Some fantastic trail rides recently. Well, they’re always fantastic. But currently just a bit better thanks to all the mushrooms and flowers. So much going on! One of several observed on today’s ride; BlackBerry lily, Iris domestica. Also known as leopard lilly.
Firepink seen while riding the creek trail.
Riding a fat bike on a curvy trail through the woods is about the best thing ever.
Back in mid-April, I purchased a Gravity Bullseye Monster (what a terrible name for a bike, I’ll abbreviate as GBEM!) from Bikes Direct. I’d written up a brief initial impressions post after riding it for a week or so. Since that time I’ve shared many photos and various mentions of my fat bike rides but never followed up with a proper review. With my knee problem now (apparently and hopefully) solved I’ve been back on the fatty for a couple weeks of daily trail riding and it occurred to me to check my mileage on the bike: a bit over 2,200. So, yeah, time for a long-term review.
I’ve made no secret of my love for this bike. Truth is, I’d likely love riding any decent fat bike but this is the one I have so it’s what I’ll be writing about. Of the miles I’ve put on the bike I’d estimate that about 55% were road miles, 10% gravel and 35% trail. While many fat bikes are bought for use on snow I bought mine for year-round trail riding. In the late 90’s I’d done a good bit of riding on various mountain bikes, aluminum and steel, most with front shocks. Of course, fat bikes are a relatively new thing and while many people are still riding mountain bikes, I went with fatty for a few reasons:
- The ride felt cushy enough without shocks, including the rear wheel.
- 4” Fat tires are forgiving in a way that 2.5” mountain bike tires are not. Which is to say, they roll over things that a mountain bike tire might catch on.
- The fat tire experience provides for a kind of slow, casual trail ride. Sure, I can go fast, but the fat tire form factor almost suggests a slower ride which appeals to me. Almost like a beach cruiser for the woods!
So, getting on with the review of the GBEM, I’ll get the negatives out of the way first.
This is a budget bike which sells for $499 to $599 so that means it’s got some compromises (actually, I’m cooking up a separate post about budget bikes and direct consumer bikes as compared to the name brand, more expensive bikes found at bike shops). That said, only three specific components really stood out to me as worth mentioning as negatives: the pedals, handlebar and the chain.
I changed the pedals within the first week. Not much to say about the pedals other than they are just cheap pedals fine for a casual ride around the neighborhood or occasional trail ride. It’s assumed many riders will replace the pedals anyway, the stock pedals are there so that it’s a functional bike out of the box. I replaced them with Rock Bros platform pedals which have worked well. They could probably ship with a slightly better, wider plastic composite platform pedal that would work for some people without a change. In fact, these platform pedals are the pedals that ship on the Poseidon X and I’m still using them on that bike with no problem.
The handlebar, 620mm, is really too narrow a bar to be the default. It works but should be a bit wider. But on many new bikes, like the pedals, it is assumed they will be changed by more “serious” riders. I changed it out to an Origin8 Space Off Road II Handlebars. Still, would be nice if they started the bike with a wider handlebar.
The chain included with the GBEM was a fairly cheap chain that should have been replaced at about 1,300 miles. I forgot to check wear until I hit the 2,000 miles mark. I let it go too long and as a result also had to replace the rear cogs too. My bad. I should have started checking for wear at about 1,000 miles. That said, a well cared for, quality chain on a bike that’s not being ridden hard might be expected to last 2,000 miles or more. That was the case for the chain on the Poseidon X which lasted well over 2,000 miles. Oh well. I’ve replaced the chain (a higher quality chain) and cogs and will be sure to stay on top of chain wear this time.
Some nitpicks that don’t affect the ride quality but I think are worth mentioning.
- The stem has a 2 bolt, handlebar clamp size of 25.4, both of which are old standards. More modern stems are 4 bolt attachments and have a clamp size of 31.8. When I upgraded the handlebars I should have also upgraded the stem to the modern standards. Oh well.
- The head tube is not tapered which limits fork upgrades. Not a deal killer as I don’t intend to upgrade my fork but again, worth mentioning for others that might not be aware of the issue.
