1984 Trek 520, This is gonna get messy...
Results 1 to 18 of 18
  1. #1
    RoadBikeReview Member
    Reputation: lonelobo's Avatar
    Join Date
    Sep 2009
    Posts
    57

    1984 Trek 520, This is gonna get messy...

    I just got an older Trek 520 in the largest frame size they made. I am 6'3" and approaching 300lbs though I am turning the corner and going the other way now. I have several steel lugged vintage road bikes and an aluminum framed mountain bike. I bought the Trek with the thought of converting it to run the fattest tires possible to take on gravel/hard pack/caliche farm roads. Besides "fat" rubber, the next "no compromise" requirement is fenders.

    Since the 27" wheels that are original to the bike use hubs that nobody thinks are good, I am planning on building up new wheels using either 700c or 650b rims.

    The existing 27 x 1 1/4 Kenda tires are problematic in regards to the front fork. There is less than 1.63mm clearance between the tire and the fork crown. That's not enough room for a fender...so I can't just get by for the time being by putting fenders on the bike...my goal is full fenders and not splits or anything that is too much of a compromise...right...

    700c wheels fit fine and the existing canti brakes need little if any adjustment to work...weird as it sounds. 2 bike shops and several friends have all tried 700c's on this bike and are surprised that there is not more difference in where the brake pads land on the rims.

    WARNING: If you can't think outside the box, TURN BACK NOW!!!
    I've had my fill of mechanics at bike shops telling me that I don't want to go with big tires, I don't want to even think about 650b's, there's no such thing as a Swiss Threaded bottom bracket, etc.. All with a holier than thou pantyfaced sneer on their puss. As a tax payin loyal American I have a right to ignorance, stubbornness, and down right audacity cause I'M GONNA PAY FOR IT!!!!

    Here is the first exercise in deductive reasoning:
    If I go with 700c rims I want to maximize the size of the tire while minimizing the height of the tire. IE. wants cake and to eat it too. IE. I want the fattest tire that I can get and still lower the rubber enough to get a fender in between it and the fork crown. Width is really not an issue here as far as I can tell/measure. So my thought process, thoroughly inept as it is, goes something like this:
    Get a wider than normal rim and that will have the effect of minimizing the rise of the tire...is this correct Neanderthal thinking?

    If so, I am thinking
    a)Sun Rhyno Lite, 27.5mm outside width, 565g
    b)Mavic A319, 25mm, 597g
    c)Velocity Dyad, 24mm, 480g

    Feel free to chime and set me straight. How do I calculate how tall any given tire will be on any given rim?

    THIS IS DEFINITELY YOUR LAST CHANCE TO TURN BACK AND THINK LOGICALLY ONCE AGAIN!!!!!

    Now, I've also had a pair of 650b's with 40mm(or so) tires mounted on the bike and they look ok considering it's a Jolly Green Giant frame (please, no attacks from any Green Giant lawyers). Plenty of room for any fender I would care to mount, including Chia Fenders. Lots of growing room and light penetration with 650b's.

    I measured from the fork crown brake hole (needs to be drilled out a bit) and the rear brake boss to the rim of the 650b and it's a little over 63mm, reachable by several different extra long reach brakes (a couple go past 70mm). Only problem, is that the cantilever brake bosses are exactly in line with the rim faces where the brake pads should travel. ARGGGGGG!!!!!!

    So, here's my hillbilly engineering idea. If I get sidepull brakes what would stop me from mounting the rear brake on the inside of the brake boss(inside the rear triangle) instead of the outside? If that would work, then I only have to deal with the front brake by machining a short extension for the front fork crown and get a longer mounting bolt for the front brake itself. If you haven't already figgured it out, I don't want to cut the bosses off the frame so that I can go baccards iffin I don't like the 650bs.

    Now, that I have totally asked too many questions for one post...we all know that nobody ever answers more than one question in ANY post no matter how many legitimate questions said post may contain, I'll ask another.

    Hubs?
    I'm thinking 130mm even though the frame is 126mm. I'm also thinking that Shimano LX's used to be made as both 130mm and 135mm and if I could get 36hole Deore LX's from a used or NOS source, they may be stronger, ie better for a fat guy. If not, I was thinking 105's or 600/Ultegras. ???

    So, if you have come this far and are not:

    a) laughing your A$$ off at what I'm trying to accomplish
    b) confused by the entire endeaver
    c) pissed off cause there's not even a good joke in this post...and NO PORN.

    then:
    a) Give me some constructive, crazy A$$ advice or ideas...
    b) point out why my ideas are completely impractical
    c) blow this off and get back to riding your pencil

    Now, it's up to all of you. How many questions are in this post? (oops, there's one more) and how many dare you try to answer before Our Blessed Lady of Qwerty Paralysis sets in and you are frozen in your keyboard tracks.

  2. #2
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Random answers/opinions....

