Make aero frame more compliant
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Make aero frame more compliant
I have aero frameset that I bought because the vast majority of my rides are solo at a good pace (minimum of 20 MPH / 32 KPH), but the bike is WAY too vertically stiff for someone who has had quite a few serious injuries. The frameset is able to handle at most a 30mm measured width tire. I foolishly bought into the hype that GP5000s were more compliant than GP4000S IIs, so I bought 23mms (I was a bit too obsessed with aero savings!) which have a measured width of 26mm on my Hed Jet 6+ wheels (Internal width 20.7mm), but I'm still getting beaten up out there - worse so than the 25mm GP4000S IIs that I was running previously. I'm 170lbs (77 kg) and am already running 65-70 PSI up front and 75 on the back, so I'm amazed that I haven't had any pinch flats to date. I also run latex tubes. Would going to a 25mm GP5000 really make that much a difference assuming that I'd be running them at 5 PSI less? Last year I tried 25mm Vittoria Corsa G+ tires, and while they were MUCH more compliant, they were also MUCH more prone to cuts. While I don't like the idea of giving up the speed of those GP5000s, I guess the order of importance would be:
1) Comfort
2) Puncture Resistance
3) Speed
4) Durability
Any other recommendations would be appreciated. The saddle is new (tried different saddles), and the shorts are all relatively new. I spend 80% of my time on the hoods, 18% on the drops, 2% on the tops, so I don't think handlebar tape would help, especially since the rear of the bike is where I feel it the most. It has a proprietary seatpost, so that's not an option. I also have a Ritchey Road Logic for a 2nd bike, and the difference in vertical compliance between the 2, even running virtually the same components, including wheels, is huge. I honestly like riding the Ritchey more than the aero bike, and when I'm running the same wheelset, I'm only around 0.5 KPH slower, if that, on the Ritchey than the aero bike as the riding positions are virtually identical. I really should just sell the thing to be honest, but it is the superbike I thought I always wanted being as obsessed with the tech side of things as I am, and I can't seem to accept the idea of selling a Ferrari because, deep down, I like my Toyota Camry more!
1) Comfort
2) Puncture Resistance
3) Speed
4) Durability
Any other recommendations would be appreciated. The saddle is new (tried different saddles), and the shorts are all relatively new. I spend 80% of my time on the hoods, 18% on the drops, 2% on the tops, so I don't think handlebar tape would help, especially since the rear of the bike is where I feel it the most. It has a proprietary seatpost, so that's not an option. I also have a Ritchey Road Logic for a 2nd bike, and the difference in vertical compliance between the 2, even running virtually the same components, including wheels, is huge. I honestly like riding the Ritchey more than the aero bike, and when I'm running the same wheelset, I'm only around 0.5 KPH slower, if that, on the Ritchey than the aero bike as the riding positions are virtually identical. I really should just sell the thing to be honest, but it is the superbike I thought I always wanted being as obsessed with the tech side of things as I am, and I can't seem to accept the idea of selling a Ferrari because, deep down, I like my Toyota Camry more!
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Put 28 mm GP5000 with latex tubes at 60 psi front and 75 rear. Get a Brooks B17. Get carbon bars.
If you still have pain, it is either you or the frame.
If you still have pain, it is either you or the frame.
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#3
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Josh Poertner from Silca has a Marginal Gains podcast and in one of the episodes they discuss vertical compliance. Turns out about 90% of vertical compliance comes from the tires and inflation.
I wish I had known that several years ago. I too had a frame I couldn't hardly stand to ride because it was so stiff. I bought a new fork, new carbon compliant seatpost, new carbon bars. Most of the differences were slight. Then I set the bike up for gravel and I put on 30c tires and looked up the right inflation. I'm at around 200lbs and I finally settled on 58/60 for front/back inflation when I went to tubeless. Amazingly plush ride. Turns out, Silca also has an inflation calculator (go for the advanced version) that came out sometime later and it confirmed my choice of pressures given the road type. Short answer: It wasn't the frame.
