The cyclingtips podcast made it pretty clear: the aero benefits are so HUGE that you can basically freewheel up smaller mountains.
2018 PRO thread
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romanmoser
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https://ride.diamondback.com/friction-p ... rivetrains
Sponsored by Sram but could use a 2X etap gear if he wanted
Nice informations frictions , clutch derailleur etc ...
Sponsored by Sram but could use a 2X etap gear if he wanted
Nice informations frictions , clutch derailleur etc ...
I think SRAM made a mistake by pushing a 1x only groupset on a pro road team. I have a 1x crit bike (10spd, no clutch, narrow-wide chainring) and it's perfect for flat or flatt-ish crit racing. Even used it in a crit with a 20 second power climb using an 11-32t. I don't use that bike on a hilly days, it's just not practical.
They should have had paid for 2 bikes, letting the riders praise the 1x in races where it's practical, and not frustrated on days where it's not. Avoid the bad press.
They should have had paid for 2 bikes, letting the riders praise the 1x in races where it's practical, and not frustrated on days where it's not. Avoid the bad press.
most people own one bike, then there are those who try to ride all year long and have some beater for winter. those who can afford few solid bikes are a margin (and often a great source of cheap 2nd hand barely used stuff). I bet smaller teams also try to get by on as little equipment as they can. it makes everything easier and cheaper. the idea of changing a bike for each race is just stupid unless your main sponsors is a bike brand and they just throw stuff at you, perhaps even pay you to use it. more bikes complicates logistics, maintenance, I believe for riders it's not a perfect situation too if they had to switch between totally different bikes.
kkibbler wrote: WW remembers.
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antonioiglesius
- Posts: 290
- Joined: Sat Oct 15, 2016 9:08 pm
Love his daughter's response...
https://www.bbc.com/news/av/uk-44503724 ... ing-record
https://www.bbc.com/news/av/uk-44503724 ... ing-record
Mark Beaumont beats 127-year-old Penny Farthing record
Scots cyclist Mark Beaumont rode 21.92 miles (35.3km) in an hour on the vintage-style bike to beat the 127-year-old British record at Herne Hill Velodrome.
But the Scottish cyclist was 290 yards short of the world record of 22 miles and 150 yards.
Mark holds the record for cycling around the world, which he did in 2017 in 79 days, 44 fewer than the previous record.
Why are chain drops so common on the road, but not in pro XC or MTB events?
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CrankAddictsRich
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The only thing I can think of that might make a difference is the sizes of the various cogs and the relationship to the angle that the chain is coming in. On MTB, the front chain rig is off pretty similar in size, if not smaller than the cogs at the back, where as on the road the front chain ring size would be bigger. I have no idea IF this makes a difference, but agree that it seems to be an issue on the road and not off-road so I'm just trying to think of what is different.
Chain retention should be better on a larger chainring.CrankAddictsRich wrote:The only thing I can think of that might make a difference is the sizes of the various cogs and the relationship to the angle that the chain is coming in. On MTB, the front chain rig is off pretty similar in size, if not smaller than the cogs at the back, where as on the road the front chain ring size would be bigger. I have no idea IF this makes a difference, but agree that it seems to be an issue on the road and not off-road so I'm just trying to think of what is different.
The difference is the clutch RD, IMO.
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Wheel speed possibly? There's a hell of a lot of stored energy in a cassette spinning at 60km/h. This was basically the only way I would ever drop chains without a clutch - stopping pedalling at high speed, conserved momentum in the cassette causes the chain to slack off on the topside much more than it does at low speed so the chain is more likely to miss its pickup on the chainring.
I think it's probably exacerbated by a dodgy freehub, but even in a 100% functional system there's stored energy - when you stop pedalling the freehub doesn't release from the wheel instantly, it has to slow down and as it does that it loosens the top half of the chain where a clutch doesn't really help. It's probably unnoticeable in lower gears with low speed. At 50kmh with a heavier, wide range cassette maybe it's enough to throw the chain from time to time?
I guess the cassette and free hub is being stopped by the lowside section of chain when you stop pedalling but if the cassette has enough stored energy then it will keep spinning and take slack from the derr (this would only happen on a non-clutch set up)...
