Home Forums Bike Forum Improving rigid MTB comfort

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  • Improving rigid MTB comfort
  • bikesandboots
    Full Member

    Fit a 25mm bar and stem. Try fitting regular chunky grips, not lock-on type.

    I’ll be trying chunky non-lockons first now rather than winged ones. They seem more appropriate for vibration issues.

    Loosen the spokes a turn or two

    That’s a can of worms I don’t want to start messing about with.

    What about a 2.4 front tire and lower psi (22-24) to start?

    Going to try the lower psi in my existing tyres. Bigger tyre is a bit down the order as it means replacing the front mudguard, which is a PITA to make everything fit with the front rack.

    Ritchey Kyote bars and SQLab 30X w/ 15 degree sweep are both known to me, have some compliance, and hugely helped my shoulder and wrist pain.

    Sounds promising, I went for the 30X 12 degree but not fitted them yet.

    Ergon GA3 grips have been very good for wrist and hand numbness, without looking too ergo, for those who care.

    They were the first grip I was going to try, but after this thread I’ll be trying chunky grips first, and then Ergon GS1 (bigger wing) if needed.

    What’s the bike?

    Kona Unit X.

    The forks are really good. I like the alliminium steerer so you don’t have to use a fork bung. I found with my previous rigid carbon fork the headset would come loose.

    The trek 1120 fork comes up for sale on ebay every now and then. The last pair sold for less than £150.

    Might give one a go at that price. They say it’s suspension corrected for 100mm same as mine, but the A2C is 510mm whereas mine is 470mm. All a bit of a PITA due to getting fork, mudguard and rack to fit nicely together though.

    For the OP, i went back Redshift on their development of shorter Shockstop stems

    Great, just done the same so they’re aware there are people out there wanting them to take our money.

    1
    legometeorology
    Free Member

    @bikesandboots, I think that Trek fork would seriously mess with the geometry of a Unit

    40mm longer, plus another 10mm or so as I think you’d need a new lower headset to accomodate the tapered steerer. So that’d probably slacken the HA by 2.5 degrees and raise the BB about 20mm or something.

    Surely with the Unit X fork, you could get a different guard and fit a 29 x 2.6″ or even 2.8″ tyre? The Unit fork clearance is good even with a 29 x 3.0″ in there if I remember rightly

    redthunder
    Free Member

    Suspension 😉

    Gravel Bikes FFS. What will be invented next 😉 … Carpet Biking with extra Baggage.

    bikesandboots
    Full Member

    40mm longer, plus another 10mm or so as I think you’d need a new lower headset to accomodate the tapered steerer. So that’d probably slacken the HA by 2.5 degrees and raise the BB about 20mm or something.

    Yes that would be needed. I wrote the “might give it a go” before I noticed that Kona and Trek disagree on the A2C of a 100mm suspension corrected rigid fork.

    Surely with the Unit X fork, you could get a different guard and fit a 29 x 2.6″ or even 2.8″ tyre? The Unit fork clearance is good even with a 29 x 3.0″ in there if I remember rightly

    Yes, the only reason to replace the fork would be for a more comfortable one.

    gs_triumph
    Full Member

    Drop your seat a little to move your weight off the bars?  Shorter stem to.achive similar?

    Del
    Full Member

    If you’re happy with a shorter a2c there’s tons of choice of carbon forks out there.

    zerocool
    Full Member

    Bigger tyres?  Maybe not fat bike sized but bigger than 2.2 and lower pressures.  Rev Grips, one up or Fasst Flex bars. Ride smoother trails on it.

    2
    jameso
    Full Member

    Bigger tyres… 2.4-2.6 on 30-40mm rims. Makes a big difference and you can still have tyre spec that works in winter, most terrain and conditions. I didn’t get that from B-Plus 2.8-3.0s. 2.4-2.6s run fine on the front at 20PSI.

    Foam+cork mix grips, fixed to the bar with photomount

    Swept bars and a rearward bias riding position, bars close to level with the saddle

    None of this 77 degree seat angle stuff, sit further back

    I have all this but not a flexy fork, not a fan of flex there on MTBs. Still it’s a comfy bike overall, good for anywhere that’s not really rocky or rooty.

    Comfort is like saving weight in that its incremental savings across all components.

