Low Trail Geometry

[Hikyle2]

Sorry to probably ask a question that's been beat to death by some, but I wanna understand more.

I have a surly cross check as a town bike with bullmoose bars and a soma porteur rack with an ILE rack bag. As you can imagine, it handles pretty poorly when even just the bag is on. I guess what I wanna know is would low trail really make the ride that much better?

I understand how low trail works and how to calculate it, but I find it hard to believe that the bike will ever be so easy to ride that i'm not having to muscle the front end because of the weight. I have debated getting a champs elysees fork as that's the cheapest fix but was just curious of opinions.

[buddybikes]

Why not traditional rear rack, rack bag and perhaps panniers?

[Old School]

"angled headset" from England might be even cheaper, and the machine work is unparalleled.

https://www.workscomponents.co.uk/15...dsets-14-c.asp

[Hikyle2]

I'll be honest I like the look of a front rack, looks cleaner on the bike, and I have it at this point.

[Hikyle2]

Originally Posted by Old School

"angled headset" from England might be even cheaper, and the machine work is unparalleled.

https://www.workscomponents.co.uk/15...dsets-14-c.asp

Never heard of that, so it just changes the headtube angle? that's pretty crazy.

[spoonrobot]

Originally Posted by Hikyle2

Sorry to probably ask a question that's been beat to death by some, but I wanna understand more.

I have a surly cross check as a town bike with bullmoose bars and a soma porteur rack with an ILE rack bag. As you can imagine, it handles pretty poorly when even just the bag is on. I guess what I wanna know is would low trail really make the ride that much better?

I understand how low trail works and how to calculate it, but I find it hard to believe that the bike will ever be so easy to ride that i'm not having to muscle the front end because of the weight. I have debated getting a champs elysees fork as that's the cheapest fix but was just curious of opinions.

Yes, this is exactly what low trail will do because of the massively decreased flop. Riding my 35mm trail bike with 30 pounds on the front end doesn't even feel as sluggish and floppy as my 62mm trail bike with 5 pounds on the front end. 38mm trail bike with a normal load 5-10 pounds? Like it's not even there.

Have you read Fred Blasdel's writings on low-trail from back in 2013? Google his threads (on another forum so I don't wanna link) and it'll give you a better idea of what happens and why. I'd say go for it, secondary market value of the low-trail Soma forks is very good if you do not find it to your liking.

[Hikyle2]

Thanks, I hadn’t read his stuff specifically at it’s awesome. I love his reply’s to people on some post as well.

[etu]

Makes a HUGE difference to have a low trail fork if you're going to carry weight up front. I have been using a mini-porteur rack with anywhere between 5-20lbs on my commuter for the last five years and it rides incredibly well. The low trail geometry provides a stable but playful ride even without any weight, but is optimal with at least a few pounds.
Also IMO, the "liveliness" of a bike is preserved by not putting any unnecessary weight in the rear. Most people notice the downsides of the rear rack when pedaling out of saddle, but I think most of us flex our bikes side to side a little bit even when riding seated, especially on any climbs where there is additional torque. This little flex is what I would suggest as the source of the magic carpet ride. When this flex is muted through a overladen saddle bag or a rear rack, the ride quality suffers.
In the end, you'll just have to experiment and experience for yourself, but I would highly recommend it.

[HTupolev]

Originally Posted by Hikyle2

but I find it hard to believe that the bike will ever be so easy to ride that i'm not having to muscle the front end because of the weight.

The question is why the weight is having to be "muscled" in the first place. Even if the steering column has a lot of inertia, it's not hard to cause a bicycle to lean into a turn.

The big issue with handlebar bags is that the weight is located in a place where it puts torque on the steering column when the bike is leaned. If the bike is leaned to the right, the bag torques the steering clockwise when viewed from above; if the bike is leaned to the left, the bag torques the steering counter-clockwise when viewed from above.
This behavior is very similar to "wheel flop" caused by the steering geometry, and higher-trail steering geometries typically have more wheel flop.
In both cases, if either of these flop effects are very high, the rider might feel like they're battling against the flop when doing stuff like rocking the bike out of the saddle. "Very high" depends on the type of bike; mountain bikes tend to have high-trail geometries with tons of wheel flop, but they also use super-wide handlebars which give the rider tons of leverage over the steering axis.
Anyway, if there's too much flop due to the handlebar bag, you can compensate by using a lower-trail steering geometry to reduce the flop from the geometry.

