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https://i.imgur.com/U8vxYCT.jpg Jeebus...when will bike manufacturers stop with seatposts like this. https://i.imgur.com/PDLvPl9.png These have been shown to consistently either: - Slip downward into seat tube, - Slide backwards on the rail up top, and/or - The single-bolt friction pivot point will allow the nose to tilt downward when "on the rivit" during hard efforts. It's like this bike was designed in 2010 :roflmao2: |
huh? says pretty clearly the frame is BSA threaded, maybe there was a mistake and they changed it.
As for the seatpost, I don't think there's anything wrong with that head design. If there was these guys wouldn't be using an identical system: https://i.ytimg.com/vi/tfb8ANBom0w/hqdefault.jpg |
Originally Posted by rustymongrel
(Post 19883148)
huh? says pretty clearly the frame is BSA threaded, maybe there was a mistake and they changed it.
As for the seatpost, I don't think there's anything wrong with that head design. If there was these guys wouldn't be using an identical system: https://i.ytimg.com/vi/tfb8ANBom0w/hqdefault.jpg The T5GB topper system is not identical to the Blue. Notice that the Blue has a single bolt that goes horizontally across the seat mast to hold the assembly together with friction. The GB Cervelos do not. The T5GB uses a 2-bolt system like Thomson that use opposing force. https://i.imgur.com/MHKSguS.png Yeah, the Cervelo has the rail system which doesn't really solve a problem that trackies have. That system is popular on road TT bikes where the saddle setback rules are...well, there are none. A 74 degree seat tube angle and long saddle rails are adjustment enough for track racing. |
And also, who says that Team GB doesn't have issues with them? I know first hand of Team USA riders that had the afforemetioned issues with the Felts and still rode them in world-level competition...and were pissed every time it slipped on them.
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The sliding head system is fairly necessary since on those bikes since the seatpost travels near vertically so as you adjust it up and down the effective seattube angle changes.
The serenity system looks similar but different. The Blue appears to use the same Ritchey one bolt head design that Cervélo uses on the production T4 and P-series bikes which was introduced to alleviate seatpost head slip with a previous design. I haven't heard of any issues with that Ritchey system which is actually saying something since my job is literally to receive complaints like that. It does appear that team GB are using a slightly different clamp that attaches to post the same way. It could just be insurance since they know they won't need to make many adjustments once they've been fit on the bike. It could also be that they've had issues with the normal production head that the general population of T4 and P-series riders haven't. |
[MENTION=34156]carleton[/MENTION], maybe all of those design "flubs" are why the thing is only $1600 complete.
I'm toying with the idea of a pursuit bike for next season to go along with my Giant. The Blue looked intriguing because it is CHEAP, it has what appear to be decent wheels, a decent crankset (and it's 144 BCD so different maker's chainrings could be used), a decent cockpit, and decent geometry. I did notice the seatpost, though, and it made me wonder. Which is why I posted it with the remark "opinions". I was pretty sure I'd get a good set of responses about it. |
A carbon expert in San Diego said he fixed aero seatpost slipping. He also said BT frames and his frames don't have any problems with seatpost slipping. So it's possible that GB team track frames(not cervelo) wouldn't have problems with seatpost slipping
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Speaking of Cervelo's and slipping saddles...
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I looked at the Lehi early last summer, the sale price was tempting but the geometry was no good (for me) for pursuit. I do have their TT/Tri bike, the Triad SL. The saddle clamp on that bike uses two bolts to adjust tilt and secure the saddle, never had any problems with it, seems to be a good design (definitely better than the clamp on the Cervelo S3 I've ridden). Can't tell from the Lehi pictures how similar/different the clamp is on that bike, though.
As far as carbon aero seatposts, I've owned three bikes with them and have never had a problem with them slipping. So I don't know if that's a problem unique to the track world or if trackies just don't know how to use carbon paste. :) |
Post in frame slip is simply an issue of contact between the two. It's difficult for manufacturers to get tight tolerances with non-round carbon parts like that. Very liberal use of carbon assembly paste and making sure to tighten the wedge clamp to the proper torque (or even a little extra) makes a big difference on these types of frames/posts. Sometimes it just doesn't solve the problem though.
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(I'll reply to the other comments in a sec.)
