Trail's End Cycling Center

Janet Breunig Mountcastle, look familiar? We posted this article about a month ago. Glad we caught it in time.

"My bike doesn't shift well."

Shifting issues can be caused by a bunch of things: derailleur out of adjustment; bent derailleur hanger; worn chainrings, chain, or cassette; worn out shifter; bad shift cable, cable housing, or damaged ferrules. Electronic shifting has its own set of possible issues. Let's just look at mechanical shifting for now and a problem that plagues Shimano 10- and 11-speed STI shifters.

We have see plenty of frayed rear derailleur cables. But the ones that will stop you dead are the ones that fray and break, or get stuck INSIDE the shifter body. If your derailleur cables exit through the side of your Shimano shifter and not the bottom, you may have a shifter that is prone to eating up cables. These cables have a fairly sharp radius where the cable exits the left/inside horizontal edge of the shifter, just before the cable enters the ferrule and cable housing. Left unchecked, the cable can part, leaving cable fragments inside the shifter. If we catch it soon enough, the cable will look like the one in the attached photo.

This is a Shimano OptiSlick cable that came from a Customer's Felt paired with Shimano 105 ST-R7000 2x11-speed shifters. The cable was replaced just over two years ago. He came in concerned that the bike shifted poorly into the smaller cogs. When we disconnected the cable from the rear derailleur and added some cable slack, we had a difficult time pulling the cable out of the shifter body. When we finally pulled the cable clear of the shifter body, we saw this rat's nest.

How to prevent it...

Well, I wish we had a good solution. For countermeasures, we always coat the last 50mm of the cable near the swaged end stop just before it goes into the shifter's cable seat with some Shimano Cable Grease (yes, there is such a thing). The part number for Shimano Cable Grease, sometimes called Special Grease, is Y04180000. The other thing that we have seen improve cable life in these Shimano shifters is Shimano OptiSlick cables (p/n Y60198100). These are not simply just coated cables. The friction-reducing compound is applied in a way more like powder coating and adheres better to cables than anything we have seen, including Shimano's Polymer coatings. But the best solution is regular service.

If in doubt, have us inspect your shifter and shift cable. Catch a worn or frayed cable before it grenades into tiny cable shards inside your shifter.

"My bike doesn't shift well."

Shifting issues can be caused by a bunch of things: derailleur out of adjustment; bent derailleur hanger; worn chainrings, chain, or cassette; worn out shifter; bad shift cable, cable housing, or damaged ferrules. Electronic shifting has its own set of possible issues. Let's just look at mechanical shifting for now and a problem that plagues Shimano 10- and 11-speed STI shifters.

We have see plenty of frayed rear derailleur cables. But the ones that will stop you dead are the ones that fray and break, or get stuck INSIDE the shifter body. If your derailleur cables exit through the side of your Shimano shifter and not the bottom, you may have a shifter that is prone to eating up cables. These cables have a fairly sharp radius where the cable exits the left/inside horizontal edge of the shifter, just before the cable enters the ferrule and cable housing. Left unchecked, the cable can part, leaving cable fragments inside the shifter. If we catch it soon enough, the cable will look like the one in the attached photo.

This is a Shimano OptiSlick cable that came from a Customer's Felt paired with Shimano 105 ST-R7000 2x11-speed shifters. The cable was replaced just over two years ago. He came in concerned that the bike shifted poorly into the smaller cogs. When we disconnected the cable from the rear derailleur and added some cable slack, we had a difficult time pulling the cable out of the shifter body. When we finally pulled the cable clear of the shifter body, we saw this rat's nest.

How to prevent it...

Well, I wish we had a good solution. For countermeasures, we always coat the last 50mm of the cable near the swaged end stop just before it goes into the shifter's cable seat with some Shimano Cable Grease (yes, there is such a thing). The part number for Shimano Cable Grease, sometimes called Special Grease, is Y04180000. The other thing that we have seen improve cable life in these Shimano shifters is Shimano OptiSlick cables (p/n Y60198100). These are not simply just coated cables. The friction-reducing compound is applied in a way more like powder coating and adheres better to cables than anything we have seen, including Shimano's Polymer coatings. But the best solution is regular service.

