84 Trek 610 650B Conversion

[mikeha...@comcast.net]

Hi,

I just got done putting the finishing touches on a 650B conversion of an 84 Trek 610.  Due to the reach I needed I chose to use the Dia Comp 750 centerpull brakes.  I did swap out the stock pads for Mathauser pads.  I tried Hetres but only had about 2mm clearance at the chain stay so I went with Pari Moto's.

Post a few pictures here https://www.flickr.com/photos/24194829@N07/albums/72157660908803763

Mike, who will be at the Brazen Dropouts Swap in Madison this Saturday, Hauptman

Nor-IL

[Ryan Watson]

Looks great, Mike!

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[Pondero]

Wonderful, Mike!  I'd be interested in hearing your riding impressions.  These kinds of projects fascinate me, and make me think about the advantages of an approach like this.  Bravo!

Chris Johnson

Sanger, Texas

[David Cummings]

Very nice! I'm planning on a '79 710 conversion this spring.  This gives me something to look forward to.  If it turns out half as nice as your conversion, I'll be happy!

[Tom Norton]

Mike,

I am also in the process of a conversion. I was wondering why you went with the center pull as opposed to the Tektro R559 Long Reach?

[mikeha...@comcast.net]

Hi Tom,

I used the the Dia Comp 750 because I tried the Tektro R559 and I needed more reach to get the brake pads centered on the rim.  Plus with all the talk about Rinko bikes I thought the centerpulls would be better if I decided to explore that.  With the 750's you can unhook the straddle cable from both arms like the fancy Compass Rinko Centerpulls.

Mike H

Nor-IL

Gratuitous self promotion

https://www.etsy.com/listing/177419288/flatlanders-bicycle-rear-view-mirror

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From: "Tom Norton" <tnort...@gmail.com>
To: "650B" <65...@googlegroups.com>
Sent: Friday, January 8, 2016 7:52:45 AM
Subject: [650B] Re: 84 Trek 610 650B Conversion

[Jim Bronson]

On Wed, Jan 6, 2016 at 9:17 AM, <mikeha...@comcast.net> wrote:

https://www.flickr.com/photos/24194829@N07/albums/72157660908803763

I definitely like the look of the 750s. How do the 750s stop as compared to the Tektro R559s?  How much clearance do you get when you release the straddle cable?  I'm running the R559s with the older (520?) Tektro levers and I have to hit the brake releases on both the calipers and the brake levers themselves to get a fully inflated 38mm tire in and out.

You really needed the additional clearance of the 750s - your pads are almost at the bottom of the slot!

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[Ken Freeman]

Hi, Mike!  I also have an '84 610.  I looked at 650'ing it a while back, and concluded the same thing you discovered about the chainstay clearance only 2 mm.  

I don't know if you are also interested in low-trail.  I added one and like it quite a bit, but it's probably a little too low for a 700c wheel.  I'm not planning to go ahead to 650b - I think the front brake reach would become un-doable with the low trail fork.  But I do like low trail.The original fork in 1984 was anything but low trail, though a beautiful design.

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Ken Freeman
Ann Arbor, MI USA

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Ken Freeman
Ann Arbor, MI USA

[Alex Wetmore]

1983 and earlier Treks have a much lower than normal trail (though I wouldn't call them low trail).  Most of the touring models were shipped with 55mm of offset and 73 degree heat tube angles for a trail near 50mm.  It is easy to rerake those forks to 65mm of rake (40mm of trail) without really affecting the rest of the geometry.  I've owned Trek 520, 620 and 630 frames that were all essentially identical in geometry but varied in tubesets (all were Reynolds, just different butting profiles and alloys).

They also convert to 650B easily, though it is better to use 38mm or smaller tires.  Hetres will fit, but with so little clearance that I wouldn't consider them safe to ride anywhere remote.

We did a lot of the early tire testing at BQ using a 1983 Trek 620 and a (single front) brake that allowed us to move the pads to fit either 650B or 700C wheels.

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Ken Freeman <kenfre...@gmail.com>
Sent: Friday, January 8, 2016 12:34 PM
To: Mike Hauptman
Cc: 650B
Subject: [650B] 84 Trek 610 650B Conversion

 

[Steve Palincsar]

On 01/08/2016 03:34 PM, Ken Freeman wrote:

Hi, Mike!  I also have an '84 610.  I looked at 650'ing it a while back, and concluded the same thing you discovered about the chainstay clearance only 2 mm.  

I don't know if you are also interested in low-trail.  I added one and like it quite a bit, but it's probably a little too low for a 700c wheel.  I'm not planning to go ahead to 650b - I think the front brake reach would become un-doable with the low trail fork.  But I do like low trail.The original fork in 1984 was anything but low trail, though a beautiful design.

