Tuesday, April 22, 2008

Q&A: Adjusting cleats, tubeless slow leak, creaking

Q: I'm installing cleats on my new bicycle shoes and don't know how to get them in the right position. Can you help?


A: Thanks for the question. It's important to get cleats right to prevent knee injuries and also to ensure you can get in and out of your clipless pedals easily. The diagram on the right shows the correct placement for cleats. It's from a page I have on my website where I explain how to find the right cleat position and give easy instructions that help you align and position your cleats in the right position. Click to learn more about cleat placement.

Hope this helps,

Q: Hi Jim,
I recently purchased a set of Dura Ace 7850-SL wheels to use with tubeless tires in part because of your positive reviews. I've noticed that the only criticisms are from those folks who haven't ridden them - you, Zinn and others who know their stuff seem to like them a lot. So far, I've been very pleased, but I have a couple of questions that I'd greatly appreciate your advice on. I weigh 165lbs and the Hutchinson website indicates the following: 65 - 75 kg / 140 - 165 lb = 6 - 7 bars / 87 - 101 psi. That strikes me as higher pressure than I would have thought. What do you recommend (especially for someone who places a high emphasis on cornering grip)? Also, my rear tire seems to have a very slow leak. It always seems to lose 10 - 20lbs of pressure overnight. Should I use the Hutchinson Protect'Air? If so, how much (ml) should I use for a 700x23 tire?

Thanks in advance!

A: Thanks for the email, Mark. I'm about the same weight as you and I run 90psi in the front tire and 95 in the rear. I have run them lower on really bad roads, approx 87 in the rear, 85 in the front. Note that gauges are usually inaccurate so it's hard to know the exact pressures, but according to my gauges, that's a ballpark setting you could try that should work nicely. And, you can certainly experiment with lower pressure to see what's right for you and your roads. I would think you wouldn't want to run too much below what the company recommends, though. Usually if a tire is run too soft it tends to crack sooner but you could try it and see if you have any problems, too.

To figure out the slow leak, I would put water around the valve and see if that's what's leaking. I had trouble with one of mine. The little O-ring wasn't sealing well. I finally replaced the valve, which wasn't easy because I had to special order it from a bike shop and it took a long time. They don't seem to be available yet so the shop could only order them from Shimano direct instead of from their usual distributors.

You could also dip the wheel in a sink to try to spot a slow leak, but the only problem with this is that there are holes in the rim and the rim will take in some water and it's a pain to get it out. So, you should seal the holes first with little pieces of tape.

I'm assuming that you haven't run over a tiny piece of glass or wire that's causing the slow leak, too.

Some feedback I've gotten from others riding these tires is that theirs lose air overnight, too. I have only had this with the tire with the bad valve. The other tires hold air overnight but need a little air every few days like regular clincher tires with tubes.

I believe if you use Hutchinson's aerosol inflator you're supposed to use one per tire. That's based on them sending me 2 with 2 tires. They told me that there's a light sealant in there that will help seal the tire. I used it on one tire and didn't notice any difference, but some people swear that sealants fix flats and are worth using. I can't tell if it made a difference or not in sealing the tire or preventing flats. I have checked that tire and rim and haven't noticed any issues with sealant eating the rim (as I mentioned in my RBR article can be caused by Stan's sealants - or so Shimano says).

I hope this answers your questions and you enjoy riding tubeless as much as I do. Last week I flatted my front tire in a race and was able to ride 10 miles on it to the neutral support tent to get a spare wheel while keeping right up with the lead group I was in. I don't think I would have dared try that on my old regular clinchers. There was no damage to the rim.

Thanks again,

Q: Jim,
I am not sure how much of a problem I am having with my bottom bracket. When I stand to climb I hear an awful lot of creaking noise. I have an aluminum frame Cannondale CAAD 4 with a Shimano Dura-Ace crankset. I am by no means a bike mechanic. Just like my car, I know where the gas goes and how to turn it on. So I don't know if this is just stress noise or if something is loose that can be tightened.

Thanks for your time and consideration,

A: Hi Rob,
Your crankset shouldn't make noise when you're riding. You probably have a loose crankarm or a loose bottom bracket, or if you wear cleated cycling shoes, you might have a noise coming from your pedals or cleats.

This article on my website goes into great detail on noises and you'll find a lot of common noises and solutions here including bottom bracket, crank and cleat noises.

Of course, you could also take your bike into any bike shop, describe the noise, ask the mechanic to take a test ride and he should be able to hear it and tell you what's needed right away and maybe fix it right away, too, for not too much money, even.

I hope this helps,


Anonymous said...

I have Ultegra 6700 wheels with tubeless tires. I tried identifying the cause of a slow leak by dipping the wheels into a sink. There's only one hole in these rims, which I taped over as you advise above. However, after I'd done my testing, I noticed that the rims were absolutely full of water sloshing about! I'm guessing that the spoke sockets aren't water-tight and that water was pouring in through these as I was testing? Anyway, I had to untape the hole and shake the wheel vigorously back and forth for ages to get all the water out!

Jim Langley said...

That's interesting. The nipples need to be sealed or else the air wouldn't stay in the tire, so there might be something else letting the water in. We might need to cut an old rim in half to understand where the leak could be. But it shouldn't be able to get in on the tire side so it has to be the valve or the nipples you'd think - or some hard to spot hole in the rim. Maybe you can check for leaks without submerging the entire rim?

Anonymous said...

Hi, me again! Update: I recently broke a spoke on the 6700 tubeless-ready wheel and was able to determine by looking into the spoke-hole on the rim that there is a cavity there which is sealed off from the outer part of the rim. Thus, the spoke-holes/nipples on this wheel do not need to be sealed/air-tight and they can let water in, but only into the internal cavity.

I've just tested tire air leakage in the sink again, but this time only by dipping the tire (and not the spokes) into the water, one section at a time. No water ingress on this occasion!

OTOH I think I shall be abandoning this road tubeless experiment pretty soon, as I have determined that the (Hutchinson-brand) tires always develop significant leaks through the casing once they've been removed from the wheel, even once!

Anonymous said...

(me again) Actually, you can see the cavity quite clearly in this Shimano tech doc!


Jim Langley said...

Thanks for experimenting on your tubeless wheels and the tip not to submerge the rim when checking for leaks (to keep water out). I have had good luck with Hutchinson's Fusion tubeless tires. They're not perfect (a tad heavy and they wear like a racing tire not a touring tire), but the performance is really nice in my experience. I haven't noticed any issues when removing and installing tires. The only slow leaks I've experiences come from valve issue or punctures. Thanks for your feedback!