|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
How Would Suspension Help?
You all remember my long tribulations with my beautiful Dutch bike,
Behemoth. She is an upright comfort bike with a 7 speed Nexus hub shifter, a hub dynamo and roller brakes ( http://www.bikkelbikes.com/images/bi.../neerhem-d.jpg ). It was extremely difficult to shop for her, because there are practically no bikes with this kind of configuration being sold here in Paris. When I bought Bethie, the issue of suspension did indeed come up. Rival models, including the Giant Energy 7, could have been ordered with suspended front forks and seat-posts. But I decided against it for two reasons. First, I had a great deal of trouble with my balance, aggravated on Behemoth by the fact that her headset was initially screwed on too tight. Whenever I had occasion to try a suspended model of bike, the bouncy, squishy feeling perturbed me further and I concluded that balancing would be even harder. Secondly, I'm very heavy, well over 100 kg, and I had heard that suspension could not be used by very fat people. Behemoth is riding much better now that the headset issue has been sorted. But I begin to notice a problem on bumpy roads. I try to avoid the bumps so as not to get my bones ground. If I can't, I try to coast over them, putting more weight on my feet and using my knees for the suspension. But if I am going fast downhill, this means that I have to stop pedalling. Restarting to pedal is an issue because I'm spinning out and, once again, this perturbs my balance. On a day to day level, this problem doesn't arise, since the ride to work is a paltry 1.5 km. However, the few times I have attempted longer rides, I have found myself increasingly phobic of road-bumps and pot-holes. The trip to the HQ of my firm is about 10 kms, of which the first 8 are almost continually downhill. Instead of this being a piece of cake, I found myself constantly obliged to prevent Bethie from picking up too much speed. The shudder from the road grew so intense it started causing bits of her to fly off - I lost a clip-on blinkie which jumped to its death from her front basket - and I was afraid of losing control over the pot holes, of which there were many. Also, to avoid the potholes I would try to veer out round them and I realize this is dangerous with cars behind me that might be trying to overtake. Recently perusing the site of the German Utopia bikes, which are sold on a semi-customized, configure-your-bike-to-spec basis, I noticed that they offered front-fork suspension options for 120, 130 and 140 kg. So in theory it is possible to acquire a suspended fork that could deal with my weight, even if I did grow fatter. So what's the advice of the FOAK? Is it essential that the fork be from the same manufacturer as the bike? I see that Bikkel does have some suspended models but there does not seem to be a weight configuration option. Is there a conflict between a suspended fork and the hub dynamo light and roller brake configuration that I have? Does suspension make the difference that I want it to make? What is the effect of suspending just the seat-post, or just the front fork? Do they have to be done together? Thanks for your thoughts. I will of course also speak to Bethie's dealer and ask him about costs and options. EFR Ile de France |
Ads |
#2
|
|||
|
|||
How Would Suspension Help?