    It’s better than that, it more than just adds up – the stacked springs effect means that the whole is greater than the sum of the parts when it comes to flex and comfort. 2 springs of the same rate have half that spring rate when they’re stacked up. I didn’t know about this until a few yrs ago, feels daft in hindsight not to have looked up spring rate calcs before when looking at rigid bike comfort, but the basic effect is simple force and equal opposite reaction stuff.

    bikesandboots
    Full Member

    Redshift said they’re working on a 55mm and 70mm for the end of this year or early next, in case anyone’s interested.

    faustus
    Full Member

    @bikesandboots i also run a Kona Unit X, it’s my only mtb. I’ve been refining the best setup combinations over the past couple of years, and it’s now in a place where it’s comfortable for long rides on all kinds of terrain. Worth saying I still find it a fairly chunky frameset, and it’s not that compliant.

    – The Unit has a fairly low stack, so getting the bars to a comfortable height needs some focus. I’ve found Stooge Moto bars really good for getting higher and having nice sweep (tried SQlabs30x16 which didn’t rise enough), paired with Ergon GE3 grips. The grips are excellent and not too extreme.

    – There’s room to play about with longer forks. I have a pair of carbon exotic forks with a/c of 490mm and they feel much more comfortable the the steel P2s, plus they increase the stack height of the frame a bit.

    – Tyres: 2.6 front and rear mostly, on 30mm rims, sometimes down to 2.35/2.4 when I want more speed on easier terrain. I know it’s a faff with mudguards and rack, but you’ll reap the benefits of a bigger tyres. And tweak pressure downwards until it feels right, small increments make a surprising difference in comfort.

    – as Jameso said, put the saddle back not forward

    bikesandboots
    Full Member

    Drop your seat a little to move your weight off the bars? Shorter stem to.achive similar?

    Probably will try a 40mm stem, but I don’t think a lower saddle will suit my pedal stroke.

    Swept bars and a rearward bias riding position, bars close to level with the saddle

    None of this 77 degree seat angle stuff, sit further back

    – as Jameso said, put the saddle back not forward

    That’s interesting and counter-intuitive, I thought a longer saddle to bar distance would stretch me out and put more weight on my hands. With the saddle central, I was finding myself shifting forward on it like the top tube was too long, so I don’t think this will work. I can try 10mm back if I put a 10mm shorter stem on though.

    Worth saying I still find it a fairly chunky frameset, and it’s not that compliant.

    I was expecting so due to what it’s designed for, despite being steel. That said, I can’t see the frame contributing much to feedback coming straight up the fork into my hands.

    – The Unit has a fairly low stack, so getting the bars to a comfortable height needs some focus. I’ve found Stooge Moto bars really good for getting higher and having nice sweep (tried SQlabs30x16 which didn’t rise enough), paired with Ergon GE3 grips. The grips are excellent and not too extreme.

    Yes, way too low for me in OEM spec with 20mm of spacers and a 15mm riser. I put a 38mm on it straight away, and my new 30X12 bar is the 45mm rise version. Will be trying non-lockon grips now before GA3s.

    Ride smoother trails on it.

    Yes there’s definitely an aspect of this. The bike needs to stay a “gravel” bike, so I’m not putting chunky tyres etc. on it. The riding position encourages me a bit to ride it like a MTB, so taking it easy downhill doesn’t happen naturally.

    1
    jameso
    Full Member

    The thing about putting your saddle back is it moves your centre of gravity back relative to the BB. That’s what really affects the weight your hands have to support, more than the distance from saddle to bar. Matching that with moving the bar / grips some way back might work well too, doesn’t need to be the same distance though.

    The bike needs to stay a “gravel” bike, so I’m not putting chunky tyres etc

    Pretty happy with Terreno 2.25s in summer, on 30mm rims, for mixed terrain gravel plus kind of rides. Would go a size bigger if they made them.

    didnthurt
    Full Member

    I’ve Stooge Moto bars on two bikes (one a Stooge) and in both cases helped move my weight off the bars. They have a nice rise and sweep. They are wide though so might need a trim.

    damascus
    Free Member

    Worth saying I still find it a fairly chunky frameset, and it’s not that compliant.

    I was expecting so due to what it’s designed for, despite being steel. That said, I can’t see the frame contributing much to feedback coming straight up the fork into my hands.

    My friend converted his carbon 456 to a gravel bike. Carbon 29er fork with a 650b front tyre and 26 rear tyre. The frame is incredibly stiff. He gets beat up on technical descents. Some of it is wheel size but it’s mainly the frame.