If in doubt, have us inspect your shifter and shift cable. Catch a worn or frayed cable before it grenades into tiny cable shards inside your shifter.

Artificial vs Genuine Intelligence...

We received a call today from a cyclist who purchased a replacement tube for his bike from Amazon, and wanted to know if we would take it in trade for the correct tube for his bike. Mary Ann responded that we do not take items in trade from other manufacturers or other retailers.

But wait, it gets even better.

Mary Ann aksed if they had sent the wrong size. Apparently, he took a photo of his tube and asked Chat GPT what type of tube he needed (Presta or Schrader). Chat GPT told him to order a tube that has a Schrader valve, which he did.

When Mary Ann asked him again if Amazon had sent the wrong size, he responded that his rim has a smaller hole and the valve on the tube he received will not fit the rim. Hmmm. Do you see the problem now?

So, you still think that AI is the future? We get it that people want to save some $$$ by purchasing online. And I am sure he will not put a dollar value on his time, or the effort has has to go through to find the correct tube and the time it takes to return this tube to Amazon.

We can't make this stuff up.

Send a message to learn more

Randy Profeta, TPU Tubes? May be fine for some riders.

What's up with TPU tubes?

We've had several roadies ask if we have TPU (Thermoplastic Polyurethane) tubes at our shop. Yes, we do stock a few of the more common sizes and will be adding more. So, what's the story?

Well, TPU tubes are slightly lighter than a lightweight butyl (black rubber) tubes and way (weigh?) lighter than standard butyl tubes. TPU tubes also are better at air retention than butyl and far better than latex tubes when it comes to not losing air pressure over time.

Latex was the "go-to" for riders looking for a lightweight "racing-style" tube for several years now. Now TPU is the darling of the tube world.

TPU Tubes:
* Fold up smaller than butyl tubes,
* Are 2-4x lighter than butyl. This reduces inertial and rotational weight,
* Have higher heat resistance. Important if you are still using rim brakes,
* Are recyclable for those who are environmentally conscious.

While some riders on FB claim that TPU Tubes are more puncture resistant citing more puncture-free rides, this may be more anecdotal and hasn't been backed up by scientific testing. Some mfrs do claim better puncture resistance, though. I've ridden butyl tubes for several years without punctures, then had three punctures in 30 days (about 200 miles) of riding.

TPU tubes can be patched, and this is a good thing since they are 2-4x more expensive that butyl tubes. They do require a special patch kit though (and, yes, we have these patch kits).

Some TPU tubes have removable valve cores and some do not. Conti TPU tubes, one of the most expensive, have RVCs (removable valve cores). Conti has RVCs, but cautions that their 7-layer TPU tubes are for disc-brake use only. FWIW, several other brands of ultra-lightweight TPU tubes are designed for disc-brake use only, so read the package. Do your research.

I use standard butyl tubes on my road bikes and have at least one road bike with tubeless-ready tires with sealant, but I'm willing to give TPU a try. All of my MTBs are set up tubeless with sealant.

When Hutchinson came out with their road tubeless tires about 20 years ago, I was an early adopter and a big fan. They offered a similar road feel to tubular (sew-up tires) and could be run at 5-10% lower air pressure than tube-type tires. The downside with tubeless road is that tubeless sealant is less effective at sealing punctures at higher pressures than MTB tubeless setups which I have also been riding and racing since Stan's NoTubes began offering tubeless MTB conversion kits about 25 years ago.

If you have had any experience with TPU tubes, please share some comments here. I am not a weight we**ie but I am intrigued by the possibility of improving air retention and better road feel.

What's up with TPU tubes?

We've had several roadies ask if we have TPU (Thermoplastic Polyurethane) tubes at our shop. Yes, we do stock a few of the more common sizes and will be adding more. So, what's the story?

Well, TPU tubes are slightly lighter than a lightweight butyl (black rubber) tubes and way (weigh?) lighter than standard butyl tubes. TPU tubes also are better at air retention than butyl and far better than latex tubes when it comes to not losing air pressure over time.

Latex was the "go-to" for riders looking for a lightweight "racing-style" tube for several years now. Now TPU is the darling of the tube world.