Since then, I've had the same experience with my road bike with 28c tires and 25c tires before that. So I'd suggest you look at the inflation pretty hard and see if that doesn't fix the problem. I still think your inflation sounds kind of high to me given your weight.
It could be the frame, but I really doubt it. Unless, of course, you're trying to talk yourself into a new bike. I know the feeling too.....
I wish I had known that several years ago. I too had a frame I couldn't hardly stand to ride because it was so stiff. I bought a new fork, new carbon compliant seatpost, new carbon bars. Most of the differences were slight. Then I set the bike up for gravel and I put on 30c tires and looked up the right inflation. I'm at around 200lbs and I finally settled on 58/60 for front/back inflation when I went to tubeless. Amazingly plush ride. Turns out, Silca also has an inflation calculator (go for the advanced version) that came out sometime later and it confirmed my choice of pressures given the road type. Short answer: It wasn't the frame.
Since then, I've had the same experience with my road bike with 28c tires and 25c tires before that. So I'd suggest you look at the inflation pretty hard and see if that doesn't fix the problem. I still think your inflation sounds kind of high to me given your weight.
It could be the frame, but I really doubt it. Unless, of course, you're trying to talk yourself into a new bike. I know the feeling too.....
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Josh Poertner from Silca has a Marginal Gains podcast and in one of the episodes they discuss vertical compliance. Turns out about 90% of vertical compliance comes from the tires and inflation.
I wish I had known that several years ago. I too had a frame I couldn't hardly stand to ride because it was so stiff. I bought a new fork, new carbon compliant seatpost, new carbon bars. Most of the differences were slight. Then I set the bike up for gravel and I put on 30c tires and looked up the right inflation. I'm at around 200lbs and I finally settled on 58/60 for front/back inflation when I went to tubeless. Amazingly plush ride. Turns out, Silca also has an inflation calculator (go for the advanced version) that came out sometime later and it confirmed my choice of pressures given the road type. Short answer: It wasn't the frame.
Since then, I've had the same experience with my road bike with 28c tires and 25c tires before that. So I'd suggest you look at the inflation pretty hard and see if that doesn't fix the problem. I still think your inflation sounds kind of high to me given your weight.
It could be the frame, but I really doubt it. Unless, of course, you're trying to talk yourself into a new bike. I know the feeling too.....
I wish I had known that several years ago. I too had a frame I couldn't hardly stand to ride because it was so stiff. I bought a new fork, new carbon compliant seatpost, new carbon bars. Most of the differences were slight. Then I set the bike up for gravel and I put on 30c tires and looked up the right inflation. I'm at around 200lbs and I finally settled on 58/60 for front/back inflation when I went to tubeless. Amazingly plush ride. Turns out, Silca also has an inflation calculator (go for the advanced version) that came out sometime later and it confirmed my choice of pressures given the road type. Short answer: It wasn't the frame.
Since then, I've had the same experience with my road bike with 28c tires and 25c tires before that. So I'd suggest you look at the inflation pretty hard and see if that doesn't fix the problem. I still think your inflation sounds kind of high to me given your weight.
It could be the frame, but I really doubt it. Unless, of course, you're trying to talk yourself into a new bike. I know the feeling too.....
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Yep. Assuming your bike fit is dialled in, most of the comfort gains will come from tyres/tubes and tyre pressure. The above advice sounds about right.
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What's the difference in exposed seatpost between the two frames? My bikes (roubaix + Fargo) both have quite a slanted toptube and the exposed s'est post is able to flex a fair amount, resulting in a more compliant rear end
The roubaix is sitting on 28s measuring out to 29F/30R, but even with 25s on I found it quite nice
The roubaix is sitting on 28s measuring out to 29F/30R, but even with 25s on I found it quite nice
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I don't know about the Brooks saddle for an aero bike
but I agree with the 28mm GP5000.

