Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Retro mountain bike stem compatibility

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Retro mountain bike stem compatibility

Old 06-29-18, 02:28 PM
  #1  
tonyfourdogs
Senior Member
Thread Starter
 
tonyfourdogs's Avatar
 
Join Date: Oct 2017
Location: Devon, UK
Posts: 251

Bikes: Marin Palisades Trail (1991)

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Liked 1 Time in 1 Post
Retro mountain bike stem compatibility

Hi folks

Apologies in advance if this is considered a stupid question. I've searched the forums and the big G and I can't find a definitive answer.

I have a 1991/2? Marin Palisades Trail which I'm converting to drop bars as an experiment. The stem takes 25.4mm bars, and the drop bars I have are 25.4mm. However, the clamp area is so wide that I can't get the bars in at the bends. Even though the stem is steel, I don't want to force it to open up and end up damaging it. Now I know the answer is probably no, but am I missing something? I saw a video recently on YT where a guy converted his retro mtb to drop bars using the original stem (although the clamp area did look narrower). Maybe my stem clamp is just too wide?

I tried using a stem from an old road bike, but discovered that the stem diameters are different...

Anyone managed this using the original mtb stem? It would be great to use it as it also saves getting hold of a cable stop for the caliper brakes.

Last edited by tonyfourdogs; 06-29-18 at 02:53 PM.
tonyfourdogs is offline  
Old 06-29-18, 05:35 PM
  #2  
nfmisso
Nigel
 
nfmisso's Avatar
 
Join Date: Mar 2011
Location: San Jose, CA
Posts: 2,991

Bikes: 1980s and 1990s steel: CyclePro, Nishiki, Schwinn, SR, Trek........

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 383 Post(s)
Likes: 0
Liked 2 Times in 2 Posts
The stem is steel ???? Please check with a magnet. I strongly suspect that it is aluminum. Aluminum does not like to be over bent and bent back.
nfmisso is offline  
Old 06-29-18, 08:47 PM
  #3  
Andrew R Stewart 
Senior Member
 
Andrew R Stewart's Avatar
 
Join Date: Feb 2012
Location: Rochester, NY
Posts: 13,767

Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Raleigh Pro, Trek Cycle Cross, Mongoose tomac ATB, GT Bravado ATB, JCP Folder

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2495 Post(s)
Liked 564 Times in 435 Posts
Yes, stem/bar clamp widths is a spec that counts if you want to keep the bars un scathed. Andy
__________________
AndrewRStewart
Andrew R Stewart is offline  
Old 06-30-18, 01:43 AM
  #4  
tonyfourdogs
Senior Member
Thread Starter
 
tonyfourdogs's Avatar
 
Join Date: Oct 2017
Location: Devon, UK
Posts: 251

Bikes: Marin Palisades Trail (1991)

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Liked 1 Time in 1 Post
Originally Posted by nfmisso View Post
The stem is steel ???? Please check with a magnet. I strongly suspect that it is aluminum. Aluminum does not like to be over bent and bent back.
I will check that. Although I'm pretty sure I cleaned rust off the stem when I was restoring the bike, but I agree stems have been alu/alloy mostly in my experience too. Thanks
tonyfourdogs is offline  
Old 06-30-18, 11:54 AM
  #5  
fietsbob
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,277 Times in 798 Posts
fork steerers come in 7/8" 22.2mm they call it a 1" because they are talking about the outside diameter
of the fork

next came a fork with a 1" inside, and a 1 1/8" outside.. some were threaded , now a lot are threadless.

you can get conversion plugs to use in a threaded fork, and then put a threadless stem on that.
fietsbob is offline  
Old 06-30-18, 01:50 PM
  #6  
tonyfourdogs
Senior Member
Thread Starter
 
tonyfourdogs's Avatar
 
Join Date: Oct 2017
Location: Devon, UK
Posts: 251

Bikes: Marin Palisades Trail (1991)

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Liked 1 Time in 1 Post
Originally Posted by fietsbob View Post
fork steerers come in 7/8" 22.2mm they call it a 1" because they are talking about the outside diameter
of the fork

next came a fork with a 1" inside, and a 1 1/8" outside.. some were threaded , now a lot are threadless.

you can get conversion plugs to use in a threaded fork, and then put a threadless stem on that.
I bought a conversion stem thingy from ebay just before I found this reply. (Thanks btw.) I'm hoping it fits one of the modern stems I have lying around. Also should probably get some calipers for future projects.
tonyfourdogs is offline  
Old 06-30-18, 02:50 PM
  #7  
onyerleft
Senior Member
 
onyerleft's Avatar
 
Join Date: Jan 2018
Posts: 485

Bikes: Pedaling for the Lord!

