Ottrott ST and Spectrum Superlight

[Michael Katz]

A couple of posters had inquired about the differences between the two and now that I've put about 300 miles on the Ottrott, here're my impressions.

Both bikes reflect among the finest in materials, workmanship, and design expertise that is available. Both bikes were fitted and designed based on the same set of ride and use parameters which I requested - quick responsive handling and efficient power delivery for testosterone laden group club rides, stability for high speed descents, and absorption of road buzz and comfort for century rides. Not withstanding the identical design objectives, they are very different bikes reflecting distinct "design signatures" of their respective designers.

To put my impressions in an objective context, here are the specs for both bikes:

Spectrum Superlight -
Top Tube - 55.2 c-c @ 3 degrees
Seat Tube - 56 c-t (54.5 c-c?)
Head Tube - 13.3
HTA - 73
STA - 73
Stem - 10 cm @ +10
Fork Rake - 4.5
Chainstay - 41.5
Wheelbase - 98.4
BB Drop - 7.5

Ottrott ST -
Top Tube - 54 c-c @ 3 degrees
Seat Tube - 51 c-c
Head Tube - 12.66
HTA - 73
STA - 73
Stem - 10 cm @ +6
Fork Rake - 4.3
Chainstay - 41.5
Wheelbase - 96.77
BB Drop - 8

With its shorter top tube and seat tube, the Ottrott both feels and is a smaller bike. However, both bikes fit very well. The Spectrum has a more aggressive feel to its upper body positioning, with its longer reach, that matches its handling characteristics very well. The Ottrott's upper body position is more relaxed, however, for long rides but does not in any manner impede its handling characteristics. From what I've seen of Spectrums, upper body positioning tends to be more stretched out with longer top tubes than seat tubes as compared to Serotta's which tend to lean towards "square" designs with shorter top tubes compared to seat tubes (the Ottrott's seat tube would have been a 54 w/o the slope in the top tube, the Spectrum's seat tube is about 54 c-c). In terms of upper body comfort, the nod goes to the Ottrott. Spectrum gets the nod for a racey stretched out feel.

Both bikes handle magnificently. The Spectrum has extremely responsive but neutral handling that begs you to push the limits in each curve. It tracks like on a rail but I can change my line with the speed of though while maintaining complete stability. High speed descents are rock solid. The Ottrott also has extremely responsive handling whose limits I have yet to fully explore but which invites me to do so with confidence in every curve. It makes me feel like a "boy racer". It is also rock solid and stable on descents and responds without a twitch to changing lines mid curve. The bikes differ in handling in that the Ottrott has a noticeably more nimble and quicker front end. The Spectrum feels a bit more solid on high speed descents, which is not to suggest that the Ottrott is deficient in this regard. It's not at all. The Ottrott simply feels like a faster handler and the Spectrum a bit more solid during high speed descents. Both, however, provide more handling, responsiveness and stability at speed than will ever be tested by mere mortals.

Both bikes are also stiff through the drivetrain and efficiently deliver without flex all the power my 185 lb carcass can deliver. The Spectrum delivers the power with a sense of "thrust" that makes you aware of the acceleration while the Ottrott provides turbine like smoothness that can feel deceptively effortless. On a ride last night, I suddenly found myself at 28 mph in a paceline and had no perception of the effort it took to get there (unfortunately, the perception of effort to stay there for a prolonged period was quite evident. I blame that on the motor and not on the bike). Also, the Ottrott seems to keep the rear wheel on the ground better over rough patches and undulations in the road.

In the area of vibration absorption, the Ottrott is noticably better than the Spectrum. Whether it's the carbon tubes, ST seat stays or both,who knows but it is noticable. Which is not to say that the Superlight is a slouch in this area. Not at all; I've done back to back centuries on the Spectrum and have never felt beaten up by the road.

Bottom line - both bikes are a total blast. If anyone wants additional info on my impressions of both bikes, feel free to ask either in this thread or through a private message.

[Sandy]

Superb and informative analysis. Extremely well done.

Sandy

[Kevan]

a similar experience in his 2.8 mph paceline. :D


Sorry, I don't mean to detract. Both bikes are indeed beauties.

[Smiley]

I would like to know the TRAIL number for both bikes as this will tell and explain what you felt in steering for both frames and what are the BRAND of forks used please. My guess is Kellog gave you more trail on the Spectrum versus the Serotta's typical trail of around 5.8 ? Thanks for the added information as I am designing my own Ottrott for 2005 and would be leaning to a trail of around 6 versus the standard default of 5.8 just to make the bike track even more stable than normal. Ask Sandy about that one.

