Ha! DougP finally has come out of the low-trail closet! Thanks Rene for your thoughtful review.
I too went low trail on my load carrying bike, in my case a Surly LHT with a 72 degree head angle. Tom Matchak built a fork with 68mm of rake compared to the original 45mm. That is nearly an inch of extra rake. With 1.5inch tires, trail went from mid 60s to low 40s. Nothing else changed in my experiment. I found the new steering to be only subtly different, subtle but distinct. As others have said, less wheel flop makes the bike handle heavier front loads with more stability. The LHT does have a tendency towards a light shimmy now that wasn't there before. It is easily controled with a kneee against the top tube. I put a 28mm tire on this bike and did not like its handling at all, that felt very skittish and unstable. Descending was different but not necessarily better. Low trail was more responsive at speed but high trail feels more stable. I don't think I descend faster with either setup. So my impressions are both high and low trail handling have their strengths and weaknesses. Low trail requires a larger tire and handles front end loads well. High trail is quite fun with skinny (I use 27-33mm tires) and only a light front load or no front load. I just carry stuff on them differently. That said, my 26inch AllRounder seems to carry a moderate front load without any compaints. And I often commute on my Quickbeam, a short flattish ride, with 5-15lbs in the front basket with no bother. I am glad I changed the LHT. It had an ugly dog-leg fork before and the new handling is an improvement. I have no desire to change my Rivendells. They ride wonderfully. On Jun 5, 4:41 pm, dougP <[email protected]> wrote: > Rene: > > You are indeed brave to post about your experiment, and I hope > everyone else reviews it thoughtfully. > > Something we all need to keep in mind is that as brilliant a designer > as Grant is, every bike is the sum of a large number of compromises. > The fewer the compromises, the more specialized and hence less > versatile a bike is. For me, one of the major attractions of > Rivendell is the versatility of my Atlantis. There just isn't any > ride I would hesitate to do because "my bike can't do that". > > This confidence building versatility has also led me to a lot of "why > not?" adventures in loading, and I'm probably not alone here. It > would be impossible to design a single bike that would be equally > competent handling all the possible combinations of front, rear, high, > & low loading. Rivendell, IMHO, does it better than most, probably > because they actually think about it, load their bikes & go banging > about the hills in the real world. > > I took delivery of my Atlantis in early 03, and it's my go-to bike for > everything. Over the years, I came to prefer having my basic, daily > stuff in a front bag, first a Riv Hobo, then an Acorn Boxy Rando > (holds more). It seemed that with the front bag fairly well stuffed, > the bike had a bit of a wander when climbing at low speed, nothing as > you describe but an irritating tendency to want to go somewhere else. > I always dismissed it as the load and my inattentiveness. Stumbling > into some low trail discussion or article, it seemed like maybe there > was room for improvement, at least to my tastes. > > When touring with a load, the bike was a bit dodgy with everything on > the rear, the problem being an infrequent but unpredictable shimmy. > Spreading the weight around among 4 bags restored stability. Since my > lodging load is 2 bags, on-tour ezperiments with them front vs rear > showed front to be a more stable location. However, the previously > mentioned "wandering" was more annoying with all the weight up > front. > > Tom Matchak also came to my attention courtesy another list member, > and built the same fork for me. Since my issue was not as dramatic as > yours, I was only hoping to get the same stability with a front load > that the bike had with no load. The result meets expectations. The > 40 mm trail is not a relgious experience but a rather subtle change > that solved my personal problem without disturbing anything else about > the bike. > > Note that I did not leap into this without a good deal of second > guessing and self-argument. The Atlantis is a great bike and I did > not want to screw it up. Fortunately, the results justified the > deliberations. It would not surprise me if another Riv owner rode my > bike & hated it. It just works for my & my quirky habits. > > Side bar re: shimmy. If you get shimmy, don't assume the 40 mm trail > is the cure. On a recent S24O (2 bagger) I rode with the bags in > front on the way out and the rear on the return. On a straight, > level, smooth bike trail at perhaps 12 mph, I got a nasty shimmy when > I had to stop quickly, with the load in the rear. After that, all the > way home, I tried to induce it again with no success. The typical > "tail wag when standing" is still there. I've been experimenting with > trying to move the load lower & as far forward as practical. I may > need a change of rack (currently using the Nitto Big Back rack) to get > things where I want them. > > Funny that you want to paint both bikes. I really like the gray & > kidney bean red Hunq paint scheme, and have considered doing that on > my Atlantis. It's spent enough time traveling that I'm thinking new > paint for it's 10th birthday would be nice. Of course, my wife tells > me "it's you; sorta old & beat-up looking". I think there's a > complement in there but I could be just wishing. > > dougP > > On Jun 5, 1:37 pm, René Sterental <[email protected]> wrote: > > > > > Disclaimer: > > > This is a very long post and I want to start by stating that I don't mean > > to start another heated debate on high vs. low trail fork, or Jan vs. Grant > > philosophies, etc. I just want to describe this experiment and its initial > > results to the group so anyone thinking along the same