My old xc bike is faster than my newer full suss :(

danlightbulb

Hi all.

Ive posted recently about my Boardman Pro FS bike (27.5", 140mm front, 130mm rear, 14.3kg) feeling draggy on the trails. I thought it might have been the weight or tyres so I bought some new tyres and went tubeless. Im very impressed with the new tyres and it has helped a little I think and certainly made it feel better on the descents.

However yesterday I took my old Rockrider 8.1 hardtail (26", 100mm front, 12.8kg) out for a ride on the same trails. I got Strava PBs on some of the climbs without even really trying. It was loads faster, for considerably less perceived effort, on the flat singletrack and climbs. I could accelerate it far better and maintain momentum far better.

I am running considerably higher gearing on the Rockrider as well. 32-32 (2x9) is my lowest gear on that bike compared to 32-42 (1x11) on the Boardman. Despite this, my physical effort on the climbs felt easier and my legs were not running out of steam anywhere near as fast as on the Boardman. On the Boardman I am forced to sit and spin in lowest gear most of the time because my legs are done in trying to push a harder gear on it.

The downside was on the descents where the steeper angle of the Rockrider was noticeable and made it a bit sketchy on some steeper sections of the trail. I dropped the chain as well on a rocky section which never happens on the Boardman.

So Im left with a dilemma now. I enjoy hitting descents fast and securely but i also really enjoyed being able to maintain momentum on the flat and climbs yesterday on the xc bike. The trails I ride are a mix of features. How do I get the best of both?

danlightbulb

I wouldn't mind if I was slower on the FS if it didn't feel so draggy and hard to pedal. Its frustrating to be pedalling along in 1st gear all the time and having to grind out climbs at no faster than walking pace. As soon as I go up a gear, I grind to a halt.

I thought it may have been a fitness issue hence why i decided to take my old XC bike out yesterday and see what the difference was. In a substantially harder lowest gear I was able to sustain momentum without my legs going to jelly so its not a fitness issue I don't think.

On the Boardman it has a climbing position on the shock which stiffens up the travel. It doesn't have a full lockout on the shock. Other than that I already have the sag and rebound set appropriately.

The full suss is way more comfortable and way more capable on the descents but the draggyness of the climbs and flat singletrack is really frustrating me lately. I just grind to a halt too easily on it, and when I try to push harder my legs go to jelly too easily. This just didn't happen yesterday on the XC bike.

Do I have any options for improving this without sacrificing much downhill capability?

whyamihere

It's not really a surprise that the XC bike is faster on XC trails. The full sus should be a lot more capable going downhill though, which should mean you can go faster and have more fun when the trail points downhill once you're used to the bike. Everything in mountain biking is a compromise - For a bike to be capable of going faster downhill you generally have to sacrifice climbing speed, and vice versa. The good thing you have now is that you have options - If you're on a less technical ride where climbing speed is more important (maybe a race if you want to do one), ride the Rockrider. One a more technical ride where you want to enjoy the downhills more, ride the Boardman and don't worry too much about climbing speed.

danlightbulb

oxoman said:

My Anthem is 2x10 so I can replicate the gear ratios I had on my old hardtail very easily. Your riding 1x11 with bigger jumps between ratio,s so you will suffer. My brother has a 1x11 trance and suffers the same issue with gearing as you. He's seriously considering going to a 2x set up to increase his speed on some stuff he does and reduce the big jumps inbetween gear ratios.

I wouldn't want to go 2x because then I introduce chain dropping issues, a problem I experienced yesterday on the Rockrider but have never had once on the Boardman.

My Rockrider used to have 3x9 gearing it but I dropped the granny ring as never used it. So the lowest gear is 32-32 (ratio of 1). The second lowest gear is a ratio of 32-28 (1.14).

On the Boardman my lowest gear is 32-42 (0.76) and the second lowest gear is 32-36 (0.89) and the third gear is 32-32 (1).

