Handlebar Shims
 

Going from 7/8” to ¿one inch?


https://cimg3.ibsrv.net/gimg/bikefor...e7b8fddbd.jpeg
Hi Rise Bars on a vintage Trek 950 Needs shims.


Bought 25” x 13.5” x 7/8” handlebars so I can sit upright as I ride. Didn’t check the stem diameter.
I had some galvanized steel handy so I made shims.
Might have to slip in one more small shim, it’s almost tight enough.
I checked Google and there are commercially available handlebars shims, do you think they’re worth the $8.59?

I’d say it depends on how much time you have to spend fabricating something, assuming the materials won’t cost you anything. But it seems like a reasonable price to make it work properly and safely. You really don’t want your bars rotating at the wrong time while riding.

I do not like to shim handlebars, homemade shim for me is no go. If you have to use those bars I would get a new stem.

I don't have any problem with the shim. But I do have a problem with that one bolt clamp on the stem. If it works for you, then that's all that really matters.

I’m thinking about a new stem, but this one has a hole in it for the f brake cable . Bike has cantilever brakes.

its 1” stem with quill, and my new handlebars are 7/8th”

For a 22.2 mm or 7/8” handlebar you’d probably need a bmx stem which would have shorter reach, plus a cable hanger of some kind for your front brake. Probably would need to replace the cable and housing too. I’d just use the proper shim, though if it still won’t clamp tight enough you might also need a stem with a faceplate and more than 1 bolt.

Yes, because your life might be worth at least a slightly more than that amount?

Ideally, bar shims should come with a purchased aftermarket stem or headset.

Do what you want. It's your bike. I'll never ride your bike :D

Yea commercial shims work fine. I've used them for years because I have a couple of 1" handlebars that I really like and use them with 1-1/8" stems without incident. I torque properly, use friction paste for the CF bar, nothing with the aluminum bar. I've fabricated shims for a seat post that just won't stay put in my old titanium frame even though both are 27.2 and I use friction paste. I use beer cans and have been successful in keeping the post from slipping. But slippage is an inconvenience not the possibility of going over the front wheel. I wouldn't screw around with a home made handle bar shim either for the steer tube or the handlebar. Plus the commercial shims can be bought in black or silver and the edges are finished nicely so they won't scar the handlebar material, they're hardly noticeable, and if so, look better than something cut from sheet metal.

I didn’t use beverage cans, I have a roll of galvanized steel roof flashing leftover from a job we did.
I had to put four shims in , one at a time, I couldn’t put one large piece in at once. But it’s holding now.
Thought about a BMX stem , I have used them with BMX handlebars on several other builds, but this time I bought large chopper bars, and since they don’t have a crossbar … I figured I might as well use the bike’s existing stem.
I might have to buy tandem cables now because of the distance from the handlebars to the rear derailleur…

This takes shade tree mechanic to another level. I would really want to be sure that the edges of your shims were not able to score the handlebars as this would be a serious stress riser leading to failure of the bars (assuming they are aluminum).

I used beverage can shim for a seat post where the required shim is very, very small and the post and seat tube were the same spec (but slightly off). I wouldn't use them for shimming a mis-match of handlebar-stem issue. I'd use a commercial stem shim for the reasons I posted.

Steel bars.


https://cimg9.ibsrv.net/gimg/bikefor...7ecb6b583.jpeg
Trek 950 modifications


The yellow lights blink. Switches control left , right, or 4-way...

Steel bars “Sunlite” brand,


https://cimg1.ibsrv.net/gimg/bikefor...8f8803ba6.jpeg
$48.99 I think I paid


I can’t bend over or crouch, I find higher handlebars more comfortable.
These are higher than BMX bars.

I’ve tightened these 4 times already. Think the shims are setting in. First ride is called “shakedown” for a reason...

https://cimg7.ibsrv.net/gimg/bikefor...aa16c8b8a.jpeg
Handlebar Shims. 7/8” to one inch


Here’s a photo of the handlebar shims. I’ve stopped to tighten the bolt 4 times, but it seems to be compressing.
I’d get a BMX stem, except it needs a hole for the brake cable...