- The seat post paint scratches off instantly with any kind of adjustments or post movement. Also, no height indicators on the post. It’s a cheap post so not surprising.
- Front wheel foot strike! Common to a lot of these bikes is that when turning the front wheel, you may hit it with the toe of your shoe as you pedal.
That’s it for the specific component related negatives.
The rest is generally positive.
The brakes and drive train have performed fairly well. They were pretty well set out of the box.
The Tektro mechanical brakes are fine for me. They may not have the smooth modulation associated with more expensive hydrolic disc brakes but I suspect they are also easier to maintain. I’ve seen complaints online about the brakes but my hunch is that it’s often the case that buyers either are not adjusting the brakes that need adjusting or they are not given a little time to “bed-in”. These brakes, if properly set, should be able to lock-up the wheel when pulled fully. In that case it’s just a matter of learning how to operate them which is to say, careful modulation by the rider. They may never be as smooth as more expensive brakes but they do stop the bike very quickly if needed.
Moving onto the drivetrain, when I was replacing the cog set and chain I noticed that my rear derailleur hanger was very slightly bent (likely out of the box). I should have looked closer on initial set-up. When I bent it back I was able to change the limit screws a bit. Previously one was maxed out due to the bent hanger. I’d tweaked it when I set it up and didn’t realize the problem was actually the bent hanger. Anyway, the SRAM shifters and X4 rear derailleur have been fine. The Shimano Alivio front derailleur is good too. These are low-mid level components, so, not the best, but not bad. Perhaps heavier and slower to shift but nothing that has bothered me. The SRAM x4 trigger shifters work as expected.
It’s a 2x drive system with a generic crank, 22/32T chain rings and an 11-34T 8 speed cassette. I found this range to be perfect for the mix of riding I do: A bit of road, gravel, trail with short, punchy climbs on the trail. The lowest gear enables me to get up the steepest climb with no problem. For some riders that might have health issues or physical constraints a lower gear might be helpful on the trails but I think this range is good for most. All that said I think I’d prefer a 1x 10 speed on this bike. Similar to the Poseidon X but with a slightly lower gearing. The second chainring on a fat bike seems unnecessary given that it is likely going to be primarily ridden off road.
The WTB saddle, “Speed V Sport” is commonly seen on mountain bikes and fat bikes of this mid-range. It’s a pretty decent seat and I’ve got no complaints other than it’s a bit on the heavy side with a bit too much cushion but it’s a good choice for a starter bike for new cyclists might not ride all the time. I’m currently using the Charge Spoon saddle that I purchased for the Poseidon. The seat post is the same size so it was easy enough to swap it over and I’m used to the Spoon saddle so, why not?
The wheel set is pretty typical at this price range. Hubs and rims are generic and on the heavier side though rims do have weight saving cut-outs. They were true out of the box and have stayed true for 8 months of riding so I’ll consider them fairly durable. They’re not tubeless ready or compatible which is fine with me as I’ve had no problem with tubes and slime. To my knowledge no tube punctures yet. I think the thick rubber of fat tires are pretty durable by default. I’ve ridden over a lot of thorny areas as well as brush-hogged fields full of very woody stems, creek beds with large rocks and no problems. Speaking of tires…
The GBEM comes with Vee Tire Co. Mission Command tires. Durable wire beads and bit heavy but a good overall tire to start with. I rode mine for a few months before I changed to a pair of Maxxis Mammoths. They’re a folding bead which means they’re a bit lighter, more supple with a solid center tread that rolls very well on pavement or trail. Given that I now have the Poseidon X to cover longer road/gravel oriented rides my next set of tires, Maxxis Minions, are more aggressive as I won’t have to worry about the smooth center tread for the little pavement I do on this bike. I’ve found in recent days that a layer of partially frozen sub-soil with a top layer of melted mud really creates an ice-like surface that the Mammoths slip on. I’ll likely post a comparison of these two tires in the near future. I mentioned above that they seem fairly thorn resistant and they should be, they’re expensive. Decent fat bike tires cost $90 for ONE tire. So, $180 (or more) for a pair. Yikes.
