Intro and question

[TARDISBlue]

Hi folks. I have an ancient Proflex 4000 (no idea what size) that I used to ride casually in high school. Some trails, some backwoods, mostly as my primary form of transportation. I went away to college, left the bike at home, and ballooned to like 280lbs. I'd really like to lose some weight by getting back on it, but I tried riding and the bike just bounces as I pedal now. Spring is too light I presume. It's an awful sensation, and I'd really like to keep the bike so I just need to stiffen up the back end. I'm probably never going to do anything more hardcore than gentle trails and riding across fields again. Can anyone point me in the right direction? I'd like to do this without spending too much money if at all possible. Thanks all.

[Willie_B]

What rear shock does it have? You should be able to go to a stiffer rear spring. Can you see any numbers on the spring you have now? May have to rotate it to see all the way around.

Also, where are you located? May be someone close bu that could lend a hand.

[fyrstormer]

I don't think I've ever lost weight from riding. When I start riding in the spring, I usually gain ten pounds of water mass, which doesn't go away again until I stop riding for a week. The only way I've ever been able to lose weight is by intentionally not eating for a couple days straight so my digestive system shuts off, and then resuming eating much smaller portions. If I screw up and eat until I'm stuffed, and my digestive system stretches out again, I have to start all over.

That being said, a stiffer spring will help but you'll also need to tighten the damping too. The stiffer spring may overwhelm the damper mechanism when the spring rebounds from a bump. If your bike can fit an air shock, that's probably the best option because you can shove as much air into the shock as you need to get the proper spring rate, and they tend to be less bouncy than coil shocks.

[TARDISBlue]

What rear shock does it have? You should be able to go to a stiffer rear spring. Can you see any numbers on the spring you have now? May have to rotate it to see all the way around.

Also, where are you located? May be someone close bu that could lend a hand.

I don't have the bike with me now, but I'll check the spring for a number when I go to get it from my parents house. Where would I get a stiffer spring?

I don't think I've ever lost weight from riding. When I start riding in the spring, I usually gain ten pounds of water mass, which doesn't go away again until I stop riding for a week. The only way I've ever been able to lose weight is by intentionally not eating for a couple days straight so my digestive system shuts off, and then resuming eating much smaller portions. If I screw up and eat until I'm stuffed, and my digestive system stretches out again, I have to start all over.

That being said, a stiffer spring will help but you'll also need to tighten the damping too. The stiffer spring may overwhelm the damper mechanism when the spring rebounds from a bump. If your bike can fit an air shock, that's probably the best option because you can shove as much air into the shock as you need to get the proper spring rate, and they tend to be less bouncy than coil shocks.

I'm going into my 3rd year of law school and have been largely sedentary for so long, any exercise will help. I can't stand running and I don't want to buy an elliptical. I'd rather go biking again, as I've discovered there are great bike paths out here. I've considered going with an air shock, but I'd like to keep my investment minimal. It seems like a great choice and is still an option as it stands.


Thanks all.

[Colin]

Well I do lose weight when I cycle regularly, so go for it!
(as long as you observe Energy Out > Energy In!)
It's a lot less damaging on the body than running and a damn sight more interesting than using an elliptical, (although I do have mine set up in front of the TV and a big fan to keep cool!)

At 280lb , yes you really do need stiffer springs than the standard ones, a 650lb/in was the highest that K2 spec'd on the rear of the 4000 for 210-250lb riders so maybe you even need a 700.
Bear in mind that the fork spring (if a Crosslink) may also need to be upgraded.
take the shock off of the bike and then the coil off of the shock and measure the end to end of the coil plus the internal and external diameters and you have your spec, then go searching for any make spring that will meet that spec.
Whilst you have the coil off, check the compression and rebound damping of the shocks by pressing in the piston, there should be resistance in both directions and depending upon shock model, you should be able to vary this, sounds like the shocks could have leaked during their long rest and that's why the bike is so bouncy..........search on here for Noleen service or consider an air shock as Fyrestormer says.

Good luck and keep us informed!

Col.

[Willie_B]

I think I have a 650 spring.

[fyrstormer]

Well I do lose weight when I cycle regularly, so go for it!
(as long as you observe Energy Out > Energy In!)

It's not quite that simple. The mass of the food you eat is the primary factor in determining whether you gain or lose weight. Conservation of mass applies in dieting as well as everywhere else. Even if you burn more calories than you consume, if your overall calorie AND protein intake is higher than it would be if you weren't exercising, you'll add muscle mass faster than you burn fat. That's why bodybuilders will eat 4000 calories a day, a large portion of which is meat. Muscles are good, of course, and for a sustained exercise-based weight loss program you do need to have a good supply of muscles, but if that's the approach you take, don't be surprised to see weight gain for the first month or so -- unless you starve yourself, which is generally not good for muscle tone no matter how much you exercise.

