Saturday, February 26, 2022

Cervelo Aspero: PRO Stealth Off-Road Saddle

Here is the off-road version of the PRO Stealth road saddle, where there are some differences with the road type. The differences will be explained in a separate post later.

As an off-road version, it has some different designs that are more suited to off-road usage, such as MTB or gravel. After the bike fitting session at LOUE Bicycles, I have decided to replace all the Selle Italia saddles on my bikes, as the saddle width (130 mm) is too narrow for me. The PRO Stealth saddle width of 142 mm is more suitable, with better shape and support.

After the Focus Paralane all-weather road bike, the next bike which I wanted to swap the saddle was the Cervelo Aspero gravel bike. In this case, the off-road version of the PRO Stealth saddle would be more suitable.

PRO Stealth Off-Road saddle

Differences with the road version include the saddle rail material and the padding design.

142 mm width, with round 7 mm stainless steel saddle rails.

Also comes with a saddle tool on the cardboard packaging, of doubtful usefulness.

The center cutouts are not through holes, to prevent dirt from splashing up through the holes. Surface texture is relatively rough for reduced slippage.

Generally flat profile, with a slight upward curve at the rear. Padding is relatively thick and firm. Tough side layer to prevent scuffs.

Round stainless steel rails. Tough for off-road usage, but heavier than carbon rails.

Conventional saddle construction, with the rails going into the fixing points on the shell.

Most PRO saddles have this accessory mounting point, which are basically two threaded holes under the saddle.

If you get the PRO Camera Mount, it will have a Gopro-style mounting point for your camera or light.

Two M4 threaded holes that are 17 mm apart.

Relatively heavier than the road version, at 195 grams. Still pretty good for an off-road saddle with more padding.

Latest bike specifications, with this PRO Stealth off-road saddle installed.

My initial impression of this off-road saddle is good, due to improved comfort from the additional padding and better support. The top layer is quite grippy, and the butt stays in place securely even over bumpy ground. It is well worth the slight weight addition (+50 grams) over the previous Selle Italia SLR Titanium saddle.

The shorter nose (about 30 mm shorter) also makes it easier to straddle the bike when I stop and put my foot down. So far, I cannot find any downside to this saddle. I think it would be suitable for other bikes such as folding bikes as well, unless you are looking for a lighter weight saddle.

Sunday, February 20, 2022

Focus Paralane: PRO Stealth Superlight Saddle, PRO PLT Stem, GRX Rear Derailleur

On the Focus Paralane all-weather road bike, I have installed a few new components recently. This was partly done during the bike fitting session at LOUE Bicycles, where some components were swapped or adjusted to optimize my pedaling efficiency on the bike.

Prior to the bike fitting session, I had already purchased a new saddle, the PRO Stealth Superlight Saddle, as I have heard many good reviews about it. I was not able to test one before buying it, so it was a leap of faith to buy a new saddle. That said, most saddles are bought without testing, unless there is already a bike with your targeted saddle for testing.

Previously I have been using the Selle Italia SLR Kit Carbonio Flow saddle, which has served me well. I used it across quite a few different bikes, also in the SLR Titanium version. It is lightweight and quite comfortable as well. However, the saddle width seems to feel a little narrow, especially after I tested some slightly wider saddles recently.

These pictures were taken before the bike fitting session, where the new PRO Stealth saddle was installed onto the bike at LOUE Bicycles.

One of the many PRO Stealth saddles in the Stealth saddle family.

This is the superlight version, with a one piece carbon base, and of course the highest price tag.

142 mm wide saddles seem to be the most common nowadays. It has a claimed weight of 145 grams, more than the Selle Italia SLR Kit Carbonio Flow, which is just 121 grams. Still lightweight though.

The cardboard packaging has a tool to help you set your saddle position as shown. However, I am not sure how useful it is.

Here it is, the PRO Stealth Superlight saddle! Subtle decals at the top, not flashy white ones like the older Stealth saddles.

Large center cutout with carbon bridges going across. The nose is quite wide as well.

Carbon shell at the end, with the Stealth logo.

Side view, with a thin shell and low profile. Slight upward curve at the rear of the saddle.

Carbon saddle rails, with a 7 x 9 mm oval dimension.

Carbon rails are moulded right into the carbon shell! This is why it is so expensive.

Same integrated construction at the front of the saddle.