On Wed, Jan 6, 2016 at 10:17 AM, <mikeha...@comcast.net> wrote:

Hi,

I just got done putting the finishing touches on a 650B conversion of an 84 Trek 610.  Due to the reach I needed I chose to use the Dia Comp 750 centerpull brakes.  I did swap out the stock pads for Mathauser pads.  I tried Hetres but only had about 2mm clearance at the chain stay so I went with Pari Moto's.

Post a few pictures here https://www.flickr.com/photos/24194829@N07/albums/72157660908803763

On the other hand, there's nothing at all shabby about a 650Bx38 tire, and you have a choice of some very nice tires in that width.  Not quite as plush as a 42mm, but still plenty nice and much more so than anything that would fit on a Trek 610 unconverted. 

I don't understand the comment about brake reach with a low trail fork: the reach depends on the distance from the fork crown or brake arm mounting points to the rim; greater or lesser fork rake wouldn't affect it at all.   You do need a lot of extra brake reach going from 27 x 1 1/8" to 650B, but obviously Mike has solved it with the DC750 centerpulls.

[Lyle]

Looking really clean!  Have you considered crimping the chainstays for Hetre clearance?  

[Mike Hauptman]

I did but I wanted to keep the conversion simple and didn't want to go to the trouble.

Mike

Sent from my iPad

[John Wilson]

There are ways to gain a few more millimeters of brake reach.  I used some offset brake pads on my rather unorthodox Austro Daimler 700C to 650B conversion. Good news is I can change it back in just a few minutes by flipping the pads and doing a right left pad swap.

Best,

John Wilson

Greensburg, PA  USA

[Brad]

If you set the rear dropout so that the axle sits at the very front of the slot you can change the headtube angle to steeper and the trail and and flop to lower. 

On Friday, January 8, 2016 at 3:44:56 PM UTC-5, Alex Wetmore wrote:

1983 and earlier Treks have a much lower than normal trail (though I wouldn't call them low trail).  Most of the touring models were shipped with 55mm of offset and 73 degree heat tube angles for a trail near 50mm.  It is easy to rerake those forks to 65mm of rake (40mm of trail) without really affecting the rest of the geometry.  I've owned Trek 520, 620 and 630 frames that were all essentially identical in geometry but varied in tubesets (all were Reynolds, just different butting profiles and alloys).

They also convert to 650B easily, though it is better to use 38mm or smaller tires.  Hetres will fit, but with so little clearance that I wouldn't consider them safe to ride anywhere remote.

We did a lot of the early tire testing at BQ using a 1983 Trek 620 and a (single front) brake that allowed us to move the pads to fit either 650B or 700C wheels.

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Ken Freeman <kenfre...@gmail.com>
Sent: Friday, January 8, 2016 12:34 PM
To: Mike Hauptman
Cc: 650B
Subject: [650B] 84 Trek 610 650B Conversion

 

Hi, Mike!  I also have an '84 610.  I looked at 650'ing it a while back, and concluded the same thing you discovered about the chainstay clearance only 2 mm.  

I don't know if you are also interested in low-trail.  I added one and like it quite a bit, but it's probably a little too low for a 700c wheel.  I'm not planning to go ahead to 650b - I think the front brake reach would become un-doable with the low trail fork.  But I do like low trail.The original fork in 1984 was anything but low trail, though a beautiful design.

On Wed, Jan 6, 2016 at 10:17 AM, <mikeha...@comcast.net> wrote:

Hi,

I just got done putting the finishing touches on a 650B conversion of an 84 Trek 610.  Due to the reach I needed I chose to use the Dia Comp 750 centerpull brakes.  I did swap out the stock pads for Mathauser pads.  I tried Hetres but only had about 2mm clearance at the chain stay so I went with Pari Moto's.

Post a few pictures here https://www.flickr.com/photos/24194829@N07/albums/72157660908803763

Mike, who will be at the Brazen Dropouts Swap in Madison this Saturday, Hauptman

Nor-IL

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Ken Freeman
Ann Arbor, MI USA

[David Cummings]

Interesting.  The BDops give 7mm more clearance.  Just barely enough for some not-so-long-long-reach calipers?

[satanas]

Alex, how difficult do you think it'd be to re-rake a Ritchey Logic fork by 10mm, from ~40mm now to ~50mmm. This would be for an old lightweight MTB frame that could use a slightly longer front centre if RTPs and fenders are going to fit. Lowering the BB would also be a good thing!

Later,

Stephen

[John Wilson]

Actually, I used a combination of brake reach change on the AD VNll. I wanted to keep all Campy Record/NR/GS so I went from the standard short reach Campy side pull brakes to long reach. Now neither 700C or 650B would work. Next comes the offset shoes, BDops and Aican. A few minutes to flip the shoes and swap side to side, and I can have 700C's or 650B's. I must confess, though, since I switched it to 650B the 700C wheels are hanging from the hooks because the ride with the 650's is awesome. Next step is fenders, on a racing frame with no fender brace mounts so it's Blackburn dropout adapters for the rear and modified "lawyer wheel retainers" for the front.

