The lure of the new Reverb
10/05/25 21:59 Filed in: Gear
My Slash has a full AXS Flight Attendant group on it. Which includes the rather short-drop 170mm Reverb A1 version dropper (the longest they made in A1 version). In contrast, I have a 200mm drop Reverb C1 (latest version, hydraulic activation) on my Ripley, which is close to the longest drop I could fit in it and the seat is _so_ out of the way when dropped I am not sure more would be of any use in practice. Back to my wireless dropper. The new AXS Reverb drops up to 250mm. That's a whopper of a dropper.
I can definitely bump the seat at times on steeper or rougher trails. I'm very likely to "upgrade" to the new B1 AXS Reverb in around a 200mm drop. Might squeeze the 225mm drop into the bike, might not - have to measure before the posts come into stock and can be ordered. The "plan" at the moment is to head to Whistler in August and the Slash will be going, so a longer dropper would help out on some of the techy trails I'm liable to ride.
Integrating a new wireless post into the bike is simple - remove seat, remove post, insert post, install seat, re-pair all the components, ride.
The new Reverb is air-only. No hydraulic circuit. Apparently uses 600psi in the skinny posts (30.9 and 31.8) and a 'meagre' 450psi in the phat 34.9 post I need. I know I don't have a 450psi shock pump to refill that air chamber. I'm sure they'll be a thing once these posts go up for sale.
I can definitely bump the seat at times on steeper or rougher trails. I'm very likely to "upgrade" to the new B1 AXS Reverb in around a 200mm drop. Might squeeze the 225mm drop into the bike, might not - have to measure before the posts come into stock and can be ordered. The "plan" at the moment is to head to Whistler in August and the Slash will be going, so a longer dropper would help out on some of the techy trails I'm liable to ride.
Integrating a new wireless post into the bike is simple - remove seat, remove post, insert post, install seat, re-pair all the components, ride.
The new Reverb is air-only. No hydraulic circuit. Apparently uses 600psi in the skinny posts (30.9 and 31.8) and a 'meagre' 450psi in the phat 34.9 post I need. I know I don't have a 450psi shock pump to refill that air chamber. I'm sure they'll be a thing once these posts go up for sale.
What's different in a modern MTB?
02/05/25 22:35 Filed in: Gear
Why you should have a modern MTB.
I've encountered a lot of very casual mountain bikers. They like to ride, but it isn't a priority for them and so they have a bike they bought about 10 years ago. It still works OK. Why not ride it?
Well, there is no compelling reason not to ride it, except that you might just have a lot more fun on a new one. Let me explain.
Over the past ten years mountain bike geometry has changed a LOT. Longer. Lower. Slacker. Longer reach. Longer wheelbase. Lower bottom bracket. Slacker head tube angle. The result of these changes is a bike that is much easier to point through corners (they almost steer themselves), with higher stability. They climb a bit better. The descend a bit better. They send riders over the bars less often. They try to wheelie less.
A couple of other things have changed in that period too. Rims got wider. Seat posts got mechanised. Those wider rims provide vastly better tyre support than skinny rims ever could. They allow lower tyre pressure and still the tyre is supported in side loads - meaning you can run lower pressure, get better grip (and lower rolling resistance) and still have better rim protection than you had on the skinny rim (fewer rim dents). The dropper post has now become part of all but the least expensive bikes. In fact, the dropper post drove the adoption of the longer, lower and slacker geometry, because they really do not work as well for actual people with the seat at full height. There's your big compromise, if you move to a modern bike with a dropper post, you need to drop the post in order to ride it at its best.
Mountain bikes have also become heavier in the real world. Brakes that work. Wide rims. Fatter tyres. Dropper posts. Wider bars. Longer travel suspension systems. All add weight. And you know what? Unless you are racing up a steep climb, it doesn't matter at all. The weight of the bike has so little impact on climbing prowess as to be almost unimportant. Even XC pros are using wider rims, dropper post and full suspension bikes now (in stark contrast to a few years ago) because the overall package is faster and funner than going old school. It requires adding about 5 kg to a bike to slow a big climb by one minute. One minute is heaps in racing, but insignificant in a social ride.
I've encountered a lot of very casual mountain bikers. They like to ride, but it isn't a priority for them and so they have a bike they bought about 10 years ago. It still works OK. Why not ride it?
Well, there is no compelling reason not to ride it, except that you might just have a lot more fun on a new one. Let me explain.
