Marathon / XC bike choice - dumb questions.

[patchsurfer]

Long-term roadie just dipped his first toe into this world...

I've just done my first mountain bike race, at the ripe old age of 52 - the whaka 50 in NZ. When I started this journey six months ago, I didn't have a clue what I was looking at. I went with a hardtail - a vitus rapide with xt and a 100mm rockshock sid sl fork - as that was what I've ridden before and something I felt comfortable maintaining and getting ready. It was a killer price for XT and what seems to be a well regarded fork.

Not saying it was an awful choice, and that I couldn't have done more with my fitness, but after the whaka 50 I was pretty beaten up. I'm pondering looking at finding a FS frame suitable to swap my parts from the hardtail onto - something 100mm front and rear.

I've not spent any time on a FS before. How much difference will adding 100mm travel at the rear make to all-day comfort and ability on the technical bits?

[js]

I started off-road, but spent much of my riding time as a roadie, including a few seasons where that was my job. I'm also turning 48 this year, so can hopefully appreciate what you're feeling.

When I returned to off-road riding at 40'ish years old, I was on a hardtail for a few seasons. I recall thinking that nothing I did ever beat me up like a 90 minute mountain bike race - that includes properly racing a half-ironman triathlon (which feels very different to 'doing' a half) or riding 160km with 6000m of climbing in the Alps.

For the last five years, I've been on a FS bike for off-road riding and racing. The difference is quite notable, but I recall still being quite tired after races in the 2019 season. The pandemic gave me space to focus more on off-road riding, which included focused strength training for my upper and lower back. That seems to have made more of a difference than anything else. Now I'm completing marathon races and heading back out to cheer in my friends.

With regards to ability on the technical bits, a newer geometry will be the biggest advantage there. Going to FS likely only helps from a technical sense in that you have slightly better grip on rough climbs and may be less likely to flat on rocky sections if you get a line wrong. Modern geometry helps to ensure that your centre of gravity stays in a place of balance and control while descending or taking on course features.

For my money, 66.5-67.0 is a nice head-angle for XC riding, with a reach about 15-18% longer than your road frame seeming to hit the sweet spot for many.

[patchsurfer]

Thank you very much, that's a super helpful info dump.

[nickf]

I have been racing multi-hour MTB events for years now. FS all the way. I will never race a hartail ever again. When I am 5 hours into a 6hr MTB race I am pretty gassed and might not choose the best lines. FS is forgiving, just sit and pedal. I find that I get more traction and control through technical sections because the rear suspension keeps the rear wheel in contact with the terrain. Excellent grip even on punchy rocky climbs. I am currently on a 2017 Trek Top Fuel, 100mm front and rear. 100mm is the sweet spot for rear suspension travel, takes the edge off without being too squishy. My next bike will be an Ibis Exie 100mm rear and 120mm front.

Depending on the frame you go with make sure the fork offset you have is what the frame was meant for. A lot of the older forks are around 51mm offset, new frames are running 44mm offset forks, a little more slack.

[Kurt1980]

I'm the opposite to you, Patchsurfer. I'm an old school mtber who got in to road only a few years ago. My background is more all round, a bit of DH and general mucking about though, not really into full on XC marathon until the last year.

As the above posters and yourself say, short travel FS all the way. Makes line choice, climbing and descending much easier. It also means you're less beat up over the 6 hours of racing. Every hit and bump is a minor energy suck, and after 6 hours that's a signficant toll.

I just purchased a Specialized Epic. This is the model without the "brain" (look it up), so no weird proprietary shocks. 100mm of travel via flex stays. Really good bike, simple, light, efficient and they were on special so something like that might suit you well. Throw a dropper on there, get some fast rolling tyres with more grip at the front and you're good to go.

You COULD go a hardtail, make it a 29er for sure if so, but short travel FS with lockout feature on the shock will give you the HT advantage when you need it, and FS advantage when you need it. The cost of extra weight is a minor price to pay.

Let me know if you have more questions.

[aer0]

Hey Patchsurfer, I signed up to the forum just so I could reply to you.
I was at the Whaka a few weeks back too, ive done both the 50 and in more recent years moved up to the 100k, I know all the trails in the course very well and have raced them on both hardtail and full sus so I can completely understand your query.
While there is probably nothing wrong with your hardtial for most riding, if you are out there for 3+hours I can understand being a bit beaten up. Especially when you come to the later part of the course and are descending Split Enz in its completely blown out state. That is going to be very taxing on the body.

You will have a lot more fun and feel better on a full suspension bike for sure, no arguement there.
Yes there are some FS frames out there you might be able to pickup to swap to but keep your current componentry the ones that come to mind would be Giant Anthem, Scott Spark (older model) or Specialized Epic.
However one other thing to consider would be to keep your hardtail, maybe as a training bike and get yourslef something that aligns with modern XC.
Most modern XC bikes will be 120mm fork and between 100-120mm rear suspension. The new Scott Spark, Epic Evo, Canyon Lux TR, Orbea Oiz all come to mind.
These will all help you feel more confident on the technical bits too.

Additioanlly there are some tweaks you can make to your hartail to make it more comfortable or compliant on the tech:
Consider higher volume tyres and lower pressures, Aspen 2.4 WT and pop in a vittrora air liner for the rear to enable running lower preassure.
Fork tune, talk to your suspension tech about tweaks to the fork to improve comfort (highly recommend Jono at Suspension lab)
Grips, experement with foam grips lik ESI's or floating grips like revgrips
Saddle, are you getting beaten up by the wrong saddle?
Shoe inserts?