A few words about the frame and fork… it’s a 6061 aluminum frame and a cromoly fork. Nothing fancy here. There are lots of attachment points on the frame and fork. One set on the inside of the down tube, one on the outside. 1 set of 3 on each fork leg. That’s 4 possible water bottle cages or anything cages if I wanted to go camping and carry larger items. And plenty of mounting points for fenders or racks. I’d initially planned to skip adding any kind of rack but recently ordered one for the back. I do a lot of trail work and would like to have the option of toting tools out there. Also, it’s just generally convenient to have a rack and bungee cords for picking up packages or transporting anything that won’t fit in a backpack.
The overall bike as recently weighed with the above mentioned parts (no rack yet), was 38.4 lbs and that was with the front fender, bottle cages, water bottle/feeder bags. Which is to say that for a fatty it’s on the mid-upper end of expected weight. I’ll save detailed comparisons to more expensive bikes for a future post but for now I’ll just say that in this price range, a fat bike like the GBEM offers the rider a fairly easy and stable ride on trails that might normally cause problems on bikes with smaller wheels and tires. The fat tires just roll over things such as larger rocks, fallen branches or holes. I think they allow a rider to feel safer and more confident when encountering the things often found on a trail.
Related, another benefit of a fat bike (generally speaking) is the added traction for steep ascents and descents. Whether I’m riding on a gravel road or trail, assuming average conditions, I’m likely to feel like I’ve got good traction on the GBEM. Certain muddy conditions can eventually get a bit slippery but with the large tires a fatbike tends to provide solid footing. I really notice this when riding up steep hills with loose debris on the surface. Whether a loose gravel road or a trail with leaves, sticks, rocks, acorns, etc, a steep slope can often cause enough loss of traction to get you off the bike. The wide contact patch of the GBEM gives me the best chance of slowly peddling up and over these conditions. The steepest portion of my trail is a 13 to 14% grade, rutted hill with roots, leaves and fairly large rocks. It’s not easy but I make it up every time on the GBEM.
What about road riding? Well, a fat bike is definitely not a bike I would buy if I intended to mostly ride the road. Going forward the GBEM will be primarily a trail and gravel bike. That said, I put over 1,000 miles on our county roads in July and it works just fine. It’s heavier and has more rubber on the road than needed but it was much easier than I expected. In fact, when I switched to the much lighter gravel bike with much narrower tires I was surprised that my average speed and effort were not changed all that much! No doubt, the gravel bike is faster with less effort but I expected the difference to be greater than it actually was.
These bikes come 90% assembled. I took it out of the box, removed the packing materials, attached the handlebars, front wheel and pedals. I think that was about it. I checked the shifting and brakes and a quick once over to make sure everything was tight. Removing all the zip-tied packaging took about 20 minutes, the little bit of assembly and check-over took 40 minutes or so. I think most can handle it with the help of YouTube videos for the basics of adjusting derailleurs if need be. If not you can take it into a local bike shop. They’ll assemble and set-up for a fee. If you’re the sort that plans to maintain the bike on your own then you can learn as you need to assuming you don’t already have the skills. If you’re not going to maintain it then take it to a local bike shop as you’ll need to take it there in the future for tune-ups, etc.
As I said at the end of my initial review, I’d have no problem recommending this bike to anyone considering a fat bike. It’s on the heavier side with mid-level components but at 38 lbs it’s still a fairly light and easy ride on the trails. The GBEM sells for $500 to $600 and compares fairly well to bike store brands (Giant, Trek, Specialized, Salsa, Surly)which generally start around $1,500 and weigh in at around 33lbs. I’m working on a future post to compare these two general choices because it’s worth considering before purchasing a bike. That said, I’ll continue to ride my fat bike with no regrets.