Elisa Francesca Roselli wrote:
When I bought Bethie, the issue of suspension did indeed come up. Rival models, including the Giant Energy 7, could have been ordered with suspended front forks and seat-posts. But I decided against it for two reasons. First, I had a great deal of trouble with my balance, aggravated on Behemoth by the fact that her headset was initially screwed on too tight. Whenever I had occasion to try a suspended model of bike, the bouncy, squishy feeling perturbed me further and I concluded that balancing would be even harder. First up, there's suspension and there's Suspension. The difference is that suspension is primarily there to make the bike look better with a More Whistles and Bells factor, while Suspension is there primarily to make the bike more efficient, which not only makes it more comfortable for the rider in terms of bumps but in using less energy to cover the same ground. And another difference is that suspension uses cheap tat and Suspension costs Actual Money as good engineering is required and isn't generally cheap. Typical suspension forks on general purpose bikes come in as suspension, rather than Suspension. Secondly, I'm very heavy, well over 100 kg, and I had heard that suspension could not be used by very fat people. Well, that'll be Bollox (TM) then. The point of good suspension is that the wheels go up and down but the saddle and rider don't, so you don't lose the forward energy by moving everything up over the bumps. Suspension is thus /most/ effective when the suspended mass is greatest, as long as it's up to the job. So what's the advice of the FOAK? Is it essential that the fork be from the same manufacturer as the bike? Not at all. Forks are made for standard fittings. The thing to realise is that different forks are for different jobs and you get what you pay for. Is there a conflict between a suspended fork and the hub dynamo light and roller brake configuration that I have? As long as the fork will take the brake, no. The dynohub should transfer fine. Does suspension make the difference that I want it to make? Suspension done properly means the wheels move over bumps without moving the rider. It makes the bike more efficient and, crucially, easier to control because the steered wheel follows the road rather than taking off over bumps. Suspension done badly absorbs bumps but bounces back without proper damping and may actually reduce your control level, albeit with less nasty bumps for your wrists. I think you'll be wanting the former. What is the effect of suspending just the seat-post, or just the front fork? Do they have to be done together? The idea in any configuration is that the rider (easily the heaviest part of the whole set up) stays stationary while the bike moves under them. With a sus seat post the whole bike plus luggage will move, but that's still better than whole bike plus rider. Nothing's perfect, and adding a sus fork can help the seatpost do a better job at keeping you relatively level. But again bear in mind all forks are not created equal, or for the same jobs. A downhill MTB fork is to absorb huge impacts, something designed for the road will aim to keep high frequency but small bumps in check, like cobblestones. You can get a good sus seatpost for a lot less than a good sus fork. A neater option is something like the Pantour suspension hub, which only has 10mm of travel but is designed for the road. Downside is you'd have to lose the dynohub, probably a more useful item on an urban bike. Pete. -- Peter Clinch Medical Physics IT Officer Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital Fax 44 1382 640177 Dundee DD1 9SY Scotland UK net http://www.dundee.ac.uk/~pjclinch/ |
#3
|
|||
|
|||
How Would Suspension Help?
Peter Clinch writes:
First up, there's suspension and there's Suspension. pedant Surely 'suspension' is the one that does what it says on the can and 'Suspension' is the one that doesn't actually suspend. /pedant A |
#4
|
|||
|
|||
How Would Suspension Help?
|
#5
|
|||
|
|||
How Would Suspension Help?
Elisa Francesca Roselli wrote:
You all remember my long tribulations with my beautiful Dutch bike, Behemoth. She is an upright comfort bike with a 7 speed Nexus hub shifter, a hub dynamo and roller brakes ( http://www.bikkelbikes.com/images/bi.../neerhem-d.jpg ). It was extremely difficult to shop for her, because there are practically no bikes with this kind of configuration being sold here in Paris.......... Behemoth is riding much better now that the headset issue has been sorted. But I begin to notice a problem on bumpy roads. ..... On a day to day level, this problem doesn't arise, since the ride to work is a paltry 1.5 km. However, the few times I have attempted longer rides, I have found myself increasingly phobic of road-bumps and pot-holes. .................. Is there a conflict between a suspended fork and the hub dynamo light and roller brake configuration that I have? No. Does suspension make the difference that I want it to make? It might. But it needs to be fairly short-travel designed for road use suspension. Good suspension is often expensive. What is the effect of suspending just the seat-post, or just the front fork? Do they have to be done together? They can be done separately. I would start with the seat - possibly trying a saddle with springs unless you are particularly fond of the saddle you currently own, rather than a sprung seat post. eg: http://www.wiggle.co.uk/?ProductID=5360007950 http://www.sjscycles.com/store/vIndex.htm?item1865.htm (Brooks saddles are a peculiarly British thing - people seem to love or loathe them. It seems that if you suit them, its hard to do better, but not everyone suits them. With Brooks models, research carefully as many models only suit old-fashioned seat posts, not modern single-rail fittings). I would also look at the tyres fitted to Bethie - generally larger section tyres can be more forgiving of bumps/vibration provided they are to the correct pressure for the rider. Given the style of Bethie (upright), I expect there is less weight on the front than rear, therefore would run a lower front pressure. Sheldon Brown's website has some suggestions on where to start with tyre pressures. If Bethie is as per the picture you provided in the link, the front forks look very straight. Classically, UK forks are curved. I don't know if curved forks reduce vibrations better than straight. eg: a timeless (some might say excessively old fashioned) UK traditional bike with curved forks: http://www.pashley.co.uk/products/cl...ic/splash.html (Also notice that this "traditional ladies comfort" bike has a sprung Brooks saddle. ) Thanks for your thoughts. I will of course also speak to Bethie's dealer and ask him about costs and options. - Nigel -- NC - Webmaster for http://www.2mm.org.uk/ Replies to newsgroup postings to the newsgroup please. |
#6
|
|||
|
|||
How Would Suspension Help?
