Coverting a Rivendell to Lower Trail

[John Hawrylak]

Has anyone converted a Rivendell to a lower trail front geometry?  If so, did the change result in problems?   

Was wondering if the laid back STA & HTA used on Rivendells has an affect when going to a lower trail.

John Hawrylak

Woodstown NJ

[DarinM]

Like you said, shallow hta could be an issue, but wheel size is also a factor. Any hta could be made to be low trail with enough fork offset, but flop will increase as a result. You could change the fork length to steepen the hta but that will also lower the bb, which is already pretty low on Rivendells. I think you could probably convert a 72 degree hta Riv to low trail without serious effects to the rest of the geometry, but models with 71 degree might not handle great. Take a look at JimG’s trail calculator if you haven’t yet.

I love the way my Atlantis and Bleriot handle, but am working on my first low trail project just to see what it’s like. I’ve been considering the above geometric factors to determine if the frame/fork combo will work out, but in the end I just decided to go for it. So many small things will change it’s hard to say what the net result will be. The frame and fork I’m using were both used and pretty cheap so I’m not committed to anything custom, but the result is a bit of a crap shoot.

Darin

[Joe Bernard]

Is this a thing you're really into? I tried low trail and it ended up being a very expensive way to learn I don't like it much. I love the way Grant designed his bikes to ride.

[Dave Small]

I'd think that the best way to convert a Riv to low trail is to sell the Riv and buy a low-trail bike.  Low trail, mid-trail, and high trail are fundamental aspects of a bike, IMO, and if the trail doesn't match what you're looking for then get one that does.  

Dave

Boston/Indy 

[dougP]

Several years ago, I converted my 58 cm, 700c wheeled Atlantis to 40 mm trail, vs the 65 mm of stock.  The reason for the change was to cure an irritating wander at low speeds on hills.  I always have several pounds up front in an Acorn Boxy Rando bag.  Like you, I was concerned about the law of unintended consequences, and fortunately encountered none.  The wander as reduced noticeably, and there are no problems created by the low(er) trail. 

The 40 mm figure was suggested by several people knowledgeable about trail and Rivendells, including the builder who had done several Rivs before mine.  The change is admittedly subtle and certainly not an "aha" moment.  It is definitely not the religious experience claimed by some of the low trail adherents. 

dougP

[iamkeith]

Group member René had both an Atlantis and a Hunquapillar with low trail forks. And I believe he shared experiences well. If you use his name as part of the search terms, you'll probably find some good info and pics as well.

[Fullylugged]

Just changing the wheel size or forks with different rake will change your trail. I found that converting my Road to 650B decreased the trail and it felt very squirrelly at first. Once used to it, I love the faster handling and have no trouble with it. My Ram still has the higher factory trail and "rides on rails" feel. I enjoy it too.

[Garth]

   This is worth reading .... http://normaali.net/temp/Front-End-Geometry.pdf

 If you really want to do this and work with someone who experience adding a new fork on existing frames, and not just out of mere curiosity or thinking you can save a buck by not buying another frame that handles differently  .... it'll work out just fine. 

[bruce.h...@gmail.com]

Thank for posting Garth. Interesting. My Waterford has 2 forks with different rakes and brakes that allow 2 wheel sizes. There is a definate difference in handling when you change any of those.

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[John Hawrylak]

Garth

Thanks for the BQ article.  Very informative.

John Hawrylak

Woodstown NJ

[Craig Montgomery]

Hey John, 

I converted an early All Rounder to low trail with a new fork. Got tired of manhandling a front load with the style of touring I do.  The geometry was more traditional British with a 72 seat and 73 head but the fork rake gave it something like a 60mm trail.  Unladen this geometry was fine but you can feel the difference with loads in the new configuration:  https://www.flickr.com/photos/24722971@N05/albums/72157630754272634

The result was interesting. Not awe-inspiring but satisfyingly smile-worthy.The 60mm rake made the front end lighter, a bit flakier (you get used to that), and more amenable to front loads. I still get the wobblies up front but that's more the older weaker me than the bike. Hellfire, anyone who can keep a front end straight at 3 mph up a dirt incline on a fully loaded bike is alright in my book. I can't. Here's my typical set up:   https://www.flickr.com/photos/24722971@N05/29460145875/in/album-72157673327069476/

Your issues will be minimal and none should be bad. I've converted a couple of frames now and you won't get warts. 

