Trail, Stack & Reach

[Nomadmax]

I grew up on and raced "traditional" frames from Italy and Belgium, and still ride them. They handle and ride the way I want, fast or slow, never making themselves known to me while we go down the road, climbing or sprinting. I have but one modern bike amongst my fleet of Merckxs and Guerciottis. To say that bike is the worst handling bike I've ever ridden, and that includes my 1971 Schwinn Varsity, would be a massive understatement. I only knew how to ride and race, math was never my strong suit, heck, let's be honest, it's a suit I don't even own.

I have two questions that may or may not have clear answers.

What is the trail number (in general) that won't try to flop the front wheel from left to right when out if the saddle climbing or sprinting?

Note:
The bike I'm talking about has (with 700x38)
Trail
77mm
Wheel Flop
24mm
Mechanical Trail
73mm

60mm? Is that the magic number?

I have no idea what the trail numbers are for any of my current fleet. All I know is that they do exactly what I want, and nothing I don't.

Second question.

What would be the general stack and reach on a 55cm square frame with a 130mm head tube?

I'm in the mood for a new bike, Ti frame (maybe carbon w threaded BB), disc brakes, external EVERYTHING, clearance for up to 35mm tires and a stack and reach that will put my 72.5cm saddle height no more than 4cm higher than the tops of the bars. Without using a stack of spacers. Most importantly, it has to be invisible beneath me when it comes to climbing and sprinting.

I think the two questions will allow me to search for the bike on my own, once I can compare them in my mind to what I've always ridden. If that makes ANY sense. Thanks for all answers, including those at my expense for having both feet firmly in the past but intrigued by the "kinda" modern.

[Hilltopperny]

You have to account for stem stack on those older race bikes. 13cm head tube for a 55cm frame is definitely more of race type stack, so if you only want 4cm of drop then I would look for something a bit longer given that most modern bikes do not look to have as much stack when accounting for quill stem and external headsets of old.

I know nothing about trail, so no help there, but I ride similar sized bikes and if I only wanted 4cm of drop on a modern bike my headtube would be between 14-15cm.

Sent from my SM-S127DL using Tapatalk

[NHAero]

The trail and flop values you cite would drive me nuts.

A very reasonably priced Ti frame is Habanero Cycles. Their road frame in a 55.5cm TT has a 73 HTA, so with a 45mm fork rake and a 700x28 tire you'd be at 58mm trail and 16mm wheel flop. That's pretty much what my Firefly road bike has and its a lovely bike to ride. If you look at build sheets posted for road bikes Dave Kirk has built, you'll see trail numbers of 56-58mm quite commonly.

Habanero lists the stack and reach at 570mm and 386mm, so a bit more stack than many road frames in that size. They can supply any of various forks with the frame.

I have no interest in Habanero, but I'm a satisfied customer riding one of their cross/all road frames, and found them very service oriented people and the pricing was good. Lynskey would be another possible choice, but watch for slack HTAs and too much trail and flop on some of their frames.

[unterhausen]

Classic race bikes had around 60mm of trail. Many gravel bikes nowadays have the option of a 55mm rake fork, which gives 62mm trail with a 71 degree head tube. So not too bad. If you are stuck with a 45mm fork, it's going to have a lot of flop and it will take 2 rides before you are used to it.

[thwart]

Some related and possibly helpful info here: https://forums.thepaceline.net/showthread.php?t=291837

Yeah, that does seem like a high trail bike… which would be a rather dramatic change from a standard road bike geo.

[benb]

I have two relatively modern high trail/whatever bikes and I kind of have that feeling I prefer the classic handling too. I don't know what the answer is. One is steel and cheap and the other is carbon and expensive but both are/were marketed as being better on bad roads than a more classic road bike.

The one thing I'd say is my bikes that have these "issues" are quite temperamental with fit.

One of them gets weird if there's not enough weight on the front. I have that bike setup as a commuter right now and it's extremely important I don't put the saddle too far back.

But the other one I have setup aggressive and it seems more nervous aggressive.. I need to actually back that one off. It bizarrely handles so much better with a more upright riding position.

I feel go back to bikes I had before 2010 and they were much more tolerant of variations in fit or sizing?

[spoonrobot]

60-65 would feel pretty good

We have the same saddle height, and apparent distaste for high trail.

What would be the general stack and reach on a 55cm square frame with a 130mm head tube?

I'm in the mood for a new bike, Ti frame (maybe carbon w threaded BB), disc brakes, external EVERYTHING, clearance for up to 35mm tires and a stack and reach that will put my 72.5cm saddle height no more than 4cm higher than the tops of the bars. Without using a stack of spacers. Most importantly, it has to be invisible beneath me when it comes to climbing and sprinting.

55x55 ctt w/130 headtube stack at 551 and reach at 387 with 74°/73° - this would be a road frame with 28mm max.

56x55 ctt w/134 headtube stack is 555 and reach is 390 with 74°/72° - this is a cross bike with 38mm tires. With my saddle height at 72.5 I use 30mm of spacers to get the top of the handlebars 5cm below my saddle.

You're going to need a lot more stack to get the handlebar tops 4cm below your saddle w/o spacer stack. Probably on the order of ~155mm headtube which would be ~590 stack (measurement without headset/integrated headset) and 390 reach.

