Thorn Cycles Forum
Community => Non-Thorn Related => Topic started by: RST Scout on April 05, 2017, 09:56:38 pm
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Hi all,
Getting some lower back pain and was playing with the idea of a light weight carbon fibre vibration reducing seat post. The problem is, Scout will only take a 300mm length max. The one I was hankering after is the Specialized COBL GOBL-R Carbon Seatpost (https://www.evanscycles.com/specialized-cobl-gobl-r-carbon-seatpost-EV180943) but it's 350mm. Just that bit too long.
Any thoughts or should I give it up as a bad idea?
Janet
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Just cut the 50mm off.the carbon seatpost are good .janet you need a probike fit done you will be amazed at the difference It makes.think about it before you go spending your money.
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Getting some lower back pain and was playing with the idea of a light weight carbon fibre vibration reducing seat post. The problem is, Scout will only take a 300mm length max. The one I was hankering after is the Specialized COBL GOBL-R Carbon Seatpost (https://www.evanscycles.com/specialized-cobl-gobl-r-carbon-seatpost-EV180943) but it's 350mm. Just that bit too long.
Any thoughts or should I give it up as a bad idea?
This is a bad, bad idea.
ANECDOTE WARNING. A few years ago a man in lycra waits for me at my parked bike in front of the library to ask directions to the LBS for an emergency component purchase. It turns out he came off the plane and started riding, and shortly his carbon fibre seatpost splintered and shafted him. Looking at his bike, on which everything, including the bolts, were from some boutique brand that I wouldn't have on my bike for fear that the local tradesmen would start thinking I was gullible, I explain that the local LBS is in his eighties, from the blacksmith age of bike mechanics, and won't have any stock he'll want, or know what to do with it if he had it. I take the wounded cyclist home with me to call around and find him a place to stay (tourist town in the middle of the summer, not callousness about his wounds; I couldn't put him up as I already had friends staying) and, most important, to call the bike shops in the city before they closed to find him a suitable seat post. Then I took him downstairs to the surgery to have the wound in his bottom seen to. The guy was a physician himself (Scottish GP, retired early from the NHS to tour on his bike) so I reckoned he would tell me if he was in so much distress or even a dangerous condition that he couldn't wait for attention. It turned out when I got him to the surgery to be quite a serious wound, though not so debilitating that, after a side trip to the city the next morning to buy a new seatpost, he couldn't ride on in the afternoon. Received a nice note from him a while later from which I gathered he was fully recovered and reconsidering carbon seat posts.
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Jags has already mentioned the importance of correct posture on the bike. On a badly fitted bike when I started cycling I paid for my physio's new BMW. Then, over three new bikes I gradually sorted out a proper fit. The first thing is to raise the bars as far as they will go, using an extension if your steerer tube has been sawn short. The next thing is to buy or borrow an adjustable stem; you can always replace it with a fixed stem later if you ride with weight weenies and must fit in. (They don't try to patronize me twice but you may be more socialized than I am.) Rotate the stem for further height and also to bring the bars closer to you and thus to reduce the angle on your back. Now move the seat back as far as it will go; the ideal effective seatpost angle is 68%. Then rotate the bars until the grips are at a comfortable reach (slightly bent elbows) and angle (very nearly straight wrists)s If at this point your back is still at too acute an angle, first try a shorter stem, and remember, it is only habit that the stem points forward -- there is no engineering reason you can't reverse the stem.
Next, remove all sources of transmitted vibration (and noise, which is psychological vibration) from your bike. A far better idea than a carbon seatpost is fitting low pressure tyres, as wide as the forks on your bike can accommodate. (I seem to remember a thread which concluded that the Thorn tourers can take 55mm/2.15in Big Apples.) Unless you ride in mud offroad, zero tread is best, and will together with the width and low pressure, surprisingly to many, give you lower rolling resistance, which again is less strain on your back (and more security in the roadholding and handling at huge speeds, if you care).
In the same line of thinking, removing vibration from your spine, a hammock type Brooks leather saddle is far superior to gel saddles and suspended seat posts, and a hammock with additional helical (coil) springs is better still. I ride on a Brooks B73, which has triple rail (those rails are straight springs) plus helical coils at each of the three corners. SJS sells them for a reason but they are difficult to fit to standard micro-adjustable seat posts (out of the box they come with a fitting to attach them to a so-called "candle" seatpost, which is not hard to get but today limited to Brooks saddles). The more common, less extravagant-appearing (but not much cheaper) style with two helical springs and fewer rails, also available with a micro-adjustable fixing for modern seat posts, is the B67/68. One of those is a lady's model, somewhat shorter in the nose. If you have no Brooks experience, don't be put off by the mansplaining about how painful it is to break in a Brooks; cyclists just love to brag about how they suffer for their hobby. Soak the entire saddle in neatsfoot oil (about a fiver from a saddlery near you) for twenty minutes, let it sit overnight, wipe, ride in old clothes, and soon you will only let it go over your dead body. My B73 was hugely more comfortable than any gel seat right out of the box.