TPU Tubes:
* Fold up smaller than butyl tubes,
* Are 2-4x lighter than butyl. This reduces inertial and rotational weight,
* Have higher heat resistance. Important if you are still using rim brakes,
* Are recyclable for those who are environmentally conscious.

While some riders on FB claim that TPU Tubes are more puncture resistant citing more puncture-free rides, this may be more anecdotal and hasn't been backed up by scientific testing. Some mfrs do claim better puncture resistance, though. I've ridden butyl tubes for several years without punctures, then had three punctures in 30 days (about 200 miles) of riding.

TPU tubes can be patched, and this is a good thing since they are 2-4x more expensive that butyl tubes. They do require a special patch kit though (and, yes, we have these patch kits).

Some TPU tubes have removable valve cores and some do not. Conti TPU tubes, one of the most expensive, have RVCs (removable valve cores). Conti has RVCs, but cautions that their 7-layer TPU tubes are for disc-brake use only. FWIW, several other brands of ultra-lightweight TPU tubes are designed for disc-brake use only, so read the package. Do your research.

I use standard butyl tubes on my road bikes and have at least one road bike with tubeless-ready tires with sealant, but I'm willing to give TPU a try. All of my MTBs are set up tubeless with sealant.

When Hutchinson came out with their road tubeless tires about 20 years ago, I was an early adopter and a big fan. They offered a similar road feel to tubular (sew-up tires) and could be run at 5-10% lower air pressure than tube-type tires. The downside with tubeless road is that tubeless sealant is less effective at sealing punctures at higher pressures than MTB tubeless setups which I have also been riding and racing since Stan's NoTubes began offering tubeless MTB conversion kits about 25 years ago.

If you have had any experience with TPU tubes, please share some comments here. I am not a weight we**ie but I am intrigued by the possibility of improving air retention and better road feel.

Thread-together replacements for Press-fi Bottom Bracket cups...

Yeah, I know that Bottom Brackets are not sexy. But Wheels Manufacturing has developed a replacement for the press-fit cup-style bottom bracket.

So, what's the big deal? Well, press-fit bottom brackets are notorious for squeaking at the interface between the BB cup and the frame. Press-fit BB cups are virtually impossible to remove without destroying them, making this style of BB a One-Time use component.

Since they are pressed into openings in the frame, there is a possibility that the bearings will not be aligned concentrically. For those who didn't take geometry, two or more objects are said to be concentric when they share the same center. The opposite of concentricity is eccentricity, the degree to which two forms fail to share a common center. Eccentric BB mountings will create unwanted friction, squeaks, and can lead to premature bearing failure.

A few years back, Wheels Manufacturing came out with a unique solution. They have thread-together BBs that work with most non-threaded BB shells. A few advantages:
-Perfect bearing alignment
-Can be removed and re-installed
-Has replaceable bearings.

They are offered with several different cartridge bearings:
-Standard ABEC sealed bearings
-Angular contact
-Ceramic hybrid
-Zero ceramic

You can get a standard ABEC bearing and upgrade to the angular contact or ceramic bearings at a later date.

These BBs are a little more expensive, but the advantages far outweigh the negatives.

We stock most types and can get many others in a few days.

Braze-on?

A few days ago, a good friend and long-time riding buddy brought his late 2000s carbon fiber Dura Ace Di2 BMC road bike in for a tune-up. He said that shifting had deteriorated. When he dropped it off, we were slammed and I told him that I would inspect it and follow up to let him know what it needs.

Well...

I had it in the stand on Wednesday and found that the rear derailleur hanger was a tad tweaked. The bigger issue, however, was the "Braze-on" front derailleur bracket (see the video). The bracket was completely loose. The braze-on should be solidly attached to the seat tube and provide a strong foundation for the front derailleur, especially a Di2 front derailleur.

There were several potential problems:
1) The aluminum pop rivets had failed.
2) The structural adhesive that bonds the braze-on to the carbon fiber had failed
3) The seat tube was damaged.

Until we had the braze-on removed from the seat tube, I was just speculating. The owner had been snowbound in the Sierras and responded to my texts and emails yesterday morning. As soon as he approved the preliminary work, I started the process of stripping components, removing the rivets and the braze-on.