Basically, the aero gains from the aero post over a round post don't justify the risk. Period. Especially with budget frames that have lower quality control than manufacturers like LOOK and BT. Of all of the equipment and rider, the frame provides the least amount of aero gains. Further, the air coming into and behind the seatpost is so "dirty" due to the legs churning like pistons that the tapered backside that an aero seatpost has over a round one isn't significant...or probably not even measurable. With that being said, at this point, an aero seatpost is pretty much cosmetic. So, that leaves us with a proprietary (read: gotta buy replacements from the manufacturer) device that can lead to a race-losing failure. Why bother? |
Originally Posted by rustymongrel
(Post 19883485)
The sliding head system is fairly necessary since on those bikes since the seatpost travels near vertically so as you adjust it up and down the effective seattube angle changes.
The serenity system looks similar but different. The Blue appears to use the same Ritchey one bolt head design that Cervélo uses on the production T4 and P-series bikes which was introduced to alleviate seatpost head slip with a previous design. I haven't heard of any issues with that Ritchey system which is actually saying something since my job is literally to receive complaints like that. It does appear that team GB are using a slightly different clamp that attaches to post the same way. It could just be insurance since they know they won't need to make many adjustments once they've been fit on the bike. It could also be that they've had issues with the normal production head that the general population of T4 and P-series riders haven't. Forward seatpost option: http://tsutaoka.com/wp-content/uploa...4/Felt-TK1.jpg Setback seatpost option: http://autobus.cyclingnews.com/photo...0110123523.jpg That would easily solve that issue for Cervelo as well. People have been buying straight or setback seatposts for decades to address the same problem. I have both styles of Thomson seatposts for that same reason, and I'd rather have 2 that one with a sliding rail. That first gen seatpost for the TK1 had a different issue, though. It was a "traditional" aero seatpost, not like the current dead-stop post on the TK1 today. It was also traditional in that it slipped down into the frame.
Originally Posted by sarals
(Post 19883641)
[MENTION=34156]carleton[/MENTION], maybe all of those design "flubs" are why the thing is only $1600 complete.
I'm toying with the idea of a pursuit bike for next season to go along with my Giant. The Blue looked intriguing because it is CHEAP, it has what appear to be decent wheels, a decent crankset (and it's 144 BCD so different maker's chainrings could be used), a decent cockpit, and decent geometry. I did notice the seatpost, though, and it made me wonder. Which is why I posted it with the remark "opinions". I was pretty sure I'd get a good set of responses about it. Not to say that the Blue is cheap. The Blue bikes that I've seen were well-made. Sarals, I recall you being a shorter rider. You may not weigh enough or make enough force for these things to matter. That being said, I've seen small riders wrestle with Serenity posts.
Originally Posted by sarals
(Post 19883760)
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[MENTION=34156]carleton[/MENTION], I am a smaller rider, yes. I don't make the kind of power that would pull my cleats out of my pedals, either. ;)
I completely understand "cheap" vs. "inexpensive". And I agree with you! I've seen an aluminum Blue track bike, my training partner has an older one, and it seems quite nice. I've never seen one of their carbon offerings. |
BTW, on the seatpost issue, I own and race a 2014 variant of the Specialized Venge. It has an "aero" seatpost, with an odd clamp, and the saddle perch is secured to the seatpost with one bolt. Even though I am small, I had a few fights with that seatpost/saddle mount the first few months I had that bike. The bike shop finally got Specialized involved, and they replaced the clamp and replaced the cones that hold the saddle perch in place. That and carbon paste (each time the post or saddle is fiddled with) equaled "problem solved".
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I wonder why Felt never opted for using the clamping and seatpost design as used on the AR and the IA models. I have read a couple of reviews basically touting the clamping mechanism to be the most secure and clyde friendly on the market, the clamp is the splined 3T fitting that although being a PITA to set up doesn't budge, and the AR version post can be faced forward or rear which one would assume a big bonus for the track community for the differing offsets.
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Originally Posted by brawlo
(Post 19884802)
I wonder why Felt never opted for using the clamping and seatpost design as used on the AR and the IA models. I have read a couple of reviews basically touting the clamping mechanism to be the most secure and clyde friendly on the market, the clamp is the splined 3T fitting that although being a PITA to set up doesn't budge, and the AR version post can be faced forward or rear which one would assume a big bonus for the track community for the differing offsets.
