Gear

Technical FAQ: Thumb pain, toe clearance, derailleur springs

Lennard Zinn answers questions about coping with arthritic pain, fixing toe overlap, and making a rear derailleur spring back to life.

Dear Lennard,
I’m a 46-year-old anesthesiologist from the UK and keen rider of bicycles. I have developed osteoarthritis in the MCP joint of my left thumb which causes pain in rides lasting more than about 20 minutes, which is rather pitiful.

I have taken NSAID anti-inflammatories and had my bike fit optimized but to no avail. It is seriously curtailing the sport and hobby that I love.

Do you (or any of your readers) have any suggestions to help ameliorate these symptoms before I turn to intra-articular steroid injections or a recumbent?
— Louis

Dear Louis,
Here’s what my good friend and world-renowned bike fit guru Andy Pruitt has to say about your issue.

“Hand, thumb, and wrist arthritis can be debilitating for cyclists! I was a long time Campy user but had to give it up because of the thumb shifting. Lever or electronic shifting has helped. The mountain bike remains a bit of a problem; however, the 1X systems save my left thumb. If terrain and/or road surface vibration is the issue, you might try a suspension stem. Some find a larger bar circumference helpful, accomplished with double wrap tape. On the medical side, the occasional intra-articular steroid injection (pre-season) can be helpful!

From one sufferer to another, good luck!

Andrew Pruitt, EdD
Sports Medicine Consultant
CUSM&PC”

Good luck!
― Lennard

Dear Lennard,
Very interested in SRAM eTap for my primary road bike. However, it sports mid/long reach brakes which SRAM does not make. The BR650s on presently have the updated pull ratios for new Shimano. I still have the original 600s in a box which should be traditional pull. Can they be pressed back into service?
— Ryan

Dear Ryan,
Yes, the BR600 long-reach Shimano dual-pivot road brake was designed for older Shimano levers, which have “standard” cable pull (as opposed to the low-leverage/high-cable-pull design of current Shimano road levers), so they should work fine with SRAM (and Campagnolo) road levers.
― Lennard

Dear Lennard,
I have a Felt Breed that I raced a couple years ago and loved it. Last season I made the jump to a Cannondale Super X that I also loved, but for different reasons. Now when I hop back on the Breed (with its more classic geometry), I find my foot hitting the front wheel in sharp turns (toe overlap) on corners where on the Cannondale, I wouldn’t have any issues. My first thought was to get shorter cranks, but that coupled with singlespeed might not be the best idea.

My question is this: If I were to get a different fork with a bit more rake, would that help solve this issue? Or would I be opening a Pandora’s box, messing up the geometry and therefore the handling of the bike? I’m thinking this might be a worthwhile upgrade, as I could get a disc brake compatible fork and as an added bonus, create a proverbial ‘mullet’ of a bike (business/disc in the front, party/canti in the back).
— Jesse

Dear Jesse,
I get the impression from your question that you didn’t notice toe overlap on the Breed before, and now you do. Are you sure that you don’t have toe overlap on the Breed due to a crash in which you flipped over the bar? I am further inclined to think this has happened, since you indicate you have lots of toe clearance on the Cannondale SuperX and none on the Felt, but the head angle, seat angle and top-tube length (and fork rake) on almost every size of these two bikes is the same or nearly so.

Feel under the down tube and under the top tube of the Felt just behind the weld at the head tube. If there is a bulge or kink there (and corresponding stretched area on the top of the tube just behind the head tube weld), you have a steeper head angle now due to front-end impact. The bulge or kink indicating that the tube has been bent would tend to be most noticeable under the down tube. If that is the case, the bike’s handling has already become twitchier due to the steeper head angle and corresponding decrease in fork trail, so don’t worry about making it worse with a change to a fork with more rake. That said, your frame will eventually crack at that bulge under the down tube, so I don’t see the point in investing any more money in the bike.

Regarding the fork change idea, a standard rake (offset) for carbon cyclocross forks is 47mm, which is only 2mm more than the 45mm rake you have on both your Cannondale and your Felt. If 2mm is a sufficient change to eliminate the problem, it’s worth pursuing, and it’s not enough to throw off the handling of your bike significantly. If you need more than 2mm additional clearance, good luck finding a fork like that …

Furthermore, almost all carbon disc ’cross forks have a tapered steerer that accepts a 1.5-inch lower bearing, and I’m not sure if your Breed has that. If your Breed’s fork has a straight 1.125-inch steerer or a tapered 1.125/1.25-inch steerer, the WoundUp Team X Disc fork may be your only choice; it, too, has 47mm of rake.
― Lennard

Dear Lennard,
Is there a way to increase the parallelogram spring tension on a rear derailleur? That is often the point of failure for me that leads to the derailleur’s replacement, namely its inability to pull all the way back down to the 11T cog. (My current issue is with a SRAM Rival component.)
— David

Dear David,
Not that I know of, but you can sometimes get the same effect by putting a washer between the derailleur hanger and the derailleur and then readjusting the limit screws and cable tension.
― Lennard

Feedback on last week’s column:

Dear Lennard,
Re: dropped chains and worn SRAM chainrings, it’s not just CX-1, as described in the article. I needed to replace a SRAM 34-tooth inner ring (compact) well before it did any skipping, because the teeth were worn enough to cause self-activated unshipping and other shifting problems. And that was on a road bike with no winter environmental exposure. The tooth profiles were worn down to points and this seemed to adversely affect smooth operation.
— Larry

Dear Lennard,
I have been using a single-ring setup on the cross bike now for a few years, and I have never dropped a chain. I first used 2 BBG bash guards to wedge the chain on the chainring before narrow-wides. But now with narrow-wide chainrings, I have one BBG guard on the on the outside and a K-Edge single ring chain catcher on the inside. This doesn’t require a clutch derailleur, but I do wrap the chain stay in some old bar tape to stop chain slap, mind you I would wrap the chain stay and use this setup if I had a clutch derailleur, too.
— Erik

Dear Erik,
Sounds good, and that should eliminate almost any instance of chain drop, especially from chain bouncing. However, in the case of ice in the chain from riding through puddles repeatedly at temperatures in the 20s F or below, I doubt this would be sufficient, since the chain can still lift.
— Lennard