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 299 Post(s)
Likes: 0
Liked 39 Times in 26 Posts
If the cycling gods had wanted you to fit drop bars to an old mtn bike, you wouldn't be having these problems. Take it as a sign to move on to another project, rather than attempt to defy the gods.
onyerleft is offline  
Old 06-30-18, 04:15 PM
  #8  
SquidPuppet
Calamari Marionette Ph.D
 
SquidPuppet's Avatar
 
Join Date: Dec 2013
Location: Coeur d' Alene
Posts: 7,859

Bikes: 3 Chinese Gas Pipe Nerdcycles and 2 Chicago Electroforged Boat Anchors

Mentioned: 74 Post(s)
Tagged: 0 Thread(s)
Quoted: 2352 Post(s)
Liked 13 Times in 12 Posts
Originally Posted by tonyfourdogs View Post
I bought a conversion stem thingy from ebay just before I found this reply. (Thanks btw.) I'm hoping it fits one of the modern stems I have lying around. Also should probably get some calipers for future projects.
It's a 1-1/8 inch quill. The standard of old MTBs. A variety can be found on the bay. Nitto even makes one that would work.
SquidPuppet is offline  
Old 06-30-18, 04:23 PM
  #9  
2cam16
Senior Member
 
2cam16's Avatar
 
Join Date: Oct 2016
Location: San Mateo,Ca.
Posts: 3,572

Bikes: TOO MANY

Mentioned: 44 Post(s)
Tagged: 0 Thread(s)
Quoted: 867 Post(s)
Liked 397 Times in 279 Posts
Originally Posted by onyerleft View Post
If the cycling gods had wanted you to fit drop bars to an old mtn bike, you wouldn't be having these problems. Take it as a sign to move on to another project, rather than attempt to defy the gods.
Have you even read this thread?
Show Your Vintage MTB Drop Bar Conversions
2cam16 is offline  
Old 06-30-18, 04:30 PM
  #10  
thumpism 
Bikes are okay, I guess.
 
thumpism's Avatar
 
Join Date: Jan 2015
Location: Richmond, Virginia
Posts: 6,088

Bikes: Waterford Paramount Touring, Trek 510 city build, Giant CFM-2, Raleigh Sports 3-speeds in M23 & L23, Schwinn Cimarron oddball build, Marin Palisades Trail dropbar conversion, Nishiki Cresta GT

Mentioned: 49 Post(s)
Tagged: 0 Thread(s)
Quoted: 1753 Post(s)
Likes: 0
Liked 488 Times in 349 Posts
Probably not recommended but I have done this on my own bike, grind the stem at the bottom near the pinch bolt so the clamp part does not have parallel ends but is sort of V-shaped. May take more of an angle than the stem shown, so grind a little and test fit, repeat as necessary.
thumpism is offline  
Old 06-30-18, 05:34 PM
  #11  
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Posts: 11,739
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 106 Post(s)
Liked 4 Times in 3 Posts
Yeah that works. Road stems typically have that V for dealing with bends in road-bars. Also helps if you rotate bar so that narrow part of V is on inside-radius of bar.

Another tip: remove clamp-bolt and insert penny into slot. Install bolt from back side (threaded side), and turn it to press against penny and it'll spread clamp to make getting bars through easier.

Steel's much more forgiving of abuse than aluminium so not too much to worry about. It has much, much higher strength per unit-volume than aluminium (that's why less is used), and also has fatigue-limit which aluminium doesn't. If you keep stresses below certain level, steel will never fail. Aluminium doesn't have fatigue-limit, so any and all stresses will accumulate and part will eventually fail.
DannoXYZ is offline  
Old 07-08-18, 11:22 AM
  #12  
tonyfourdogs
Senior Member
Thread Starter
 
tonyfourdogs's Avatar
 
Join Date: Oct 2017
Location: Devon, UK
Posts: 251

Bikes: Marin Palisades Trail (1991)

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 86 Post(s)
Liked 1 Time in 1 Post
So, I finally did it!

I knew the stem was steel, but since there were a few doubters, I decided to buy a quill stem adapter for a modern stem (which I already had).

Fast forward to the stem arriving, and I couldn't use it because the clamp size was too big (I hadn't even considered that). So I rummaged in my bag of parts and found a similar mtb stem, and the bars went of first try - no prising open required. And it was a *very* similar stem to the original marin one.

So I installed the stem/ bars and had to use one of those cable stops that bolts into the top of the forks. However, it wasn't high enough, and I couldn't wire the brakes so they'd actually stop the wheel.

In desperation, I went a got my magnet, confirmed my existing stem (with cable stop brazed on) was steel, prised it open just a little, installed the bars, and now the project's complete!

If only I'd tried to work with what I already had in the first place I'd have saved so much time!

Thanks to everyone who replied. Drop bar retro mtb projects highly recommended. It's loads of fun to ride
tonyfourdogs is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Airburst
Bicycle Mechanics
18
09-08-18 10:25 AM
Lakerat
Classic & Vintage
11
08-01-16 01:40 PM
tjkwood
Classic & Vintage
6
04-05-13 12:03 PM
likebike23
Classic & Vintage
13
02-13-13 08:49 PM
lobstermike
Bicycle Mechanics
21
12-04-11 02:46 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.