So on paper the Boardman does not seem to have an issue. Why can I push a ratio of 1 to 1.14 on the Rockrider with what felt like relative ease, yet on the Boardman if I go into second cog 0.89 I simply grind to a halt on the climbs? That is what is frustrating me so much. Is it simply the extra 1.5kg? Or is it the suspension sucking up all my pedal power?

fenix

The heavier FS is obviously going to be tougher on the climbs. Why do you think people obsess over getting the lightest and stiffest bikes for climbing ?

I'd think it's both the weight and the suspension that's slowing you down but that's the price for the faster descending.

danlightbulb

So are there any improvements I can make to my Boardman to make it climb better? I was looking into changing the wheels recently but it would only save a few hundred grams. Ive already gone tubeless.

If not, what bike would offer me better climbing without sacrificing too much on the descents? The Rockrider is an old school XC bike really, what about a modern XC full suss? I could potentially build a bike up from scratch.

I know I probably don't need another bike but the draggyness on the climbs and flats is really frustrating me lately. If I did buy another bike I would have to force myself to alternate between them both to make sure I got the use out of them.

danlightbulb

oxoman said:

I've never dropped a chain yet on my Anthem 2x on the trail and it gets used way beyond its intended XC use. Rear mech clutch is all I rely on.

Im not convinced my problem is caused by the gearing jumps though. I find the Boardman hard to pedal up some climbs in 1st gear (0.76) whereas I got up the same climbs yesterday on the Rockrider in a significantly higher gear (1.0). I really noticed the difference in the ability to accelerate the bike, even when going uphill, and the ability to maintain the momentum of the bike once travelling at a certain speed.

danlightbulb

oxoman said:

Maybe worth looking at playing with rear suspension settings to get a happy medium. My rear shock has the old CTD lever system and I have it dialled in so it's constantly on Trail. Not sure if the boardman has similar to play with.

It has a fully open or a half open setting. I do switch to the half open setting on the climbs and it makes a difference. Other than that I have nowhere else to go with it.


Is it worth replacing the shock for one which has full lockout? Would that make a noticeable difference to climbing or will the weight still be the overriding factor?

The current shock is a Rockshox Monarch RT Debonair 190x51mm. It has a open and a pedal mode which stiffens the shock but does not lock it out completely. The alternative could be the Monarch RT3 which has a full lock as well as pedal and open modes.

danlightbulb

Modern XC bikes do seem to have more aggressive geometry than they used to. Short travel c.100mm front and rear with 68 degree head angles, chunky rims and tyres, 1x12 gearing, and dropper posts. The only difference between one of those types of bikes and mine would be the travel and the weight - these bikes seem to come in around 10-11 kg depending on the price. They seem very expensive though - they are more expensive than trail/enduro bikes.

Or even a modern XC hardtail now seems to have 68 degree head angles, through axles and 1x12 gearing as well. I'm not sure its a good idea for me to go back to a hardtail though, the trails I ride are very rough.


Or - could I change the rear shock for one which locks out fully? Would that help things noticeably do you think? Or is the weight difference still going to be the overriding factor? The current shock is a Rockshox Monarch RT Debonair, 190-51 size.

danlightbulb

The other thing Ive just noticed is the difference in stiffness between the two bikes in the drivetrain. If I backpedal the pedals on the Rockrider with my hand, they are noticeably easier to turn than on the Boardman. I don't know how this could be, but could there be something wrong with the drivetrain on the Boardman somehow so there is too much friction in the drivetrain? Or is it the clutch rear mech that adds that stiffness?

steve_sordy

Don't forget that your wheel diameter and your crank length is also part of your gearing. Normally this is not an issue when you only have one bike. But when you have two different bikes then it does matter.

If your bikes both had the same gearing, the 27.5" wheeled bike would feel harder to accelerate than the 26er. If the cranks were different lengths, the shorter crank would feel harder.

Then there are the tyres. This has been done to death elsewhere; but wider, stickier and chunkier rubber, and lower tyre pressure will all feel harder to ride uphill.