The tyres and the saddle will remove most vibrations, but microvibrations might still get into your hands and via your arms into the muscles that cause pains in the lower back. I use Brooks grips of thick leather rings at right angles to the bars, held together by mini-bicycle spokes seated in custom-cast stopper ends, to isolate my hands from the steel bars (these grips also came from SJS and I soaked them in neatsfoot to match the saddle visually) but all kinds of gel grips are available; an excellent, inexpensive gel grip is made by Herrmans of Finland, fitted to many upmarket German touring bikes. My grips are pretty hard, but nonetheless I cycle in dress leather gloves, without any gel or padding whatsoever because there is zero transmitted vibration through the compressed leather so I hold the bars very lightly.
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It's been about fifteen years since I put together my systems approach to specifying my bicycle, starting with the fit and proceeding to eliminate all vibration and noise, and it's been fifteen years since I last paid a physio a penny. My back feels no pain, nor do my hands ever go numb. Since I'm old and my cardiologists and GPs are all convinced that it's cycling which has kept me alive, it's been a worthwhile journey. If I had to put up with constant back pain, I'd have stopped cycling long since.
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Janet,
I have been very happy with my Thudbuster brand suspension seatposts. Because they are a parallelogram design, the distance between saddle-top and bottom bracket remains constant; the saddle declines rearward and downward. I've found them to be reliable in my use and ideal for damping both bumps and vibration, though the two models vary in what they do best.
My Nomad and another "rough-stuff" oriented bike each have the LT (Long Travel) model best suited for damping large bumps, but it requires a considerable amount of room to fit between saddle rails and seatpost clamp. This version uses stacked elastomers and is very amenable to tuning so you can make it more squishy or stiff as desired. While my Nomad always rode beautifully when fully loaded, I found the frame too stiff for comfortable riding on really rough logging roads when unladen. The TBLT addressed this completely and I could not be more happy with the Nomad in all conditions now. In nautical terms, the effect is like heavy ocean chop converted to gentle swells. This completely solved my shock-caused headaches and neck pain.
Two of my randonneur bikes with horizontal top tubes have less vertical space available and are each fitted with the ST (Short Travel) version. This model doesn't have enough travel or damping to handle big bumps well, but nicely damps pavement joints, chip-sealed roads, and decent gravel. I find myself coming in from 300+km day rides feeling fresher and less fatigued as a result. This version uses a rubber puck available in various durometers (stiffness) and so is tunable but not as finely as the LT version. Because it is smaller and requires less space to fit, it is often the only choice for small-framed bikes. I find my lower back no longer hurts after long day rides after fitting the ST version to my rando bikes.
My seatposts have made my hands more comfortable because bumps hit by the rear wheel no longer pitch me forward as sharply.
If you decide to get a Thudbuster, it is a Very Good Idea to also fit the optional neoprene cover (ThudGlove). It keeps water and dust out of the pivots, extending their life and reducing the need for lubrication. Thudbusters are easily rebuildable. I replaced a faulty pivot on one of mine in less than five minutes using a kit sent under warranty.
All the Thudbuster shafts are made of butted aluminum (the butts are fore and aft) and can be easily trimmed to length with a saw or pipe cutter.
All four of my Thudbusters are paired with Brooks B.17 saddles (3 Standards, one Champion Special). I find the combination sublime. We are all different in our requirements so it is worth noting that unlike Andre's preference for a more upright riding position, I like to have my back at a 45° angle when my hands are on the brake hoods of my drop handlebars with my elbows slightly bent for shock absorption. I prefer my handlebar-tops level with the saddle, and my drops compact so they are easy to reach.
I've written considerable amounts about my experience with each and included photos. A quick search of the Forum will quickly bring them to light.
Best,
Dan.
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I have no clue if this thing is available or still in prototype phase:
https://roadbikerider.com/latest-rbr-newsletter-2017/273-issue-no-755/2760-rinsten-spring-ultimate-bicycle-shock-absorber
I have had lower back pain for quite some time, but about three times a week I do several lower back exercises at a health club to try to maintain strength and flexibility in my lower back and abdomen muscles. I used to have trouble cycling before I started doing regular exercises, I credit exercises for part of the improvement and also some weight loss for part of the solution. That said, yesterday morning I had to take two ibuprofen to be able to function due to back pain.