There are two threaded holes at the bottom of the saddle, which can be used to mount accessories like lights, cameras, tool kit, etc. Unless you DIY, a PRO camera bracket is needed.

Weighs 157 grams, instead of the claimed 145 grams. 8% overweight, which is unacceptable for such a high end product where weight is a key selling point.

Here is how it looks on the bike! From this angle it looks really wide.

More details on the saddle fit over at the LOUE Bicycles post, but the first impression is that it fits me well. There is better support due to the wider shape and upward curve at the rear.

Other than the saddle, the stem was also changed. Similarly, I had also purchased a new stem prior to the bike fitting, as I felt that the stem length was not quite correct.

To be fair to Timothy of LOUE Bicycles, he did not switch to the new saddle and stem just because I brought it along. Rather, he first noted that what I had on my bike wasn't quite suitable, and asked me if I brought anything to swap. What he recommended was exactly what I had brought along, both in terms of a wider saddle and also a longer stem, as shown below. Seems that I already had an intuition about what I needed to change on my bike, even before the bike fitting session.

A 90 mm version of the 80 mm PRO PLT Stem that I first used when building up the Focus Paralane.

90 mm stem installed on the bike! A slightly longer stem was recommended to get the proper reach and riding posture for road bike riding.

Looks exactly like a normal road bike, before I reinstalled the SKS mudguards.

Finally, another modification that I made was to change the rear derailleur. Previously, when I installed the Sunrace RX1 11-36T cassette on the Focus Paralane, I used a Wolf Tooth Roadlink DM adapter to extend the reach of the Dura-Ace rear derailleur. This is to allow the Dura-Ace rear derailleur (rated for max 30T sprocket) to reach the larger 36T sprocket.

It worked quite OK, but there was always a bit of problem when shifting between the smallest 12T and 11T sprockets. At this position, the guide pulley of the rear derailleur is too far away from the sprockets to produce reliable shifts. This is because the Wolf Tooth Roadlink DM basically just shifts the rear derailleur lower, allowing it to reach the larger sprockets. However, this also moves it too far away from the small sprockets, sacrificing shifting performance.

Since I have the GRX RD-RX815 rear derailleur available for use, I decided to install that on this bike. Previously it was used on the Canyon Endurace and then the Cervelo Aspero, for a 2x11 speed gravel/road hybrid drivetrain. Since I have already converted the Aspero to a dedicated front single gravel drivetrain, it uses a different rear derailleur (RD-RX817).

The GRX RD-RX815 is a rear derailleur that is designed for a maximum sprocket size of 34T, instead of 30T for the Dura-Ace rear derailleur. That means using this GRX rear derailleur on a 36T large sprocket is only slightly beyond the rated capability, which I believe it will handle with no issue. Most of all, I hope it can solve the intermittent shifting problems I faced between the 12T and 11T sprockets.

GRX RD-RX815 rear derailleur installed onto the Focus Paralane.

The GRX rear derailleur has a clutch, which can be useful for chain management, but probably not required on this road bike. It can be turned off to reduce shifting effort and thus conserve battery power.

After testing, I am pleased to find that it shifts well across all the gears, including the smallest 12T and 11T sprockets! Shifting performance restored.

The SKS mudguards look pretty stealthy, as the high profile carbon wheels helps to camouflage it.

With a new saddle, new stem and new rear derailleur (relative to this bike), the Focus Paralane has been refreshed yet again. My bikes are always evolving, as I test and swap various components, depending on my requirements (which also changes from time to time).

Sunday, February 13, 2022

United Trifold: 11 Speed Drivetrain Completed

Final post on the United Trifold derailleur drivetrain modification! It has been really challenging to do this modification, due to a lot of incompatibility and interference issues.

Finally, I have managed to make it work, albeit with some limitations. Let's take a look at the final setup.

At the second lowest gear of 27T sprocket. Chain is stretched to the maximum here.

There is still some chain tension halfway though the fold, which is good.

When fully folded, the chain will still hang loose. But the additional chain tensioner keeps it in place on the rear derailleur and cassette.

It is recommended to fold this trifold bike with the chain in the larger sprockets, because this is where the chain will have the least slack.

As shown above, due to the small chain tensioner on the rear derailleur cage, it is not sufficient to take up all the chain slack when folded. The chain still hangs slack, but it does not go all the way to the ground, unlike when I used the super short cage Saint rear derailleur.

