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Technical FAQ: Compatibility questions, stuck shifters, and more

SRAM 10-, 11-speed compatibility

Dear Lennard,
I’m a reader from Brazil and a fan of yours. I have a road bike with a 10-speed groupset and a SRAM 10-speed Rival Double Tap shifter. I need a new rear derailleur, but it’s hard to find SRAM 10-speed spare parts around here. Most of the dealers just have the new SRAM 11 gears to sell. Do you know if an 11-speed SRAM rear derailleur will work properly on a 10-speed SRAM road groupset?
— Fabio

Dear Fabio,
The SRAM 11-speed rear derailleur will work fine with your SRAM 10-speed shifter.
― Lennard

Campy shifters stuck

Dear Lennard,
All three of my Campagnolo rear shift levers “stick” at times. That’s for 2002 and 2010 Campy Record and 2016 Campy Chorus. It only happens when shifting to a smaller cog using the thumb lever, which “freezes up.” It can always be cured with a slight tap on the other shift lever, which commonly results in the shift downward. It seems like there is a burr on a pawl or something else that prevents the shift from happening. I can’t be the only person to have experienced this and am hoping there’s a fix.
— Art

Dear Art,
In my long experience riding on Campy Ergo Power levers, I find that the sticking you describe only happens when I am touching the large shift lever at the same time I’m pushing the thumb lever. If you experiment with this, you will find that you can get the thumb lever to jam every single time if you put a little side pressure on the large shift lever when you push the thumb lever.
― Lennard

Feedback about a broken rear derailleur

Dear Lennard,
I thought I might be able to shed a little light (or misinformation and an old bloke’s tale) on the closing point from your November 29 post.

I was cycling in France 18 months ago, and we came across a section of road which was in the process of being resurfaced as we rode though — it was covered in small gravel with the steamrollers waiting further down ready to lay the tarmac.

As we went through, one of the guys I was riding with — a pro for several seasons in the 1970s — told us to be careful, as the loose bits of gravel can flick up and get stuck in your chain. I figured this was probably nonsense, but barely 10 seconds later I heard an awful crunch and turned around to see my rear mech in my back wheel.

We were on a false flat at the time, so though I can’t remember my gear exactly, it was unlikely to be my lowest, 39×29.

His theory was this; if a gravel chip flicks up and manages to land on and wedge itself into of the links of the chain traveling back toward the lower jockey wheel, it will jam when it reaches the bottom of the derailleur cage and not allow the chain to continue traveling through. The pull of the chain above the rear derailleur of course pulls it up and over, until it tears the hanger off and ends up sitting on top of the cassette, looking as if the spokes have taken it over.

While the likelihood of this happening seems very small, it does seem to make sense, and be in theory possible. I certainly can’t think of a better explanation.
— Jim

Dear Jim,
It never ceases to amaze me the number of ways to ruin a perfectly good bicycle while just riding along on a sunny day.
― Lennard

Dear Lennard,
I just finished reading about derailleur suck and you seemed baffled at how a derailleur could suck in at medium effort from a middle cassette position.

Having sucked a few derailleurs in myself, don’t malfunctions in the freehub account for some types of derailleur suck, especially if you stop pedaling?
— Mark

Dear Mark,
Yes, a frozen freehub can drag the derailleur over the top of the cogs just like the sticky gravel mentioned above can.
― Lennard

Feedback about Carogna in wet conditions

Dear Lennard,
In your December 6 article about gluing cyclocross tubulars using Carogna basetape, you mentioned the challenge presented by wet conditions because the cotton base tape absorbs water. I have long used Aquaseal to coat the sidewalls on my tubular ’cross tires (Note that Dugast even sells it on their website). I spread the Aquaseal from rim to rubber, covering all of the tire’s cotton sidewall. Having used the Carogna tape for all of my ’cross wheels with no problems, is there any chance the Aquaseal might help keep the base tape drier during wet conditions, thus helping preserve the bond?
— John

Dear John,
Yes, the Aquaseal will likely make this less of an issue. On the other hand, Aquaseal always gets worked right along the rim edge due to the high amount of tire flex and abrasion there. So I imagine that, in time, water will still be able to soak into the base tape.
― Lennard

Dear Lennard,
I picked up a set of new Tufos on eBay, and I would like to mount them on some older Mavic alloy wheels I have. On the rim bed, there is a very slightly raised flange surrounding each of the spoke holes. My question is whether the Carogna tape will adhere thoroughly enough to this surface, given that it’s not perfectly smooth/flat. I have very thoroughly cleaned the old glue from the rims and I assume it should work, but I thought I would check with you first since you have been using the tape for a few years.

I have used Carogna on newer carbon rims; no issues with setup.
— Chris

Dear Chris,
That’s an interesting question!

I don’t know the answer, not having tried it, but I suspect it would be a minor issue with Carogna. Back in the day, we never used to worry about gluing to those reinforcing flanges that tie the upper and lower walls of the rim together at each spoke.

If you’re putting on ’cross tires, the raised-up flanges would probably improve adhesion by coming up the center of the base tape of the 33mm tires that would be bridged up and not be contacting the bottom of the rim bed, due to its smaller radius of curvature. With road tires, I would think that the little flanges would just press up into the tire, rather than lift it off the rim bed.
― Lennard

Radial vs. crossed lacing on wheels

Dear Lennard,
I was talking recently with a cycling friend who said he would never ride radially laced front wheels because he claimed that they would not hold up when hitting holes in the road. I’ve ridden radially laced wheels for many years and never had a problem. What’s your take on radial vs. crossed lacing on front wheels?
— Marshall

Dear Marshall,
There is nothing wrong with radially laced front wheels (for rim brakes). Radial lacing won’t work for disc brakes for obvious reasons.
― Lennard

Mixing chain links

Dear Lennard,
Is it possible to mix chain links from different manufactures? I have a Co-Motion tandem that I want to upgrade to SRAM eTap. Using Park Tool’s chain-length calculator, I came up with a chain length of 57 inches. SRAMs 11-speed chain has 114 links, which should be 57 inches and it should fit. If I need some extra length, do I have to use links from a SRAM 11-speed chain, or can I use some Shimano 11-speed chain links (which I have in my tool box)? Or would it be a safer bet (and perhaps better shifting) to use a Dura Ace 11-speed chain that has 116 links?
— Steve

Dear Steve,
Other than adding master links into chains of a different brand, I’ve only tried mixing chain link brands when doing emergency repairs on mountain bikes. It worked fine, but anything I might say about long-term use of a chain with a mixture of links from different manufacturers would be purely speculation. In general, your chances of having something untoward happen will be reduced by using chain links that are all the same.
― Lennard