I suspect that an alternative seatpost will not give you everything you want, I think posture and lower back strength/flexibility may be more important. But your short note does not tell me much so i am only guessing at your situation.
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Just cut the 50mm off.the carbon seatpost are good .janet you need a probike fit done you will be amazed at the difference It makes.think about it before you go spending your money.
I am thinking on it, Anto. However, Dave at Thorn has warned me not to cut carbon.
Janet
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Dear All,
I am rapidly going off the idea. I think I need to tweak Scout some more. Would love to get the handlebars up higher but they are at their max. May need to look at another stem. I've looked at the Thudbuster but not sure if it will fit. The saddle is not very high ;) cos I'm so short. Also, it weighs a ton compared to carbon. I do have a Brooks B17L and very nice it is too. haven't had any problem with it as some do. Oh, and the widest tires I can have on Scout are 1.75" so unfortunately Big Apples wont fit. :(
Back to the drawing board I think.
Janet
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Janet, I currently am running marathon racers like you. They are fine, rather like standard marathons but lighter. However, they are harsh in comparison to say a marathon supreme. I ran 1x1.6 supremes for many years and they were excellent in all respects. The key difference with the supremes was the sidelwalls were much more compliant and absorbed more road buzz. The supremes did 10,000 miles or so and I would have bought them again but decided to use up the racers that came with the bike.
I'd guess that the difference in tyres might be comparable to changing a seat post from aluminium to carbon. It might not fix your problem but should help if micro vibrations are part of the cause.
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I have no clue if this thing is available or still in prototype phase:
https://roadbikerider.com/latest-rbr-newsletter-2017/273-issue-no-755/2760-rinsten-spring-ultimate-bicycle-shock-absorber
Yeah, I've seen that before. They crowd-funded it and got way more than they needed. Not sure I'd sit on it tho.
Janet
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Janet, I currently am running marathon racers like you. They are fine, rather like standard marathons but lighter. However, they are harsh in comparison to say a marathon supreme. I ran 1x1.6 supremes for many years and they were excellent in all respects. The key difference with the supremes was the sidelwalls were much more compliant and absorbed more road buzz. The supremes did 10,000 miles or so and I would have bought them again but decided to use up the racers that came with the bike.
I'd guess that the difference in tyres might be comparable to changing a seat post from aluminium to carbon. It might not fix your problem but should help if micro vibrations are part of the cause.
Thanks for the tip Geo. It said in the blurb that the bike had Marathon Racers but when I checked I found they were Marathon Classics :o
Supremes might be the way to go.
Janet
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The supreams are great .janet when I got the bike fit the dropped my stem by a full inch also longer stem 110 I was using an 80mm stem.I went from sitting upright to be much lower taking all the weight off my spine. I have swollen discs so if t he pressure on as in speed I still get a lot of pain but once I pace myself im far better off.so get the bike fit done its well worth it.
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I have 35c Supremes on Doli, and at the AB recommended pressures they are very comfortable but I would not fancy them on any other surface than tarmac.
Thomas has 2 inch Dureme on at the moment, in India they were superb across a mixture of surfaces. For Scout it would mean new mudguards but it is worth thinking about.
For more years than I care to remember I subscribed to the Higher the pressure the better theory but I have to admit that fat tires at low pressures get me where I want to go just as fast but with added comfort.
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Tyres could make a bit of difference.
I did the swap from 44 mm Marathon to 42 mm Marathon Supreme on my old 650B tyred bicycle.
Despite the slightly smaller dimensions the Marathon Supreme felt significantly more comfortable, as well as slightly faster.
I have since replaced the 42 mm Marathon Supreme tyres with the same in 50 mm (even more comfortable, and cope better with sandy tracks), and passed the 42 mm tyres to my wife's bike (her frame doesn't have clearance for 50 mm). On my wife's bike, I use 30 psi front and 40 psi rear, for a total weight (bike + rider + luggage) of about 60 Kg.
42 mm is close to the maximum for a Raven Sport Tour frame with mudguards.
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I also use a short travel Thudbuster and find it great,on my commuter bike I have the suntour version https://www.amazon.co.uk/SUNTOUR-SP12-NCX-Suspension-Seatpost-Approx/dp/B0080L22A2/ref=sr_1_3?ie=UTF8&qid=1491683818&sr=8-3&keywords=suntour+suspension+seat+post
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...I have the suntour version
Our own Forum member Stuntpilot gives the SunTour high marks.
See: http://thorncyclesforum.co.uk/index.php?topic=7089.msg47547#msg47547
...and...
http://www.touronabike.com/sr-suntour-sp12-ncx-suspension-seat-post-review/
Best,
Dan.