Rear suspension bob robs you of energy. If the suspension design (like the Horst link for ex) does not minimise this, then pedalling smoothly from a seated position instead of hero heaving up the hill will give great benefits. Shock designers are aware of energy-sucking pedal bob and often add a firm setting that damps out suspension bob. But for me, it is the last resort and I almost never use it.

Ask someone to ride behind you on your FS and watch to see how much your saddle is bobbing up and down and give you a running commentary. Try different things to see if you can minimise bobbing.

Body position is another one to watch. Recently, bikes have been produced with steeper seatpost angles (74-75 deg) that put your weight further forward. This is designed to assist steep technical climbing and shouldn't be a feature on grinding up a smooth slope. But as soon as you bum comes off the saddle, seatpost angle becomes irrelevant anyway.

When climbing technical slopes, the rear suspension comes into its own and will generate contact with the trail more of the time, driving you forward.

danlightbulb

Hi Steve. I have learnt to control the bobbing somewhat and I have a relatively smooth pedal motion I think, and you're right that on very technical climbs its better have the suspension available and that's what I do. I climb seated 99% of the time.

The issue for me is the long slog climbs. I've tried to describe the problem but I think its hard to describe properly.

Put simply I really struggle to accelerate the bike and maintain its momentum - and therefore on a climb I rarely get out of 1st gear which is no more than walking pace. It is so energy sapping, that if I try and push 2nd gear or higher, after maybe 10 to 30 seconds my legs have gone and I have to drop back into 1st and spin the rest of the way.

Now I can ride the whole trail this way no problem, but it doesn't feel enjoyable.

On a flat section I also struggle to push above a certain gear as I can feel the energy sapping out of my legs. This means my momentum is not maintained on flat sections either and upon encountering a slight incline I end up dropping gears to prevent stalling, which lowers my pace even more and so on until I eventually end up back in first gear.

As I said above, I thought it might be a fitness issue but upon switching back to my old XC bike, its obvious its not. Not only was I faster on the climbs and flat sections, but that was in a harder gear as well and I felt like I could always push a little harder and get more speed - my legs did not give up on me at all.

What I'm struggling to determine is whether this is down to the weight difference between the bikes, or the geometry, or the suspension sapping up my power.

I notice there is a new breed of bikes out now which didn't really exist before. They seem to have the suspension travel and weight of a lightweight XC bike of yesteryear but with modern geometry, stiffness of components and gearing setups. Eg this one:

https://www.scott-sports.com/gb/en/product/scott-spark-rc-900-team-red-bike

It looks like a really capable XC trail bike cross. Its only 11.5kg (claimed) with 100mm travel but has all the geometry, stiffness, gearing of a trail bike. But its very expensive. A bit like how expensive trail bikes or enduro bikes were a few years ago when they first started getting popular.

I'm not sure what to do. I enjoy riding the Boardman on the descents but I don't enjoy climbing with it. Cannock is hardly very steep either - it won't be fun taking this bike somewhere like Coed-Y-Brenin with its monstrous climbs. I can't really use my Rockrider either - its too old school XC to cope with modern trails - I'll be over the bars on it in no time - my skills on the descents have outgrown that bike now.

reaperactual

I struggled for a while with climbing on my new bike but didn't know why my quads ached as soon as I started climbing and struggled to keep up with my Buddies.

Looked up and followed the 109% rule method on YouTube and realised my saddle was too low so raised it by around 40mm felt instantly better. Problem solved.

danlightbulb

reaperactual said:

I struggled for a while with climbing on my new bike but didn't know why my quads ached as soon as I started climbing and struggled to keep up with my Buddies.

Looked up and followed the 109% rule method on YouTube and realised my saddle was too low so raised it by around 40mm felt instantly better. Problem solved.

Hi thanks for your suggestion. I've always set my saddle using the heel method and can generally tell if I'm not getting full stretch when pedalling but I just checked out the 109% method and followed it to check - my saddle height was correct.

reaperactual

😎 Worth a shot Pal! 👍

danlightbulb

I've just measured my rear shock pressure and it was lower than expected at only about 170psi. Despite this it was still showing me 25% sag. I just upped the pressure to 250psi and its still showing me 25% sag.