lines has another > > point of reference. I'll gladly answer any questions that are posted, > > either privately or publicly but let's handle it as the controversial topic > > it usually is. Also worth noting is that this is a modification I chose to > > do on my own to my bikes and while Rivendell certainly supports the > > exchange of information and knowledge about bikes, they certainly stand > > proudly by their bikes and their design philosophy. This post is in no way > > an attempt to challenge that. They are aware of my experiment. > > > Ok, here I go... > > > For a number of reasons that I can just summarize, in no particular order, > > as the tendency of my Rivendell bikes to shimmy with any loads (especially > > my Atlantis), my dislike for how they handle with any front loads > > and especially heavier ones, as well as with heavy rear loads, all of which > > magnify the tendency of the front steering to pull and require > > overcorrection when turning, as well as the interesting and very educating > > online discussions and articles on bike geometry and fork geometry and its > > effects on the handling characteristics of a bike, I decided to try it to > > see for myself what the whole low trail geometry claims were about. > > I wasn't able or willing to go buy a new bike just to experiment, and even > > if I did, there would be no way I could tell what the low trail fork would > > do to the handling of my Rivendell bikes which, aside from the > > nuances/issues stated above, I love. And yes, while I could > > certainly adjust to all of these quirks, I just didn't like having them on > > my bikes. The obvious solution recommended by some people on this group in > > addition to several articles online pointed me to Tom Matchak in the East > > Coast who had already built low trail forks for other Rivendell bikes. Tom > > seemed to have a great reputation as a builder and immediately knew what > > this was all about when I contacted him. Due to the long lead time to have > > the low trail fork built for my Atlantis as was my original intention plus > > a few additional considerations that came up as part of this process, like > > the need to have the Atlantis repainted and why not, the Hunqapillar as > > well (never did like that gray color much), I decided to take the risk of > > ordering two low trail forks for both the Atlantis and the Hunqapillar as > > these are the bikes I mainly ride loaded. > > > I asked Jan Heine for his low trail recommendation as well as Tom Matchak > > and they both came out with the same number: 40mm of trail, which requires > > a rake of 70mm for 40/50 mm tires. On the Hunqapillar, the same 70mm rake > > comes out to 42mm of trail. For comparison, the standard Rivendell fork for > > the Atlantis has 45mm rake/65mm trail and the standard Hunqapillar fork has > > 50mm rake/63mm trail. I had to send several detailed measurements to Tom > > Matchak so he could preserve the crown race to axle distances on both > > bikes. He also specked cable guides for my dynamo lights as well as fender > > attachments so I no longer need to fiddle with the darumas to mount the > > front fenders and can screw in the fender directly to the underside of the > > crown. Additionally, the fork for the Hunqapillar was spec'd with a Pacenti > > MTB bi-plate crown to run the 50mm tires with 60 mm fenders and the fork > > for the Altantis with a Long Shen A16 crown to be used with 40mm tires and > > 50 mm fenders. Regretfully but understandably so, I got a negative response > > to my inquire at RBW on whether I could buy a pair of Rivendell crowns for > > this project, so while none of these crowns is as beautiful as the original > > Riv crowns, they're sort of Rivish, especially the A16. Both forks were > > also spec'd with the usual set braze-ons for the normal array of racks > > including the Nova and Duo Lowrider racks. Tom put these braze-ons on the > > front of the fork instead of on the back where the Riv forks have them with > > the effect that it will be easier to level them properly. I didn't ask for > > the braze-ons on top of the crown as I have no use for them. > > > After the long expected wait (this whole project started in december of > > 2011 and it took until febrary for the orders and details for both forks to > > be completed. Tom was going to schedule them to be built in March anyway > > and was done in April. He shipped both forks to the local painter Keven > > recommended (D&D cycles); for some reason I never understood, he refused > > from the start to ship the unpainted forks to me, but agreed to ship them > > to the painter of my choice since the bikes were going to be repainted and > > the forks would have to be painted to match the frames. > > > The second phase of this project is for me to disassemble the Atlantis > > first and take it to Rick to be repainted. This repaint was necessary (as > > these things are) since I had the right down tube braze-on replaced after > > almost destroying it during the original build (another long story). Not > > wanting to be without both the Hunqapillar and the Atlantis at the same > > time, I asked Rick if he could give me the Hunqapillar fork to use while > > the Atlantis got repainted including the new fork (4 - 6 weeks waiting > > time) and when I took possession of the Atlantis, I'd drop the Hunqapillar > > so he could repaint it to change the stock gray color. He gave the new low > > trail fork for the Hunqapillar its primer coat and a quick coat of > > Hunqapillar gray so it wouldn't look bad as I rode it and tested it before > > the repaint. > > > I had such a hectic travel and work schedule that I just didn't have the > > time to disassemble the bikes to take them to Rick's shop to be painted, so > > it wasn't until this past Friday, a bit over a month after > > ... > > read more »- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. 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