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The Suntour SP12-NCX seatpost continues to please, especially after last summer's trans-europe tour involving a few very rough tracks in Northern Italy and Greece. Just read the manual and it advises a re-grease and apply a drop of oil to the bushings every 500km. Well, I have not touched it over 10000km and it is still works fine. Fit and forget! (OK, maybe I will give it a service before the next tour!).
There was a tiny bit of road vibration with the standard Thorn Raven supplied seat post and saddle. With the Suntour seat post there is less vibration. Maybe this could be down to the fact that the Suntour post is more solidly built and has a big spring inside. Maybe the spring absorbs some road vibrations? Just a thought.
The rear bushings of the seat post rests against the internal post with a small rubber block which would also reduce any vibration. The Brooks B17 Select saddle helps too.
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...I have the suntour version
Our own Forum member Stuntpilot gives the SunTour high marks.
See: http://thorncyclesforum.co.uk/index.php?topic=7089.msg47547#msg47547
...and...
http://www.touronabike.com/sr-suntour-sp12-ncx-suspension-seat-post-review/
Best,
Dan.
Thanks for that,it was an interesting read and very imformative.
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Hi Janet
i'd swap your b17 for a brooks flyer before i spent money out on bouncy seatposts
i run ribmo 1.25's on the xtc classic at max pressure and the flyer absorbs all but the worst of the bumps, and softens the the pot holes very nicely (btw 2 knackered discs and stenosis)
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I have Brooks B17 saddles on my drop handlebar bikes, but on my bikes with a more upright riding position I prefer a sprung saddle.
On my new utility bike and the two visitor bikes I have Brooks Flyer saddles, these are basically a B17 with springs, which adds a bit of weight. B66 Champion is similar but has twin saddle rails, so cannot be used on modern seatposts without an adaptor.
They work for me, but I am fairly heavy, the fairly stiff springs in the modern saddles are probably less suited to lighter riders.
Old B66 Champion saddles from about 30-40 years ago (not sure of the date when the springs were changed) had softer springs. I have one on my old utility bike, still going strong after more than 60,000 kms. If you can find one of these it might be better than a modern saddle.
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They work for me, but I am fairly heavy, the fairly stiff springs in the modern saddles are probably less suited to lighter riders.
This proved true for me, Martin, but the cause was not so much my weight but position. I found with my preference for a 45° back angle with hands on the brake hoods and drop handlebars, I simply didn't have enough weight on the saddle to activate the springs on my Conquest and Flyer, so the solution was a rigid saddle (a bit lighter in weight than the spring-loaded once I couldn't actuate) on a parallelogram sus-post.
Riding position is so important to the larger bike setup, speed, and riding style!
Best,
Dan.
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My guess is that I only depress the springs about 5mm on my Conquest when I am riding on the flat and level. I weigh about 80 kg. I agree that a lighter rider might not get much advantage from the springs, as they are quite stiff. I find that they smooth out the vibration some on a rough road, but if I expect to hit a bump, I still lift myself off the saddles and use my knees for shock absorbers.
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just spotted the Rinsten spring, adjustable fore and aft and also spring loading for your weight
looks like it might be worth a look www.rinsten.com (http://www.rinsten.com)
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just spotted the Rinsten spring
<nods> There's just something about it that screams "metal fatigue" to me, but a friend who was a major contributor to the campaign is convinced. Perhaps if I had not broken so many of the old chromed Brooks saddle rails....
I do love the simplicity of the design, but wonder if the saddle clamp will stay tight as the saddle rocks from side to side.
That said, I'd love to try one!
Best,
Dan.
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To quote a cyclist from Leeds (UK) "Eat more pies"
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To quote a cyclist from Leeds (UK) "Eat more pies"
I'll try!
Janet
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Actually, I've given up on susp seatposts. I have bought Scout a new adjustable handlebar stem and set it at 40 degrees and have altered the level (horizontal angle) of the saddle. I think I'm getting there. Still hanker after the Specialized CG-R setpost but have run out of money :(. Scout has got a new Carradice saddlebag, new Ortleib front panniers (black) and a Tubus Duo low-loader rack. She look the bizz now.
Janet
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There like kids our bikes spoil them rotten buying for them all the time ;D
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Janet do you use spd shoes if so make sure your cleats are set properly.ihad mine all over the place when I got the bikefit done.the guy shoved them all the way back no more painfull feet.just a thought ;)
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I think I've got Scout sussed now, Anto. She is as comfortable as I'm going to get. I think part of the problem is the shoulder I damaged falling off my Brommie last year. It is giving me hell today after my ride yesterday. Time to see the doc methinks. :(
Janet
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Or a chiropractor click you back into place.hope you get sorted .