speks22

Howdy,
I'm a fairly tall guy, about 6'3" with a long cycling inseam. After a professional fit the other day, my position didn't change much on my bike, nor was I on a bike the wrong size. Though I guess it is very "quick" and short wheelbase ('05 Fuji Team SL) for its size (60cm).

When I was sprinting yesterday in a training crit, and pretty much everytime I sprint, I feel very scrunched up/unstable and my back wheel jumps around a lot. For reference I feel good and stretched out when just sitting and riding normally.

So my questions are these:

What do I need to work on to correct this problem, technique-wise? (i have done some of the really "slo-mo" type training techniques, as written by carpedieme racing, stuff to try and smooth myself out, but hasn't helped much yet, is there more I can try)

When I'm in the market for a new bike, which is soon, what types of things should I be looking for? More/Less trail? Longer wheelbase? More/less rake? (I guess I am asking becuase I'm wondering if it's all technique or if in the future there are things I can look for in the geo of the bike to help me be more stable)

Thanks for input in advance!

ridethecliche

The issue doesn't sound like it's fit based. Sounds like you just need to position yourself better because you're loading the front wheel too much and not distributing enough weight to the rear.

waterrockets 

I'm 6'4", riding on a 60cm Fuji as well.

The hopping is because you are pushing too long on the down stroke. When the pedal comes around the bottom, it can't go any lower, so your down push ends up pushing your hips up. This causes your body to jump a bit, and your much higher mass easily brings the bike along for the ride on the way up.

You can mitigate this somewhat by shifting your weight back a bit, but this will likely have you feeling more scrunched, so I don't do it. I keep my weight forward, and can generate 1700W without a hop.

I would recommend some really high cadence (downhill/small ring) sprints to smooth out your stroke.

Also, work on swinging the bike. At the top of the stroke, the bike should be leaned toward the top foot, and you pull it to the other side as the pedal goes down. This has the effect of lengthening your stroke and allows your arms to generate some of your sprint power (probably good for 200W or more).

Being tall, you want to keep your torso low, and I feel that's a bit easier to do if I'm forward. Another note about being forward: it's much easier to handle lower cadence if you move way forward. It's similar to lifting a heavy box: it's just easier if your hands carrying the weight are closer to your core than if you're holding it out in front of you.

carpediemracing 

Waterrockets describes this "weight the back wheel" thing in some long past post.

Some rear wheel movement is inevitable, but a skilled rider will be able to stay upright on extremely slick surfaces. Check out Petacchi sprinting in the rain - his rear wheel is moving around and guys around him crash when their front wheel just washes out. It's a recently past Giro, 2005 or something, where Petacchi was unstoppable. One stage ended in the rain and about 20-30 guys crashed including Bettini in the pink jersey. Petacchi not only didn't crash, he was sprinting really hard, really fast.

/\ what WR said

shovelhd

What WR and CDR said.

I'm smaller than you, and not a pure sprinter, but I can hold my own. I think the key for you is going to be practice sprinting at high cadence out of the saddle. My sprint starts at 95rpm and goes to between 130-135rpm depending on many factors. At these cadences, you must have a smooth stroke to produce power. Note that smooth stroke doesn't mean no rocking from pulling on the bars, I mean your pedal stroke.

When sprinting out of the saddle, your body is like a scissor jack, or one of those telescoping wall desk lamps. Your torso is the lamp, and your knees, hips and ankles are the pivot points. To avoid hopping the wheel, your body's center of gravity has to be balanced over the bike throughout the pedal stroke. It will find it naturally with practice at high cadence. Once you know what that feels like, you can adjust your initial jump to keep from hopping the wheel.

carpediemracing 

I had the wrong year before. At 35 seconds or so they do a slower-mo, from the front shot. Pretty incredible how he can put down massive power on a wet road, throw the bike, and stay upright.

I haven't really experienced a rear wheel hop in sprints so I don't have advice on that.

I usually lift my front wheel when I'm going hard, planting it on each down stroke, one side then another, left, right, left, right, like a slalom skiier.