    Some times you need to accept a bike doesn’t work for you and you need to move on.

    https://www.ebay.co.uk/itm/235208667401?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Cd7FRqvBRTi&sssrc=4429486&ssuid=XQz0tf3FQJC&var=&widget_ver=artemis&media=COPY

    TheBrick
    Free Member

    Foam grips work well.

    VanHalen
    Full Member

    my rigid (singlespeed too!) has plus tyres (2.8s). its the only valid use for plus tyres in existence haha!

    abut 20 psi. comfey enough to ride fast, jumps etc but makes teh flat trails locally interesting.

    I`m baffled why someone would ride rigid offroad with skinny tyres?? makes no sense to me!

    there used to be plenty of fatter (but not full fat) fast rolling tyres out there.

    legometeorology
    Free Member

    I think the unit also got significantly longer and slacker in 2020(?), and the seat angle got steep at the time — 65 deg or something, which is quite steep for a rigid bike

    So a super short stem with the saddle moved back could help

    bikesandboots
    Full Member

    Some times you need to accept a bike doesn’t work for you and you need to move on.

    Agreed, I’m wary of trying everything to make a bike something it can’t be. Hence just a few things to try before I decide whether to accept it as is and amend some of my routes, or swap or N+1.

    bikesandboots
    Full Member

    Went another step down with tyre pressures, to 23 psi front, 26 rear. Made more difference than 29/32 to 26/29 did. Front of the bike feels a lot less lively, and you can feel both ends of the bike bounce a little on bigger (but still relatively small) impacts/landings. My hands now feel fine post-ride.

    Still going to try 12deg bars as I can feel pressure points, and also push-on grips.

    bikesandboots
    Full Member

    The tyre pressures were a huge improvement as I said, but after a few rides I realised it still wasn’t perfect. I think it mostly solved the vibration and shock aspects, but not the weight going through my hands. The softening of the ground in winter probably helped too, and the lower speeds due to slipperiness.

    Tried the SQlab 12deg bar in 45mm rise which was too much backsweep. I could feel the ends digging into my outer palms, the weight not distributed across my hands. I already knew 9/10deg was better than 8 for me, so this confirms it as the sweet spot. Refitted my 9deg 38mm bar for a while to reset my perceptions.

    The small amount of additional rise was good though, so I went looking for a 9deg 31.8mm handlebar with a higher rise. Very few options around (most are 8deg or 35mm only), so I went for the Deity Highside in 50mm (they also do 80mm). This was indeed better so it’s staying on.

    Next experiment was push-on grips. Replaced Gusset S2 lock-ons with Wolf Tooth Karv silicons (round variant). Didn’t want to go for chunky ones straight away so as to avoid changing multiple things at once, these are the same diameter and feel the same to hold. Again these are comfier, didn’t have to move my hands for relief and felt completely fine throughout and after the ride. Also a bit more absorbing of small bumps and broken tarmac. I wasn’t really expecting them to do anything for weight pain as they’re the same shape, more an improvement in absorption due to the softness, but they did both and I guess it’s all related.

    Going to leave it like this for a while now, but I want to try a winged grip at some point. Ergon GS1 or SQlab 710. I wonder if the shape and wing would make up for going back to a lock-on.

    The top of the grips are now 13cm higher than the top middle of the saddle, so unless anyone would recommend it I’m not particularly inclined to try those 80mm bars.

    Northwind
    Full Member

    Exotic’s carbon forks are pretty comfortable ime, also very flexy- you can literalyl see them bending on braking. That helps with comfort in a couple of ways, they transmit less but also they work in some ways like a sort of lateral leaf spring, and that soaks up/redirects a little force. I was never really aware of it when riding but to be fair I’m not generally very aware of fork stiffness after a few minutes. They’re also pretty confidence inspiring- I had some super light super stiff carbon forks and I was always a bit scared of them but I felt very comfy riding hard on the exotics, and Scotroutes has my set still and I think they’re still in use how ever many years on.

    If you can find a set then Crank Bros did a slightly deranged carbon bar, the Cobalt 11, which is 780mm wide, flat, weighs as much as a wet fart and bents like it’s made of rubber. Long discontinued but I absolutely love mine, I had them on a rigid scandal then on my fatbike and they are bloody disconcerting to see bend, but it doesn’t seem to add up to any loss of control.

    jameso
    Full Member

     I think it mostly solved the vibration and shock aspects, but not the weight going through my hands. 

    Did you try a layback post or just sliding the saddle back 10-20mm?

    tall_martin
    Full Member

    Going from 2.3 to 2.6 tyres made a noticeable difference in comfort to me on my hardtail.

