1985 Trek 620 Cantilever to V-brake conversion
#1
I'm Carbon Curious
Thread Starter
Join Date: Aug 2005
Posts: 2,190
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 0 Times
in
0 Posts
1985 Trek 620 Cantilever to V-brake conversion
Any here with a 1985 Trek 620 or similar vintage Trek that converted their cantilever brakes to V-brakes?
The '85 Trek 620 had 27" wheels and cantilever. Right now I have 700c wheels which work fine with the original cantis. I'm more comfortable adjusting V-brakes than cantis and I like the stopping power of V-brakes better.
Anyone do this with success?
I know some of the earlier cantis bosses were not compatible with the V-brakes. Also V-brakes don't have as much wiggle run for adjustment and since this bike was originally designed for 27" wheels, I don't know if V-brakes will work.
The '85 Trek 620 had 27" wheels and cantilever. Right now I have 700c wheels which work fine with the original cantis. I'm more comfortable adjusting V-brakes than cantis and I like the stopping power of V-brakes better.
Anyone do this with success?
I know some of the earlier cantis bosses were not compatible with the V-brakes. Also V-brakes don't have as much wiggle run for adjustment and since this bike was originally designed for 27" wheels, I don't know if V-brakes will work.
#2
Senior Member
Cantilevers, if adjusted properly stop, as well as anything except a disc. With that said, You would have to check if V-brakes have enough adjustment to take a 700C wheelset. I think it's a try it and see kind of deal.
#3
surly old man
Join Date: Sep 2006
Location: Carlisle, PA
Posts: 3,392
Bikes: IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Likes: 0
Liked 42 Times
in
18 Posts
I have an 85 620 that I converted to 700, using old Deore cantis because they had a very wide range of adjustment.
The bosses are narrower than more modern bosses, so they are not ideal for v-brakes. I have not tried it however.
Two thoughts:
-the conventional wisdom is that narrow bosses do not work with v-brakes. I think because you need more width so that the brake arms do not touch at the top.
-I really had to use a radical brake-pad angle to get my cantis to fit. I am very doubtful that any v-brakes would have that kind of adjustment range.
I am all for trying however. Hopefully you have a set in the parts-box to dry-run.
jim
The bosses are narrower than more modern bosses, so they are not ideal for v-brakes. I have not tried it however.
Two thoughts:
-the conventional wisdom is that narrow bosses do not work with v-brakes. I think because you need more width so that the brake arms do not touch at the top.
-I really had to use a radical brake-pad angle to get my cantis to fit. I am very doubtful that any v-brakes would have that kind of adjustment range.
I am all for trying however. Hopefully you have a set in the parts-box to dry-run.
jim
__________________
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
#4
Bike Junkie
Join Date: Jun 2005
Location: South of Raleigh, North of New Hill, East of Harris Lake, NC
Posts: 9,622
Bikes: Specialized Tarmac, Specialized Roubaix, Giant OCR-C, Specialized Stumpjumper FSR, Stumpjumper Comp, 88 & 92Nishiki Ariel, 87 Centurion Ironman, 92 Paramount, 84 Nishiki Medalist
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 68 Post(s)
Likes: 0
Liked 37 Times
in
27 Posts
If the bosses are more narrow you can modify the V brakes by relocating the thick washer from the inside of the V brake (pad side) to the outside. I've had to make this change when updating some older MTBs to V's.
__________________
Roccobike BF Official Thread Terminator
Roccobike BF Official Thread Terminator
#5
surly old man
Join Date: Sep 2006
Location: Carlisle, PA
Posts: 3,392
Bikes: IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Likes: 0
Liked 42 Times
in
18 Posts
Definitely worth trying. But this case will be a little harder than the run of the mill conversion because he is not just fighting against the narrow bosses, but also the lost 4mm of the smaller rims.
jim
__________________
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
#6
Senior Member
Join Date: Mar 2002
Location: NJ
Posts: 3,084
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 5 Times
in
4 Posts
i'd be stunned if you couldn't run it with 700c rims, at least in terms of brake-reach issues.
hth,
-rob
Likes For jtgotsjets:
#8
Senior Member
Join Date: Jun 2009
Location: Montereyish
Posts: 2,306
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 2 Times
in
2 Posts
If you want to use your road levers, you may need a Travel Agent to take up the extra cable required by V-brakes.
https://www.rivbike.com/products/show...l-agent/15-144
https://www.rivbike.com/products/show...l-agent/15-144
#9
Champion of the Low End
If brake reach is an issue, they do have mini V brakes and BMX V brakes that might do the trick. YMMV. There are Tektros and an inexpensive 'Rockwerks' brand that are actually Tektros.