A year ago today I got my first bike in 20 years, an electric folding bike, the LectricXP. I’d sold my last two bikes 20 years ago after an aggravated knee injury that didn’t seem to get better. Over the years I would occasionally try a bike ride on a borrowed bike but the discomfort was there every time. When I bought the LectricXP last winter I expected to just use it to ride a mile to visit my folks and check the mail when I wanted something faster than my usual walk. I had no idea that I’d be able to consistently pedal again. The day of this photo I ended up riding a 12 mile round trip to town. The bike did most of the work as I didn’t yet have the confidence that my knee would hold up to much effort. Over the weeks I put in more of the effort and was riding farther, as far as the battery would safely last.
After a month I’d bought a second e-bike, the Rad Rover that had a larger range (45 miles instead of 35) and I was riding nearly every day up to 30 miles. Then 35 miles. Then 40 miles. By March I was trying to pedal as much of my 45 mile rides with little to no assist from the bike for as much of the ride as I could. I rode 800 miles on the Rover in March.
With the Covid virus getting worse my sister started working remotely and began a long-term visit in early April that would end up lasting through the summer. I decided to cut my long county rides short and focus on building some trails to ride closer at hand. As a result, in April I bought the non-powered Gravity Bullseye Monster fat bike. I wasn’t sure I’d be able to ride it unassisted but the Rover had allowed me to build up some confidence. A year ago the idea of riding a bike unassisted wasn’t a thought when I tapped the “buy” button on the Lectric webpage. 50 miles with no assist? I would have rolled on the ground laughing. Or that I would be riding nearly every day week after week? I’m feeling a lot of gratitude for the folks at Lectric and Rad Power Bikes as they got me back peddling on my own again. And for anyone thinking of an electric bike, go for it! That said, if you are healthy enough to pedal on your own, keep at it as much as you are able. There’s no technology better than a bike that I can think of that has made me a happier, healthier person in the course of my life.
It seems weird that in this terrible, bizzaro nightmare of a year I have had perhaps the best year of my previous 20 years thanks to these bikes and the socially distanced life I’ve been living for most of the past 12 years. As the pandemic, social struggles, and related nightmares raged on I’ve been out in the quiet countryside peddling along blissfully. It’s a strange disconnect. Regardless, I’m thankful that my year has been a healthy one.
Alternate post title… Fat Bike, I just can’t quit you!
Alternate alternate post title: I think I fixed my knee discomfort caused by the wide Q-factor of the fatbike!
A couple weeks ago I posted about using the Poseidon X as a trail bike. An update: After a week or two of riding the trails we had several days of rain and hoo-boy does it get tricky on wet, muddy trails. Still, it’s doable and I did it for a couple days. But muddy trails in the cold of winter freeze, re-thaw, freeze and overall don’t tend to dry out. So, while I don’t mind the challenge, the prospect of riding consistently wet, muddy trails for weeks at a time, likely doing damage to the trail that I would have to fix, led me back to the fat bike.
To reiterate, I love the fat bike. It’s a blast to ride and the only reason I was avoiding it was knee discomfort due to the wider stance. So, I made a few more seat adjustments and, I think crucially, decided to try riding with my feet positioned all the way up against the crank. I think the general norm is that you place your foot squarely on the pedal. It occurred to me that if I pulled my feet up closer to, and in contact with the crank arm, I’d be that much closer to the more comfortable riding position I needed for my knees. The Poseidon X has my foot at about 3 1/8” (80mm) away from the seat tube. By comparison, the inside of the pedal on the fat bike is 4” (102mm) away from the seat tube. Putting my feet up against the crank arm has my foot at about 3 1/2” (89mm) away from the seat tube. It’s only a half inch difference but this adjustment seems to have done the trick! That’s the funny thing about bike fitting. Often times it’s just an adjustment of a half inch or an inch, be it seat height, stem length or angle, etc that can make a big difference. This is especially true if you’re doing longer hours on the bike. 30 minutes here and there likely won’t matter much. But 2 to 3 to 4 hours a day, several days a week, well, that’s makes a difference.