I don't know, this is pretty much the only way I used to throw chains on my 1x when I was using a powertap and an XT 11-36 cassette. Maybe the powertap freehub was crappy enough that it caused problems that wouldn't exist with another hub, but the issue definitely stopped once I installed a clutch.
I guess the cassette and free hub is being stopped by the lowside section of chain when you stop pedalling but if the cassette has enough stored energy then it will keep spinning and take slack from the derr (this would only happen on a non-clutch set up)...
I don't know, this is pretty much the only way I used to throw chains on my 1x when I was using a powertap and an XT 11-36 cassette. Maybe the powertap freehub was crappy enough that it caused problems that wouldn't exist with another hub, but the issue definitely stopped once I installed a clutch.
That’s a pretty cool yardstick you’ve got there- we’ll done hanging on! Is he as much of a jackass in real life as he comes across in the media?
With respect to chaindrop, there’s some pretty significant differences simply in frame geometry that could contribute to more frequent chain drops on a road bike than a mountain bike. Probably the biggest one in general is the chainstay length. Road bikes have shorter chainstays which just exacerbates the chainline issue. With two chainrings, the actual true chainline is smack dab in the middle of the two rings and in the centerline of the cassette, and the probability is high that when at either end of the cassette, chances are you’re going to be in the chainring that favors that side (small chainring with the climbing cogs and large chainring with the “gofast” cogs. Because of that, on average over the course of a ride, that in itself should produce a more favorable chainline than a single chainring would when using cogs farther away from the middle of the casette.
Another thing is the speed at which the chain is moving as it comes into contact with the chain ring(s). I don’t know... you tell me... but I suspect the average cadence over the course of a road race is going to be higher than that of a mountain bike race. This could make it slightly easier to miss the tooth it needed to grab when it had the chance, and drop. Then, as already mentioned, the size, and thus curvature of the rings may have something to do with it but I’m kinda reaching and just guessing on that one without actually experimenting a bit. But the biggest thing I believe that contributes to a greater incidence of chaindrop is simply a poorer chainline occurring a greater percentage of the time using a 1x system than a 2x, over the course of a race, which itself is the result of shorter roadbike chainstays.
And that bad chainline is made even worse by the actual bikes they are using. I believe the chainstays on those bikes are 405mm across the board. Don’t even get me started on the “logic” of having one chainstay length regardless of framesize. But 405mm is at the absolute minimum of, for example, Campy’s spec for rim brake bikes with 130mm spacing. For disc brake bikes the minimum chainstay spec goes up to 410mm. Shimano specs 410mm as the minimum regardless of 130 or 135mm spacing. So combining short chainstays with 1x is going to make for a lot of not ideal chainline combos. Result... the occasional, or in AquaBlues case, not so occasional dropped chain.
Ok, so I really think those are some very real differences between the mountain bikes and the road bikes which could account for more frequent chain drops, plus... SRAM isn’t exactly noted for their chain/chainring interface reliability.
So what about a quick rear wheel removal. Forget the disc vs rim brake differences for a moment. Again, frame geometry differences could easily account for some of the greater difficulty in wheel removal for a road bike vs a mountain bike. First up, again... is the shorter chainstays. You simply don’t have the wiggle room in front of the tire to quickly and easily throw things around unobstructed by the seattube and BB. You need to be a little more precise and careful with the right clearances of the road bike. Add in a bit of panic and things go wrong (wasn’t like this in practice). Take a look at the clearance between that downtube and tire on their bikes. There’s not a lot.
Next up, combine that lesser clearance just talked about with the fact that mountain bikes have less BB drop than road bikes. On a road bike, the wheel generally has to come forward a bit and further down to clear the derailleur easily upon removal, specifically the upper pulley. A lower BB can get in the way. I don’t know about the SRAM derailleur, but on the new Shimano derailleurs, there are certainly cases where wheel removal has become more difficult. If the bottom bracket were higher, as it is on a mountain bike, it wouldn’t be causing near the problems as the rear wheel would be able to clear the upper pulley (where it typically gets jammed up) that much sooner when trying to remove the wheel.
So yes, there are mechanical and geometric differences that could certainly make wheel removal harder on a road bike than a mountain bike as well.
1x is a simply poor choice for a road bike at a Grand Tour kind of race, for so many reasons. I feel sorry for AquaBlue riders.