Elisa Francesca Roselli wrote: You all remember my long tribulations with my beautiful Dutch bike, Behemoth. She is an upright comfort bike with a 7 speed Nexus hub shifter, a hub dynamo and roller brakes ( http://www.bikkelbikes.com/images/bi...t/neerhem-d.jp g ). It was extremely difficult to shop for her, because there are practically no bikes with this kind of configuration being sold here in Paris. When I bought Bethie, the issue of suspension did indeed come up. Rival models, including the Giant Energy 7, could have been ordered with suspended front forks and seat-posts. But I decided against it for two reasons. First, I had a great deal of trouble with my balance, aggravated on Behemoth by the fact that her headset was initially screwed on too tight. Whenever I had occasion to try a suspended model of bike, the bouncy, squishy feeling perturbed me further and I concluded that balancing would be even harder. Secondly, I'm very heavy, well over 100 kg, and I had heard that suspension could not be used by very fat people. snippage I've ridden a friend's shopping / town style bike (Ridgeback Nova) off road a few times. It's got a suspension seatpost, and it makes for a comfortable ride IMO. No reason for you not to put one on your existing bike. As for suspension forks, my MTB has some cheapo RST ones fitted. There doesn't seem to be much appreciable difference riding my friend's town bike (steel forks) and my mountain bike in terms of bumps coming through to your wrists. This might have something to do with the fact that on the MTB more of the rider's weight is on the handlebars of course. As for weight - there are plenty of 100kilo blokes riding mountain bikes, so suspension should be pretty strong. |
#7
|
|||
|
|||
How Would Suspension Help?
in message , Elisa Francesca
Roselli ') wrote: You all remember my long tribulations with my beautiful Dutch bike, Behemoth. She is an upright comfort bike with a 7 speed Nexus hub shifter, a hub dynamo and roller brakes ( When I bought Bethie, the issue of suspension did indeed come up. Rival models, including the Giant Energy 7, could have been ordered with suspended front forks and seat-posts. But I decided against it for two reasons. First, I had a great deal of trouble with my balance, aggravated on Behemoth by the fact that her headset was initially screwed on too tight. Whenever I had occasion to try a suspended model of bike, the bouncy, squishy feeling perturbed me further and I concluded that balancing would be even harder. Secondly, I'm very heavy, well over 100 kg, and I had heard that suspension could not be used by very fat people. Air suspension forks can easily be adjusted for the weight of the rider simply by pumping them up harder. Suspension units with metal springs can be adjusted by using a firmer spring - almost all makers of suspension forks make a range of springs of different firmness for different weights of rider. And many adult men who ride mountain bikes - including downhill mountain bikes where the strain on the forks is particularly high - are as heavy as you are. So you can be confident that you can get forks which are strong enough for you. Whether they would actually be useful to you I can't say - the strongest forks are the long-travel downhill forks, which might feel amazingly wallowy on a road bike. So what's the advice of the FOAK? Is it essential that the fork be from the same manufacturer as the bike? No, not at all. Most of the (good) forks are made by specialist manufacturers of components. Virtually the only bike manufacturer which actually makes most of their own suspension forks is Cannondale. Good fork brands include Fox, Manitou, Marzzochi. I see that Bikkel does have some suspended models but there does not seem to be a weight configuration option. Is there a conflict between a suspended fork and the hub dynamo light and roller brake configuration that I have? Almost certainly. I'm not aware of any suspension fork with fitments for a roller brake, although disk brake mounts might be adapted. Alternatively, you could just fit disk brakes. Does suspension make the difference that I want it to make? I doubt it, frankly. For road bike suspension you want relatively limited travel (50mm) whereas most of the strong adjustable suspension forks are long travel (150mm or even greater). The bike is likely to show a considerable amount of 'pedal bob', where the front suspension bobs in time with the pedalling. This is inefficient. However, there are a few suspension forks manufactured with limited travel specifically for road bikes and you may be able to get one of these fitted with an appropriate spring for