The location of the front weight matters a lot in its effects. Panniers on lowrider racks don't tend to hold their weight way out in front of the steering axis, for instance, so well-balanced weight there can add inertia to the steering without adding flop.

[Hikyle2]

It all is starting makes sense since I’ve been riding the bike like this for over a year. The rear of the bike still behaves just as I would expect, it’s just the front end that is a worry so if I can solve that with the fork it’s definitely worth a shot. I think if anything I can then understand how it handles and if it’s ever worth getting a bike designed around it. This is just my commuter bike but I have a tendency to make every bike nicer than they might need to be.

[ColonelJLloyd]

A Surly with a high rake fork producing low-trail will still be a Surly. It will not magically transform the bike. And nothing happens in a vacuum so you will not confidently be able to say the change in fork is what made you like/dislike the result.

I would encourage you to try a bike or two that was designed out of the gate with low-trail geometry and see what it's like for you. Opinions differ greatly. I realize this is difficult to do in many cases. I bought a used low-trail bike. Then I sold it and ordered a custom one.

[spoonrobot]

Originally Posted by ColonelJLloyd

A Surly with a high rake fork producing low-trail will still be a Surly. It will not magically transform the bike. And nothing happens in a vacuum so you will not confidently be able to say the change in fork is what made you like/dislike the result.

I would encourage you to try a bike or two that was designed out of the gate with low-trail geometry and see what it's like for you. Opinions differ greatly. I realize this is difficult to do in many cases. I bought a used low-trail bike. Then I sold it and ordered a custom one.

That's exactly what a low-trail fork did for me. I have a Soma Fogcutter that had 57mm trail with the stock fork. I swapped in the Soma low-trail disc fork and dropped the trail to 35mm and it's a completely different bike both with and without a front load - but moreso with. Especially on anything loose or on wet pavement.

The vast majority of frames designed around low-trail are effectively no different than those designed for mid-trail. For the OP's complaint wrt the Surly Cross Check - certainly a low-trail fork will offer the change he's looking for without other major geometry considerations:

but I find it hard to believe that the bike will ever be so easy to ride that i'm not having to muscle the front end because of the weight.

This BQ PDF is also interesting reading, one frame with three forks: http://yojimg.net/bike/kogswell/kogs...20brochure.pdf

[ColonelJLloyd]

Originally Posted by spoonrobot

That's exactly what a low-trail fork did for me. I have a Soma Fogcutter that had 57mm trail with the stock fork. I swapped in the Soma low-trail disc fork and dropped the trail to 35mm and it's a completely different bike both with and without a front load - but moreso with. Especially on anything loose or on wet pavement.

The vast majority of frames designed around low-trail are effectively no different than those designed for mid-trail. For the OP's complaint wrt the Surly Cross Check - certainly a low-trail fork will offer the change he's looking for without other major geometry considerations:

I don't disagree that a fork swap can make a night and day difference in the handling with front loads. I don't disagree with your experience or what you are effectively saying for you.

However, my overall point is in disagreement with your bolded statement. I think it's far from certain.

It likely sounds like I'm trying to be argumentative, but I'm not so I'm going to stop commenting here after saying that low-trail geometry is really one of those things that one has to try for themselves and the "feel" of it is interpreted very differently by people.

[jwin]

This may be to OT but related to low trail. I'm new here and learning so much about bikes that I never knew.

What I'm wondering is what exactly does trail do to affect the steering feel? I understand what trail is, but I can't seem to understand what the effect would be if say trail were 0mm? Your contact point is now on the steering axis - what does that feel like? What if your contact point was in front of the steering axis?

[cmg]

Originally Posted by jwin

This may be to OT but related to low trail. I'm new here and learning so much about bikes that I never knew.

What I'm wondering is what exactly does trail do to affect the steering feel? I understand what trail is, but I can't seem to understand what the effect would be if say trail were 0mm? Your contact point is now on the steering axis - what does that feel like? What if your contact point was in front of the steering axis?

look at the diagram. As the trail gets smaller (cen of axle meets cen of fork angle ) front end becomes twitchy. bike will not center itself, can't ride no handed. As the trail increases or steering axis angle increases wheel increases it's tendency to want to flop over. bike will have a tendency to ride in a straight line. rider's weight is behind the fork normally but with a front rack center of gravity is shifted forward. Discuss