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One of these:
https://redshiftsports.com/products/...uspension-stem
And these:
https://canecreek.com/product/eesilk/
https://redshiftsports.com/products/...uspension-stem
And these:
https://canecreek.com/product/eesilk/
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#9
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Don’t know what your seat post diameter is, but if it’s 27.2 mm, I highly recommend the Ergon CF3 VCLS seatpost. They are quite expensive but provide a significant degree of dampening of both road buzz and major bump vibration. I use this post on two of my stiffest bikes and find it very effective at reducing fatigue without any detectable reduction in power output or pedaling efficiency.
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Don’t know what your seat post diameter is, but if it’s 27.2 mm, I highly recommend the Ergon CF3 VCLS seatpost. They are quite expensive but provide a significant degree of dampening of both road buzz and major bump vibration. I use this post on two of my stiffest bikes and find it very effective at reducing fatigue without any detectable reduction in power output or pedaling efficiency.
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The OP already noted that the bike has a proprietary seatpost. In any event, as almost everyone above has indicated, wider tires/lower pressure. If it's any consolation, the contribution of any given frame to comfort or lack thereof is small. My favorite bike for long-distance riding has an aluminum frame with large-diameter tubing and a straight-blade aluminum fork. I prefer it to all my steel-frame bikes.
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My main issue is neck pain from old injuries. So I'm always looking for tricks to make my older road bikes more tolerable. The widest tires I can squeeze in are 700x25, so that limits my choices.
I use Conti GP Classic skinwalls (700x25 only) with latex tubes on one bike, and Soma Supple Vitesse SL (700x23) on another, and both are remarkably comfortable and durable.
The GP Classics have been terrific. Long wearing, puncture resistant, very good ride, more affordable than the Conti GP 4k and 5k. The GP Classic has a raised center tread strip that seems to wear longer, very comparable to the road tires I rode in the 1970s-'80s. I'm on my second set and haven't worn out a tire yet, although one suffered a cut that would have ruined any tire -- I overlooked a shard of razor thin slate that fell off a construction truck and blended in with the pavement. Sliced through the tread and just barely nicked the fabric puncture shield and tube. I didn't even need to boot the tire but I replaced it anyway.
I've been very surprised by the Soma tires because I expected the SL version to wear out quickly or cut easily. But I got 'em for only $15 each so I wasn't too worried. But a year and a lotta chipseal miles later they're still doing fine and hardly look worn.
The 700x23 tires on my old steel bike which is already pretty comfy. I put 700x25 tires on the carbon fiber bikes which tend to be stiffer. The ride is pretty comparable between the three.
Saddles are a major factor. I've gone through several and settled on a couple of Selle Italias and an older Selle San Marco, all with similar configuration -- pretty flat, narrow (around 130, I think), long nose. The SI Kit Carbonio is fairly minimal but comfortable. The other Selle Italia appears to be influenced by the older Cobb TT/tri-bike saddles -- a bit more padded with a perineum relief cutout -- and perhaps a bit more comfy than my older Cobb saddle.
The 20 year old Selle San Marco is my favorite. Minimal padding but the shell is quite flexible, so it really soaks up the road chatter without being too squishy or flexy, or feeling like I'm losing efficiency through bouncing. The closest I can compare it with is a Selle Anatomica, which I've test ridden on a friend's bike. If I had to pick an all leather saddle, not just leather stretched over a plastic shell, I'd go for the Selle Anatomica. The only potential drawback is the hammock-type ride, which might hinder scooting around on the saddle. I do tend to scoot back and forth on the saddle to suit the terrain and cadence, so I'm not sure whether I'd feel limited by a hammock saddle.
And heavily padded bar wrap. Sometimes I'll first wrap the bar with strips cut from old inner tubes, then wrap around that with good bar wrap from Arundel or comparable stuff.