Craig in Tucson

On Saturday, October 27, 2018 at 12:13:07 PM UTC-7, John Hawrylak wrote:

[Bill Schairer]

Ooooh, I like that. I have noticed some moderate speed wobble at times on my Atlantis when loaded up like that on the road. I did not notice it off pavement. I thought maybe it was just I was concentrating on my path more or something but the BQ article seems to suggest there might be other reasons. Paying more attention to the balance of my load seemed to help quite a bit. I have no complaints about handling with a front load only.

Bill

[phil k]

IRRC he loved low trail. He put low trail forks on his hunq and his atlantis. He sold his Hunq, and he ended up getting a custom from Steve Rex based off the low trail atlantis for more integrated bike, and to try compass centerpulls.

I haven't seen him on the boards in a bit though.

[Tim Gavin]

Yes.  I have a 1997 Rivendell Road Standard, which I have adapted into a Randonneur/Light touring bike.  

I had previously swapped the wheels for 650x38, and installed a Mark's rack with a small rando bag (from list member, Treetop designs).

Last winter, I swapped the original fork (42.5 mm rake) with a Crust Romanceur fork (65 mm rake, disc brake, rack mounts).  I rebuilt my front wheel with a PD-8 hub from SP.

I had never been able to "no-hand" ride this Road Standard, either on original 700x25 tires, or on the 650x38 tires I use now.  

But now the bike seems to track more predictably, without the twitchy feeling of the original setup. 

I realize that the (classic sport-touring) geometry of my bike (73.5 head tube angle) doesn't really match that of Grant's more recent designs.

But I'm very happy with the result.

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[John Hawrylak]

Craig  Thanks for the reply and the pictures.  From what you stated, you must have gone from about 60mm trial to 45mm trail.

Does the 45mm trail and the LARGE rear loads give you problems??

John Hawrylak

Woodstown NJ

[dougP]

My Atlantis shimmied a bit with a rear only load.  For self contained tours (4 bags) it was more stable.  I experimented with load balance & concluded 60% front / 40% rear worked well.  This was all with the original fork.  The lower trail (40 mm) of the custom fork seems to have cured the shimmy and the ride is solid & stable with 2 bags in front.  With 2 bags in the rear, the back wiggles a bit but nothing annoying.  It is more stable with the weight in front.  Could be just me & my quirks.

dougP

[Craig Montgomery]

On Monday, John Hawrylak wrote:

Craig  Thanks for the reply and the pictures.  From what you stated, you must have gone from about 60mm trial to 45mm trail.

Does the 45mm trail and the LARGE rear loads give you problems?

             45 is about right John. LARGE rear loads don't necessarily mean HEAVY. Think about your packing.

            I like trails between  45 and 50. The British liked low trail for the most part and all my British bikes (which are all my bikes) are in that range and are a joy to ride so decided to make the All Rounder like them. I never really noticed any wobblies (Jan's infamous "tail wagging the dog" syndrome) with a rear load but when I was running one I was usually running a front load with it. BUT you can't overload the rear. You gotta practice and learn your parameters. With overnighters I usually do it with a Baggins Hoss saddlebag and a Carradice Camper in the front and/or a pair of front panniers. 

           But touring bikes built with some thought usually have stiffer rear triangles. Helps with the panniers. I have a '68 Condor tourer that I can load with just rear panniers and a handlebar bag, get out of the saddle, and climb hills with nary a wag du fido. Trail about 55.  Both Jack Taylors and the HR Morris are like that too. Trails in the mid/upper 40's. All tourers. Those old guys knew what they were doing. 

     Your Riv is going to do just fine. Trust me. 

Craig in Tucson