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internal to external gears
Hi
I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Obviously the rear wheel would either need to be replaces, or at least fitted with a new axel and spokes.... or what? Thanks, Peter |
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#2
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internal to external gears
On May 13, 3:06 pm, "Peter" wrote:
Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Possible? Yes. Practical? No. If you're in the part of the world where 700c 3/5/7/8 Nexus replacement wheels are common, then this is the best option--if the part needs to be replaced. Has the obvious been checked? Is there bearing play? Is the shifter worn? Is the cable adjusted properly? It could be a cheap fix--but seven years on a well used city bike could very well mean that it's time for a fresh hub. |
#3
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internal to external gears
landotter wrote:
On May 13, 3:06 pm, "Peter" wrote: Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Possible? Yes. Practical? No. If you're in the part of the world where 700c 3/5/7/8 Nexus replacement wheels are common, then this is the best option--if the part needs to be replaced. Has the obvious been checked? Is there bearing play? Is the shifter worn? Is the cable adjusted properly? It could be a cheap fix--but seven years on a well used city bike could very well mean that it's time for a fresh hub. Thanks for your comments. The bike mechanic said the hub was shot, not that he opened it to look at what exactly was wrong. It would be cheaper to replace the whole hub than to try to fix it. The entire real wheel rocks about 1 to 2 cm from side to side, so I guess something is pretty broken. /Peter |
#4
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internal to external gears
On May 13, 9:06*pm, "Peter" wrote:
Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. It might be rebuildable (probably expensive) or you could just buy an entire new wheel with a new Nexus 7 speed already fitted. It might be smart to buy an appropriate so-called "fitting kit" at the same time, depending on how battered the anti-turn washers are. There are some wheels with Nexus hubs he http://sport.search.ebay.de/nexus_Fa...Qsacat Z22688 and it looks like you should be able to get a 7 speed gear hub wheel for around 100 Euro plus postage. The 8 speed Nexus goes for around 120-130 Euro now on Ebay, but to use that you would need the appropriate fitting kit, possibly a rollerbrake (unless you have rim brakes), and a gearchange controller (similar to the most likely rotary control for the 7 speed you have now but for 8 speeds). If you have a coaster brake on your 7 speed Nexus hub, you should probably avoid expense and fitting difficulties for another brake by buying another coaster brake hub. If you go look on the Paul Lange site you will find exploded drawings for the Shimano parts which will show you how the parts relate. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Obviously the rear wheel would either need to be replaces, or at least fitted with a new axel and spokes.... or what? It depends on the frame. If it was custom-made to fit the internal gears, there is usually nowhere to hang the derailleurs and chain tensioner. HTH. Andre Jute http://members.lycos.co.uk/fiultra/B...20CYCLING.html |
#5
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internal to external gears
On May 13, 9:30*pm, "Peter" wrote:
landotter wrote: On May 13, 3:06 pm, "Peter" wrote: Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Possible? Yes. Practical? No. If you're in the part of the world where 700c 3/5/7/8 Nexus replacement wheels are common, then this is the best option--if the part needs to be replaced. Has the obvious been checked? Is there bearing play? Is the shifter worn? Is the cable adjusted properly? It could be a cheap fix--but seven years on a well used city bike could very well mean that it's time for a fresh hub. Thanks for your comments. The bike mechanic said the hub was shot, not that he opened it to look at what exactly was wrong. It would be cheaper to replace the whole hub than to try to fix it. The entire real wheel rocks about 1 to 2 cm from side to side, so I guess something is pretty broken. That might just mean the axle is loose in the track ends. Get the fitting and maintenance instructions from the Paul Lange site and just check for a start that everything is bolted up correctly, and then follow the instructions for adjusting the gearbox -- it is a lot easier than you might think, and you can do it without any tools. Andre Jute |
#6
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internal to external gears
Peter skrev:
I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Obviously the rear wheel would either need to be replaces, or at least fitted with a new axel and spokes.... or what? Appearently on can add the device below on bikes without gear drop out: http://www.roseversand.de/output/con...0&detail2=1807 So if you could live with only 8-10 gears* you could perhaps get away with such a device, one new rear shifter. Eg. Sram Shimano compatible "Attack" shifters are sold individually, a new derailleur, cables, chain, cassette and rear wheel. A Deda "Dog Fang" and a bash guard would be nice too, so as to avoid chain drops. * The gear spread would be closer though than on the Nexus hub. Not sure if it is a much cheaper option even if you do it yourself. Do check if the axel is broken. I vaguely remember that roll brake hubs can snap axels if the "contra torque" arm wasn't attached when braking. Also check the races in the bearings. I do believe that the races aren't replaceable on the Nexus hubs, so if the races are shot, then so are the hub. Converting it to a singlespeed is perhaps the cheapest thing to do. -- Regards |
#7
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internal to external gears
Peter wrote:
Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. This sounds like far too much money to me. I'd seek a second opinion. I can't find any links but a replacement hub can't be much over a hundred, and in my experience, that's the same cost a new wheel. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Obviously the rear wheel would either need to be replaces, or at least fitted with a new axel and spokes.... or what? I wouldn't, you'd need cables, shifters, new wheel, cassette, hanger, it wouldn't be the cheap option, brake levers might be an issue as well. |
#8
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internal to external gears
