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I seem to be seeing more and more bikes with it. Probably 8/10 hardtails I see second hand have some. Is it more common than it used to be? What's causing it - makers being too optimistic with Tyre sizes, more flexible Tyre casings more flex in frames?
Is it really possible to weaken a frame with it?
Whatever size tyre or fork a designer specs, people will go bigger.
Whatever size you design for people go one louder.
Same for fork length.
It’s a bit better now people are less obsessed with very short chainstays.
But basically sizing up. It never stops.
Funniest one for me is people fitting 650b tyres into 26in hardtails to “update” then. Utterly stupid.
In the old days it used to be an insufficiently tightened QR slipping. Happened on my road bike on its first ride, the scars are still there 12 years later.
On an MTB a slight buckle in the wheel can do it.
Funniest one for me is people fitting 650b tyres into 26in hardtails to “update” then. Utterly stupid.
Well.... it works fine if you trim the side knobs down to get clearance, plus file off the gear cable stop from the back of the seattube and run it as a 1x9. Only downside is that it sucks off road because the back tyre slides as soon as you lean the bike over and you spin out on road because of the limited gear range. Apart from that, it's a brilliant idea.
I wondered if it was that simple. Presumably they fit tyres with a mil or 2 clearance when static, not realising how much a tyre moves. Must suck quite a lot of speed off the ride.
I imagine they are selling the bikes to buy a newer version with more Tyre clearance so they can exceed that again.
On an MTB a slight buckle in the wheel can do it.
I'd expect that to cause an asymmetrical rub?
Wider rims make a surprisingly large difference to tyre shape and clearance too.
I've worn a groove in an alu (Specialized M2 Stumpjumper) chain stay by - a/ probably an insufficiently tight QR (as above) and b/ trying to fit 2.1" gnarly tyres in a late 90s race hardtail.
How did the Tyre not eat itself before it wore a groove in the ally?
Sand and stuff on the tyre acting as grinding paste I imagine.
I don’t see it that often but then I don’t buy a lot of second hand frames. Always people looking to put inappropriate wheels and tyres in the back of their bikes. I’m on a whyte owners thing in Facebook and always people asking about putting 29” wheels in the back of a bike specifically designed around 650b+ and short chainstays
Funniest one for me is people fitting 650b tyres into 26in hardtails to “update” then. Utterly stupid.
Ok, but then reportedly santa Cruz chameleon from 2014 was a 2013 frame with 27.5 wheels.
Most manufacturers recommended tire widths are wrong.
They say things like 2.4 fits fine but actually they mean a 2.4 fits but only just. This means the actual max tire size you should fit in the frame is one size down. This has been my experience for years.
Take a Sonder Transmitter for example which is sold as a plus bike.
The Width between the chain stays is 77.1mm and the width of most 2.8s on wide rims is around 72mm. This is what the 2.8 nobby nics measured on love mud rims. This leaves 2.5mm tire clearence which is poor. If you factor in tire wobble/variation then on a perfectly true wheel its still coming very close to the stays.
Actually the max tire should be 2.6 and in the real uk mud a 2.4 is the best choice for clearance.
So while I agree with Brant that people will size up I also think manufacturers aren’t as honest with consumers as they could be. This goes for bike reviewers who never mention this stuff.
I have 2 sonder transmitters and they are still brilliant with smaller tires though.
Lack of additional tyre to frame mud clearance is probably a big factor in this,as many buy hardtails as the tool to get them through muddy wet winters in the UK.Older hardtails had much less clearance and were designed more for skinny sub 2" tyres. I love the clearance on my Slackline as it's designed to run up to 2.8" allowing me to run 2.35 mud tyres with loads of clearance and no rub and therefore no build up of compacted of mud on to sidewalls.
They say things like 2.4 fits fine but actually they mean a 2.4 fits but only just.
There are a couple of problems with this. The biggest is that 2.4 tyres from different manufacturers can be massively different in width. The other problem is that the same tyre will be bigger if you fit it to a 30 mm rim than a 17 mm rim. The only way to really know is to try fitting the tyre and see how it goes.
Stock tyres, typical UK muddy conditions -> chainstay rub
Weaken a frame? Yep - one of my pals wore a hole in his chainstay! Glad to say he scrapped the frame when he realised, could have been nasty. To be fair, he is a monster, so it was probably both the frame and the wheel flexing under the weight! ;_)