Slowtwitch Forums: Triathlon Forum: rear frame dropouts

Bike Shops Coaches Fitters Race Calendar NEW Running Stores Stack & Reach Training Log Triathlon Clubs
		MAIN INDEX	RULES & LEGEND	LOG IN

Search for (options)

Newsletter Signup

Slowtwitch Forums: Triathlon Forum:
rear frame dropouts

kustom

Feb 10, 03 1:00

Post #1 of 5 (125 views)

rear frame dropouts	Can't Post

Greetings all,
I'm presently looking at getting a custom frame built using Columbus Altec aluminium tubing, they conveniently offer a seat tube with a rear wheel cutout. In order to tuck the rear wheel in nice & tight I'd like to use rear-facing dropouts (preferably with adjustable screw stoppers) Columbus only offer 'standard' drop outs. The only other thing I've found so far is track dropouts (with no derailleur hanger)
Does anybody know of manufacturers that offer this type of dropouts for custom frame building?
Also - any consensus on what nominal outside diameter a 700C X 23 tyre has? (it's not 700mm which is what the michelin website suggests...)

Cheers

gerard

Feb 10, 03 5:36

Post #2 of 5 (117 views)

Re: rear frame dropouts [kustom] [In reply to]	Can't Post

As for the diameter of a 23mm tire, the manufacturers don't even agree on how big to make these, let alone that they would give the right dimensions. The difference between two 23mm tires from different manufacturers can be as large as the difference between a 19mm and 23mm tire from the same manufacturer. And then there's the difference between clincher and tubular. Years ago we measured dozens of tires to find out the diameter, and the reason we developed out rear-entry dropout is that the differences were so big.

As for who sells a rear entry Alu dropout for road with setscrews, I don't know anybody.
Gerard
Cerv�lo SA

Note: This forum is not my Inbox. Please choose: Slowtwitch cust. service or Cerv�lo customer service.

ajfranke

Feb 10, 03 5:49

Post #3 of 5 (107 views)

Buy the P3 [In reply to]	Can't Post

What Gerard is too polite to tell you is that you should buy a P3. Great bike. Rear wheel cutout. Horizontal dropouts. It is available in lots of sizes, so fit shouldn't be a problem.

You may have a good reason for a custom bike, but if it isn't a really good reason, think about the Cervelo.
____
This forum is going to be a place of civil discourse, and those who wish to foment hate and discord are no longer welcome here. -- slowman 11/8/04

Art Franke

R10C

Feb 10, 03 6:57

Post #4 of 5 (88 views)

Re: Buy the P3 [ajfranke] [In reply to]	Can't Post

Sure - Cervelo are nice (cough! cough!, did I say that?) (kidding)

BUT...nothing beats a full custom for soul. Soul is very important in a bike. A custom bike and a handshake with the guy who built it, and knew who the bike was for before the torch was litis very cool. Soul will mean allot to a rider who knows that he is on "his/her" bike. Made just for him.

And...if you really want something special, you can have darn near any advanced machine shop cut you drop outs out of darn near any material you want. I have a buddy who had a local company "water cut" his drop outs. It was an "After hours" deal that took the machine shop about an hour to do - cost him $200.00 for the work, and his initials are in the drop out much like the Litespeed "L" is in theirs. He also had his Social Security number etched into the BB shell as his serial number...that is cool.

----------------------------------------------------------

f.k.a - Record9, Record9ti Record10, Record10ti, Record10Carbon, but not SuperRecord11 as there are no bar ends.

(This post was edited by Record9ti on Feb 10, 03 6:58)

brider

Feb 10, 03 7:56

Post #5 of 5 (66 views)

Re: rear frame dropouts [kustom] [In reply to]	Can't Post

[reply]Also - any consensus on what nominal outside diameter a 700C X 23 tyre has? (it's not 700mm which is what the michelin website suggests...)

Cheers[/reply]

The bead seat diameter of a 700C rim is 571mm. You'll get pretty close by adding 23mm to 571 to get 594. Why not add 23x2? Well, for one thing the round cross section of the tire will rest partially inside the bead seat, and the deflection of the tire when weighted completes the halving (or pretty close).

As for rear-facing dropouts -- if you're going custom, any builder should be able to cut their own dropouts from plate -- that's what TiCycles did with mine.
---------------------------------------------------------------------
Non-racing member of Team Zoot/GU and part of the ST PowerCranks review squad