Best,

John Wilson

Greensburg, PA   USA

[Mark Bulgier]

Stephen/satanas wrote:

> Alex, how difficult do you think it'd be to re-rake a Ritchey Logic fork by 10mm, from ~40mm now to ~50mm.

Adding rake moves moves the canti posts down compared to the rim.  The effect is stronger if the curve is added more near the bottom and/or with a tighter radius.  If the blades are bent forward near the top, then the brake boss height might not change at all.

Depending on where the rake is added and what brand/model of brakes you have now, you might need to switch to a model with more up/down pad adjustment range.

The canti posts also interfere with raking on certain raking forms. Trying to add rake higher up the blade is more likely to cause the post to impinge on the raking form.

I think you may not get to be super picky about the shape of the rake, you'll probably have to go with whatever your framebuilder is equipped to do.  I suppose you could shop around for a builder who has a raker of the sort you like.  But since you're adding just 10 mm, frankly I don't think it matters one bit what radius you bend it to, so I'd just go with whatever builder you have available to you, whom you trust.

On the other hand, just bending the blades forward near the top of the blades can be done with a solidly mounted bench vise, a 2x4 or a strong steel pipe, and a rope.  I have also done it by striking the dropout with a very large rubber mallet, with the steerer held in the vise.  I'd recommend steel or alloy tube blocks to hold the diameter of your steerer, i.e. 1" or 9/8", versus just holding the steerer in flat jaws.  V-blocks can work too and are not size-specific.  Even hardwood blocks can work, but with an MTB fork like your Ritchey, bending forces might be high enough to damage the wood blocks.

A little risky, and you are weakening the fork a bit at least in theory, but many people have ridden forks bent like that for zillions of miles.  Bonus benefit, it's guaranteed not to move the placement of the canti bosses relative to the rim. 

Measuring the offset to know when you've gone 10 mm, and ending with the fork still properly aligned, are both a bit advanced for most bike shops, but the skills to pull this off are not limited to just framebuilders.  A very experienced shop mechanic who has done fork alignment might be closer to you and/or cheaper.  Or you may feel up to it yourself.

Mark Bulgier
Seattle

[Alex Wetmore]

Mark covered most of it below.

Most mass produced forks have a very high radius in the curve for the fork rake.  The nice thing about that is that you can add a little rake without moving the canti post location too much.  The fork bender that I have access to has a 10" radius mandrel on one side and 6" on the other, and the 10" is about right for most production forks.

My guess is that it would be just fine, but it's hard to say without handing the fork myself.  Adding more than 10mm would likely be problematic unless you do it all up near the crown as Mark is describing.

I forgot that I wrote a blog entry about doing just this, with photos:

http://alexwetmore.org/archives/473.html

alex

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From: 65...@googlegroups.com <65...@googlegroups.com> on behalf of Mark Bulgier <ma...@bulgier.net>
Sent: Tuesday, January 12, 2016 8:36 AM
To: 650b
Subject: Re: [650B] 84 Trek 610 650B Conversion

 

[Steve Chan]

How is the braking with the offset brake pads? It seems that moving
the mount point of the pad up 7mm from the center of the pad would
introduce additional flex in the connection between the pads and the
brake arms.

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[John Wilson]

I haven't noticed any difference in braking, although I haven't done any serious downhills since the conversion. Most of my riding is on the local rail trail, and the bike is lightly loaded. The offset shoes were my only option in keeping the bike all Campy, so I'm satisfied. 

Best,

John Wilson

Greensburg, PA. USA

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[Nick Favicchio]

If you want to lower the trail from 50 to 40, you don't want to increase the offset by 10mm. That will give you a trail # well below 40 b/c of the increase in head tube angle - unless, like Mark suggested, you make the tweek at the top of the fork blades and don't change the tube angle but by a hair.

If you're continuing the existing bend, do a 5mm tweek, then measure the head tube, then check the yojimg calculator and see if you're not where you wanna be at.

[Jay Swenberger]

MIke,

I also did a 650b conversion of an older Trek, my original '85 560. It took the Tektro calipers easily and now rides on a pair of Compass Pass Cypress tires. I bought a set of VO hammered fenders but haven't got around to finding the p-clamps needed to attach to the frame.

I'm never giving this bike up...

Enjoy the ride,

Jay

On Wednesday, January 6, 2016 at 7:17:03 AM UTC-8, Mike H wrote:

[Hugh Smitham]

Curious has anyone done a 650b conversion on a Trek 520 size 53cm? And if yes what was the largest tire you could fit? Was it worth it versus 700c? I don't know whether the smaller sizes have less clearance as opposed to the larger frame sizes?

~Hugh 

On Wednesday, January 6, 2016 at 7:17:03 AM UTC-8, Mike H wrote: