[Closed] Same geo on your full suss and hardtail?

I would try and make the bikes different regards geometry and wheel size - then you'll have more reason to pick one over the other for any given ride.

Worth remembering that, because there isn’t any sag in the rear of a hardtail, the same HA will feel steeper on a HT than and FS due to only the fork compressing

I'd agree that different wheel size is worthwhile but think getting a similar geometry is a good idea. I spent years buying quite different ht/fs but found I just rode the one of the two (three, four, etc) I preferred all the time. I then got a 650b ht that had very similar figures to my 29" fs and found I happily swapped between them and didn't really have a favourite.

Ended up selling the ht as I'm struggling to ride any bike atm but it was a difficult decision which to let go as they were/are both ace.

I’d agree that different wheel size is worthwhile but think getting a similar geometry is a good idea.

This.
HT with 2,6 inch rubber or so.
And: for my style of riding I have the feeling that the HT needs much more fork travel - even when biking on "tamer trails".

Fatter tyres, longer travel fork, long and slack (like the FS).

See, I'd go for the same wheel sizes (and axle standards if you can) but completely different geometry, just because you'll have spares should you ever need them and you can swap tyres about if you want. If the FS is a bit long and slack, get a an older 'hardcore' HT or DJ/4X bike that can take take gears. I reckon HTs work best (for a given value of best) with shorter forks, but I tend to prefer smaller and shorter travel bikes anyway. I spaced the forks down to 120mm on my Switchback and it's brill.

Mine are completely different in geo... it does mean however that i don't like the HT riding position nearly as much as i do the FS... I do wonder at times if i should get a closer geo to the FS on my HT and see how it rides.

Everyone is different with this sort of thing. I’ve got a fairly LLS fs bike - 170f / 160r travel, big reach, 64 ish degree head angle, 650b wheels 30mm internal width and 2.5/2.4wt Maxxis tyres.

I had an old hardtail that I quite liked but it was short / steep / 26” wheels and got a bit twitchy on rocky stuff or at speed. So I decided to build up a 650b hardtail.

I ruled out the LLS ones as I wanted something a bit more playful and poppy rather than to just hammer through stuff flat out - so I was looking at modern but not slack geo. Considered the Orange Clockwork 137 / Vitus Sentier / Sondor Transmitter and ruled out the slacker staff like the Nukeproof Scout 275 / Airdrop Bitmap etc.

In the end I went cheap and bought the virus sentier vrx+ as the frame was going cheap on CRC and it looked pretty good. The reach is about 40mm shorter than my fs, the fork travel is 140mm and head angle is 66 degrees. It also has shorter chainstays.

Built up with a Pike / Dt e1900 wheels (650b) / gx 11 speed / guide r brakes / 2.3 ish wide tyres and a 150mm dropper it’s so much fun. I haven’t ridden the fs since the start of December - I only use that for big days out / rocky fast stuff really - all the local flatter pedally stuff is more fun on the hardtail. I’ve even been going out here and then to mess about on local pump tracks / in the local woods just because it’s so much fun.

So personally I’d recommend going a little less extreme on the hardtail if it’s for messing about on. It’ll still do bigger stuff - I did a half day at Flyup 417 with some uplift and some push up - but if it had been a whole day I’d definitely have taken the fs. You do get a battering on rock gardens / drops etc in comparison.

At the moment there are some Orange Clockwork 137 frames going for £300 I think online - could be a good option.

My HT and FS are different geo.
The reach on my HT is shorter by about 25mm and the HA is slacker on the HT.
I feel comfortable switching between the two bikes.

Worth remembering that, because there isn’t any sag in the rear of a hardtail, the same HA will feel steeper on a HT than and FS due to only the fork compressing

This is very important...my last 2 hardtails have felt way to steep for this reason and I have ended up getting rid. If I get another it will have to be a good 2 degrees slacker than my Full susser.

You haven't said why you want an HT at al (given that you enjoy your FS). That would probably have a bearing. If you want a HT for "something different" then make it different. If it's just to save the FS from the worst of the winter then make it similar. Although there is probably a debate to be had there over whether you really need to "save" a FS from the crap and whether a HT is really significantly less complex anyway.