Bike fit is a big deal. I mostly use the Bike Fit Adviser videos on YouTube as a guide. I tweak my bike fit as needed to accommodate how I feel. I already do physical therapy but over time I've needed to adapt the bike to my body rather than the other way 'round. I have stems ranging from 90mm-120mm, compact handlebars with shorter reach and older bars with longer reach and deeper drop, etc. Often a fairly small change in reach and height can make a big difference in neck comfort.
I use Conti GP Classic skinwalls (700x25 only) with latex tubes on one bike, and Soma Supple Vitesse SL (700x23) on another, and both are remarkably comfortable and durable.
The GP Classics have been terrific. Long wearing, puncture resistant, very good ride, more affordable than the Conti GP 4k and 5k. The GP Classic has a raised center tread strip that seems to wear longer, very comparable to the road tires I rode in the 1970s-'80s. I'm on my second set and haven't worn out a tire yet, although one suffered a cut that would have ruined any tire -- I overlooked a shard of razor thin slate that fell off a construction truck and blended in with the pavement. Sliced through the tread and just barely nicked the fabric puncture shield and tube. I didn't even need to boot the tire but I replaced it anyway.
I've been very surprised by the Soma tires because I expected the SL version to wear out quickly or cut easily. But I got 'em for only $15 each so I wasn't too worried. But a year and a lotta chipseal miles later they're still doing fine and hardly look worn.
The 700x23 tires on my old steel bike which is already pretty comfy. I put 700x25 tires on the carbon fiber bikes which tend to be stiffer. The ride is pretty comparable between the three.
Saddles are a major factor. I've gone through several and settled on a couple of Selle Italias and an older Selle San Marco, all with similar configuration -- pretty flat, narrow (around 130, I think), long nose. The SI Kit Carbonio is fairly minimal but comfortable. The other Selle Italia appears to be influenced by the older Cobb TT/tri-bike saddles -- a bit more padded with a perineum relief cutout -- and perhaps a bit more comfy than my older Cobb saddle.
The 20 year old Selle San Marco is my favorite. Minimal padding but the shell is quite flexible, so it really soaks up the road chatter without being too squishy or flexy, or feeling like I'm losing efficiency through bouncing. The closest I can compare it with is a Selle Anatomica, which I've test ridden on a friend's bike. If I had to pick an all leather saddle, not just leather stretched over a plastic shell, I'd go for the Selle Anatomica. The only potential drawback is the hammock-type ride, which might hinder scooting around on the saddle. I do tend to scoot back and forth on the saddle to suit the terrain and cadence, so I'm not sure whether I'd feel limited by a hammock saddle.
And heavily padded bar wrap. Sometimes I'll first wrap the bar with strips cut from old inner tubes, then wrap around that with good bar wrap from Arundel or comparable stuff.
Bike fit is a big deal. I mostly use the Bike Fit Adviser videos on YouTube as a guide. I tweak my bike fit as needed to accommodate how I feel. I already do physical therapy but over time I've needed to adapt the bike to my body rather than the other way 'round. I have stems ranging from 90mm-120mm, compact handlebars with shorter reach and older bars with longer reach and deeper drop, etc. Often a fairly small change in reach and height can make a big difference in neck comfort.
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I totally agree with the seatpost being an important part of vertical compliance, but this is unfortunately an aero frame with a proprietary aero seatpost, so I don't believe I have an option there. There is about 18cm of seatpost above the top tube. The seatpost has virtually no compliance. When I look at the carbon seatpost on the Ritchey, I can visibly see it move when I put weight on it, but the aero seatpost on the F10 has zero movement. I remember when I had a Thomson seatpost on my titanium (R.I.P.) frame and swapped it out with a carbon Ritchey seatpost, there was a HUGE difference in vertical compliance.
