ran slightly higher pressures (maybe 35psi both ends).
That said, whilst I've pinch flatted a few times even with tubeless, I can't remember the last time I hit a water bar...
But you kind of know how I ride so I would say it sounds like the rims. I don't tend to run the lightest of rims though I always have one eye on weight.
You have 2 basic set up options, one that copes with 90% of everything and gives you some better performance - the trade off being the 20% of hits that are outside of this and you risk damage
or you set up with enough pressure to not ding the rim but lose the performance aspect.
I'd generally put the hitting a water bad edge or the heavy compression type rim ding as the unfortunate indecent type things - if it's happening a lot then you need to look at how you ride or get much tougher gear!!
Couple that with people not being a fan of giant wheels - though I've heard the hopes can be a little cheesy too
thanks for replies, philjunior, yes, tend to agree - the first one was the gaps on Loch Ardinning, the second at the bottom of dead gnomes.
Will set new ones up a little higher, 30 on back, cheers
Riding is firmly wheels on ground stuff..
Learn to pick them up when required
and Yes. run higher pressure. it's surely not that difficult to grasp that if you're destroying rims you need to run higher pressure in the tyre.
why thankyou geex, to the point and useful as ever 🙂
I was simply seeking opinion on pressures and rim damage, on a bike forum....
I do have a grasp of physics, and a modicum of bike technique (though others may disagree 🙂 ), thanks though
I reckon from reading other threads that my pressures were about right….
Well.. clearly not. and yet you sill continue to trust the opinion of these same people instead of using that grasp of physics to your advantage 😛
I'll quit right now with the "straight to the pointness" and instead offer something a little more useful for you to think about.
Tyre pressures isn't ever as simple as choosing the same pressure as another rider the same weight as you.
riding style, weight distribution, personal preference, bike/rim/tyre choice and terrain all matter loads. Trial and error as you've found out can be costly. But there are ways of using trial and error to get better results without breaking rims. I find the easiet/safest/cheapest way to test for correct pressures is repeatedly cornering as hard as you can and feeling for the pressure at which tyre sidewall fold/sqirm starts at (not full folding/squirming... just where it begins to. Once you've found it you need to run at least a few psi higher than this point. You don't need to go anywhere special to do this. Depending on just how hard you push in corners and your tyre width this should also be around the minimum you can run to avoid rim strikes on square edges too. But not always. eg. if riding somewhere with a lot of unavidable square edge hits or somewhere with highspeed hits/rough landing zones. so if riding places like this always er on the side of caution. Don't be afraid to add pressure when required while on a ride either. using the method I explained above you can easily get pressures right without a guage, it's only handy to know the numbers for at home or at the car. But most certainly don't simply try individual tyre pressures because a stranger online told you that's what they run.
😉
HTH
geez, that is jolly useful advice, appreciated, thanks 🙏
You have 2 basic set up options, one that copes with 90% of everything and gives you some better performance – the trade off being the 20% of hits that are outside of this and you risk damage
While we're being direct can I ask if mikewsmith is a footballer? Or has 110% superseded 100% now? 😉