[zap]

Smiley, interesting.

My Klein's trail is 6 :)

[Michael Katz]

Smiley, the fork on the Spectrum is a Wound Up. I don't know the trail. On the Ottrott, the fork is an F2 with 5.9 trail. Hope this is helpful.

[Sandy]

The trail on my Ottrott is 5.9 cm. Both the hta and the sta are 73 degrees. F2 fork. The rider is old, slow, and fat. He is getting older, getting faster, and losing fat. 10 pounds down and 25 to go. I am seeing a nutritionist tomorrow.
Goal of 190 pounds.

I would say the I must stay on top of the Ottrott a little more than the CSi. The Ottrott seems a little quicker handling, but remarkably stable at speed.

Seeking Slim Supersonic Speedy Sandy

[ericmurphy]

Smiley, interesting.

My Klein's trail is 6 :)

My Legend's trail is 5.9, which Kelly said would lead to a great handling bike, especially on crappy pavement. He was, of course, right.

[Needs Help]

Hi Michael,

Thanks for your impressions.
Both bikes were fitted and designed based on the same set of ride and use parameters which I requested -

quick responsive handling

and

efficient power delivery for testosterone laden group club rides,

stability for high speed descents,

and

absorption of road buzz and comfort for century rides.

But, I wonder how you can characterize those as design objectives? How are you telling the builder anything if you tell him you want everything? It seems to me you have to make a choice somewhere if you are going to give the builder any guidance:

quick responsive handling<---->stability for high speed descents

efficient power delivery<------>comfort for century rides

[Michael Katz]

Hi N.H,
The characteristics I used in my post were really just "catch phrases" that summarized in general terms much more detailed discussions I had during the design and fit process. I spent several hours with both Spectrum and Serotta not only in the fit process but also discussing in depth the type of riding I do, my riding style and the desired characteristics I wanted both with respect to the individual characteristics themselves and the balance of the integration of them into the whole. My point was that both bikes were intended to hit the same design objectives. The differences between the bikes are reflective, I think, of different perspectives each builder/designer brings to bear in the process in interpretting my words and of different design concepts (i.e. "signatures") inherent to each builder/designer. The goal of my post was to was to point out what I think those differences are.

Hope this clarified my original post a bit.

[Michael Katz]

Sandy's comment of needing "to stay on top" of his Ottrott more than his CSI mirror's my experience compared to my Spectrum. This is most evident if I have only one hand on the bars, like when reaching for a water bottle, and I hit road imperfections. The Ottrott's front end is more reactive - not overly so, but none-the-less more than the Spectrum. It also seems to dive deeper into a curve faster with a given level of input than the Spectrum consistent with my sense that the Ottrott's front end is more nimble and quicker. Which is not at all to denigrate the Spectrum's handling. Within the range of "neutral responsive handling", the Ottrott leans towards "quickness" and the Spectrum towards "stability".

[93legendti]

.

[Climb01742]

93--interesting that your strong feels more comfortable to you. can you identify why?

[93legendti]

.

[Climb01742]

interesting. the one area where my former ottrott shone was soaking up road noise and vibrations. my IF CJ ti -- a compact -- is very comfortable but i'd say the ottrott just beat it in that department. as i said, interesting.

[93legendti]

.

[kansasbluestem]

Does the Ottrott ST wobble up front when riding in the upright position with both hands off the bars? I couldn't ride in the upright position while riding my '94 Serotta Colorado unless I braced one thigh against the top tube because of the wobbling.

[Michael Katz]

There is no wobble at all. I can ride with no hands on the bars without any inherent front end movement (other than movement caused by my own biomechanics during a pedal stroke - i.e my form probably sucks). If I hit road imperfections without both hands on the bars, the front end is more reactive and quicker to react than my Spectrum. As I've mentioned before, the Ottrott is a quicker more reactive front end than the Spectrum and the Spectrum is a more stable front end.

[davids]

"while eating a banana"?

[michael white]

I've been looking high and low for a bike

for eating bananas no hands.

[jl123]

Michael,
It would be great if you could post some pics! Thanks, JL

[tch]

looks to me that both bikes would fit me just fine. Wanna ship them to NW Ct so I can personally check out the differences and respond to your evaluation? I think a trial of about 5 years ought to give me enough time to decide....

[Fivethumbs]

I plugged the numbers into and online trail calculator and these are the results:

The Spectrum with 73 head angle and 4.5 fork offset has a trail of 6.0.