Of course, you might just want something new and shiny. In which case, just buy whatever lights your candle.

Hardtail tends to get ridden round local trails

What are they like?

TBH generally use the HT to avoid the crap destroying the bearings on the FS too quickly. My current HT is a carbon 456 with 140 forks on. It just feels small after time on the FS but guess it is more playful.....
My local trails are short sharp tech for a few seconds or short flowy descent and quick climb back up - there’s not too much ascent and no really long descending

TBH generally use the HT to avoid the crap destroying the bearings on the FS too quickly.

I know what you mean and I tend to go even further (riding a rigid fatbike in the slop) but I do wonder whether it is necessary. The worst you will do is wear out a few cheap bearings a bit quicker I think. Maybe an extra service on the rear shock every now and then. Nothing that gets close to the cost of a new bike. But new bikes are always fun 🙂

The lure of new shiny is hard to resist

My FS bike is a Knolly Fugitive, and my HT is a Pipedream Moxie. Pretty similar geometry and purpose. I save the FS for good conditions when I am descending hard, and ride the HT when it's wet, or I just feel like riding a HT. I would have little use for a more XC biased HT and it would just gather dust. If I take out the Moxie I don't feel like I'm missing our somehow. If you are going to ride the HT on different trails than the FS, then it makes sense to go more XC, but I don't.

I've found it easier to swap between them if they're similar. You need to compare them sagged or they won't make much sense, because hardtails get a fair bit longer but steeper and a little lower when sagged, whilst full-sus bikes get a little shorter and slacker and a lot lower.

I'm on a 2017 Banshee Spitfire (large) with a 160mm fork and a Bird Zero AM (medium) with a 150mm fork. The Spitfire is a bit longer and a bit slacker, which suits its ability to carry more speed in the rough but there's not that much in it.

Im still not convinced that a steeper headangle really makes the bike that much faster, well not enough to justify the loss in technical ability.

For me the hardtail is about having something a little cheaper which i care less about, also mine is lighter and runs faster tyres so its better for bigger less technical rides

"Im still not convinced that a steeper headangle really makes the bike that much faster, well not enough to justify the loss in technical ability."

What do you mean by "a steeper head angle makes the bike faster"? Downhill steeper bikes are slower, uphill it's all about your legs!

My fs is a 140mm travel 29er, not full on lls but built burly and for ‘playing around. Weighs nearly 15kg.
My hard tail is a carbon xc 29er with 100 forks, weighs just under 10kg.
They are both very different bikes for very different purposes but that means they both get used whereas when I had a burly hard tail I rarely used it.

pedalling obviously :p
I don’t see how a steep head angle makes the bike pedal much better

I tried having a true xc bike but found most the speed came from the tyres and overall weight

I cannot see any super lightweight slack hardtails yet though 🙁

You are going to ride a hardtail differently though. The back is going to be skipping about the place more, your legs are going to get tireder sooner on descents so you are going to take mitigating action for that. And other stuff.

“pedalling obviously :p
I don’t see how a steep head angle makes the bike pedal much better”

It doesn’t! It’s a steep SEAT angle that does.

“I cannot see any super lightweight slack hardtails yet though 🙁”

The thing is, make a hardtail good enough at descending via a slack head angle, long reach and long wheelbase, you then have something which invariably people want to put a big fork on. So you have to make the frame strong enough to withstand the fork leverage, and handle being ridden very fast in rough terrain, with no rear suspension to mitigate the loads. And if it’s being ridden hard it needs to be reasonably crash proof.

There are some slacker XC bikes out there though. If you have deep pockets Unno have a 29er hardtail with a 67 deg HA, whose frame weighs only 790g.

Not sure if it counts as 'super lightweight' but I have a Titanium 'hardcore' hardtail build planned out based on a XL Kingdom Vendetta LS frame (1900g), with Hope brakes, headset & BB, 150mm Revelations, 1600g wheels, magic mary/hans dampf 2.35, carbon bar & stem, xx1 cranks, dropper and GX/X01 eagle groupset, which comes out at under 25lbs/about 11kg.

64 HA (static), 486 reach, 1235 wheelbase, so nice and long/slack. With a bit of weight weeny thinking (and a load more money) it could go close to 23lbs.