I wonder if this is contributing to the issue. How can I dial in correct pressure if the sag doesn't appear to change?

Also I had a play about with the two settings (pedal and open). The pedal mode stiffens up the shock but there is still alot of movement there. Bobbing up and down on the bike with just my bodyweight easily produces 30% shock compression even in the pedal mode.

A new shock with a full lockout is easily gonna cost me £200 ish so i'd need to be sure it was going to make a difference before trying it. Plus I'd need to find a shock to fit the older imperial standard which is now redundant.

danlightbulb

oxoman said:

Dan, Cannock, Brenin and Llandegla for that matter are no problem for either bike to be honest. I've done all 3 on handrails and xc full sus. Nobody races up the long slogs at any of them and both your bikes are plenty good enough for the rest of the short uphills.

Hi. Yes I know that I can get round all those trails on the Boardman but Im not happy with its climbing pace. It feels so sluggish and I don't like that. It really does sap my energy too. I struggle to keep up with my riding buddies on the Boardman (but had no problem keeping up with them on the Rockrider and was even pushing them harder at times).

Im just not happy with how sluggish it is on the climbs and want to improve that.

danlightbulb

oxoman said:

Having ridden a Boardman full sus I'm surprised tbh, might be worth looking at how you've set up the shocks pressure wise. Stupid question, but when you set your shock pressure / sag up were you kitted up as you would be on the trail. I used to set up mine as I was until it was pointed out that 3 litre hydration pack, repair kit / bottle can add another 3 plus kg. Made a big difference to me.

I am wondering this myself now after just messing about with the bike for a bit. I had it set to about 25% sag which is on the firm side of the recommended 25-30% range. I just checked the pressure and it was only about 170psi though which is lower than I'd originally set it to.

So I've upped the pressure to 220psi and checked the sag again - still showing 25%.

Then I chucked my backpack on with a 2l water bottle in there to add another 3kg - still showing only slightly higher than 25%, obviously the sag gauge is not too accurate to read off.

So I'm not sure whats going on here but somehow the shock is being sticky and showing around 25% sag no matter what the actual pressure is.

Also I noticed there is still a good 20% movement on the shock when in pedal mode.

The way the bike feels on the climbs - with it feeling so energy sapping if I try and push hard - it could well be the suspension sucking up all my pedalling effort. If for some reason that sag measurement is not right and my pressure of 170psi was far too low, then that could be the reason. I'll need to ride it at 220psi now and see how it feels.

The Rookie

Get someone to measure sag while you're on the bike, its hard to not move the shock in it's travel when getting off, plus you want the damping open so it settles properly. Don't forget that when you attach the shock pump you loose pressure straight away in filling the pump from the air chamber.

As noted above, your FS is 27.5 and your RR 26" wheel, so just for that you need to multiply the gearing on the FS by 27/26 (a 27.5 wheel is 27" on the same determination that makes a 26") or add 0.04 (as a rule of thumb on ratios around 1). Plus if you have wider (larger rolling radius) tyres you have to factor that in as well.

I like strong pedal support for climbing, when I first rode my T129 it had a basic Monarch on and climbing was a chore, I now have an RP23 which is much much better. I came from a very lightweight (sub 10kg) XC FS bike with a fifth element shock which also had a strong platform. Sitting and spinning effectively means circa 90rpm, not many riders 60rpm.

From the specs a Pro has a Monarch RT, so you have a single threshold (pedal platform) setting, there should be a small sticker on the shock telling you which of hard/med/soft (from he stock offerings) Boardman specified for your bike.

danlightbulb

@The Rookie If changing the shock to a full lockout version or some other better version is a viable option then Id definately consider it.

The current shock is a Monarch RT debonair 190x51 fitting size. The sticker on the shock says:
-M
-then a little open padlock symbol with L3 on it
-then a dash (-) symbol
-then a closed padlock with the numbers 320 underneath

The Rookie

The M is medium rebound damping.
L3 (low3) is the unlocked compression damping
320 is the lockout compression damping.