your weight (or, if it's an air unit, just pump it up). What is the effect of suspending just the seat-post, or just the front fork? Do they have to be done together? They don't have to be done together. Generally, the more weight you place on your hands, the more benefit you'll feel from suspension forks. The more you place on your bottom, the more benefit you'll feel from a seatpost. My guess is that with the relatively upright riding position of Behemoth, you will be better off with a seat post. The Cane Creek 'thudbuster' suspension seatpost is available with different elastomers to suit people of different weights, see URL:http://www.canecreek.com/site/product/seatpost/04_elas.html (I'm sure other good makes are too). I would advise you to start with a suspension seatpost with the firmest spring or elastomer setting and experiment from there. A seatpost will be substantially cheaper than forks. -- (Simon Brooke) http://www.jasmine.org.uk/~simon/ There are no messages. The above is just a random stream of bytes. Any opinion or meaning you find in it is your own creation. |
#8
|
|||
|
|||
How Would Suspension Help?
Elisa Francesca Roselli Wrote: You all remember my long tribulations with my beautiful Dutch bike, Behemoth. She is an upright comfort bike with a 7 speed Nexus hub shifter, a hub dynamo and roller brakes ( http://tinyurl.com/5hvlm ). It was extremely difficult to shop for her, because there are practically no bikes with this kind of configuration being sold here in Paris. When I bought Bethie, the issue of suspension did indeed come up. Rival models, including the Giant Energy 7, could have been ordered with suspended front forks and seat-posts. But I decided against it for two reasons. First, I had a great deal of trouble with my balance, aggravated on Behemoth by the fact that her headset was initially screwed on too tight. Whenever I had occasion to try a suspended model of bike, the bouncy, squishy feeling perturbed me further and I concluded that balancing would be even harder. Secondly, I'm very heavy, well over 100 kg, and I had heard that suspension could not be used by very fat people. Behemoth is riding much better now that the headset issue has been sorted. But I begin to notice a problem on bumpy roads. I try to avoid the bumps so as not to get my bones ground. If I can't, I try to coast over them, putting more weight on my feet and using my knees for the suspension. But if I am going fast downhill, this means that I have to stop pedalling. Restarting to pedal is an issue because I'm spinning out and, once again, this perturbs my balance. On a day to day level, this problem doesn't arise, since the ride to work is a paltry 1.5 km. However, the few times I have attempted longer rides, I have found myself increasingly phobic of road-bumps and pot-holes. The trip to the HQ of my firm is about 10 kms, of which the first 8 are almost continually downhill. Instead of this being a piece of cake, I found myself constantly obliged to prevent Bethie from picking up too much speed. The shudder from the road grew so intense it started causing bits of her to fly off - I lost a clip-on blinkie which jumped to its death from her front basket - and I was afraid of losing control over the pot holes, of which there were many. Also, to avoid the potholes I would try to veer out round them and I realize this is dangerous with cars behind me that might be trying to overtake. Recently perusing the site of the German Utopia bikes, which are sold on a semi-customized, configure-your-bike-to-spec basis, I noticed that they offered front-fork suspension options for 120, 130 and 140 kg. So in theory it is possible to acquire a suspended fork that could deal with my weight, even if I did grow fatter. So what's the advice of the FOAK? Is it essential that the fork be from the same manufacturer as the bike? I see that Bikkel does have some suspended models but there does not seem to be a weight configuration option. Is there a conflict between a suspended fork and the hub dynamo light and roller brake configuration that I have? Does suspension make the difference that I want it to make? What is the effect of suspending just the seat-post, or just the front fork? Do they have to be done together? Thanks for your thoughts. I will of course also speak to Bethie's dealer and ask him about costs and options. EFR Ile de France When I got my new bike (no suspension) my teeth were rattled by every little bump in the road. When I checked the tyres they were like concrete! I let them down very slightly and now it is great and no more difficult to pedal. -- Shoyu |
#9
|
|||
|
|||
How Would Suspension Help?