My measurements are assuming -17° stem. If you use a positive rise stem you can subtract 19mm from the headtube for -6° or 10mm for -10°.

[Nomadmax]

I came to the right place!

I should have mentioned, my current road bikes mentioned above mostly have a Nitto quill adapter showing 15mm between the top headset nut and bottom of the VO stem clamped to it, in a +6 position. I'm not against having to put a stem at +6, especially on a bike with a sloping TT. I think the best part of this thread is to find that I'm not crazy

[NHAero]

Originally Posted by Nomadmax

I came to the right place! Snip
I think the best part of this thread is to find that I'm not crazy

These are totally independent of one another

[Nomadmax]

Originally Posted by spoonrobot

60-65 would feel pretty good

We have the same saddle height, and apparent distaste for high trail.



55x55 ctt w/130 headtube stack at 551 and reach at 387 with 74°/73° - this would be a road frame with 28mm max.

56x55 ctt w/134 headtube stack is 555 and reach is 390 with 74°/72° - this is a cross bike with 38mm tires. With my saddle height at 72.5 I use 30mm of spacers to get the top of the handlebars 5cm below my saddle.

You're going to need a lot more stack to get the handlebar tops 4cm below your saddle w/o spacer stack. Probably on the order of ~155mm headtube which would be ~590 stack (measurement without headset/integrated headset) and 390 reach.

My measurements are assuming -17° stem. If you use a positive rise stem you can subtract 19mm from the headtube for -6° or 10mm for -10°.

In looking at the Litespeed Arenberg, it seems to fit the criteria. I'm 5'8" but have an 82cm inseam. I run my saddle @ 72.5cm because I'm a heel dropper. My bikes have 55cm TTs and I run an 11cm stem in the +6 position. However, the Lynskey GR300 has enough stack that I can run the 110cm stem in the -6 position.

Here are the Arenberg angles, I'm kinda homed in on the M/L despite only being 5'8".

https://litespeed.com/collections/en...ducts/arenberg

And here is the Lynskey GR300

https://lynskeyperformance.com/gr300...plete-bicycle/

I currently have a medium.

Looking at Spoon's post, I think the Arenberg might be a fit? The Lynskey with 30mm tires comes to:

Trail
74mm
Wheel Flop
23mm
Mechanical Trail
70mm

The Arenberg with the same 30mm tires:

M/L frame
62mm
Wheel Flop
18mm
Mechanical Trail
59mm

M frame
65mm
Wheel Flop
19mm
Mechanical Trail
62mm

This bike will be used on the road almost exclusively, I'll kill the Lynskey with winters and gravel riding.

[Nomadmax]

Originally Posted by NHAero

These are totally independent of one another

Wait, let me consult with other guys inside my head

[AngryScientist]

Originally Posted by Nomadmax

Note:
The bike I'm talking about has (with 700x38)

Don't ignore the tires in the equation of how a bike rides. If you are used to riding european racing bikes, which likely means you are on skinny racing tires, a 38mm tire is going to feel very different.

I know some people like wide tires on the road, but I think riding anything over a 25 on the road sucks. That might just be part of your issue.

[NHAero]

Another point - HT length relates to the wheel and tire size and the appropriate fork. Of my three road bikes which all have 55cm ETT lengths:

- my Firefly road bike has a 161mm HT, runs 700Cx25 tires, has an Enve 2.0 fork that is 367mm axle-to-crown
- My Bingham has a 170mm HT, runs 650Bx38 and has a Whisky 9 Road+ fork with an A-C of 383mm
- My Habanero has a 140mm HT, runs 650Bx42, and has a Columbus Futura disc fork with an A-C of 395mm.

I have the same contact points by messing with amount of spacers and stem angle. The Bingham has a 9.5 degree TT slope, and I run a -7 stem which is parallel to the TT - to my eye, that looks nicer than the +6 and +7 stems on the other two bikes. But the bars end up in the same place relative to the saddle.

Including my 1972 Bob Jackson, and doing the math with the tire/wheel sizes I most commonly run on each bike, flop varies from 14-17mm, and trail from 49-58mm. All handle nicely. I shortened trail on my Bingham when designing it because I was expecting some added perceived pneumatic trail from the bigger tires, but in practice I'm not sure this was necessary. For me, I do think mid-to-upper 50s is a good trail range, even though two of these bikes are all road and see plenty of dirt roads.

People do have different preferences, I'm not putting this out there as gospel! I had a CAAD10 and its trail was 56mm with a 73 HTA and that bike always felt "nervous" to me. My Bingham has the same HTA and with the 700Cx25 wheels has a trail of 51mm and feels totally stable. So there's still a lot I can't explain! But I know I don't prefer high trail bikes.

[Ozz]

Originally Posted by AngryScientist

...I know some people like wide tires on the road, but I think riding anything over a 25 on the road sucks. That might just be part of your issue.

I have found 28s to be my sweet spot....maybe cuz I am old now.

[Nomadmax]

Originally Posted by AngryScientist

Don't ignore the tires in the equation of how a bike rides. If you are used to riding european racing bikes, which likely means you are on skinny racing tires, a 38mm tire is going to feel very different.

I know some people like wide tires on the road, but I think riding anything over a 25 on the road sucks. That might just be part of your issue.

Good point. I have ridden the Lynskey with 25s, it was still terrible. I figure 28mm is where I'll land, I weigh 150 on the nose.