The Ottrot with 73 head angle and 4.3 offset has a trail of 6.2.

Everything I have read about bike geometry would suggest that the Spectrum would be the quicker handling bike while the Ottrott would have the greater high speed stability. I wonder what is making your experience the opposite? The longer wheelbase of the Spectrum maybe?

[Archibald]

I plugged the numbers into and online trail calculator and these are the results:

The Spectrum with 73 head angle and 4.5 fork offset has a trail of 6.0.

The Ottrot with 73 head angle and 4.3 offset has a trail of 6.2.

Everything I have read about bike geometry would suggest that the Spectrum would be the quicker handling bike while the Ottrott would have the greater high speed stability. I wonder what is making your experience the opposite? The longer wheelbase of the Spectrum maybe?
Your trail numbers are off unless he's running cyclocross tires. Should be 55 and 57 respectively with 23mm tires.

What makes the bikes handle differently? Tires, tire inflation, differnt forks, HTA, offset, trail, actual geometry instead of published, BB drop, front center, wheelbase, chainstay length, handlebar reach, RIDER POSITION AND BALANCE ON THE BIKE. I could go on but you guys should get the picture.

I'm sorry, but the whole comparison is ridiculous on its basic premise. Take two bikes that are EXACTLY the same except one has a TT 1.2cm longer, compensate with stem length, and you're going to have differences in the rider's perception of the ride. Now, take two bikes that are entirely different geomentry in addition to the 1.2cm TT difference, don't compensate with stem length and make all kinds of other changes....well, yeah, you're going to have some major differences in handling and response. To try to define the frames basic characterisitics by comparing one to the other using this scenario for anybody but the OP is, as I said, ridiculous.
:bike:

[atmo]

To try to define the frames basic characterisitics by comparing one to the other using this scenario for anybody but the OP is, as I said, ridiculous.
:bike:
gets it atmo.

[Michael Katz]

My original post had two purposes. First, someone had asked me to contrast my impressions of both bikes, so I did. My impressions, no body elses, and certainly not intended to suggest that anyone else would have the same impressions with the same or different geometries.

The second purpose was to comment on and describe what I concluded were some nuances of the "custom" process. At the time, a hot topic in some threads involved different approaches taken by different fit systems and designers. What I found interesting was my experience of telling two different builders/designers that I essentially wanted the same handling/ride/fit characteristics from both bikes and that I ended up with 2 very different bikes (and not a bad thing in this case). I was pondering whether this was a reflection of "design signatures" of each builder and whether my perceived differences could be explained by the objective stats on each bike and if so, which ones with what result.

As to why they handle so differently, I'm inclined to think wheelbase has a big impact. The question I have is why, in the design philosophy, are the wheel bases so different and how does the wheelbase integrate into the other design specs.

Unfortunately, this thread smells like it's about to veer towards judgemental pissing on fellow posters, which is hardly informative and very boring.

[Archibald]

My original post had two purposes. First, someone had asked me to contrast my impressions of both bikes, so I did. My impressions, no body elses, and certainly not intended to suggest that anyone else would have the same impressions with the same or different geometries.

The second purpose was to comment on and describe what I concluded were some nuances of the "custom" process. At the time, a hot topic in some threads involved different approaches taken by different fit systems and designers. What I found interesting was my experience of telling two different builders/designers that I essentially wanted the same handling/ride/fit characteristics from both bikes and that I ended up with 2 very different bikes (and not a bad thing in this case). I was pondering whether this was a reflection of "design signatures" of each builder and whether my perceived differences could be explained by the objective stats on each bike and if so, which ones with what result.

As to why they handle so differently, I'm inclined to think wheelbase has a big impact. The question I have is why, in the design philosophy, are the wheel bases so different and how does the wheelbase integrate into the other design specs.

Unfortunately, this thread smells like it's about to veer towards judgemental pissing on fellow posters, which is hardly informative and very boring.
I hate to repeat myself since I only have about 110 posts left to my internet life here on Serotta but to restate my position: "To try to define the frames basic characterisitics by comparing one to the other using this scenario for anybody but the OP is, as I said, ridiculous." You are the OP. No offense. But...the biggest difference is how you drape yourself over the bike. You have two wildy different bikes, I'm assuming that unless you're the stretchy fella' from the Fantastic Four, you have wildly different position on the bike. Which brings me to my point: you're not really characterizing the differences in the frames, you're characterizing the differences in your fit. Big difference.