NC wrote:
(Brooks saddles are a peculiarly British thing But IIRC a substantial part of the company's earnings come from exports, so that wouldn't appear to be the case. Pete. -- Peter Clinch Medical Physics IT Officer Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital Fax 44 1382 640177 Dundee DD1 9SY Scotland UK net http://www.dundee.ac.uk/~pjclinch/ |
#10
|
|||
|
|||
How Would Suspension Help?
Thanks to all who helped me with this query. I summarize my present course of
action as: 1) Slightly reduce tyre pressure (it's true that I have only recently repumped Bethie's tyres and that they are well over 4.5 Bars). 2) Explore the market for suspended seatposts 3) Explore the market for quality suspended front forks for road and city bikes that are compatible with roller brakes, if these exist. I already have a sprung saddle that I adore, a Velo VL-266. Bethie came with a San Marco saddle that everyone says is a great saddle, but I hate it. I switched it round with the Velo that I had been using on Myrtille. Peter Clinch wrote: And another difference is that suspension uses cheap tat and Suspension costs Actual Money as good engineering is required and isn't generally cheap. I know it will cost money and am thinking in terms of long-term investment. Since Bethie has been rehabilitated with the correction of her headset problem, I am disburdened from the problem of finding a new bike. I'm hoping she and I will be together for a long time. Improvements can be made slowly, as and when. But she deserves the best. Suspension done properly means the wheels move over bumps without moving the rider. It makes the bike more efficient and, crucially, easier to control because the steered wheel follows the road rather than taking off over bumps. Suspension done badly absorbs bumps but bounces back without proper damping and may actually reduce your control level, albeit with less nasty bumps for your wrists. I think you'll be wanting the former. That is exactly the effect I want. It's worth putting in the research to make sure it is done properly. Simon Brooke wrote: I'm not aware of any suspension fork with fitments for a roller brake, although disk brake mounts might be adapted. Alternatively, you could just fit disk brakes. That would be a significant negative point. The Utopia bike I tested in Paris did indeed have disk brakes. They were fantastic - so smooth, strong and gentle you didn't even notice you were using them. But I love Bethie's roller brakes too, and they are supposedly the most rainproof and maintenance free kind of brake. I wouldn't want to have to make an expensive modification to these excellent brakes just to modify the fork. Generally, the more weight you place on your hands, the more benefit you'll feel from suspension forks. The more you place on your bottom, the more benefit you'll feel from a seatpost. I could benefit from both, to be sure, but I do have this sore wrist problem that really does kick in on longer voyages. That's probably coming from poor riding style, and I do try to practice sitting more on my ass. But if I had to commute to HQ I'd have a worry over Carpal Tunnel Syndrome going rampant sooner than I could help it. Thanks again to all. There's plenty here to get started with. EFR Ile de France |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
How Would Suspension Help? | Elisa Francesca Roselli | General | 23 | July 28th 04 04:51 AM |
Does the world have room for another full suspension design? | Simon Brooke | Techniques | 31 | January 5th 04 04:21 PM |
Linking forward and rear suspension | Simon Brooke | Techniques | 18 | November 27th 03 03:22 AM |
Is seat suspension enough? | optimistx | Recumbent Biking | 6 | August 19th 03 01:03 AM |