I think this condition is still acceptable, as it only occurs when folded. The chain does not drop off even when the bike is pushed around in this condition. Also, when the bike is unfolded, the chain still stays on the cassette.

Chain tensioner goes close to the rear tire when folded, but I think it is still OK since the rear wheel does not roll when the bike is folded.

The chain sometimes rests on the rear derailleur body itself, since it becomes slack. Main thing is, it does not derail from the rear derailleur pulleys.

However, there are still other issues, such as chain interference with the frame. This one is also tricky as there is not much I can do.

Cannot use top gear of 11T, as the chain rubs the frame as shown by the marks here.

Also cannot use lowest gear of 30T, as the chain will rub the frame (semi-circle loop for routing the rear brake cable).

If you really want to avoid the chain rubbing, the rear brake cable guide can be sawed off the frame, since it is not required any more.

I had an idea to shift the entire cassette towards the non-drive side, by moving the hub adapter that is currently on the non-drive side of the rear hub. From the start of the single speed conversion, the hub adapter has been installed on the non-drive side of the rear hub, to boost the wheelset OLD from 130 mm to 135 mm in order to match the frame. It was natural to place the adapter on the non-drive side, so as not to affect the freehub body side.

However, I realized that if this hub adapter can be moved to the drive side instead, it will solve a few problems at one go.

By placing the hub adapter on the drive side, instead of the non-drive side, the cassette position is pushed inwards by 5 mm.

With the cassette pushed towards the non-drive side, the chain does not touch the frame in the 11T sprocket nor the 30T sprocket.

This means that the 11T top gear can now be used, giving a good top gear of front 52T and rear 11T on the 16 inch 349 wheelset.

On the other hand, the lowest gear of 30T still cannot be used, despite no more chain interference with the frame. Due to the inward offset of the cassette, the cross chain effect from the chain ring to the 30T sprocket is just too much. During pedaling, it makes quite a bit of noise and also vibrates a lot.

In this case, I decided to use the low limit screw of the rear derailleur to lock out the lowest gear (30T sprocket), limiting the drivetrain to 10 speeds, which is equivalent to a 11-27T casssette.

Another downside of this modification is chain drop when backpedaling in the lowest few gears. Again, this is due to the skewed chain line and short chain stay. It is annoying when pushing the bike backwards, but it can be avoided.

Gear range of this 11 speed setup (limited to 10 speeds) is 30 to 75 gear inches. Quite a nice gear range for folding bikes used for casual riding.

11 speed road shifter for flat handlebars, SL-RS700, with BL-R780 brake levers.

Additional shifter to the handlebar, unlike the previous setup with only brake levers.

The modification is not done yet! During the experimentation, I found that the rear brake cable outer casing kept getting in the way of the chain. From the earlier pictures, you would have seen that I moved the brake outer casing to the outside of the frame. Now I will show the final brake cable routing that is needed for this derailleur drivetrain setup.

Instead of passing through the loop (that was interfering with the chain on the 30T sprocket), the cable needs to run outside the rear triangle.

Also, the outer casing needs to stay close to the chain stay, to avoid crank interference or tire interference.

Here is how the outer casing needs to be routed, to avoid all interference.

Final bike picture with the derailleur drivetrain setup!

When fully folded, the chain becomes slack but this condition is acceptable for me.

Even though the chain is slack, it remains on the crucial areas.

Final setup is 9.8 kg with pedals.

With this, the modification is complete! It is possible to modify the United Trifold to use a derailleur drivetrain, although the process is not straightforward at all.

The end result is not as ideal as I want it to be, due to the unresolved chain management issue. As of now, I don't have a good solution for it, so I will let it be.

As for the ride, the multi-speed drivetrain allows me to use the bike for a wider range of rides, even those with a bit of road riding and also slope climbing.

Finally, the weight of the full bike has increased to 9.8 kg with pedals, up from the 9.3 kg of the single speed setup. This is a weight increase of 500 grams, for the additional derailleur drivetrain. Not as lightweight, but still a good weight reduction of almost 3 kg from the stock setup.

By changing to this derailleur setup, the function and purpose overlaps more with the Fnhon DB12 that I have. In a way, the United Trifold is an inferior version of the Fnhon DB12, being heavier, slower, with smaller gear range, and poorer braking performance. Only advantage the United Trifold has is being slightly shorter when folded compared to the 20 inch Fnhon DB12.