1st gen: - 2-bolt design like Thomson (and others) to avoid saddle tilt. - alternate seatposts - straight shaft that went into the frame...even when you didn't want it to :lol: http://tsutaoka.com/wp-content/uploa...4/Felt-TK1.jpg 2nd gen: - Dead-stop seatpost system. - Need to cut seat mast precisely to measure. - Ritchey topper with fore/aft sliding rail and single friction bolt for up/down tilt. - This stopped the sliding into the frame, but the tilting was a big issue...even with carbon grit paste. - This is why I sold my new TK1. I was like "f that. I'll be damned if I pay $4000 for a bike that has a tilting saddle." (my old TK1) https://c1.staticflickr.com/6/5181/5...5383c450_b.jpg 3rd gen: - 3T Difflock system. - Same as 2nd gen but, - Uses a different topper that has indexed tilt. http://2012.feltracing.com/Resources...per_SM_jk1.jpg I believe that all 3 are interchangeable with the frames. Don't quote me on that, though. I have no doubt that the current TK1 has a bullet proof seatpost now with the dead stop bottom and indexed top...without a sliding rail :D |
I'm not a fan of that indexed tilt system from 3T. I bought a round seat-tube for my BTB with that system, and found I couldn't get the saddle angle right because the tilt increments are just too coarse.
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Originally Posted by jsk
(Post 19887364)
I'm not a fan of that indexed tilt system from 3T. I bought a round seat-tube for my BTB with that system, and found I couldn't get the saddle angle right because the tilt increments are just too coarse.
See this video: |
Originally Posted by jsk
(Post 19887364)
I'm not a fan of that indexed tilt system from 3T. I bought a round seat-tube for my BTB with that system, and found I couldn't get the saddle angle right because the tilt increments are just too coarse.
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[MENTION=34156]carleton[/MENTION] The BB is a standard threaded on these, not a BB30/PF30/BB86/T47/OSBB/Nightmarish-other-BB-"standard". Rotor just uses low-engagement, tiny splineson their bearing cups so you can't get good leverage on them. (I don't like Rotor, if you couldn't guess.) |
I've never seen this mentioned elsewhere on the internet, but I figured you folks would find this interesting.
I've handled and measured both 35cm and 37cm Scattos and found something interresting. They are V-shaped. The 35s and 37s both measure 35cm and 37cm center-to-center at the end of the bars (where the bar plugs go) as one might expect. But, they measure 34cm and 35cm, respectively, where they hands go deep into the drops, like this: https://www.pedalroom.com/f/aef89686ed_1.jpg So they are actually more narrow than people think :D 35cm: - C-C at the back: 35cm - Deep in drops at the front: 34cm 37cm: - C-C at the back: 37cm - Deep in drops at the front: 35cm |
Originally Posted by carleton
(Post 19917260)
I've never seen this mentioned elsewhere on the internet, but I figured you folks would find this interesting.
I've handled and measured both 35cm and 37cm Scattos and found something interresting. They are V-shaped. The 35s and 37s both measure 35cm and 37cm center-to-center at the end of the bars (where the bar plugs go) as one might expect. But, they measure 34cm and 35cm, respectively, where they hands go deep into the drops, like this: https://www.pedalroom.com/f/aef89686ed_1.jpg So they are actually more narrow than people think :D 35cm: - C-C at the back: 35cm - Deep in drops at the front: 34cm 37cm: - C-C at the back: 37cm - Deep in drops at the front: 35cm |
On my road bike I've always preferred microtex type fake leather bartape. When I started riding at the track I found I wanted something with a bit more grip but similarly thin and not cushy so I tried lizard skins 1.8mm bar tape. I really liked it but with recent switch to the Look sprint bars on my bike I found the diameter of the bar a bit big. I was looking into even thinner tape options when I discovered that lizard skins does a 0.5mm version of their tape... but not for bicycles, for baseball bats!
I figured I'd try it out and ordered 4 rolls online. Turns out each roll covers about as much handlebar as a track grip would. First impressions are good, feels just as good as the 1.8mm tape but with even less give. Only downside is that they come with angled cuts on the end of the rolls that require to wrap both sides the same way unless you want to sacrifice a few inches of tape. Figured I'd mention it for anyone else looking for something like that. |
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