Over the past ten years mountain bike geometry has changed a LOT. Longer. Lower. Slacker. Longer reach. Longer wheelbase. Lower bottom bracket. Slacker head tube angle. The result of these changes is a bike that is much easier to point through corners (they almost steer themselves), with higher stability. They climb a bit better. The descend a bit better. They send riders over the bars less often. They try to wheelie less.
A couple of other things have changed in that period too. Rims got wider. Seat posts got mechanised. Those wider rims provide vastly better tyre support than skinny rims ever could. They allow lower tyre pressure and still the tyre is supported in side loads - meaning you can run lower pressure, get better grip (and lower rolling resistance) and still have better rim protection than you had on the skinny rim (fewer rim dents). The dropper post has now become part of all but the least expensive bikes. In fact, the dropper post drove the adoption of the longer, lower and slacker geometry, because they really do not work as well for actual people with the seat at full height. There's your big compromise, if you move to a modern bike with a dropper post, you need to drop the post in order to ride it at its best.
Mountain bikes have also become heavier in the real world. Brakes that work. Wide rims. Fatter tyres. Dropper posts. Wider bars. Longer travel suspension systems. All add weight. And you know what? Unless you are racing up a steep climb, it doesn't matter at all. The weight of the bike has so little impact on climbing prowess as to be almost unimportant. Even XC pros are using wider rims, dropper post and full suspension bikes now (in stark contrast to a few years ago) because the overall package is faster and funner than going old school. It requires adding about 5 kg to a bike to slow a big climb by one minute. One minute is heaps in racing, but insignificant in a social ride.
How long do knicks last?
25/04/25 23:55 Filed in: Gear
That seems like a pretty simple question, but it proves to have a very complex answer.
I've been considering the answer for some time now. And I feel no more prepared to answer the question than when I began.
By the time the fabric is thin and see-through, they are long past their use-by date. On some of my older bibs the end came when the straps stopped being so stretchy - if they can't stay up then they aren't fit to wear. On others, it was the gripper elastic around the leg opening that perished first. My newest shorts were purchased for commuting to work and now have approximately 125 trips through the washing machine on each one. My race shorts from the same brand have the same pad in them, and worn back to back the less worn race pair either seem a little firmer in the padding, or no difference (I think it depends on the day more than which particular shorts that are being compared). The back-to-back wearing thing is what I do with my cycling shoes to decide when they are worn, as long as the current shoe feels similar to the unused new shoe, they can keep going. It seems easy with shoes and hard with shorts.
I don't believe the end comes strictly from numbers of wash cycles - time in the saddle also contributes. And in the case of my commuting shorts, they've had comparatively few miles. At 30ish km per day and 125 days, that's approaching 4000 km. Where I could find a mileage for top quality shorts, it was around double that. But neither is it just mileage - each washing is also contributing to the demise. If I did 100 km per outing, then I'd have no quandary around saying "worn out". Because 12,000 km is on the far side of everyone's line. If 50 km is typical and 8000 km is worn, then that's 160 washing cycles.
By neither distance nor washing can I definitively state that these shorts are worn out. I don't want to drag them past their end, that doesn't look, feel or perform best. Neither do I want to abandon them before they are ready to be abandoned. That's wasteful and expensive.
Like I wrote at the beginning, I still don't know the answer.
I've been considering the answer for some time now. And I feel no more prepared to answer the question than when I began.
By the time the fabric is thin and see-through, they are long past their use-by date. On some of my older bibs the end came when the straps stopped being so stretchy - if they can't stay up then they aren't fit to wear. On others, it was the gripper elastic around the leg opening that perished first. My newest shorts were purchased for commuting to work and now have approximately 125 trips through the washing machine on each one. My race shorts from the same brand have the same pad in them, and worn back to back the less worn race pair either seem a little firmer in the padding, or no difference (I think it depends on the day more than which particular shorts that are being compared). The back-to-back wearing thing is what I do with my cycling shoes to decide when they are worn, as long as the current shoe feels similar to the unused new shoe, they can keep going. It seems easy with shoes and hard with shorts.
I don't believe the end comes strictly from numbers of wash cycles - time in the saddle also contributes. And in the case of my commuting shorts, they've had comparatively few miles. At 30ish km per day and 125 days, that's approaching 4000 km. Where I could find a mileage for top quality shorts, it was around double that. But neither is it just mileage - each washing is also contributing to the demise. If I did 100 km per outing, then I'd have no quandary around saying "worn out". Because 12,000 km is on the far side of everyone's line. If 50 km is typical and 8000 km is worn, then that's 160 washing cycles.