I know the blog is hard to search (heck I can't find my own posts in it without going into my own dashboard) but there are bits on max rpm, max optimum sprint speed.

I think my posts are more about "if you do the stuff enough you'll get rid of bad habits". I know that I used to bounce a lot, but to increase my max rpm I had to learn instinctively to stop the bounce. Now I don't bounce, it's like my hips are bolted to the frame. They remind me of my violin practice drills, things that focused on one particular aspect of playing violin, like bow pressure, changing strings, finger dexterity, tone, intonation, etc.

*edit* those violin practice stuff didn't make me play music better at that moment. But later they really helped. For violin it's all about form and intonation, without both you're limiting yourself. With cycling it's about form and tactics; optimize both and you're good to go. Well those and fitness I guess. And your parents' genetics. Genetics limits violin too - ironically for me it was the speedwork that I just could not conquer. I'm not very coordinated nor do I have good balance. Therefore I'm a cyclist

carpediemracing 

An addendum. The best man at my wedding, my good friend that hosts me in SoCal each winter, my former Primary Leadout man, is about your height, rides a 63 cm Fuji (blue/silver Scandium), and is a decent sprinter himself. He has a very long inseam, maybe 35"?, and his bike fits him fine, he is okay sprinting on the thing.

His stem is pretty low, saddle high, and he has a smooth pedal stroke. Hasn't raced since 2001 but he still kicks my butt when I go out there.

speks22

Thanks for the input so far everyone!

Ok, so for the most part sounds like I just need to continue working on technique. I kind of figured this, as when practicing I feel great and smooth sometimes. (Try and do alot of the things mentioned, but obviously its not ingrained enough yet) But when I really, really go for it, like all out effort in practice or like the crit yesterday, I just get to the point where I feel like I still have more power to give, but I get sketched out because of the hopping/unstableness. (Of course it would help if I had some sort of powermeter to see if this is actually true but not yet, its on the list of things to get)

Waterrockets- I think you ride the SST 60 cm right? As far as my second question went in terms of things to look for when purchasing my next bike, it seems that the wheelbase on yours is a big longer than on mine, I would assume that I should be looking at numbers like this more? (I ask now because in my fit I was/am flexible enough to fit on alot of 58s in terms of stem height, but seems like the longer wheelbase would be to my advantage. My cycling inseam is 36.5" by the way)

Also anyone else who would like to offer some insight on that question, please do!

bernside

I am your height and have the same inseam as well.

I had a problem lifting the front when I started, then briefly the rear when I first got my new bike.

Things that have helped me are higher cadence and getting lower.I now start my jump with cadence around 95 and run up to 125 - 135 like someone else mentioned.

As for getting low, I am running more seat to bar drop this year which means I stay on the hoods a lot of the time but the drops are perfect for sprinting. Think about getting lower instead of forward (like Cav... except bigger...and slower )

CDR's advice is the best though - just do a lot of it.

bernside

CDR - thats an awesome video!

I had missed that one

carpediemracing 

I have the full DVD. It has slo-mo that's incredible (apparently Italians like their slo-mo, but not as much as the Germans - it's something you learn with F1 coverage). The slo-mo is really educational because you see how much movement there is with the back wheel. Front wheel, not so much, rear wheel, lots of movement. It goes to show that the front wheel keeps you upright. It also shows that these guys are at 100% when they're sprinting - they are totally at their limits.

waterrockets 

That's correct, 60cm SST. This bike is a lot shorter than my previous bike, and I actually like it with the short wheelbase. I don't think the wheelbase has much to do with your hopping problem. With our big bikes, we're at a disadvantage when it comes to cornering, and a longer wheelbase just makes it worse. If I thought I could fit on a 58, that's what I'd ride. I already have a 130mm stem, and 140s are rare enough that I didn't want to mess with it -- plus, that's just a bit too much leverage for one pipe to deal with, IMO.

speks22

Thanks, all the info and knowledge I can intake helps, 'ppreciate it!

Nick Bain

I never had wheel hop after getting a shorter stem.