[Closed] Long VS short chainstays on a hardtail

Or do people think that hardtails aren't meant to be stable like I feel this would be, but should be 'fun and whippy' instead? How much of an influence on this feeling do you think the chainstays have?

Stays on MTB HTs have probably grown a little in recent years with 27+/29" wheels, although I'm quite impressed at how many manufacturers find ways to keep the rear wheel tucked in close to the BB.

"Stability" comes from more than just chainstay length, overall wheelbase length has probably gone up too on newer HTs as the front ends get longer and head angles get slacker.
Rider weigh distribution being more centred should have a positive effect on stability too.

TBF an extra inch on most bikes chainstay would still be rideable, but I think you'd perhaps be sacrificing technical cornering ability and make the bike feel slightly more barge-like...

longer stays are probably more of a touring bike solution for seated climbing and rolling along on the flat "stability" where growing the front end too much could compromise the riders comfort, and out of the saddle, chucking the bike about type handling isn't such a concern...

What do you regard as long reach and slack?

I'm riding a Cotic Solaris which is pretty middle of the road (I have sized up though), with 440mm-odd stays.

I think the long stays help keep it calm on technical bits, up and down hill. Feels more balanced than the last HT I was riding, which was very similar geometry but shorter at the rear.

HTH

I think it's a question of balancing the ease of whipping the bike into a turn just by shifting your hips (which is how I perceive shorter chainstays greatest handling benefit) with having good front:rear weight distribution so you neither lose the front nor back on flat turns.

Hardtails have inherently less grip on the back tyre due to the lack of suspension, and the more travel the fork has, the greater the reduction in rear grip vs the front - to me that means you want shorter chainstays on a hardtail than a full-sus, particularly a long-forked one.

I do think chainstays should get longer in proportion to front-centre measurements (if head tubes are longer on bigger sizes then the front-centre increases by more than the change in reach alone).

The Bird hardtails do this - the 150mm AM has 420mm chainstays on XS/S/M and 425mm on L/XL. The 130mm TR (which is longer reach size for size but the same front-centre due to the less slack head angle and shorter fork) has 430mm chainstays on XS/S/M, 435mm on L and 440mm on XL.

Check out the Orange Clockwork 100 (29) or 120 (650).

Long is 490 ish mm reach, and slack is 64 or 65 degrees in my opinion.

I understand that cookea, just wondering if longer stays as well would be a bad thing.

Thanks Chief that's good info. I'll look at the oranges as well.

Any excuse to wheel some history out... short stays have been done 🙂

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I'm running 26" wheels in a 650b long, low, slack frame (dartmoor hornet), so I think I can tick this box

compared to my old frame (ns surge) it is more stable, but definitely harder to get the front up - I have to really make an effort to hoist it, and on some larger jumps (say, 15' and above), I'm a little nervous that i can't shift my weight around as much. That said, its only been out a few times and it might just be a case of getting used to it

Longer chainstays (making front and rear wheelbases more equal) ought in theory to make for a softer ride because [url= https://en.wikipedia.org/wiki/Bogie ]bogie[/url]. My experience of a really short chainstay is that it gave me a right battering off-road, but that frame was well stiff in addition (Planet-X Hammerhead).

I think another reason for long chainstays on tourers is heel/pannier clearance?

I had 2 pretty similar HTs (one geared, one SS, but similar travel etc.) and I found I preferred one. The only real difference I could find was shorter chainstays on the one I preferred.

It made it more huckable (I am of course referring to 2" rather than 20ft drops, but better for lowish speed drops all the same)/chuckable and I had more confidence on techy stuff.

I'm sure there is a limit, but if the front end is long enough you won't end up putting your weight too far back. Probably. Or something.

I rode a Jones Plus, that has huge chainstays. 'Poppy' and fun to ride as anything, bit harder to bunny hop at first but all in all backs up what I think about short stays - as often about marketing noise and instant or test-ride effect rather than anything to do with really good, balanced geometry. Where your weight is and how well you can move it around as needed is what makes a bike ride well, so for some that will be a slammed rear, others will find benefits in a long bike.

The two bikes I have with -IMO- the best all-round handling ie nimble/stable mix, balanced on flat corners inc the ability to hop, wheelie-drop or get fun and floaty over fast crests, both have longer rather than shorter stays but both also have my weight in the right place from a neutral or rested position.
I think very short stays are over-rated for all but the DJ/4X riders among us. I'd go shorter on a HT over a susser though, also not go toooo long up front, as I think a HT should be fairly nimble and involving to ride. Just my preference though.

If you're ok with the seat tube length (~19.5") then the XL Bird TR has 495mm reach and 440mm chainstay length - and with a Works -2 deg headset that gets you the 64 deg static head angle (with a 130mm fork).

I've actually gone the other way with my Zero AM, as detailed at length in this thread:

http://singletrackworld.com/forum/topic/bird-zero-am-review-warning-bicycle-content

One thing that was very obvious when riding some very rocky trails a few days ago (normally only the full-sus goes to gnarly places - I wasn't expecting to find stuff like this in Brittany), is how much the 150mm fork (Pike with Luftkappe) contributes to rear suspension, partly through allowing the BB to drop by about a third of the fork travel when you huck to flat and partly because it allows the whole frame to rock fore and aft more around the BB than if the fork was rigid. It's a lot of fun!

just wondering if longer stays as well would be a bad thing.

I don't think they'd be a 'bad' thing as such it's just going to change how a bike handles and what it's better at, My current bike has 425mm stays (IIRC) on a 26er, it could definitely have been made shorter, and I think anything up to ~445mm would probably be acceptable to most riders. Plus as chiefgrooveguru said, making them proportional to sizing/front reach makes sense also...

But if we're talking about an "all-rounder" HT mountain bike I think going too long say ~480mm would compromise it as much going up as down, being able to lift and place the front wheel or move the bike about at slow speeds over nadgery rocks/roots and tight turns on a climb...
It's not all about Rad^Gnarr, I think the 420-440mm that most seem to sit in has been arrived at after a bit of experimentation over the years...

It's worth noting that there's 31.5mm radius difference between 26" and 29" wheels but generally stays didn't seem to grow by an inch and a half on 29ers, instead designers found ways to carefully cram those bigger wheels into about the same length rear end...

because it allows the whole frame to rock fore and aft more around the BB than if the fork was rigid. It's a lot of fun

My hardtail (Ti Switchback) has short stays at 415mm which is the same for all of the sizes. It feels pretty good to me in terms of stability and is still a hoot on the descents and is probably a far more capable bike than I am rider.

The stays are shorter than they were on my previous BFe and I think it rides better.

Current 29er hardtail (Chromag Rootdown) has 429mm chain stays.

Previous 29er (well 29+) had 435mm chainstays.

I also have had a Karate Monkey (431mm)

Not sure in the grand scheme of things that spread of 6mm makes much difference.

However I did have 2 26er bikes with vastly different CS lengths.
Dialled PA with short-ish CS and Ragley Blue Pig with much longer chainstays.

The biggest difference was the BP was much more planted at speed and also due to the longer CS it climbed steep stuff way easier.

CS length a) probably shouldn't be viewed in isolaton and b) is inevitably a compromise.

Well I have a jones 29 and a jones 29+ - the plus is a lot slacker and has 50mm anger chain stays and TBH I thought it would handle like an old bus based on the numbers but its the complete opposite - rides really well as is probably better off road than my jones 29 so no idea how that works

moral the story is that the longer chain stays don't seem to make a negative difference , perhaps longer chain stays on a jones 29 might be different but maybe the slacker head angle, fork off set and longer chain stays of the plus all balance out? - might just be me though