As for the Brooks saddle, I ride in a pretty aggressive position and prefer a healthy cutout, especially toward the front of the saddle, so I don't THINK it would work based on pictures I've seen. I've also blown way too much money on saddles recently trying to find the perfect fit, so I'm a little hesitant to keep experimenting. My latest saddles were Selle SMPs (Evolution and F20), which weren't cheap and have a good amount of compliance, but even though they are for people with a narrow pelvis, I STILL get a bit of thigh rubbing, even after repositioning my cleats to get a bit more Q-factor. I'm currently using a San Marco Aspide Open-Fit narrow saddle, which is pretty close fit-wise, although I probably should have opted for a flatter saddle. I tried an Arione with a cutout, but there wasn't enough of a cutout on the front of the saddle.
I wouldn't be able to fit 28mm GP5000 tires on my Hed + rims (either my Jet 6+ or Ardennes+) since the internal width is 20.7mm. 23mm Gp5000s swell to 26mm actual width. 25mm GP5000s would PROBABLY swell to 28mm (25mm GP4000IIs measured 29mm on these wheels), and the absolute most I can fit between the chainstays is 30mm, so I THINK a 28mm GP5000 would be too wide.
I'm surprised by the comment that running 65-70 PSI up front / 75 PSI on the back on a set of 23mm tires (26mm actual width) for someone whose body weight is 170lbs / 77kg (6 feet tall / 183 cm) is too much pressure. Is that really the case? I thought I was pushing the limits of pinch flats, although I've had none to date. I run latex-tubed clinchers - had bad, messy experiences with tubeless! Also, another person recommended 28mm tires at 60 PSI front / 75 PSI back, which is only 5 PSI less up front, and the same on the back. I've always wondered if you ran an identical tire pressure with 2 different width tires, 23mm vs 28mm in this case, would they absorb bumps equally, or would the wider tire be more compliant? A 28mm GP5000 probably wouldn't fit in this case, but just wondering.
A carbon handlebar definitely helps with compliance, but the front end of the bike isn't much less compliant than the Ritchey Road Logic - it's the rear that gives me problems, likely because of the seatpost, so up until now I've kept the aluminum bars on there since I love the shape of them with their super-short reach (65mm) and narrow profile (38mm).
As for the Brooks saddle, I ride in a pretty aggressive position and prefer a healthy cutout, especially toward the front of the saddle, so I don't THINK it would work based on pictures I've seen. I've also blown way too much money on saddles recently trying to find the perfect fit, so I'm a little hesitant to keep experimenting. My latest saddles were Selle SMPs (Evolution and F20), which weren't cheap and have a good amount of compliance, but even though they are for people with a narrow pelvis, I STILL get a bit of thigh rubbing, even after repositioning my cleats to get a bit more Q-factor. I'm currently using a San Marco Aspide Open-Fit narrow saddle, which is pretty close fit-wise, although I probably should have opted for a flatter saddle. I tried an Arione with a cutout, but there wasn't enough of a cutout on the front of the saddle.
I wouldn't be able to fit 28mm GP5000 tires on my Hed + rims (either my Jet 6+ or Ardennes+) since the internal width is 20.7mm. 23mm Gp5000s swell to 26mm actual width. 25mm GP5000s would PROBABLY swell to 28mm (25mm GP4000IIs measured 29mm on these wheels), and the absolute most I can fit between the chainstays is 30mm, so I THINK a 28mm GP5000 would be too wide.
I'm surprised by the comment that running 65-70 PSI up front / 75 PSI on the back on a set of 23mm tires (26mm actual width) for someone whose body weight is 170lbs / 77kg (6 feet tall / 183 cm) is too much pressure. Is that really the case? I thought I was pushing the limits of pinch flats, although I've had none to date. I run latex-tubed clinchers - had bad, messy experiences with tubeless! Also, another person recommended 28mm tires at 60 PSI front / 75 PSI back, which is only 5 PSI less up front, and the same on the back. I've always wondered if you ran an identical tire pressure with 2 different width tires, 23mm vs 28mm in this case, would they absorb bumps equally, or would the wider tire be more compliant? A 28mm GP5000 probably wouldn't fit in this case, but just wondering.
