Track Geometry Questions
So i'm hoping to get into track cycling eventually, and i'm completely lost on geometry. So far I think I've figured out that there's three different types of geometry. Pursuit, Sprint, and that all-round kind (is it called omnium, or am i just making that up?). What are the differences between these? Where would the debernardi or tsunami frames stand in all this?
Also, i know in cyclocross, they advise to size down one size. Is there any rule like that in track cycling?
And does anybody have any positive or negative reviews on either the debernardi or tsunami frames? Right now I believe my plans are to buy the tsunami and set it up as a pursuit type bike and train for individual and pursuit races here at penrose park 'drome in saint louis. Then eventually i'll build up a sprint bike for mass events over this summer or next summer at kissena. Does that sound like a decent plan? I don't really want to buy a built up bike like the bianchi pista because, well, I really like building up bikes myself and I rode at penrose once before and I loved it, so I'm pretty sure I'm gonna be hooked on track racing.
People tend to advice go down one size because they dont realize that a track bike has the BB like 1 cm higher than a road bike. I'm guessing they do that so they wil be able to put their feets in the floor easyly when they ride in the street???? As i said before, they dont realize the BB is higher.
My recomendation is to get the same size of bike u have right now. Or something similar. About the angles looks like you just want to start on this track matters so get any entry level track bike, fuji, bianchi or even go to ebay and something in steel that probably will be better than a brand new fuji and bianchi pista, but it will cost u more. Thats all u may need untill u get used to it. Besides, if u r good enough u'll win the races riding any junk. Thats other thing people dont realize... in a 30 Km - 50 Km per points race after the 1st half no matter what bike u use, u'll be tired anyways, make sense, right? Get good and reliable stuff, no matter if its heavier than the average but get super stiff stuff, the same for the frame... as stiffer the better. WHy? because u wont lose energy, thats the point right? Oh! use TUBULARS!... clinchers are for aficionados
ps: just teasing about the clinchers ok? but after all a race bike isnt a race bike w/o tubulars
so much for physics
I thought the higher BB was for clearance on the bank.
All I can tell you about is the Tsunami. I ordered it thinking that I would save money on a frame which seemed to resemble in the pictures the Fuji Pro and Pista Concept. The frame is constructed similarly, with near identical aero tubing. The fork looks identical also. Here is the problem; the steel? inserts in the track ends are a joke. They are made crudely from two pieces of metal welded together. They are not straight or even. It was nearly impossible to slide a standard 120mm wheel in there with out pulling the seatstays apart-and even then the nuts did not rest flush against the inserts.
Then, I noticed a ding in the seat tube and the top of the head tube was pressed/caved in. The threading on the BB was very rough and the seat tube boring was also bad. While the paint is not a functional issue per say, and I was planning on painting it anyway, there was lint and what resembled a small splinter in the paint.
Needless to say, I returned it. I hope that I have better look with the Colnago Dream I found on ebay!
There is really no need to have two bikes. Find a frame that fits you properly and just have a pair of bars/stems. If you limit yourself to one type of event, you will soon notice that you will not get alot of riding time during track events. Think about it, you are going to go all the way to your Velodrome, race for maybe ten minutes and go home? Why not have one bike, two combos and be able to do every event? Check out the Van Dessel Drag Strip Courage bike Philosophy if you don't believe me.
When I was racing in New York, 98% of the guys had one bike and others would still tt/pursuit with drop bars!
hm...good points. i might have to rethink this all. so far right now i have some deda track drops, a nice oval fork and a disc rear / deep front wheelset (and yes, they're tubular). maybe i'll just try to get a cheap regular wheelset for mass start events and stick with one bike. i don't know what to do about the frame anymore. well i'll have time to figure it out. this was supposed to be a winter project for me, but i don't know if i can last that long!
it is!... but people tend to buy one 1cm smaller frames because of a floor/feets clearance in the street. THats why the rule for some is "get an smaller frame"
Originally Posted by humble_biker
[QUOTE=Walkercycles]for the OP in this thread...
So, whats all this mean? You can use a mass start bike for any track race, by making simple adjustments to position, but you wouldnt sprint on a pursuit bike, or vice-versa.
I agree with mr walker. Usually a persuit machines are more hmm.. relaxed bikes... well if u r good enough u'll be able to win any race even using a bed with wheels... and I have seen those cases many times.
Cant remmber his name anyways, a rusian kid who won the road WC when he was a junior by the begnning of the 90s. I saw his bike and was a real desaster but he won a WC in it. Old 70's frame with really old stuff in it, but we kicked ass using that yunk!... I think he is in professionals in europe right now but since i cant remember his name who knows where is he right now.
ps: i love mr walker work. wonder if would like my Del valle. Btw, who is doing your paint jobs mr walker?