[obtuse]

I hate to repeat myself since I only have about 110 posts left to my internet life here on Serotta but to restate my position: "To try to define the frames basic characterisitics by comparing one to the other using this scenario for anybody but the OP is, as I said, ridiculous." You are the OP. No offense. But...the biggest difference is how you drape yourself over the bike. You have two wildy different bikes, I'm assuming that unless you're the stretchy fella' from the Fantastic Four, you have wildly different position on the bike. Which brings me to my point: you're not really characterizing the differences in the frames, you're characterizing the differences in your fit. Big difference.


archie-

i like tall skinny blond girls and curvy short brunette girls....i'm confused as to which one is a better fit.

confused in wichita

[Too Tall]

Reminds me of a circular argument Groucho Marx once had a circular argument.

Anywho,I'm no yes man HOWEVER SteveP is paying long Canadian for me to fluff Archie's opinions. Forgive me.

What bugs me is that these are two dynamite bikes. How about you start over?


"Well, you've wasted another perfectly good hour listening to Car Talk." ...

[Archibald]

archie-

i like tall skinny blond girls and curvy short brunette girls....i'm confused as to which one is a better fit.

confused in wichita
In my professional opinion, based on years of indepth research and testing (much of which was conducted at great expense and risk to my personal safety), curvy short brunette girls fit better, require much less maintenance, and give you much more bang for your riding dollar. Bottom line: You can rely on them when you hit the cobbles.

Tall skinny blonde girls are for weight weenies and coffee shop posers who paint their house walls beige to match their earthtone carpets.

YMMV of course,

:beer:

[michael white]

Archie,

everyone knows you're supposed to get an ugly girl to marry you, but I have so far not been inspired to do that, and have suffered greatly as a result.

but--and sorry about not getting all the in-depth jargon here, but what is the OP? Otherwise I am in agreement. But I don't think the comparison is all that ridiculous: it sounds to me that Michael is enjoying his bikes, as the LB (lucky bastard) damn well ought to, and writing about them is one way of doing that.

[atmo]

...but what is the OP?
eveyone knows that one atmo -

http://www.allaboutjazz.com/articles/otaylor2004.jpg

[SoCalSteve]

Archie,

everyone knows you're supposed to get an ugly girl to marry you, but I have so far not been inspired to do that, and have suffered greatly as a result.

but--and sorry about not getting all the in-depth jargon here, but what is the OP? Otherwise I am in agreement. But I don't think the comparison is all that ridiculous: it sounds to me that Michael is enjoying his bikes, as the LB (lucky bastard) damn well ought to, and writing about them is one way of doing that.

ATMO, sorry for raining on your parade (I'll make it up to you in San Jose)..., but OP= Original Poster

[obtuse]

i was wondering why we were discussing naughty by nature.

[michael white]

thanks.

[pdxmech13]

ride a schwinn and you'll forget about your silly custom bike

le tour, gran sport, varsity

[Fivethumbs]

Your trail numbers are off unless he's running cyclocross tires. Should be 55 and 57 respectively with 23mm tires.:bike:

I don't know what I did wrong. I used these two:

Trail Calcuator 1 (http://trouser.org/cgi-bin/trailulator)

Trail Calculator 2 (http://www.kreuzotter.de/english/elenk.htm)

[atmo]

ATMO, sorry for raining on your parade (I'll make it up to you in San Jose)..., but OP= Original Poster
ron howard is the original opie atmo...

[Fivethumbs]

A Desilu production?

[Archibald]

I don't know what I did wrong. I used these two:

Trail Calcuator 1 (http://trouser.org/cgi-bin/trailulator)

Trail Calculator 2 (http://www.kreuzotter.de/english/elenk.htm)
You used the wrong wheel diameter. A 700C rim is 622mm in diameter. a 23mm tire is 23mm in profile. (23mm + 311mm (radius of 622)) * 2 = 668mm

Enter 668 into your calculator for "wheel diameter" and check your results.

I rule!

[Fivethumbs]

That's very interesting. Thanks for the info. I have a 89 Bottecchia that has a head angle of 75.3 with a fork offset of 40. That makes the trail 46.3! No wonder that sucker is twitchy.

[davids]

ron howard is the original opie atmo...
o.o.p?

http://divinesetcelebres3.free.fr/images/images_diverses/oops%20i%20did%20it%20again.jpg

[davids]

o.o.p?

http://divinesetcelebres3.free.fr/images/images_diverses/oops%20i%20did%20it%20again.jpg
And the original oops:

http://www.cynical-c.com/archives/bloggraphics/oopspage_01.jpg

OK, I'm done now...