What I found was that the rivets had indeed failed and the seat tube was intact. The 1/8" holes in the seat tube had not been elongated or damaged. Oddly, there was no adhesive behind the braze-on. So, basically, it was attached to the bike by four pop rivets!

We cleaned the carbon fiber, lightly scuffed the braze-on and put a dab of structural adhesive on the bracket. I relocated it on the seat tube with four new aluminum rivets and re-secured it.

My test bead of adhesive had tacked up nicely and was starting to solidify when we left the shop yesterday evening.

The adhesive has a 24-hour cure time, so I will finish it up today.

In the days of steel bikes, the brackets would indeed be brazed in place. Brazing is a metal-joining process (think soldering, not welding) using a filler rod (typically brass) that has a lower melting point than steel. This prevents the frame from distorting and losing strength. I guess that this name just stuck.

Winner, winner, wheel set dinner?

Some of you know that every year we have donated a custom wheelset to the Rwanda Ride, which now has morphed into the Good Dirt Ride. This year's winner, Donnie A, just picked up his new wheelset. Built around Shimano XT hubs and DT Swiss rims. Black Spokes, Black Spoke Ni***es, CenterLock disc rotor splines, and the latest Shimano MicroSpline rear cassette freehub body.

This set of custom wheels would sell for over $1,000. The ride still supports several charities. But mostly, it fosters and builds community with about 1,000 mountain bike riders participating in four rides of 10, 15, 25 and 50 miles.

Hard to believe that what started as a birthday ride for Doug Grant 18 years ago has grown into such a popular and well supported event. Also hard to believe that Randy from TECC did several 50 milers on his single speed MTB. Ugh!

Enjoy your new hoops, Donnie A!

Regular maintenance counts!

This week, we performed a brake bleed for a customer. After completing the brake bleed, as is our custom, we did a bike inspection. We uncovered a bunch of other issues with the bike:

-Chain worn 225%, possibly causing cassette and chainring damage,
-Front brake rotor worn 140%. Yes, brake rotors do wear out. Although the front pads were just worn down 50%, they will need to be replaced when the new rotor is installed
-Front Toggle derailleur far out of adjustment,. The chain is rubbing horribly in several gear selections
-Rear shift cable needs to be replaced. There is a short piece of standard shift cable housing from the chainstay opening to the derailleur. Per Shimano, to improve shift quality, this needs to be replaced with a section of super-flexible OT-RS900. The OT-RS900 helps ensure smooth shifting action of the rear derailleur thanks to its superior construction and materials
-Tires badly cracked and have lost all plasticizers. This can result in reduced braking and cornering traction
-The crankset is an Ultegra FC-R8000 whose production code falls within the range of cranks that need to be inspected because of potential for delamination and possible failure. We are not sure if the crank has ever been inspected.

We have talked about the crank issue before. Here is the safety warning from Shimano...

https://bike.shimano.com/en-SG/information/customer-services/corrective-actions/important-safety-notice-11-speed-hollowtech-road-cranksets-inspection-program.html

It's unclear what the owner wants to do. The bike is his wife's and they are getting ready to sell it.

Virtually all of these issues could have been addressed during regular bike service. While the cost of repairs could have been spread over a few years, the key here is that regular service and inspection helps reduce added wear to other components, and more expense. There is a high likelihood that the entire drivetrain is now worn and the bike will need chainrings, a cassette, and a chain. The lower derailleur tension pulley also shows accelerated wear. Before replacing chainrings, a crank inspection should be performed. If the crank fails inspection, it will be replaced by Shimano at no cost to the owner.

Just like your car, your bike should be serviced and inspected regularly.

Important message to customer about inspection program Shimano has launched a voluntary inspection and replacement program for some bonded 11-speed HOLLOWTECHⅡ road cranksets produced before July 2019 for a possible bonding separation issue.

E-bike end of the year sale!

We have three KHS eBikes in stock that are being discounted 50% or more! There are also several other models on sale right now as well. The Extended 2.0 is currently available in a Small or Large. Normally sells for $2,499; on sale now for $1,299!. Only a few left. Great commuter bikes!

E-ikes currently available from Salsa as well. Call us for details.