It may also be possible to find some different cranks with less of an outward bend and I may look into cranks that are closer to the frame. For now this adjustment to my foot-on-pedal position seems to have done the trick. It’s been about 10 days of riding and the issue has not returned. So happy to be back on this bike!
Since late July I’ve ridden just over 3,000 miles on the Poseidon X. The first 1,500 or so were on the 700c wheel set using 40c WTB Nanos which were an upgrade over the stock 35c stock Kendas that I never rode. The second 1,500 were on the 650b wheels with the Hutchinson Touaregs. I thought I’d offer up a mini-review/comparison of the two tires.
First, the Nanos. I rode them on gravel and pavement, about 30% to 70% respectively. I chose them knowing that I’d be riding at about that ratio and they performed exactly as I’d hoped. They role fairly quietly and well on pavement thanks to the fairly solid center tread. But they have enough knobby structure to do well on gravel and dirt/gravel. When and if I go back to the 700c tires I’ll use those again. If they were made for the 650b wheel size I’d definitely consider them but at the moment they are not. No punctures. I kept them at about 40 to 45psi with tubes so, not a very cushy ride.
The Touaregs, 47c tires, have been excellent on the 650B wheels. Smooth rolling on pavement thanks to the tiny, closely spaced knobs that make up the center tread but grippy enough on gravel that I’ve never felt out of control. Now, to be honest, I tend to be a slow, conservative rider. Not sure how either of these tires would do for more aggressive riding on gravel. In recent days I’ve been doing all my riding close to home which means a mix of trails, gravel and road. My 8 mile loop is about 4 miles trail, 2 miles gravel, and 2 miles of pavement. I’ve been using the Poseidon for much of this riding and while the Touaregs do great on the dry dirt they do slip a bit when it gets wet and they get really squirmy when it get really muddy. There’s just not a lot of tread for the thicker, stickier mud and so they clog up. That said, they tend to shed that mud pretty quickly once ridden on the gravel.
A few other things to note about the Touaregs. Since riding my mixed 8 mile home loop I’ve lowered the pressure down to experiment. I’m not tubeless and was concerned that with lower pressure and bumpy trails I might get some pinch flats. Well, that’s not happened yet and I’ve been running at about 28 to 30psi for days. It’s a fantastic improvement over the 40 I was running on the longer gravel rides. Certainly not fat bike levels of comfort but so much cushier than 40psi. Perhaps with some bigger bumps and more aggressive riding I’d get a pinch puncture but so far it’s not happened.
I have had 2 flats but both of those were large thorns picked up off the side of the trail and I can’t really complain about that!
Final notes about installing Touaregs and flat fixing. The initial installation was difficult! I broke 3 plastic tire levers trying to get them on the rims. They were tight! That said, it might have been poor technique as it’s been awhile since I’ve worked with tight fitting tires. Also, being clincher tires and tubeless ready rims, they’re slightly different in that as they air up they look off kilter until they get about 45psi in them and then they begin to “seat” on the rim. At about 55psi they seat evenly all the way around. Took me awhile to figure out that I had to pump in more air to get them to seat evenly.
With that tight fit I was worried about flat fixing on the roadside. A fatbike or mountain bike tire tends to go on and off pretty easily. The WTB Nanos on the 700c wheels were pretty easy too. The Touaregs took a while. That said I hoped that after riding them for a month they would stretch/loosen up a bit and I think they did. When I got my first thorn puncture popping the tire off and getting it back on was MUCH easier than the initial install.
Also, I think working with clincher tires on tubeless ready rims just requires slightly different technique and experimentation in terms of how the tire seats and how you go about breaking that seal when you need to take the tire back off. Mostly it seems to be a matter of finger strength and really pushing the tire down and away from the inside of the rim. Once the seal is broken in one spot you just work all the way around the tire breaking the seal on that one side.