    Put 2.6 on the front for grip, then noticed the comfort and went to 2.6 on the back as well.

    I didn’t notice a difference in speed or rolling resistance, but mostly the bike gear used for sub 15 miles sliding round the woods. Bit of rain making the trail change makes quite a difference to speed

    trail_rat
    Free Member

    Has anyone mentioned 29er and modern geometry…

    Old bikes with old geometry are generally crashy in the rough which in turn beats you

    steezysix
    Free Member

    Going to leave it like this for a while now, but I want to try a winged grip at some point. Ergon GS1 or SQlab 710. I wonder if the shape and wing would make up for going back to a lock-on.

    Having switched from silicon push-on grips to the the Ergon GS1 Evo on my Ritchey Kyote bars, I wish I’d done it years ago. The difference is phenomenal, took a few adjustments to get the angles right but I don’t get any hand pain on longer rides now. Much more support on the outside edge of the palm and I don’t have any issues gripping the bars on more technical stuff.

    bikesandboots
    Full Member

    https://www.ebay.co.uk/itm/315030784652?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=lx9ttmvasdq&sssrc=4429486&ssuid=XQz0tf3FQJC&var=&widget_ver=artemis&media=COPY

    Cheers, unfortunately we already established this would mess up the geo.

    Did you try a layback post or just sliding the saddle back 10-20mm?

    I did think about this a few times after you suggested it, but then forgot.

    The bike came with a 20mm layback and I was finding myself sliding forward on the saddle despite it being all the way forward. Also feeling my body bent forward more than I wanted, having to bend my neck to look forward when sat down. So I replaced it with an inline post which was better but still sliding forward. Then I replaced it with a Thomson bent tube layback post fitted back to front giving 16mm of layforward, which solved it.

    The saddle-stem clamp distance is the same as my FS bike now, and the centre of the saddle is 13cm behind the BB (9cm on FS bike). As it came from the factory with the layback post, it would have been 16.6cm behind. I think the most I could try without unsolving my aforementioned issue is an inline (not layback) post, and going down from a 50mm to 40mm stem to compensate (possibly with steering feel effects). Can’t be running a shorter stem than that to compensate for a layback post.

    Has anyone mentioned 29er and modern geometry…

    Old bikes with old geometry are generally crashy in the rough which in turn beats you

    It’s a 29er Kona Unit X. Geo doesn’t seem massively old school for this type of bike.

    sillyoldman
    Full Member

    Low tyre pressure with inserts.

    Relax.

    Don’t slow down unless you have to.

    IMG_8603

    cp
    Full Member

    +1 on the exotic carbon fork. I’ve got a 490mm long version on my 2012 trek superfly. It’s by far the comfiest rigid fork I’ve tried, but it also feels great from a handling point of view.

    (It’s actually the comfiest rigid bike I’ve ridden, the frame is also really nice).

    Mugboo
    Full Member

    If you don’t find an answer, keep your eye out for a cheap fat bike, you can always sell it on if its not up your street.

    Mine was originally used as a hardcore winter hardtail with tyres to suit, a role it performed admirably. These days it wears 4″ Jumbo Jims and is used for the kind of rides that you describe and occasional bike packing. It handles the duties that a gravel bike did but can also be ridden down technical trails when required. Its limitation is down to the tyres as they are sketchy as f*** in the wet. Its the only bike that remains a constant in my life.

    I did used to suffer a bit with my wrists on the FS, I now run carbon One Ups and ESI chunky grips (with a lock on collar to protect the ends) and that has worked for me.

    rone
    Full Member

    All rigid bikes/frames don’t come equal.

    I previously had a titanium frame with carbon forks and plus tyres. Not particularly comfortable. Jarring.

    Couple of years ago upgraded to a Turner Nitrous titanium (similar bike on paper) and went for enve MTN forks instead of any sort of suspension – and this rigid rides really well.  It’s totally at home on rough terrain. Modern geo.

    But big wide bars probably play a big part as a option you could try.

    I only run 2.25 tyres but did have 2.4s.  That just sharpened things up for me.

    So try a better fork and wider bars on a 35mm short stem with chunky grips a la Odi rogue.

    But it won’t overcome the frame obviously.

    damascus
    Free Member

    Cheers, unfortunately we already established this would mess up the geo.

    I’d suggest trying it, seeing how it felt and if it doesn’t work, sell them on, they will keep their value. 