A carbon handlebar definitely helps with compliance, but the front end of the bike isn't much less compliant than the Ritchey Road Logic - it's the rear that gives me problems, likely because of the seatpost, so up until now I've kept the aluminum bars on there since I love the shape of them with their super-short reach (65mm) and narrow profile (38mm).
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Keep the 23 on the front for aero, it won't affect the ride as much as the tyre under your bum.
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Since a compliant seat post is not an option, how about this Rinsten Spring thingamajig?
The reviewer says it works.
The reviewer says it works.

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Ride, Rest, Repeat

Last edited by terrymorse; 07-01-21 at 02:16 PM.
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Ew. Add 400g to the top of the bike, or put on a lighter seatpost with more flex, hmmm
Whoops, misread. Extend a grinding bit and hollow out your post
Whoops, misread. Extend a grinding bit and hollow out your post

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I have aero frameset that I bought because the vast majority of my rides are solo at a good pace (minimum of 20 MPH / 32 KPH), but the bike is WAY too vertically stiff for someone who has had quite a few serious injuries. The frameset is able to handle at most a 30mm measured width tire. I foolishly bought into the hype that GP5000s were more compliant than GP4000S IIs, so I bought 23mms (I was a bit too obsessed with aero savings!) which have a measured width of 26mm on my Hed Jet 6+ wheels (Internal width 20.7mm), but I'm still getting beaten up out there - worse so than the 25mm GP4000S IIs that I was running previously. ... I really should just sell the thing to be honest, but it is the superbike I thought I always wanted being as obsessed with the tech side of things as I am, and I can't seem to accept the idea of selling a Ferrari because, deep down, I like my Toyota Camry more!
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Kind of ironic how wider rims have made tyres of a given size get smaller

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I agree - the tires will likely have the biggest impact. But...
Don't ignore fit. I don't have any discomfort on my (apparently very uncomfortable looking) setup - high saddle, slammed stem, etc. But I did create an issue a couple years ago. I read that the pros (see where this is going?) angle their saddles down 3-6 degrees to accommodate that large saddle to bar drop. I thought "I have a large saddle to bar drop" and quickly got on board. I nudged the nose of the saddle down maybe 3 or 4 degree. Holy $&@* did that ruin the ride. Wrists, hands... I was really surprised how those few degrees transformed the ride.
Punchline: If you haven't yet, make sure your fit isn't the culprit before throwing parts at the problem.
Don't ignore fit. I don't have any discomfort on my (apparently very uncomfortable looking) setup - high saddle, slammed stem, etc. But I did create an issue a couple years ago. I read that the pros (see where this is going?) angle their saddles down 3-6 degrees to accommodate that large saddle to bar drop. I thought "I have a large saddle to bar drop" and quickly got on board. I nudged the nose of the saddle down maybe 3 or 4 degree. Holy $&@* did that ruin the ride. Wrists, hands... I was really surprised how those few degrees transformed the ride.
Punchline: If you haven't yet, make sure your fit isn't the culprit before throwing parts at the problem.
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#20
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Josh Poertner from Silca has a Marginal Gains podcast and in one of the episodes they discuss vertical compliance. Turns out about 90% of vertical compliance comes from the tires and inflation.
I wish I had known that several years ago. I too had a frame I couldn't hardly stand to ride because it was so stiff. I bought a new fork, new carbon compliant seatpost, new carbon bars. Most of the differences were slight. Then I set the bike up for gravel and I put on 30c tires and looked up the right inflation. I'm at around 200lbs and I finally settled on 58/60 for front/back inflation when I went to tubeless. Amazingly plush ride. Turns out, Silca also has an inflation calculator (go for the advanced version) that came out sometime later and it confirmed my choice of pressures given the road type. Short answer: It wasn't the frame.