In putting the tire back into the rim, I tried a technique that was mentioned on a youtube video which was to NOT focus on using the thumbs to get the tire bead back into the rim but to first use the palms of your hands to sort of stretch the whole tire back over the rim. Pushing first with the palms, almost massaging the tire backwards and then using my thumbs to do a final push of the beat over the rim. Using that technique I was able to get 95% of the tire back on and only used the levers for the very last bit. It’s all good now that I’ve done it a couple times.
First, a bit of backstory… I’ve had issues with my left knee since a junior high injury over 3 decades ago. It plays into my bike riding experience and is the reason I stopped riding twenty years ago. My hope is that by being careful my newfound ability ride bikes again will continue for many years but with that hope comes a caution regarding how I ride.
I’ve been riding the Poseidon daily since the last week of July and have put on 2,700 miles of road and gravel riding. This past couple of weeks I decided to stay closer to home and return to some trail riding. Naturally I used this as an excuse to pull the fat bike out of the shed for a ride and what a blast! It’s such a soft, cushy ride! But after three or four days I started to get an occasional tension in my left knee. I’d felt this over the summer too when I rode but was careful and adjusted my seat, riding position and a few other things which reduced the problem somewhat. At least enough to keep riding. Then I started riding the Poseidon X in late July and the problem went away. I didn’t even think about it really. Then I started riding the fat bike and the discomfort returned. Hmmm.
My first thought was to try to figure out if it was the fat bike or the nature of riding trails. So, to test I decided to try riding the trails with the Poseidon. It wasn’t too bad. Not as cushy as the fat bike which also meant taking it a bit slower. I figured if I could manage a few days I might see if the discomfort persisted. If it did I would chalk up the different kind of riding required by the trail to be the problem. Lots of standing then sitting and standing and sitting. And more torque and strain on the many little hills, twists and turns. It’s an over-all slower speed but I think more pressure on the knees. If the problem decreased or disappeared I figured the problem would point to some aspect of riding the fat bike specifically. After three days the discomfort had decreased and nearly disappeared. After an additional two days of riding there was no discomfort at all.
So it seems the problem may be the fat bike and I think I figured out that it is the width of the bike to accommodate the fat tires. Wider hubs, chain stays and, most importantly, a wider bottom bracket which means that the pedals stick out further too. The final result is that my feet are also out to each side a bit further and at somewhat of an angle. In the bike measuring world this is often called Q factor or “stance width” which is the better, more descriptive term. I noticed the difference when I got back on the fat bike after 2,700 miles on the narrower gravel bike. I actually felt it in my legs that my feet were farther apart but it didn’t occur to me that it would be a problem until it was a problem. Bummer because I do love riding that fat bike on these trails.
Okay then, to move onto the question, can a gravel bike, specifically the Poseidon X, be a trail bike? After riding the X on the trails for the past two weeks I’m feeling increasingly confident and comfortable using it as a trail bike. In fact, I have to say that I’m enjoying it more with each ride. Comparing it to the fat bike, it feels more agile and gets going more quickly. It feels faster. The fat bike with it’s heavier wheels requires more effort at the start and overall feels more comfortable but also less lively. In the first few days I rode the X with more caution and a bit slower. With less tire cushion and volume comes an overall bumpier feel especially at higher speed. I’d say that I feel a bit more focused when riding the X though as the days go on I’m increasingly more comfortable riding the trails at higher speeds.
I’m still experimenting with tire pressure, currently keeping it at 30 psi and will discuss further in the upcoming review of the Hutchinson Touareg tires and recently discussed the switch from 700c to 650b wheels. But for now I’ll conclude that trail riding (at least my trails) are very doable on the X with this wheel set and these tires.
Aside from tire volume and width of the tires, another notable difference is that the fat bike has a more upright position with higher handlebars which I prefer for comfort and feel. I was already thinking of changing to a shorter, steeper angled stem on the gravel bike to bring the bars closer and raise them up a bit. So, that’s next on the list.
