English Custom Steel Integrated di2 USB - Updated Pics pg20

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a.davis12
Posts: 259
Joined: Mon May 25, 2009 12:33 pm

by a.davis12

nickel does look hot. i had it on an orange p7. it was great.

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

Received the first draft of the design and geometry today. We're making a few minor adjustments based on my fitting and the builder's concepts. I'll post final geometry once we've reached a consensus. I have to admit, I like actually working with someone to build MY bike, rather than buying parts to get the best fit to a stock frame. This is going to be fun even if not the lightest bike I've ever owned.

Still undecided on di2 though...

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

So we're finalizing the geometry and I'm facing a dilemma...

Option 1 calls for a 983mm wheelbase with a 554mm effective top tube and a 120mm stem to get my ideal position.

Option 2 call for a 1002mm wheelbase with a 574mm effective top tube and a 110mm stem to get my ideal position.

The first would probably result in a more nimble handling bike with a slightly forward center of gravity, very similar to the Ghisallo I am riding now (975mm wheelbase, 555mm top tube, 120mm stem). This was the initial geometry proposed by the builder.

The second would be a more stable handling bike, keeping my center of gravity further behind the front wheel. This was after some revisions based on my fitting data.

So do I stick with what's familiar or go with something new based on the fitting?

BmanX
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Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

What is the bike going to be used for. If it is long days in the saddle then I would suggest option 2.
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

That's the direction I'm leaning toward, but I'm still uncertain. I've never ridden a bike with a wheelbase that long before. I know it's not the difference between a sport bike and a chopper, but it seems pretty dramatic. Maybe I'm the one being dramatic? hahaha

Tristan
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by Tristan

How does a 20mm variation in wheelbase and toptube and only 10mm in stem correction add up? Am I missing something?

Slightly OT but shouldn't these questions be asked-to and answered-by the builder? He's (probably) got more experience than you and should be able to take your description of how you want the bike to ride and turn it into reality. That's why he's paid the bigbucks.
Wheelworks.co.nz
New Zealand handbuilt wheels

KWalker
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Joined: Mon Dec 28, 2009 8:30 pm
Location: Bay Area

by KWalker

Yah, the bb drop and the angles have to be different too to get that reach. I bet he changed at least the sta or hta and probably the rake and/or bb drop.

I don't think its going to be as dramatic unless he did that. My cross bike has the same sta, hta, and all that as my road bike, but it has a different fork rake and 25mm longer chain stays. Its not as nimble, but it takes a specific kind of turn/hill for that to matter. Lots of people I know race their cross frames in crits and do very, very well so I doubt it will stop you, as a recreational rider, from having a bike you really love. I'd go with what you know and already like.
Don't take me too seriously. The only person that doesn't hate Froome.
Gramz
Failed Custom Bike

musket
Posts: 595
Joined: Fri May 04, 2007 5:27 pm

by musket

Tristan has hit it on the head.

The biomechanics of rider are paramount, and the frame geo then designed around that to achieve your preferred handling / comfort.

If your builder is proposing a 10mm discrepancy in reach I'd be dubious.
Don't be alarmed.

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

I have been discussing it with the builder. He is great... very proactive and very responsive. I was just looking for additional input.

I wish I could post the proposed geometries but they are PDF files.

There is a 1cm change in reach between the two proposed geometries. Both share the same hta and sta. My fit numbers called for a 714mm horizontal (virtual) reach from saddle center (sit bones) to stem clamp (handlebar tops). This translated to a 720mm actual (angled) reach. My current setup has 710mm actual reach with a 120mm stem and 550mm top tube. I can't move my seat any further back to get the extra centimeter. The builder used this initial geometry for the first draft of the build plan but I asked him to work in the desired 720mm reach with a 110mm stem. I suspect the right answer is to keep the 120mm stem and get the 720mm actual reach using that instead of the 110mm stem. That gives me the appropriate reach and keeps the wheelbase shorter.

I'll try and post the two geometries for others to see. Again, I trust the builder's judgement more than my own. But I like running my ideas past people to get their opinions. You never know if I may come up some brilliant idea the builder hadn't thought of... not likely, but possible.

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

OK... I scanned the PDF files and saved them as JPEGs.

"Current" is the bike setup as determined by my bike fit. The handwritten numbers are what I was actually able to achieve with the stem, seatpost, and saddle I have on the bike. Close, but not exact.

"Version1" was the first draft the builder sent me. It was based on the 710mm actual reach on my current setup using a 120mm stem.

"Version2" incorporated my desire for the 720mm actual reach using a 110mm stem.

Looking at the pictures, it seems the 720mm reach with a 120mm stem will give me the right fight and the handling I desire.

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

Just to be clear, I believe the initial 710mm reach was the result of the "current" geometry numbers I provided him.

xnavalav8r
Posts: 2643
Joined: Mon Jan 21, 2008 12:09 pm

by xnavalav8r

OK, geometry is sorted... and I am happy with what the builder came up with. Still trying to decide to di2 or not di2... that is the question.

BmanX
Posts: 3844
Joined: Thu Nov 10, 2005 5:31 pm

by BmanX

Di2 and see what magic your builder can come up with. I can not wait to see a very cool internal run Di2 in steel. This is going to be GREAT!
BIG DADDY B FLOW
AERO & LIGHT is RIGHT

Cervelo SLC 5960g/13.13 lbs

mrfish
Posts: 1618
Joined: Wed Mar 28, 2007 12:49 pm
Location: Near Horgen, Switzerland

by mrfish

English Cycles? I feel a convergence between your weight weenie ideals and Rob's.

musket
Posts: 595
Joined: Fri May 04, 2007 5:27 pm

by musket

That's a long tt and short ht / seat height, but I guess I see why you need custom.

Di2 is fantastic. Just do it.
Don't be alarmed.

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