#10
surly old man
Join Date: Sep 2006
Location: Carlisle, PA
Posts: 3,392
Bikes: IRO Mark V, Karate Monkey half fat, Trek 620 IGH, Cannondale 26/24 MTB, Amp Research B3, and more.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 46 Post(s)
Likes: 0
Liked 42 Times
in
18 Posts
With narrow bosses and smaller wheels, its not simply a brake pad reach issue, but more problematically a brake pad angle issue.
Finding some brake set up with sufficient reach is not very hard. Getting one that can accomodate the strange new angle is a problem. With cantis, I think this angle can only be accomodated with arms that take smooth post pads. Because those can be angled any way you want. Are there v-brake arms that will do this?
jim
Finding some brake set up with sufficient reach is not very hard. Getting one that can accomodate the strange new angle is a problem. With cantis, I think this angle can only be accomodated with arms that take smooth post pads. Because those can be angled any way you want. Are there v-brake arms that will do this?
jim
__________________
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
Cross Check Nexus7, IRO Mark V, Trek 620 Nexus7, Karate Monkey half fat, IRO Model 19 fixed, Amp Research B3, Surly 1x1 half fat fixed, and more...
--------------------------
SB forever
Last edited by jgedwa; 01-01-11 at 09:25 PM.
#11
Junior Member
Join Date: Apr 2017
Location: Michigan
Posts: 131
Bikes: 82 John Howard built by Dave Moulton, 06 Lemond Croix de Fer, 85 trek 620, Trek Fx 7.2, Giant escape 2, Gt Karakoram, Electra Townie 7D,
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked 65 Times
in
34 Posts
What did you end up doing? I'm facing this at the moment, and would appreciate any help you might have found.
They'll work, kinda.. but I want to stop dead in my tracks if need be and I am planning on loading it down with racks and gear which will only intensify the need..
Maybe my LBS can get them dialed in for me.
They'll work, kinda.. but I want to stop dead in my tracks if need be and I am planning on loading it down with racks and gear which will only intensify the need..
Maybe my LBS can get them dialed in for me.
#12
Expired Member
Join Date: Jun 2007
Location: TN
Posts: 11,526
Mentioned: 37 Post(s)
Tagged: 0 Thread(s)
Quoted: 3661 Post(s)
Liked 5,408 Times
in
2,747 Posts
OP hasn't posted to BF in eight years.... Hopefully someone else can help.
Likes For shelbyfv:
#13
Junior Member
Join Date: Apr 2017
Location: Michigan
Posts: 131
Bikes: 82 John Howard built by Dave Moulton, 06 Lemond Croix de Fer, 85 trek 620, Trek Fx 7.2, Giant escape 2, Gt Karakoram, Electra Townie 7D,
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked 65 Times
in
34 Posts
I broke down and bought some 27's off of ebay until I can find another option, I'm still figuring out this platform, thanks for the heads up.
#14
Master Parts Rearranger
Join Date: Mar 2015
Location: Portlandia's Kuiper Belt, OR
Posts: 4,402
Bikes: 1982 Trek 720 - 1985 Trek 620 - 1984 Trek 620 - 1980 Trek 510 - Other luminaries past and present
Mentioned: 221 Post(s)
Tagged: 0 Thread(s)
Quoted: 1556 Post(s)
Liked 2,024 Times
in
989 Posts
Since this zombie thread has been Lazarus'ed, I will say, as a 1985 Trek 620 owner, for future readers of this thread, whenever you may be, that the rear spacing is ~77mm and height (from the axle) is acceptable (~287mm IIRC) to support V-brakes (or mini-Vs in my case). With standard 'old school' rims, (20.0mm max external width), the angle or splaying of the arms is alright. If running a wider modern rim (22.7mm external in my case), the splaying will be quite obvious and not, IMO, aesthetically pleasing. The front canti posts are spaced, CTC, at ~66mm with a height of about 294mm or so. 100% no go for V-brakes of any sort.
What I ended up doing is paying someone to position new posts at the spec'd height of 283mm and width of 80mm, which is what seems to work (and is spec'd) by many--though as always, please check with the company of the brakes you wish to run. In my case, a taller post height would have worked perfectly fine for my TRP CX 8.4 mini-V setup as the 283mm height puts the pads well into the middle of the slots, which can 'limit' vertical clearance. This is only a problem, potentially, if one wants to run large tires and fenders at the same time, and if those tires happen to be 38-40mm actual width. I am running 42mm nominal width Soma tires (Supple Vitesse EX) that measure 39.0-39.5 at 40-45 PSI, which my frame and fork clear by 3mm at least at the fork blades and chain stays.