Overall frame sizing isn't about standover height. On the track, if you need to straddle your top tube, you're in trouble. Bottom bracket heights are rising in current track frames -- most keirin frames these days are being built with 50-55 mm bottom bracket drops, Looks are built with 40-45 (depending on size), and BT's come with 40 standard now. That applies to track frames used for all purposes, including pursuit.
This just means you have to watch your top tube, rather than size your frame downwards. If you decrease your frame size, you basically drop your bars relative to your saddle. Remember that on the track you're in the drops all the time, while on the road you size your frame assuming you're on the hoods or tops most of the time. Plus, track bars tend to have significantly greater drop compared to road bars. So all told, even assuming you want a somewhat more aggressive position on the track, you still have to breathe and you still have to match your position to the ideal lower back curvature you generate so you are optimizing the use of your hip extensors and gluteals. Add to that the fact that if you are switching back and forth between road and track bikes during a season, you don't want to injure your back with position changes -- on the track in particular that's a great way to put yourself out of commission for a while. Lastly, you also have to take into consideration whether you are going from a threadless to threaded headset, change in head tube length (apart from what you get with a frame size change), and other matters that change your stack height.
So ... You should try riding some loaner track bikes at a velodrome in a couple different sizes at least to get an idea of what works best for you. It's a personal matter, not a general rule. I actually ride a Nagasawa that's larger by a centimeter than my road frame, because I'm dealing with a negative-sloped stem plus deep drop on the bars. And in a keirin you're on the track long enough to need to breathe properly, especially since you're either behind a motor or another rider most of the time. Plus, you need to be able to look up and watch not just the wheel in front of you, but all the riders ahead of you -- if you don't have the flexibility in your neck and shoulders to do so, you're asking to be the back end of a big crash.
Talk about putting the cart before the horse.
Originally Posted by 11.4
If so, then that's what most Japanese professional keirin racers do as well. Dutret, it's actually the right way around. Keirin frames and equipment are sized around European frame sizing standards of 20-30 years ago. At that time, frames were sized larger, with less seat post showing, and a negatively sloped stem was used to get an appropriate drop to the bars. Nowadays it's just the opposite, with long seatpost extensions and track riders using steep rises on long stems with lots of spacers to get their bars high enough. I was watching some Australian riders on BT's at Worlds this year riding the madison with a good four inches on spacers and a stem that looked to be at least 45 degrees up from horizontal. My own sprint frame has a riser stem and a lot more spacers than I ever use on the road. It's just a different philosophy in how to design a track bike, which is something that has oscillated back and forth over many years. I can't remember any point in time when a horizontal stem was ever actually in widespread use on the track -- it was either pointed up or pointed down at all times. So either the cart has always been in front of the horse, or never has been. Your response just seems to be a glass-half-empty one. Either method works fine.
Originally Posted by dutret
The differnce is the old stems were deep drop because the frames had really tall headtubes whereas now the headtubes are shorter so stems rise or drop less. That is the sensible way to go about things. Pick out a frame and then a stem that will fit with that frame. You however got a frame with a really big headtube so that you could use a deeper drop stem and bars. Designing a frame based on a stem is putting the cart before the horse.
Also stems commonly vary between +/-15 now so your assertion that there is never a time when they don't have a really steep rise or drop is absurd.
Since traditional frames (on which keirin frames are based) all had horizontal top tubes, if you shorten the seat post, you shorten the top tube by the same amount. It's eighth-grade geometry. Road styles in the 70's were for a bigger frame, so stems were shorter, seat post extension was shorter, etc. And yes, stems were horizontal. Road frames got smaller, stems started pointing upwards, and more spacers were needed for many people. I have a contemporary track frame that's set up with positive rise and spacers. However, a traditional keirin frame will have a threaded headset with more stack height plus its geometry is designed to be sized larger than a contemporary European frame. You can buy it small, and have a frame that fits different from how a keirin frame is fitted in Japan, and have to go for long stems and more seatpost exposed, but I preferred to build it in the same geometry and sizing used in keirin racing in Japan. Since I've raced on the circuit there, and this bike was built with racing there in mind, I wanted something that was consistent with their normal practice. One can't describe one approach or the other as more "sensible" -- I personally prefer a slightly smaller frame with a threadless headset and a slight rise in the stem, but you can't do that effectively on a keirin frame with standard keirin equipment. Granted, keirin style is old fashioned by contemporary European track frame standards, but once again, I could be riding 4 inches of spacers plus a steep rise on a long stem in order to fit a BT or Pinarello and be looking just as odd. So who are you to tell me that my sizing is backwards, or absurd?
As for your comment about stems, let me point out that my comment was about a Nagasawa which takes a quill stem. The only, repeat only, NJS approved quill stems currently available have negative drop, either 65 degree or 58 degree, and I actually had to meet NJS requirements. Even if I wasn't, I doubt I'd go buy a Salsa steel quill mountain stem to put on a Nagasawa.
Last edited by 11.4; 09-19-06 at 10:22 AM.