power question

[Eden]

And why I litterally throw my body out of the saddle on the down stroke in a max (full power ) seated sprint?

Maybe I'm strange and you all apply max power differently. There have been times in the past in a full biggest gear sprint I feel like if I'm not careful I will seriously pull/tear ligiments and tendons so I back off. 15mph to 27 on a great day 30mph, feels like a very violent and potentially bad thing, not to mention very exhausting.

hmmmm - I really think you should look into getting a comprehensive bike fit. It sounds like it is probably a combination of fit and technique? My first thought was that maybe your cranks might be way too long - hence the feeling like you are throwing your body forwards on the downstroke? It might explain the problem you are having with un-weighting the rear wheel- if your cranks were too long, standing you'd put too much weight over the front of the bike and the rear wheel could slip. You should be careful when sprinting of leaning too far forward - especially now that bikes are very light, and I certainly have this problem, if you lean too far out the rear wheel will slip. It is more common on smaller wheel bikes too, so if you are riding 650's you have to be doubly careful. I have sprinted at 30 mph and above in the past and I never have felt like I am going to do myself any injury - but yes of course it is completely exhausting. That's not to say it doesn't hurt - sure it does, but its not the kind of hurt that feels like tearing anything - its just the used muscle kind of hurt, if you know what I mean?

[CR400]

Not foreward, up like I'm on a stair master. When I'm on the down stroke the leg pushes down hard enough to lift me off the saddle and I'm trying to sit. Until I find a gear big enough to offer enough resistance I can stay down, get tired, or slow down. I also have found many times I may not come out of the saddle but hover just above, I barely have contact with it.

As for fit, two shops have given my numbers for what I should ride and both agree on frame size and such. Both men were from different states even. So it is usually how I sit on the bike. I tried riding a smaller frame for an LT test on a compu trainer. I felt so tight like everything was to close, plus boy did we have to put the seat up. Same thing when I rode a 50cm bike at the shop. My friend who has been riding much longer then me asked how it felt. I told him cramped. Which was what he thought to watching me try to ride. So I got a 52cm.

[Eden]

Well -if you bike fit is good, the sprinting problem may just be practice. It sounds like you may be starting in too low of a gear and that you are not accustomed to a fast spin - you start to bounce when you spin fast? Doing seated high cadence drills (say in the 90 to 120 rpm range, for 10 to 30 seconds at a time. Start lower and work your way up) trying not to bouncing may help. Take your cadence up to the point where you start to bounce, then back off and hold that cadence for a while. Concentrate on keeping your butt relaxed.

When you sprint you want to be in your drops, elbows out (a very good sprinter once described it to me as you want to look like a bulldog - the way they are kind of bow legged) and up out of the saddle (when you get up to speed) - you don't have to be way up. You definitley don't want to be on the hoods when you sprint - you can pitch yourself over the front of the bike! and you don't get as much power. When you get up to a good speed, shift up, stand and sprint. You'll likely find yourself pulling up on the bars and rocking the bike a bit - this is good, just try to not rock the bike so much that you are veering all over the road. It takes practice, so keep at it.

Do keep in mind that even if you bike fits your upper body to a t, you could still have issues with saddle postion (fore and aft) and/or crank length. A quick check that you can do is to put your leg at 3 o'clock and drop a plum bob (you can make your own out of some string and a nut) down from your knee cap. It should fall right about at the spindle of your pedal. That of course is a really quick and dirty way to measure, but it should give you and idea of weather or not you should look into a comprehensive fit or not. If the bob falls well behind or well in front of your pedal spindle then it may be worth it to look into a good fitter - some LBS's have them and often physical therapists can do them at minimal cost to you, as many insurance providers will now cover a bike fit.

[CR400]

Thank you Eden,

I have considered doing the checking of the bike fit with the cranks and seat for a while now. However, I noticed today that my seat can't go much farther foreward. I also wonder sometimes if it is also bad posture, meaning I have a habit of sitting wrong on the saddle. Which pushes my knee farther away from the place it is supposed to be.

As far as cadance that sounds like what I was thinking but wanted input. As far as the sprinting thanks, you are likely the first person to actually tell me how to sprint. Most of this cycling has been just ride the bike, not how to ride the bike right. Which as you know makes a big difference in speed and efficiancy.