From what I can find 320 is the 'soft' pedal platform, 430 is the stiffer one available for the RT although a specialist like TF tuned could possibly have other settings available.

Not sure what you mean by 'full lockout', shocks don't have that, they have the pedal platform/low speed damping, you could try one with an adjustable threshold like the RP23 or Monarch RT3.

A volume spacer in the air can will also tend to give you better support by increasing the spring rate progression.

steve_sordy

This may be helpful for you. It's a link to the Rockshox webpage for your Monarch shock. It provided description and also a link to a set up guide.

https://www.sram.com/en/rockshox/models/rs-mnr-rt3-d2

There is also a specific way to inflate your shock. You can no longer just pump it up and go! See page 19. Observe the graphics on 19 and 20

https://www.servicearchive.sram.com/sites/default/files/techdocs/95.4118.001.000_user_manual_rear_suspension_rev_b.pdf

Once you are sure that your shock has been inflated correctly, then there are the tuning guides to follow. By all means do what Rockshox tell you, as it's a great place to start. But if you have an interest in suspension tuning in general, I can 100% recommend the following guide from Bike Rumour. Download and store.

https://bikerumor.com/2014/10/30/bikerumor-suspension-setup-series-full-series-pdf-free-download/

danlightbulb

The Rookie said:

The M is medium rebound damping.
L3 (low3) is the unlocked compression damping
320 is the lockout compression damping.

From what I can find 320 is the 'soft' pedal platform, 430 is the stiffer one available for the RT although a specialist like TF tuned could possibly have other settings available.

Not sure what you mean by 'full lockout', shocks don't have that, they have the pedal platform/low speed damping, you could try one with an adjustable threshold like the RP23 or Monarch RT3.

A volume spacer in the air can will also tend to give you better support by increasing the spring rate progression.

@The Rookie my understanding was that the shock I have, the RT, has an open mode and a pedal mode. But the RT3 has an open, pedal and 'full' lockout mode. I cant see anything about the RT3 spec that suggests that the pedal threshold is adjustable?

I can only see 430 available in the RL variant of the Monarch which has two modes - open and 'full' lockout - no pedal mode?

I've tried searching for the Fox RP23 but can find none for sale new.


@steve_sordy thanks for the guides. I already cycle the shock when im pumping it up but I was paying attention to the sag not the pressure. That tuning guide looks good i'll take a proper look at it.

danlightbulb

How much difference would I expect to see between operating a shock in pedal mode compared to in a full lockout mode (which I note might still allow a bit of flex)?

Or is it going to come back to the weight again -1.5kg difference between my two bikes - how much difference is that making?

The Rookie

Sorry yes, the RT3 has a fixed threshold my bad.

Yes the RP23 is an older shock, the modern version is the Float DPS 3-position lever.
https://www.ridefox.com/family.php?m=bike&family=float
However the RP23 is a really reliable shock, can be found used for circa £50-80 and even with a full service you get an almost as new shock a lot cheaper.

danlightbulb

You guys were right - my shock was set too low.

Running at 220 psi yesterday was loads better. Used about 80% of the travel so arguably its a little high at 220 but the climbing was better.

It does bob in pedal mode. Sag in pedal mode is about 10-15% with about a 5% bob when pedalling. I can feel that pedalling efficiency being lost a little, compared to my hardtail bike.

So i could do with making a decision now - would I benefit from a shock with a stiffer lockout? Sticking with Rockshox either an RT3 which has 3 modes or an RL which has 2?

steve_sordy

I believe in getting the best out of whatever suspension I've got before I start swapping it out for more expensive kit.

I have had shocks of different makes and complexity. I've had a Fox RP23, I've had a Rockshox Deluxe RT3 and I've had simpler ones. The one I've got right now is a RockShox Deluxe R Debonair. In other words it has a slightly larger air chamber and has low speed rebound damping adjustment only. It has no high speed rebound, no high speed compression damping adjustment and no low speed compression adjustment (the feature you are looking at adding).
I set the sag at 28% for starters (because they all seem to end up there for me in the end). Straight away I was unhappy with how rapidly the shock used up its travel. I never once felt it bottom out though. I was about to open it up and add one or more bottomless tokens when a mate lent me a ShockWiz.

https://www.mbr.co.uk/reviews/tools/quarq-shockwiz-review

I spent two days with the ShockWiz, just on the shock. I ragged the arse off the bike and really put the shock through its paces.