The Poseidon X comes with 700c wheels with tires that have a width of 35mm. Those tires, Kenda Small Blocks, are pretty knobby so I never even rode them because I have a lot of pavement to get to my gravel rides. I put on WTB Nanos which have a pavement friendly center tread and are 40mm wide. After 1600 miles the tread on the Nanos had worn down quite a bit so I went ahead and ordered a 650b wheel set and some new Hutchinson Touareg 48mm tires that were on sale. I thought I’d offer a brief review of the Nanos and go over the difference in wheel/tire sizes for anyone interested in this kind of cycling.
First, the Nanos. I’ve been running them at about 45psi. They’ve still got some tread after 1600 miles. I could probably ride them another 500 miles so they’ll stay on the wheels and be my back-ups. I don’t expect to put the 700 wheels again anytime soon but the Nanos will be there if I need them. They’re great tires. No flats, fairly low rolling resistance on the pavement, and decent traction on the terrain I’ve been riding. I’d buy them again if I were sticking to that wheel size.
So, what’s the deal with gravel bike wheel sizes? Coming from a road bike heritage gravel bikes have historically been based on road bike wheel and tire sizes but just a bit wider for off road use. So, instead of 25mm wide (and slick), gravel tires are wider, usually 35mm or wider and with much more tread. 700c wheels are also referred to as 29” and are the standard size for road bikes. And worth noting, they are run at very high pressure giving ride that is, in theory, faster and which feels fast given the tiny amount of contact with the pavement. With a road bike you feel the details of the pavement. The idea is that by minimizing the amount of rubber in contact with the pavement there is less rolling resistance to slow you down.
Enter gravel bikes. With gravel roads, dirt and surfaces other than pavement, suddenly more traction is needed and so, wider tires and grippier tread patterns including knobs were created for the 700c wheel size. But that’s just the beginning because riding on surfaces other than pavement means roughness, vibration, discomfort and less stability. A wider tire helps but even better is more tire volume and even more width. 650b wheels are 27.5” and also offer more width for even wider tires so more volume which means even more contact with the road.
Then there’s the recent change in thinking about tire pressure generally which is that less air pressure (even on road bikes) seems to generally allow for not only more comfort but the same speed. A lower pressure tire absorbs road vibration that would otherwise be energy transferred to the whole bike which, in theory, means a loss of energy and speed. Tests seem to back this up.
I’ve had the new 650b wheels and tires on for 1,000 miles now and without a doubt they offer a softer, more comfortable ride. It’s not a huge difference but it’s better. My ride times and average speed have stayed the same. Initially I felt as though I was going slower because it’s a cushier ride but my speed and calories burned are the same so my conclusion is that it’s just a change in how it feels. I’ve been riding the new tires with tubes and kept the pressure at around 40 to 42 psi to avoid pinch flats. Until last week.
Running lower pressure with tubes? In recent years many have switched to tubeless tires. Basically, a specially designed tubeless tire tightly seats into a specially designed tubeless rim and a sealant is added added. This set-up allows for running lower pressure and a more comfortable ride thanks to a more cushy tire. With tubes a certain minimum pressure is required to limit pinch flats which is caused when a large rock, hole or other obstacle causes the wheel and tire to compress together and pinch the tube causing punctures.
I’m not quite ready to go tubeless but since I’m riding closer to home now (always within 3 miles on my current gravel, pavement trail route) I figured I’d experiment with lower pressure. I’ve lowered the psi from 42 down to 30 and without a doubt it’s a huge improvement on the gravel and better on the trail too. I’ve only ridden 4 days at this pressure, no pinch flats yet (I did actually have a flat but it was due to a large thorn and not something caused by the lower pressure). My plan is to continue at about 30 psi for the next week. Then drop to 28 then 26. I’ll spend a week at each to test the comfort, perceived rolling resistance on the pavement and wait to see if I get any pinch flats.
About that thorn… another benefit of tubeless tires is that small punctures caused by thorns or similar objects are generally supposed to seal up on their own. Once the object is removed the sealant seals the hole (assuming it’s not too large a hole). Certainly worth thinking about. But there are also downsides (tubeless can be messy, costly and sometimes difficult to set-up and repair on the road). I’ve not ruled it out but for now will stick with tubes.