With the leverage those tall bars will give, I would absolutely change your stem to one with a faceplate, and a proper shim if needed. One bolt will not get them tight enough. I say this as someone who has begrudgingly had to build and work on a lot of low riders.

https://cimg8.ibsrv.net/gimg/bikefor...1867f9a2f.jpeg
15” cube pannier Tailbox

I might not even ride this bike. I made this latest Pannier/Tailbox as an experiment. I can’t take bike’s on LIRR trains anymore, because after Covid19 was over, the “Peak Hours” fare rules went back into effect; which means I’ll have to go back to using CitiBike.
And that’s why I made this setup, so I can have my LED Turn Signals “Directional Indicators” on a CitiBike. It’ll count as baggage on the train it fits in an IKEA shopping bag...

https://cimg6.ibsrv.net/gimg/bikefor...956b6df61.jpeg

Okay, I ordered some 7/8” to one inch shims from Amazon.
The LBS didn’t have them.

When Greg LeMond beat Laurent Fignon by 8 seconds in that infamous time trial with aero bars, Greg’s mechanics used a shim cut out of a Coke can. The night before, Greg went to check out the setup. He got on the bike and pulled up on the aero bars as hard as he could and they slipped. Hence, the Coke can shim. When I get home I’ll find a pic and you can actually see the Coca-Cola pattern sticking out on both sides.

I actually went back on Amazon again, and ordered the BMX 4 bolt stem. I did not cancel the order for the shims ($9.99! For two shims!)…

Here's the pic. You can see the Coke shims on each side.

https://cimg3.ibsrv.net/gimg/bikefor...0790b1fec4.png

I'm not a fan of handlebar shims but I have used these in the past. They are purpose-made and many have serrations to help with metal to metal grip:

https://problemsolversbike.com/produ...p_shims_-_8466

https://cimg3.ibsrv.net/gimg/bikefor...40ad652c4.jpeg
Aluminum tubes support the milk crate to prevent handlebars from moving forward.

It’s impossible for the handlebars to rotate forward now.
I really enjoyed the upright sitting position with these handlebars.

https://cimg7.ibsrv.net/gimg/bikefor...347f3d926.jpeg
Polyethylene board hardware secures the milk crate to the bars
https://cimg9.ibsrv.net/gimg/bikefor...e3b8a4bab.jpeg
https://cimg1.ibsrv.net/gimg/bikefor...6a20c4c02.jpeg
Screws have backing pieces or big washers.
https://cimg2.ibsrv.net/gimg/bikefor...bb376aa56.jpeg

I bought a BMX four bolt stem (old school) but it doesn’t have a hole for the front brake cable.
Meanwhile, this milk crate is preventing the handlebars from rotating forward.


https://cimg3.ibsrv.net/gimg/bikefor...49995c7e7.jpeg

TiCycles makes their stems only in 1-1/8" and provides shims to suit the bars to be used. Beautifully machined but just simple aluminum, no patterns. I've had zero issues in 10,000 miles of so. Granted I'm no Charles Atlas and these are drop bars but TiCycles has been around nearly 3 decades and has seen everything.

https://cimg6.ibsrv.net/gimg/bikefor...cf2f37796b.jpg
F&R cycles supplied both the 4 bolt stem and the shims


I just opened the package. It’s either or. Either the shims or the stem can go on the bike, but the stem would force me to convert from cantilever to vee brakes.

It's not either/or. Bikes have had stems without stem cable holes but with cantilever brakes forever. Most use a hanger on the stem quill located with or in place of the washer between the top headset cup and the locknut. My Peter Mooney has used this for all of its 50,000 miles. And with most bikes it is not hard to use a fork crown mounted housing stop which has the benefit of preventing shudder caused by fork deflection while braking with headset or stem stops.

One example https://external-content.duckduckgo....6pid%3DApi&f=1

Newer and snazzier https://external-content.duckduckgo....6pid%3DApi&f=1

And a fork crown version https://external-content.duckduckgo....jpg&f=1&nofb=1

Any bike coop or older bike shop should have a few lying around. All older centerpull bikes came with these hangers so there are thousands out there of probably several dozen varieties. Mafac, DiaComp and Shimano all made a lot of these. Their hangers are fully trustworthy even if old enough to be past good looks. (Shimanos are probably the stiffest and best of the three but I have plenty of miles on all of them.) I've never owned a stem with the hole and stop for a brake cable and roughly half my 200,000 or so miles have been on cantilever or centerpull brakes. You can also drill your new stem for that stop and many do but I never will. I'm superstitious; having had a key front end part fail and having paid a huge price for it.