    5lab
    Free Member

    There’s no need for 20psi in a plus tyre unless you’re an absolute unit yourself. 10-15psi in something 2.6ish should work without pinch flats.

    I also don’t think you’ll get any significant comfort gain from any rigid fork. The worst impacts are upright, and the most noodly forks in the world will give less than 1mm in compression compared to 20mm in the tyre any maybe another 20 in the bars

    jameso
    Full Member

    The saddle-stem clamp distance is the same as my FS bike now, and the centre of the saddle is 13cm behind the BB (9cm on FS bike)

    That’s not much set back at all. Probably why you have the feeling of too much weight on your hands when pedalling seated – if you had a saddle height of around 730 to 750mm, 130mm of setback is roughly equivalent to a 79 degree seat tube angle. That will be pitching you fwd and everything else is trying to compensate for it. Even with the factory fitted post it’s a 76 degree angle roughly.

    Just looked up the Unit geo, says 75 degrees on the chart so maybe my 79 degree estimate is 78 in reality, but still, that’s steep for a rigid bike if you’re pedalling in the saddle much of the time. It’s workable but most people would need other adjustments to go with it and you say you’re at the limit of shorter stems / bar backsweep. 

    Maybe the bike is too big / long or is just the wrong geometry for the fit you want? 

    breadcrumb
    Full Member

    I ran a 3″ Chronicle in my 2014 P2 fork. Clearance was tight but never an issue.

    Rolls well for a wide tyre, guards would be a challenge.

    fossy
    Full Member

    I’m trying Ergon GP3’s (Xmas present) for my rigid 90’s MTB to boost comfort (I commute on mixed surfaces on it). Running narrow-ish 2.0 tyres (26″). It will take 2.4’s but not with mudguards.

    legometeorology
    Free Member

    Assuming you haven’t already done this, adding an insert to the front tyre may be the cheapest non-marginal thing to try next

    Rimpact’s are cheap, and should allow you to knock another 2-3 psi off

    I used to run a 29 x 3.0″ Minion up front with a Rimpact at about 11-12 psi (I’m 77-78 kg)

    bikesandboots
    Full Member

    That’s not much set back at all. Probably why you have the feeling of too much weight on your hands when pedalling seated – if you had a saddle height of around 730 to 750mm, 130mm of setback is roughly equivalent to a 79 degree seat tube angle. That will be pitching you fwd and everything else is trying to compensate for it. Even with the factory fitted post it’s a 76 degree angle roughly.

    150mm to the rail centre. Stock it’s 75 deg, or about 73 deg when accounting for the layback post. According to bikegeocalc.com mine is now 76.5 deg.

    Maybe the bike is too big / long or is just the wrong geometry for the fit you want?

    Possibly but it’s really ok now with the 50mm riser and push-on grips.

    It’s the right one according to the size chart (just to eliminate my own opinion for a moment to do a sanity check) – I’m 4cm taller than the min size for M, and 2cm taller than the max height for S, so for this model of bike it should be the right one.

    The fit with the layforward post is almost exactly the same as my full sus, but with the handlebar 40mm higher and 30mm narrower. Not that that makes it right as it’s a different use, but it feels right and familiar.

    The Marin Pine Mountain 2 is about a similar bike. Their sizing puts me on a size M. Stack is 36mm higher and it has a 50mm riser, so if that’s what Marin thinks maybe the 80mm riser bar would be worth a try. Top tube is 10mm longer, but no layback post stock, and 15mm shorter stem, so saddle to bar 25mm shorter than the Kona stock or 10mm shorter than mine. Here they are side by side: https://bikeinsights.com/compare?geometries=61be64c154f86b0020f050da,61be6675d4471a0024e3830a,

    whatyadoinsucka
    Free Member

    lower pressure & wider tyres, carbon bars and comfier grips, front suspension. :0)

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    matt_outandabout
    Full Member

    Maybe the bike is too big / long or is just the wrong geometry for the fit you want?

    This is the conclusion I came to after 3 years on my Merlin. It was not a bad bike, it just did not fit me so well, and in reality was an adapted CX frame and quite ‘old’ road bike thinking geometry. The geometry, as a few testers pointed out, was odd and even more for my body shape/ratio. It took a local bike fit shop to comment how hunched I was on it…

    Stepping onto the Vagabond has shown me how much weigh I had on my hands on the Merlin and how a few mm and a degree or two can radically alter comfort, particularly hands and shoulders.

    It has made me wonder about saving up for a bike fit….

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