    Hubs are the least of your concern. Rims and spokes are the important bits.

    It seems too obvious to me, but....buy a new fork. Save the old one. Use the 650B wheels and long-reach calipers on the new fork. The fork I have in mind is about $40.

    If you use the rear caliper brake reversed, make SURE that the pads, if they are cartridge, face the correct way so that the pads don't shoot out of the holders the first time you apply them.

    Yes, a wider rim will reduce the height of a fat tire. It will also give you absolutely no benefit over a narrower tire on a narrow rim. The squish is in the height, not the width.

    All current road bike hubs are 130mm. Any of them will serve you fine. I'd like to know who got you started on the hub thing so I could smack them around. There is no "fat man" hub. A hub is a hub. The only real difference is in the bearings/smoothness and in the cassette freehub body.

    FWIW, I'm 306lbs and ride whatever the hell I want - including wheels with 20/24 spokes. It's all in how you ride, not in what you ride.

    As should be obvious, I support the 650B conversion. Otherwise, try 700c wheels with 28mm Pasela tires and some Velo Orange fenders.
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  3. #3
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Here's my 650B gravel road bike, just to get you primed for the joys of 650B.....

    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  4. #4
    RoadBikeReview Member
    Reputation: lonelobo's Avatar
    Join Date
    Sep 2009
    Posts
    57

    What fork in the road?

    Mr. Platypus,
    you are both articulate and cruel. Nice bike, I am doing the Pavlovian prance right now.
    What forks do you refer to? Are they threaded? I like threaded....of course, because that makes it HARDER!!!!

    As to hubs...it's just the axles are a bit beefier on MB hubs, at least that's what I've been told. It's just that we have lots of armadillo holes on country roads. Sometimes it's just a small bump, then crash...other times it's a trap and you have to scurry in a hurry so as to not become the main course at an Armadillo revival meetin.

  5. #5
    a little too stoked
    Reputation: SystemShock's Avatar
    Join Date
    Jun 2008
    Posts
    33,613
    Quote Originally Posted by PlatyPius
    Here's my 650B gravel road bike, just to get you primed for the joys of 650B.....


    Very cool. What tires are those?

    And do you like the Rawland frame? Is it 'springy' (in a good way) or 'stout'?
    .
    MH: I want to go like my Dad did, peacefully, in his sleep, not screaming in terror like his passengers.

    Sys: Fake news?? Trump's a Fake President for God's sake.

    Plat: I'd rather fellate a syphilitic goat than own a Cervelo.

    Homer: I believe that the children are our future. Unless we stop them now.

    Seam: Saw Bjork poop onstage back in the day. It blew my teenage mind.


  6. #6
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Here's the fork (27" to keep the geometry the same)
    http://www.jbimporters.com/web/check...hgb985lio5dh40

    It's actually about $20. I was off on my guess.
    Yes, it's threaded.
    Steerer length might be an issue, though. Changing to a 700c fork (which I've done on 27" wheeled bikes before) doesn't change the geometry *much*. It really is a tiny difference, after all. You might notice the difference, though.

    Yes, MTB hubs tend to have beefier axles. They all end in tiny little nubs that sit in a dropout though, don't they? Guess where they usually bend....

    However, your observation does have merit. Unfortunately, MTB hubs that are in a 130 width probably have the same - or smaller - diameter inner axles than new road hubs such as Tiagra (the one I would recommend). There weren't many oversized axles back in the 130mm days.
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  7. #7
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Quote Originally Posted by SystemShock
    Very cool. What tires are those?

    And do you like the Rawland frame? Is it 'springy' (in a good way) or 'stout'?
    .
    Those tires are gone. They were cheapo SunLites from J&B. I have Fatty Rumpkins on there now.

    The frame is laterally stiff, yet vertically compliant.

    It has a nice ride to it. It doesn't do a whole lot of flexing - when I stand on the pedals, it goes - but it's nice and comfy to ride for long distances on gravel roads.
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  8. #8
    RoadBikeReview Member
    Reputation: lonelobo's Avatar
    Join Date
    Sep 2009
    Posts
    57

    Tektro Confusion

    OK, so I'm doing research into the extra long Tektro brakes. There is an R-556 and a R-365 that look to be identical but have different weights. What is the real difference between them. And how do I designate the Nutted version when ordering?

    Also, these brakes are sold seperately as a front and a rear at many websites. But via illustrations both look identical. But they have different prices. What is the difference?

    And finally, if I do indeed mount the rear brake inside the rear triangle (and from looking at the geometry of the front fork and down tube) I may be able to do the same trick on the front fork...does this mean that the brake designated as "rear" would go on the front and the brake designated as "front" would go on the rear since everything is flip flopped geometrically?

  9. #9
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Front brake has a long bolt, rear brake has a short bolt.