By neither distance nor washing can I definitively state that these shorts are worn out. I don't want to drag them past their end, that doesn't look, feel or perform best. Neither do I want to abandon them before they are ready to be abandoned. That's wasteful and expensive.
Like I wrote at the beginning, I still don't know the answer.
How wide will road tyres get?
20/04/25 18:42 Filed in: Gear
Remember the adage: all things being equal, the wider tyre has lower rolling resistance. Also remember the corollary: Things are never equal.
What are you supposed to make of those two statements?
Every time you move up one size of tyre, from a 20 mm to a 23 mm to a 25 mm to a 28 mm to a 30 mm, the amount that tyre has to distort to make contact with the road decreases. If the thickness of the rubber and the carcass of the tyre are identical across all the sizes, then each step sees a reduction in energy losses. Within one model of tyre it would extremely unusual for all those sizes to be offered. And if several were on offer, the larger ones tend to have a thicker layer of rubber on top, or (sometimes and) a heavier carcass. Both of which increase rolling resistance.
And then there is the matter of aerodynamic resistance. If all of those tyres are put on the same wheel, then only one can be optimally aero, and all the others are less slippery.
No matter what, increased size brings increased weight. The wider rim necessary to provide good support and good aero efficiency to the wider tyre also adds weight and complexity.
Rolling resistance is always important on a bicycle with so little power to motivate the bike, but aero resistance becomes key from around 20 kmh upwards. By 40 kmh the aero factor is so great you can almost forget about rolling resistance.
Wider tyres operate at lower pressures with lower rolling resistance when used on wider rims, but add mass and aero drag (especially when we exceed the optimal tyre size for a given rim). Increasing size reduces one aspect but increases the other aspect. Our optimum then depends on the bike's velocity.
All of that is a way of saying that they cannot become too wide or weight/aero will suffer more than rolling resistance can gain for a net loss in speed. I think that limit has to be somewhere around 30mm tyres.
There is also the question of what feels "good" too, but I haven't ridden enough good, fat tyres to know what to expect from a 30 mm racing tyre. My 28 mm tubeless training tyres surprise me by feeling quite sharp (neither heavy nor slow). But I know the measured rolling resistance puts them well behind a good racy 25 mm tyre.
Perhaps that 30ish mm limit is a temporary one? As technology improves the wider tyres could surpass the narrower ones. Regardless, the practical limit can be observed by looking at motorbikes. The biggest and most powerful litre sport bikes use about a 120 mm front tyre. Those have 150x the power of a bicycle on tap. We never need go there. Even a low powered sport bike has nearly the same front tyre - a 100 or 110 mm section. These tyres are dictated by mass (of the bike & rider combo) more than anything else.
Footnote: looks like the UCI will step in and rule a max size for road bikes. Like the minimum mass they specified around 30 years ago, if they do it will hang around a long time.
What are you supposed to make of those two statements?
Every time you move up one size of tyre, from a 20 mm to a 23 mm to a 25 mm to a 28 mm to a 30 mm, the amount that tyre has to distort to make contact with the road decreases. If the thickness of the rubber and the carcass of the tyre are identical across all the sizes, then each step sees a reduction in energy losses. Within one model of tyre it would extremely unusual for all those sizes to be offered. And if several were on offer, the larger ones tend to have a thicker layer of rubber on top, or (sometimes and) a heavier carcass. Both of which increase rolling resistance.
And then there is the matter of aerodynamic resistance. If all of those tyres are put on the same wheel, then only one can be optimally aero, and all the others are less slippery.
No matter what, increased size brings increased weight. The wider rim necessary to provide good support and good aero efficiency to the wider tyre also adds weight and complexity.
Rolling resistance is always important on a bicycle with so little power to motivate the bike, but aero resistance becomes key from around 20 kmh upwards. By 40 kmh the aero factor is so great you can almost forget about rolling resistance.
Wider tyres operate at lower pressures with lower rolling resistance when used on wider rims, but add mass and aero drag (especially when we exceed the optimal tyre size for a given rim). Increasing size reduces one aspect but increases the other aspect. Our optimum then depends on the bike's velocity.
All of that is a way of saying that they cannot become too wide or weight/aero will suffer more than rolling resistance can gain for a net loss in speed. I think that limit has to be somewhere around 30mm tyres.
There is also the question of what feels "good" too, but I haven't ridden enough good, fat tyres to know what to expect from a 30 mm racing tyre. My 28 mm tubeless training tyres surprise me by feeling quite sharp (neither heavy nor slow). But I know the measured rolling resistance puts them well behind a good racy 25 mm tyre.
Perhaps that 30ish mm limit is a temporary one? As technology improves the wider tyres could surpass the narrower ones. Regardless, the practical limit can be observed by looking at motorbikes. The biggest and most powerful litre sport bikes use about a 120 mm front tyre. Those have 150x the power of a bicycle on tap. We never need go there. Even a low powered sport bike has nearly the same front tyre - a 100 or 110 mm section. These tyres are dictated by mass (of the bike & rider combo) more than anything else.
Footnote: looks like the UCI will step in and rule a max size for road bikes. Like the minimum mass they specified around 30 years ago, if they do it will hang around a long time.
Two sizes of carbon rails
16/04/25 23:01 Filed in: Gear
Why bike industry? Why??
The seatpost that Trek included with my replacement frame - very nice of them too - was the RSL "flexy" carbon post. This ships with 7x10 carbon rail "ears". I discovered that the seat mast that shipped with my original Checkpoint used the same identical ears, but were for 7 mm round rails (ie, metal rails). I quickly put those pieces into play to mount up my Fizik saddle. And a couple of others. None of which I really liked.
Then, as I've noted previously, I tried out some other Bontrager saddles. They use a 7x10 mm oval rail in carbon.
When I decided to try the Ergon saddle, I didn't even consider that the rails might be different. Twenty-five hours of riding and listening to the seatpost head snap over bumps and I had the epiphany while on the bike - the rails are 7x9 mm and therefore too small for the ears. It explains a lot. Tightening does hold the saddle in place, but doesn't feel like it's "tight". And the bottom of the ears touch the actual post - which doesn't seem correct.
I've got the proper ears on order and will report back. Before this epiphany, I was contemplating buying a different post, since I think I like this saddle.
As a side note, I can't believe how expensive these ears are. On the Ergon post (also sold for less money with Canyon branding) they are sold with round rail ears and the 7x9 oval ears are the only other option. Trek sells the RSL post with the 7x10 oval ears installed and will sell you either of the other sizes. All of these things sell for about $60. For two bits of aluminium and a bolt (2 bolts in the Ergon post).
I ask, what was wrong with the 2-bolt post heads that all the lightweight posts used for many years? They could accommodate most any rail size - at worst with longer bolts. I don't feel like these eared posts are any better at retaining or supporting the saddle rails, and in some ways could be worse.
Fingers crossed, the new ears quiet the bike back to pure silence.
The seatpost that Trek included with my replacement frame - very nice of them too - was the RSL "flexy" carbon post. This ships with 7x10 carbon rail "ears". I discovered that the seat mast that shipped with my original Checkpoint used the same identical ears, but were for 7 mm round rails (ie, metal rails). I quickly put those pieces into play to mount up my Fizik saddle. And a couple of others. None of which I really liked.
Then, as I've noted previously, I tried out some other Bontrager saddles. They use a 7x10 mm oval rail in carbon.
When I decided to try the Ergon saddle, I didn't even consider that the rails might be different. Twenty-five hours of riding and listening to the seatpost head snap over bumps and I had the epiphany while on the bike - the rails are 7x9 mm and therefore too small for the ears. It explains a lot. Tightening does hold the saddle in place, but doesn't feel like it's "tight". And the bottom of the ears touch the actual post - which doesn't seem correct.
I've got the proper ears on order and will report back. Before this epiphany, I was contemplating buying a different post, since I think I like this saddle.
As a side note, I can't believe how expensive these ears are. On the Ergon post (also sold for less money with Canyon branding) they are sold with round rail ears and the 7x9 oval ears are the only other option. Trek sells the RSL post with the 7x10 oval ears installed and will sell you either of the other sizes. All of these things sell for about $60. For two bits of aluminium and a bolt (2 bolts in the Ergon post).
I ask, what was wrong with the 2-bolt post heads that all the lightweight posts used for many years? They could accommodate most any rail size - at worst with longer bolts. I don't feel like these eared posts are any better at retaining or supporting the saddle rails, and in some ways could be worse.
Fingers crossed, the new ears quiet the bike back to pure silence.
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