[Willie_B]

Looks like I have a 500 and 600 spring for an NR-2 I think.

[TARDISBlue]

Thanks folks. I am picking the bike up on Sunday and hope to do a full tear down after work Monday night. I'll post pictures and such. I think I have an NR4, as I remember having a remote reservoir or what ever that battery shaped thing is on the top of the shock.

At 290lbs and 6'0", I'm mostly fat at this point. That's what I need to burn off. The weight loss is mostly for waist size and look, not actual number. If I were 280lbs and pure bulk, this wouldn't be an issue, but I'd like to fit into clothes I've had to shelve for more than a year. I overeat at meals and graze between because I spend my days at a desk. I'm back to normal size portions and have mostly cut out the snacking, or if I really need to snack I'll grab an apple or a pear instead of Ritz sandwiches or some other delicious fatty food. The bike is a much more attractive option than going to a gym or running. There are some great bike paths around here that lead to the ocean, so I'd like to give them a shot. Might even switch to street tires for the time being.

[TARDISBlue]

Long day. Here are some pictures. I have no idea what the spring rates are, but they're way too soft, front and rear.

[Colin]

Great! sounds like you're really motivated! go for it!
road slicks or whatever, get out there and ride it!

Look what I've found for you...................
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=160820631566&ssPageName=ADME:B:SS:GB:1123



might be too stiff at 750lb/in, but would then be good for on road!

Col.

[TARDISBlue]

Great! sounds like you're really motivated! go for it!
road slicks or whatever, get out there and ride it!

Look what I've found for you...................
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=160820631566&ssPageName=ADME:B:SS:GB:1123



might be too stiff at 750lb/in, but would then be good for on road!

Col.

You, sir, are a gentleman and a scholar. Thank you.

And a question for all. What does the knob at the top of the rear shock do? The one mounted directly on shaft, not the stiffness knob.

[fyrstormer]

The NR-4 shock has two adjustments. The knob on the side near the remote oil canister is the compression damping adjuster, and the knob on the end near the pivot is the rebound damping adjuster.

Put a little oil on the shock threads before you crank down on the spring, if/when you need to adjust the spring preload. The grey threads may be anodized aluminum, but even anodizing wears out eventually. Oil will help prevent that.

Don't put slicks on the wheels. Maybe newer tires with shorter knobs, but not slicks. As long as you're riding a mountain bike, you should be able to take it off the pavement from time to time without risking losing control -- especially if you weigh almost 300lbs, you don't want the tires to wash out if you hit soft dirt while dodging someone on the bike path. Anyway, the rumbling you hear and feel from the knobby tires is wasted energy, and if you're trying to burn calories, wasting energy is precisely what you need to do.

[TARDISBlue]

The NR-4 shock has two adjustments. The knob on the side near the remote oil canister is the compression damping adjuster, and the knob on the end near the pivot is the rebound damping adjuster.

Put a little oil on the shock threads before you crank down on the spring, if/when you need to adjust the spring preload. The grey threads may be anodized aluminum, but even anodizing wears out eventually. Oil will help prevent that.

Don't put slicks on the wheels. Maybe newer tires with shorter knobs, but not slicks. As long as you're riding a mountain bike, you should be able to take it off the pavement from time to time without risking losing control -- especially if you weigh almost 300lbs, you don't want the tires to wash out if you hit soft dirt while dodging someone on the bike path. Anyway, the rumbling you hear and feel from the knobby tires is wasted energy, and if you're trying to burn calories, wasting energy is precisely what you need to do.

Thank you. I'm going to with a less aggressive tread, maybe a hybrid, just so I don't burn up brand new, perfectly good, aggressive trail tires.

[fyrstormer]

I like Michelin Country Dry 2 tires; they're $18 apiece, they have a uniform tread pattern from center to shoulder so there's no change in ride feel while leaning, the blocks are short and staggered so they don't buzz very much, and they can handle going off-road a bit.

My previous tires were Michelin Wildgripper Jet, which is still available but with a different name, but the hybrid tread was actually kind of annoying on pavement; smooth in a straight line, very grumbly through corners, because the center tread was made of low-profile chevrons and the shoulder tread was traditional blocks. Might've been a bit more efficient than tires with knobs all the way across, but the change in ride feel when cornering actually made the bike feel more twitchy than it is.