Since then, I've had the same experience with my road bike with 28c tires and 25c tires before that. So I'd suggest you look at the inflation pretty hard and see if that doesn't fix the problem. I still think your inflation sounds kind of high to me given your weight.
It could be the frame, but I really doubt it. Unless, of course, you're trying to talk yourself into a new bike. I know the feeling too.....
I wish I had known that several years ago. I too had a frame I couldn't hardly stand to ride because it was so stiff. I bought a new fork, new carbon compliant seatpost, new carbon bars. Most of the differences were slight. Then I set the bike up for gravel and I put on 30c tires and looked up the right inflation. I'm at around 200lbs and I finally settled on 58/60 for front/back inflation when I went to tubeless. Amazingly plush ride. Turns out, Silca also has an inflation calculator (go for the advanced version) that came out sometime later and it confirmed my choice of pressures given the road type. Short answer: It wasn't the frame.
Since then, I've had the same experience with my road bike with 28c tires and 25c tires before that. So I'd suggest you look at the inflation pretty hard and see if that doesn't fix the problem. I still think your inflation sounds kind of high to me given your weight.
It could be the frame, but I really doubt it. Unless, of course, you're trying to talk yourself into a new bike. I know the feeling too.....
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Sounds like you would be better off with an aero frame with more tyre clearance. Something like the new Factor Ostro with 32 mm clearance and a slightly less stiff looking aero seatpost. Or go for max comfort with a Spesh Roubaix. It’s actually a pretty aero bike these days.
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But I did create an issue a couple years ago. I read that the pros (see where this is going?) angle their saddles down 3-6 degrees to accommodate that large saddle to bar drop. I thought "I have a large saddle to bar drop" and quickly got on board. I nudged the nose of the saddle down maybe 3 or 4 degree. Holy $&@* did that ruin the ride. Wrists, hands... I was really surprised how those few degrees transformed the ride.
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I
I'm surprised by the comment that running 65-70 PSI up front / 75 PSI on the back on a set of 23mm tires (26mm actual width) for someone whose body weight is 170lbs / 77kg (6 feet tall / 183 cm) is too much pressure. Is that really the case? I thought I was pushing the limits of pinch flats, although I've had none to date. I run latex-tubed clinchers - had bad, messy experiences with tubeless! Also, another person recommended 28mm tires at 60 PSI front / 75 PSI back, which is only 5 PSI less up front, and the same on the back. I've always wondered if you ran an identical tire pressure with 2 different width tires, 23mm vs 28mm in this case, would they absorb bumps equally, or would the wider tire be more compliant? A 28mm GP5000 probably wouldn't fit in this case, but just wondering.
I'm surprised by the comment that running 65-70 PSI up front / 75 PSI on the back on a set of 23mm tires (26mm actual width) for someone whose body weight is 170lbs / 77kg (6 feet tall / 183 cm) is too much pressure. Is that really the case? I thought I was pushing the limits of pinch flats, although I've had none to date. I run latex-tubed clinchers - had bad, messy experiences with tubeless! Also, another person recommended 28mm tires at 60 PSI front / 75 PSI back, which is only 5 PSI less up front, and the same on the back. I've always wondered if you ran an identical tire pressure with 2 different width tires, 23mm vs 28mm in this case, would they absorb bumps equally, or would the wider tire be more compliant? A 28mm GP5000 probably wouldn't fit in this case, but just wondering.
When Zipp was trying to get carbon wheels right for the cobbles in the Spring Classics, they kept shattering rims no matter what the pressure. Then they hooked up all their pumps to a manifold with a calibrated gauge and they found the pump gauges were as much as 12psi off. That was the difference and from then on they could accurately vary inflation and not destroy rims. Things then made sense.
5psi at 60psi is 8.3% and 7% at 70. 5psi is going to make a difference. If your pump was off by 8-10psi you’d be no where near where you thought you were and if erring on the side of reading too low, you would have a very stiff ride.
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