I just ordered a IRO Mark V frame from my LBS (Natural Cycles - Winnipeg) and here is my spec. I'll be commuting, training and JRA.

Mark V frame
Ouzo Comp fork
Race Face Real Seal HS
Norco 31.8 4 bolt stem
Profile 31.8 bullhorns
Tektro brake lever
105 front brake
stock seatpost*
Titec Berzerker saddle
UN 72 BB
1989 XT 175 crank**
eggbeater pedals
46t chainring***
IRO track hubs
Miche 18t track cog****
DT comp spokes
brass nips
Weinmann rims (very tall aero, good rep at shop)
tires spec armadillo*****
SRAM PC 68 chain - I use this chain on my SS and geared bikes

* Any good seatposts in 26.0?
** Shop thinks these won't be too long. All my other bikes are mtb and I can spin pretty good with them. These are from my parts bin.
*** I think 46/18 might be too big to start
**** As I understood this is a carrier that a splined BMX cog slides on to and is secured with a lock ring.
***** I know nothing about road tires but the armadillo seems to have a good rep. I was going to get 23 - 25.

Am I out to lunch with this build?

Am I crazy or just having a mid life crisis?

um... I like my armadillos. other than that and my new dura-ace cog, my bike's all old and cheap. If it rides it's good.

"other than that and my new dura-ace cog, my bike's all old and cheap. If it rides it's good."

stop bragging about all your new parts. I'll get around to replacing that worn 16t sometime.

You may want to stay with 170mm to 172.5 cranks at the max. The ability to spin is less the problem than the chance of pedal strike on cornering. Just remember that you're not going to be able to just lift the inside pedal anymore. Other than that it looks to be a super setup. Congrats. Remember to post pics when you get it done. We love the pics.

make the tires 32s and no worry 'bout pedal strike.

Ooops, with the 'near-nose-bleed' height of the Mark Vee's BB, a 175mm crank would keep the pedals further from the ground than 165mm on say a KHS Flite 100.... Actually, 177.5mm on the Mark Vee is about the same. If you like a long crank, the Mark Vee is definitly your bike. The Mark Vee's BB is 12mm higher than the KHS.

Jim

As for 26.0 posts, no-one seems to make a good one these days but at least you can get cheap generic ones. But back in the day people did, ie such as Campagnolo:
https://cgi.ebay.com/ws/eBayISAPI.dll...101015929&rd=1

If you dig around you could probably find something that works pretty well.

Hi there,

Congrats on the Mark V. I have one too and it is a sweet ride. About seatposts: https://sheldonbrown.com/harris/french.html#seatposts has a very nice one. I run a black kalloy on mine (was 20 bucks). 46x18 should be fine, I never had any problems with this gear combo. Don't get the Miche cog. I strongly recommend an EAI. 25mm tires will work, just don't get anything bigger. Don't know about the weinman rims. I had some of their cheapies and they sucked beyond belief. Do not get a bigger rim than 700c. I got the complete wheelset from IRO with velocity deep vs. So far these have been great.
The rest sounds great. Enjoy!

46 x 18 is not very radical. You can handle it, and may soon want more.

The Mark V is a nice frame.

Great job. Keep us informed.

I am changing the rims to DT RR 1.1, settled on Specialized 23mm All Conditions Pro, and will go with a regular track cog. They should be fast wheels, I can use all the help I can get.