    I would not, under any circumstances, mount the front brake backwards. Rear one, maybe. Front one, no way.
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  10. #10
    RoadBikeReview Member
    Reputation: lonelobo's Avatar
    Join Date
    Sep 2009
    Posts
    57

    need more input

    tell me about the dangers of mounting the front brake backwards if there is plenty of room. Remember, this is a huge frame. What am I not considering?

    Only thing I can see as a problem is the cable is slow speed tight cornering, but even then it would have to be close to 90 degrees.

  11. #11
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    The front brake is the most important brake. It does probably 70% of your stopping. Normally, it flexes INTO the fork when you stop. If it's on the back, it's going to flex AWAY from the fork, and can just keep on going back. *snap*
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  12. #12
    RoadBikeReview Member
    Reputation: rcnute's Avatar
    Join Date
    Dec 2004
    Posts
    1,990
    Quote Originally Posted by PlatyPius
    Those tires are gone. They were cheapo SunLites from J&B. I have Fatty Rumpkins on there now.

    The frame is laterally stiff, yet vertically compliant.

    It has a nice ride to it. It doesn't do a whole lot of flexing - when I stand on the pedals, it goes - but it's nice and comfy to ride for long distances on gravel roads.
    Hey, nice Sogn! I thought I was the only one on here.

    Flexy bikes they ain't.

  13. #13
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Quote Originally Posted by rcnute
    Hey, nice Sogn! I thought I was the only one on here.

    Flexy bikes they ain't.
    I love my Sogn. When the new Rawland frames are ready, I'll be stocking them in my store. I'm a believer in Rawland. Should make it easier for me to sell them.
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  14. #14
    RoadBikeReview Member
    Reputation:
    Join Date
    Jul 2003
    Posts
    559
    Why not just roll with 35mm file tread cyclocross tires? Go with velocity chucker rims (deep v's but 24mm wide). They are supposedly stronger than the dyad.

    For hubs, the lx, xt and dx were made 130mm. I have two sets of the xt for cross, and they are OK, but they require a hub body transplant in order to use them. Ultegras are great hubs for the money and there really isn't much difference between them and the 105's.

    If price is no object, Chris King makes a 130mm cyclocross hub that is, well, king.

    36 holes is best. Lace em' up with dt supercomps 3x. A chucker/king/supercomp wheel would be well within tandem spec.

  15. #15
    Windermere
    Guest
    Quote Originally Posted by PlatyPius
    Here's my 650B gravel road bike, just to get you primed for the joys of 650B.....

    That is a very nice bike.

    Very nice.

    Love those fork crowns.

  16. #16
    25.806975801127
    Reputation: PlatyPius's Avatar
    Join Date
    Feb 2009
    Posts
    9,790
    Quote Originally Posted by Windermere
    That is a very nice bike.

    Very nice.

    Love those fork crowns.
    Have you seen the new models?

    Here's a tiny bit of the new Ravn...



    (Yes, that's a bottle opener on the non-drive side.)
    Other countries need to stop hatin' or we'll unfriend them. - Christine

    Apparently I left my reading comprehension glasses in my ass. - DrRoebuck

    Still, it felt great and I felt like I was sitting on some kind of vibrator -Touch0Gray

  17. #17
    n00bsauce
    Reputation: Mel Erickson's Avatar
    Join Date
    Feb 2004
    Posts
    13,507
    How does the front rack attach to the frame?
    "Those who can make you believe absurdities can make you commit atrocities." Voltaire

    There are your fog people & your sun people, he said. I said I wasn't sure which kind I was. He nodded. Fog'll do that to you, he said.

    "We are all ignorant about most things."
    Mel Erickson

  18. #18
    a little too stoked
    Reputation: SystemShock's Avatar
    Join Date
    Jun 2008
    Posts
    33,613
    Quote Originally Posted by PlatyPius
    Those tires are gone. They were cheapo SunLites from J&B. I have Fatty Rumpkins on there now.

    The frame is laterally stiff, yet vertically compliant.

    It has a nice ride to it. It doesn't do a whole lot of flexing - when I stand on the pedals, it goes - but it's nice and comfy to ride for long distances on gravel roads.
    Cool. Any thoughts on 650B vs 700C in terms of ride feel, acceleration, handling, etc?

    Btw, I hear the Grand Bois 650B tires are absolutely wonderful.
    .
    MH: I want to go like my Dad did, peacefully, in his sleep, not screaming in terror like his passengers.

    Sys: Fake news?? Trump's a Fake President for God's sake.

    Plat: I'd rather fellate a syphilitic goat than own a Cervelo.

    Homer: I believe that the children are our future. Unless we stop them now.

    Seam: Saw Bjork poop onstage back in the day. It blew my teenage mind.


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

THE SITE

ABOUT ROADBIKEREVIEW

VISIT US AT

© Copyright 2020 VerticalScope Inc. All rights reserved.