I expected the ShockWiz to tell me that I needed some air spring volume adjustment but not so. It recommended that I add some rebound damping and that was it! (So I'd got it almost right all by myself! ). After my final run the ShockWiz said that baseline psi, air spring ramp, LSR, HSR, LSC, were all OK. It suggested that the HSC should be made less firm. (I can't alter it, but maybe something for the next shock service?) The ShockWiz also reported that potential suspension problems such as Pogoing, Packing, Bottoming, Bobbing, and Bouncing were all OK.

So there was nothing wrong with the shock. I didn't have to tell the ShockWiz what shock I had, all it needed to know was the compression ratio (ratio of the volume of the shock open and fully compressed) which was established at the start of ShockWiz set up.

So I forgot about the shock for 3-4 months. But I later added one token to the air spring to reduce its volume and increased the sag to 30%. I believe that it is noticeably better. It does not use up as much travel, yet is softer over the roots and small rocks.

I have no intention of spending any money on the shock, because I'm happy with its performance. However, after a similar amount of time evaluating the fork, I spent £300 converting the Revelation RC Debonair to a Pike Ultimate by changing the Motion Control damper to the Charger 2.1. I went for the RCT3 not the RC which would have been another £100. It wasn't the extra money, but the fact that the design of the offering for the user was much more complex and I decided to be strictly honest with myself and decided that I was more likely to get value from the RCT3. It is an amazing upgrade!

steve_sordy

danlightbulb said:

You guys were right - my shock was set too low.

Running at 220 psi yesterday was loads better. Used about 80% of the travel so arguably its a little high at 220 but the climbing was better.

It does bob in pedal mode. Sag in pedal mode is about 10-15% with about a 5% bob when pedalling. I can feel that pedalling efficiency being lost a little, compared to my hardtail bike.

So i could do with making a decision now - would I benefit from a shock with a stiffer lockout? Sticking with Rockshox either an RT3 which has 3 modes or an RL which has 2?

I can't believe that you have got this far and only now discovered that the basic sag setting was too low. Yes, I know that new forks and shocks can be a bit sticky, making %sag a bit of a lottery. That is why they are always a starting point. Once you ride the bike, you alter the settings (one end at a time) until you are happy with how it rides. Then after an interval of a month or less, you take a fresh look.

After the time has passed for the newness to have gone, the suspension should be operating at peak. If you are still having problems with stickiness, then I suggest that you do a lower fork service and /or and air can service. There have been reports of forks and shocks with too little/ too much oil inside.

If the %sag is now reliable and you are still having problems with the shock, I recommend that you read the Bike Rumour article I sent you and start adjusting the air spring. There are an amazing number of devices you can buy to fit your shock that can adjust the positive and negative air chambers. These are a lot cheaper than a new shock.

Ref changing the shock: I believe that you may be unhappy with the result. You keep referring to needing a stiffer lockout. I have had shocks with a lever that increases compression damping from Open, through Pedal, to Firm (ie "lockout"), I soon stopped using it except for long climbs up tarmac and even then I believe it was only a psychological boost (but I was having it anyway)!

danlightbulb

I always felt the shock was fine on the descents so never thought to look at the shock for climbing because it had the pedal mode, which I thought overrode the travel anyway.

Alternatively I may have set up the shock right originally then its slowly lost a bit of pressure and Ive not noticed until recently when the bike felt draggy.

It still feels fine on the descents with 50 more psi in so i dont think Im that sensitive to setup on the downhills but am more sensitive to it on the climbing.

If i can feel my pedalling power being lost into the suspension then I dont know what else to do. Clearly the lockout is still allowing some travel - I guess Id just rather it didnt so the bike behaves like a hardtail and all my energy is transfered to motion.