Remember SRAM’s tagline when they didn’t have any kind of electrical shifting going on... they had the “Mechanical Advantage”. Too bad they didn’t try to actually perfect a few of those things, like simply being able to keep the damn chain on the rings. This is an embarrassment for all concerned. There’s gotta be some serious finger pointing and heated words being thrown about behind closed doors given what they’re tossing about in public.
Another thing is the speed at which the chain is moving as it comes into contact with the chain ring(s). I don’t know... you tell me... but I suspect the average cadence over the course of a road race is going to be higher than that of a mountain bike race. This could make it slightly easier to miss the tooth it needed to grab when it had the chance, and drop. Then, as already mentioned, the size, and thus curvature of the rings may have something to do with it but I’m kinda reaching and just guessing on that one without actually experimenting a bit. But the biggest thing I believe that contributes to a greater incidence of chaindrop is simply a poorer chainline occurring a greater percentage of the time using a 1x system than a 2x, over the course of a race, which itself is the result of shorter roadbike chainstays.
And that bad chainline is made even worse by the actual bikes they are using. I believe the chainstays on those bikes are 405mm across the board. Don’t even get me started on the “logic” of having one chainstay length regardless of framesize. But 405mm is at the absolute minimum of, for example, Campy’s spec for rim brake bikes with 130mm spacing. For disc brake bikes the minimum chainstay spec goes up to 410mm. Shimano specs 410mm as the minimum regardless of 130 or 135mm spacing. So combining short chainstays with 1x is going to make for a lot of not ideal chainline combos. Result... the occasional, or in AquaBlues case, not so occasional dropped chain.
Ok, so I really think those are some very real differences between the mountain bikes and the road bikes which could account for more frequent chain drops, plus... SRAM isn’t exactly noted for their chain/chainring interface reliability.
So what about a quick rear wheel removal. Forget the disc vs rim brake differences for a moment. Again, frame geometry differences could easily account for some of the greater difficulty in wheel removal for a road bike vs a mountain bike. First up, again... is the shorter chainstays. You simply don’t have the wiggle room in front of the tire to quickly and easily throw things around unobstructed by the seattube and BB. You need to be a little more precise and careful with the right clearances of the road bike. Add in a bit of panic and things go wrong (wasn’t like this in practice). Take a look at the clearance between that downtube and tire on their bikes. There’s not a lot.
Next up, combine that lesser clearance just talked about with the fact that mountain bikes have less BB drop than road bikes. On a road bike, the wheel generally has to come forward a bit and further down to clear the derailleur easily upon removal, specifically the upper pulley. A lower BB can get in the way. I don’t know about the SRAM derailleur, but on the new Shimano derailleurs, there are certainly cases where wheel removal has become more difficult. If the bottom bracket were higher, as it is on a mountain bike, it wouldn’t be causing near the problems as the rear wheel would be able to clear the upper pulley (where it typically gets jammed up) that much sooner when trying to remove the wheel.
So yes, there are mechanical and geometric differences that could certainly make wheel removal harder on a road bike than a mountain bike as well.
1x is a simply poor choice for a road bike at a Grand Tour kind of race, for so many reasons. I feel sorry for AquaBlue riders.
Remember SRAM’s tagline when they didn’t have any kind of electrical shifting going on... they had the “Mechanical Advantage”. Too bad they didn’t try to actually perfect a few of those things, like simply being able to keep the damn chain on the rings. This is an embarrassment for all concerned. There’s gotta be some serious finger pointing and heated words being thrown about behind closed doors given what they’re tossing about in public.
Last edited by Calnago on Sun Jun 17, 2018 4:38 am, edited 1 time in total.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ
Like Cancellara said “I actually don’t know you.” Without sounding like some a$$hole I guess it’s easier on the ego to smash local amateurs than to be an average pro.
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Because almost all MTB racers use an upper chain guide. Look at world cup bikes and you'll see a small plastic guide at the top of the chainring. My enduro and DH bikes have both upper and lower guides because I'll sometimes end a section of bumpy coasting with a 1/4 back pedal. I have 1 bike that I don't race without a guide (still with narrow/wide ring and clutch) that drops the chain sometimes.