I am running a post width of 82mm in the back and 79-80mm in front. The TRP brakes look good and the narrower-set fork blades aren't disrupted by the wider-than-the-center-line posts, which manage to stay mostly within the silhouette of the fork blades (when viewed front to back). A bonus of the new canti posts is the three holes for brake spring tension setting, versus the single hole originally. Additionally, I can throw in and take out fully-inflated 42s, which was not possible with the very narrow fronts.
PS: Frameset was powder coated and new decals were placed after the frameset was modified. It's not a cheap path to take, but in my case, the frame is fantastic, capable, stable, and fun, with crummy roads necessitating large tires for comfort and sanity. These are very special bikes/frames, and I have ridden many over the years!
What I ended up doing is paying someone to position new posts at the spec'd height of 283mm and width of 80mm, which is what seems to work (and is spec'd) by many--though as always, please check with the company of the brakes you wish to run. In my case, a taller post height would have worked perfectly fine for my TRP CX 8.4 mini-V setup as the 283mm height puts the pads well into the middle of the slots, which can 'limit' vertical clearance. This is only a problem, potentially, if one wants to run large tires and fenders at the same time, and if those tires happen to be 38-40mm actual width. I am running 42mm nominal width Soma tires (Supple Vitesse EX) that measure 39.0-39.5 at 40-45 PSI, which my frame and fork clear by 3mm at least at the fork blades and chain stays.
I am running a post width of 82mm in the back and 79-80mm in front. The TRP brakes look good and the narrower-set fork blades aren't disrupted by the wider-than-the-center-line posts, which manage to stay mostly within the silhouette of the fork blades (when viewed front to back). A bonus of the new canti posts is the three holes for brake spring tension setting, versus the single hole originally. Additionally, I can throw in and take out fully-inflated 42s, which was not possible with the very narrow fronts.
PS: Frameset was powder coated and new decals were placed after the frameset was modified. It's not a cheap path to take, but in my case, the frame is fantastic, capable, stable, and fun, with crummy roads necessitating large tires for comfort and sanity. These are very special bikes/frames, and I have ridden many over the years!
Likes For RiddleOfSteel:
#15
Junior Member
Join Date: Apr 2017
Location: Michigan
Posts: 131
Bikes: 82 John Howard built by Dave Moulton, 06 Lemond Croix de Fer, 85 trek 620, Trek Fx 7.2, Giant escape 2, Gt Karakoram, Electra Townie 7D,
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked 65 Times
in
34 Posts
Man Riddle, I love seeing your bike.
Likes For Jasongrace313:
#16
Master Parts Rearranger
Join Date: Mar 2015
Location: Portlandia's Kuiper Belt, OR
Posts: 4,402
Bikes: 1982 Trek 720 - 1985 Trek 620 - 1984 Trek 620 - 1980 Trek 510 - Other luminaries past and present
Mentioned: 221 Post(s)
Tagged: 0 Thread(s)
Quoted: 1556 Post(s)
Liked 2,024 Times
in
989 Posts
Thanks, man. Best part now, is that I FINALLY solved my howling brakes and shuddering fork issue. After trying all toeing in/out combos, I went back to toeing them in, just more aggressively than before (before would have been fine for a side pull caliper as there is no slop in that system, among other things). I still picked up Kool Stop salmon-colored pads. Initial brake bite is lessened a little as, naturally, less pad is making initial contact with the rim. Brake lever effort is still light, so I can still squeeze the levers harder (yet more easily? you know what I'm saying) to bring about the desired vice-like stopping power. So I suppose, in essence, I have gained modularity. The takeaway for other vintage canti-to-V convertors, is to work the pad toe angles. It can be vexing and discouraging, especially if you half built a bike around something like these TRPs and they don't cooperate right away. I should note that after redoing the toe-in, I took a rasp/file to the pads as they had glazed in parts due to heat buildup and vibration during their pretty extreme break-in period/introduction to Seattle topography. Brakes, like anything on a bike, are an ecosystem, and it can take a little bit to find the balance!
Likes For RiddleOfSteel:
Thread
Thread Starter
Forum
Replies
Last Post
ilovesalad
Classic & Vintage
11
08-01-12 11:14 PM
Von Stively
Classic and Vintage Bicycles: Whats it Worth? Appraisals.
3
12-19-09 06:30 PM