My old Prince Albert hardtail was quite old school geometry compared to my Aeris and it always took me a bit of adjusting riding style/technique between the two bikes, and I never felt as confident hitting harder features on the shorter, steeper, longer stemed PA. I looked around for a hardtail with more similar geo and handling to the Aeris and ended up with a Bird Zero AM. The Zero has 13mm less reach, 26mm more stack and the same unasgged head angle (which obviously steepens at sag) and I have found that close enough to switch between bikes with little adjustment on my part and feel at home straight away. I set the Zero up with 5mm shorter stem and 20mm wider bars as that's what I had spare. The bars have remained (so far, not sure they will) but the stem has since been swapped out for a 40mm to match the Aeris and it feels better for that. The Zero with a higher stack is running less spacers under the stem. Having now measured the BB to end of grip distance both bikes are within 5mm of each other, which probably helps them to feel similar.

Yes both bikes have similar intentions, but that suits what I tend to ride. I'm more likely favour the hardtail on shorter rides, night rides, wet rides, or just tamer rides but it's not a hard and fast rule my mood will come into it too.

My take on it, FS all year round, it's the bike I love riding, it's faster on everything except fire road climbs, and the bearing costs are nil due to SC's free bearings for life (My lbs doesn't charge me labour for this, YMMV).

Even if I had to pay £100 a year for bearings, as I did on my old SB66, it'd be nowhere near the north of 2 grand I'd need to spend on a HT 'for the slop'.

“The Zero has 13mm less reach, 26mm more stack and the same unasgged head angle“

Once you’re on the hardtail, the stack will decrease and the reach increase, as the fork sags at the front but the rear doesn’t move.

I went through a similar thing after I got my Spitfire - my old Cotic Soul started feeling way too short, tall and steep. Ended up with a Zero AM too, the original one just when they launched it.

Once you’re on the hardtail, the stack will decrease and the reach increase, as the fork sags at the front but the rear doesn’t move.

Yeah I get that, and it does bring the real world figures closer together. And also why I like the BB to grip measurement, it doesn't change with sag.

I'm also on the old non-boost AM. Interchangeable wheels with my MK1.5 Aeris. In fact interchangeable everything. I even made sure the brake hose are cut to the same length.

Worth remembering that, because there isn’t any sag in the rear of a hardtail, the same HA will feel steeper on a HT than and FS due to only the fork compressing

Also, steep seat angles on full sus bikes are to compensate for the fork extending/rear suspension sitting down when climbing.

The original idea of my Hardtail was for it to be sufficiently different that I'd choose to ride it over the 150/140 full sus but the reality has been I keep mud tyres on it and gets used through the shitty bits of winter. I'm just about to swap out the 120mm 32mm Revelation for a 140mm Pike as I'm riding it on a lot of the same trails and trying to keep up with people still riding sus bikes.

Picking different lines (when I remember to) makes familar trails interesting again but as soon as it's dry I'm back on full sus

Even if I had to pay £100 a year for bearings, as I did on my old SB66, it’d be nowhere near the north of 2 grand I’d need to spend on a HT ‘for the slop

For me it's not just a financial decision. I like having a hatdtail. Though the comfort of a full suspension doesn't go amiss at my age.

I'll more likely to lean towards the hatdtail on night and wet rides because they tend to be shorter (see above re comfort) and I'm less likely to be on the limit full charging. So it's a good opportunity to mix it up and add variety by riding the hatdtail when I don't necessarily need all the get out of jail safety net of the big bike.

And n+1 🙂

This happened to me in reverse.

I bought a long, low, slack, hardtail that completely ruined the feel of my full suspension bike even though it had fancy bits on it and was worth about double. It felt tall and jittery and like I was going over the bars at any minute. I had to get a long low slack full suspension bike just so I was happy with the right feel. That's the perfect excuse for a new bike right there.

Obviously the full suspension bike is much more capable on the rough stuff but actually I ride both bikes on similar terrain largely on what I fancy, with the FS bike being used for the faster, dryer, rockier rides when speeds are up and trail buzz through your backbone and legs makes your vision blurrry on the hardtail, irrespective of how well you can use your legs.