Tosspot wrote:
Peter wrote: I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. This sounds like far too much money to me. I'd seek a second opinion. I can't find any links but a replacement hub can't be much over a hundred, and in my experience, that's the same cost a new wheel. Actually this was 2 opinions. One guy told me it would cost about 170, another about 200. 75% of the cost was the actual gear hub - the work was about 25% of the total price. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Obviously the rear wheel would either need to be replaces, or at least fitted with a new axel and spokes.... or what? I wouldn't, you'd need cables, shifters, new wheel, cassette, hanger, it wouldn't be the cheap option, brake levers might be an issue as well. Yes - it does seem it is not easily possible. Unfortunately I have never really been completely satisfied with the internal gears - doesn't really seem to have the same "range" as an external system, and I always found external gears easy to adjust and maintain. Not that there has been much maintanence really with the internal hub, just that when something does need to be done it seems a lot harder. Thanks, Peter |
#9
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internal to external gears
Andre Jute wrote:
On May 13, 9:30*pm, "Peter" wrote: landotter wrote: On May 13, 3:06 pm, "Peter" wrote: Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Possible? Yes. Practical? No. If you're in the part of the world where 700c 3/5/7/8 Nexus replacement wheels are common, then this is the best option--if the part needs to be replaced. Has the obvious been checked? Is there bearing play? Is the shifter worn? Is the cable adjusted properly? It could be a cheap fix--but seven years on a well used city bike could very well mean that it's time for a fresh hub. Thanks for your comments. The bike mechanic said the hub was shot, not that he opened it to look at what exactly was wrong. It would be cheaper to replace the whole hub than to try to fix it. The entire real wheel rocks about 1 to 2 cm from side to side, so I guess something is pretty broken. That might just mean the axle is loose in the track ends. Get the fitting and maintenance instructions from the Paul Lange site and just check for a start that everything is bolted up correctly, and then follow the instructions for adjusting the gearbox -- it is a lot easier than you might think, and you can do it without any tools. Hi - thanks for the tip. Do you have the url to that website? /Peter |
#10
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internal to external gears
"Peter" wrote in message k... Andre Jute wrote: On May 13, 9:30 pm, "Peter" wrote: landotter wrote: On May 13, 3:06 pm, "Peter" wrote: Hi I have an approx 7 year old bike (a Nishiki 407 hybrid) which has an internal gear hub (called a "Nexus SG-7R46). The gear hub has recently become very "sloppy" and now is basically unusable. The local bicycle mechanic has told me it would cost about 170 to 200 Euros to replace. Before I accept this offer, I was just wondering if it is possible (in general) to change a bike from using an internal gear hub to using external gears? Possible? Yes. Practical? No. If you're in the part of the world where 700c 3/5/7/8 Nexus replacement wheels are common, then this is the best option--if the part needs to be replaced. Has the obvious been checked? Is there bearing play? Is the shifter worn? Is the cable adjusted properly? It could be a cheap fix--but seven years on a well used city bike could very well mean that it's time for a fresh hub. Thanks for your comments. The bike mechanic said the hub was shot, not that he opened it to look at what exactly was wrong. It would be cheaper to replace the whole hub than to try to fix it. The entire real wheel rocks about 1 to 2 cm from side to side, so I guess something is pretty broken. That might just mean the axle is loose in the track ends. Get the fitting and maintenance instructions from the Paul Lange site and just check for a start that everything is bolted up correctly, and then follow the instructions for adjusting the gearbox -- it is a lot easier than you might think, and you can do it without any tools. Hi - thanks for the tip. Do you have the url to that website? /Peter Hi Peter, Hold on there a bit. This is classic bearing failure. But so what - as long as you can spin the wheel and you do not hear or feel metal grinding on metal, the races are probably fine. In any case until someone actually looks at the bearings, your "mekanics" are just blowing air out their asses. If you go he http://cycle.shimano-eu.com/publish/...l_service.html click Technical Documents, you get http://techdocs.shimano.com/techdocs/index.jsp put the cursor over Comfort and find your hub, then download it. You will get an exploded drawing. Here is the URL for one for example: http://techdocs.shimano.com/media/te...9830615762.pdf When I looked at it I thought Sheesh how simple, I was taking apart and fixing stuff like this when I was 15 years old. If the bike mechanic you are using doesen't want to touch it (sounds like it to me) then find another one or take it apart yourself. Why not - if your convinced that the hub is shot and your going to replace it, then take the thing apart so you can see how it works - what are you going to do, break it? It's a learning experience. I doubt the race is shot, I suspect more likely that the ball retainer inside the bearing is damaged and 1 or more bearings have fallen out. That part can be tossed and new and more bearings added. Most of the time ball bearing retainers are for pussies anyway, all they do is make it easy for someone on an assembly line to slap together bearings a mile a minute. A mechanic that makes a "replace it with a new part your part is shot" diagnosis without even taking it apart, simply is either a tremendous lazy-ass, or incompetent, or just has a lot of work already lined up that he can do in his sleep, since he's done it over and over and over again. None of which you want to reward by tossing them money for taking a part out of a box and replacing it on your bike. These hubs are designed to be taken apart and rebuilt. Parts are available. Just because the locals you have talked to are too unimaginative to e-mail a credit card number to a foreign distributor and get a part mailed to them doesen't mean that it's not possible to do it. Print out the exploded diagram, go back to your mechanic, and tell him to get off his butt and show you the "shot" bearing race. Ted |
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