Is Fixing A Flat On A Wheel With IGH As Big A Pain In The Tuckus As I Think It Is?
 

I just picked up a Dr. Good a week or so ago and I'm thinking that fixing a flat looks like a big deal with the Nexus 7 speed hub. I haven't taken the wheel off, but it doesn't look fun. Fixing a flat on any other bike I have is no big deal since I've fixed at least a thousand flats (at least it seems like a thousand) in the past.

We built a bike with a Nexus 8 hub for my wife, she flatted, and I fixed it.

It's not a big deal once you find the .pdf documentation from Shimano or watch a you tube video like this

http://www.youtube.com/watch?v=rGEXjpXtw4g

an IGH alone really doesn't make wheel removal a whole lot more difficult than removing any wheel with axle nuts instead of quick release. What can make things a bit more tricky are drum brakes. My IGH bike has has an alfine 8 with disc brakes so removing the rear wheel is as simple as loosening the axle nuts (maybe 15 seconds) and then disengaging the shift cable from the IGH (about 10 seconds). It took longer at first to get the hang of disengaging the shift cable, but after some practice it's super freaking easy.

Mine has the rear brake, and that's one of the things that made it look like a pain in the hind end.

Practice the technique a few times before you actually get a flat and it will make your life much easier.

You can also patch a flat tyre without removing the wheel and can do this by dismounting the tyre while it is still on the bike and patching the hole in the tube... only issue here is finding it.

My wife cannot handle tyres and tubes due to allergies so her IGh equipped bike is fitted with Marathon Plus tyres which I make sure are in good shape and she has yet to have a flat... and by yet I mean over 10,000 miles.

On my old 3 speeds that run lower psi tyres, I use automotive tyre sealant and this has served me well... when the bikes go into storage in the fall and come out in the spring the psi is within a few psi of where I left them.

It's only tricky the first couple of times. You'll need a wrench with you if you're out on the road, unlike a quick release wheel. That's the biggest difference. When you put the wheel back in the dropouts then you'll have to readjust the shift cable carefully. If you start to ride again and the shifting isn't right, just pull over and readjust. Better to tweak it a couple of times than ride it out of adjustment.

this is the traditional method and is what I would do. When I get a flat, I pull the tube out of the tire but leave the valve stem in the rim. That way when I put air in the tube, I can match it up with the tire and find the cause. I don't usually patch tubes on the road, but I have never had a flat on the road that I couldn't have fixed by patching.

Besides a wrench, I use a small 1mm allen key or nail to rotate the cassette arm to relieve tension on the cable. Don't let go of the allen key under tension or it will end up in the next county.
The bolt at the end of the cable fits into the cassette arm with a small rotational movement. I use my mini Leatherman pliers to grab and rotate the bolt but you can do this by hand.
If you have the hub brake version, fit Marathon Plus, check the rim for sharp edges and use Velox rim tape.

It's not that hard, but practice at home a few times.
- First, shift into the lowest gear to loosen the cable.
- Then, remove the end of the cable from the slot. It will be attached to a small hex nut, so you just slide the whole thing out sideways.
- Unbolt the wheel and remove it. Fix it, then do the whole thing in reverse.
As Sixty Fiver says, sometimes you can just pull a part of the tube out, if you know exactly where the hole is. At least you don't have one of those fully enclosed chains. I don't know how people manage to get the wheel out with those things.

On disconnecting the IGH shift cable: every IGH manufacturer, and many of the different models from a given manufacturer, have a different cable interface design. Disconnecting some designs is quite fiddly; others are very easy, fast and straightforward. A few release loose parts which have to be corralled.

I thought everything was supposed to be done in position '4'.

i always thought that you're supposed to be in whatever gear is your direct drive gear when disengaging the shift cable from an IGH, which for my Alfine 8 is gear 5. that's always what i've done without issue.

I just shift to the lowest gear prior to removing the wheel but most flats I have fixed I just turned the bike over and left the wheel on.

Overall it's not *that* big of a pain. One challenge I have faced is with fenders you need to leave enough clearance if you have horizontal dropouts...the wheel needs to slide far enough back to be able to clear the back of the dropout to be removed.

i can see that being a problem, that's one reason why i like my bike's set-up with vertical drops and an EBB for chain tension (though EBB's can present problems of their own too).

Why would that be? When you take the cable off, the hub is going to jump into 8 anyway.

I am having trouble understanding the reasoning behind this.

Don in Austin

Jeez,:rolleyes:, do a rehearsal at home where it's warm and dry ,
rather than figure it out , later, in less comfortable situations..

on My winter Bike with Drum brakes , the strap around the chainstay
fitted to the hub strut with a nut and bolt.
So I went to the hardware store , got a Quick release pin,
with a spring loaded ball retention scheme in the tip.

changed it and a few fittings to make it just a skosh simpler.

the rehearsal will suggest changes You might wish to make..

shifting to where the cable is slack, means it will be in that gear
Predictably, when you hook it up again.

I find changing a flat with an IGH to be more time consuming, but the biggest problem is simply that it's unfamiliar. If I was familiar with both a derailler and an igh, I think the igh would take a little longer but not a huge deal. The biggest problem is simply that I still remember how to do it with a derailler pretty easily, while with my igh I'm like "um...how did this work again?".

For Shimano 8spd, you use 4th gear to align the yellow dots to set cable tension. This is unrelated to cable removal so you just set the gear cable to its slackest setting (1st).

Don says it jumps where the return spring pushes it, because they, the engineers,
chose to only have 1 cable make the shift, by the clicks in the handlebar end,
like the index derailleur stuff..

you have your IGH tuned up now? good.

Take some electrical tape and tape up to the stop nut on the adjustment. Then you know where your adjustment is if you need to take the tire all the way off to change a tube. On mine I can slide a tube in the brake side without disengaging the drive side. But when I changed tires I had to realign. When you mark with the tape you mark it in a specific gear, SA is second gear for a 5 speed. When you put it back together you need to have the adjustment made in that specific gear.

while it takes a bit longer than QR it shouldn't be a big deal. I have had one flat on the rear in the past year and I got over it. It is also not a big deal to make your won adjustments on the IGH, but the alignment mark is very hard to see during the day, so I use the tape method because most commuting this time of year is in the dark.

Depends on the IGH. I had a Nexus 3 that was very simple to remove. I now have a Nexus 8 that's so cumbersome I don't even bother trying to change a rear tube on the road.

I have a Nexus 8 on my DaHon Curve SL and I've fixed 4 flats on the road . . . so far (Marathon Racer tyres with Mr.Tuffy's) and while it was a major pain the first time, experience has been such a good teacher that now it's not any more trouble than changing a tube on a derailluer equipped bike.

As noted above the 2 mm Allen wrench (I use a chopped off DT spoke (14g = 2 mm) plus I've painted the little nub where the spoke goes bright yellow (yeah, my flats usually happen in the dark) so it's easier to find. Anyway, good advice above! Shift into 1st gear, insert Allen wch (or spoke) to relieve tension, cable end/nut pops out. Same procedure in reverse to re-install.

My wheels/tyres are 16" x 1.5, so their tinyness presents some awkwardness (as compared to working with "full - size" wheel/tyres), but the shift cable is (was) the fiddly bit. Now, not so much.

Rick / OCRR

this. tough tires, and fix it with tire still on bike if practicable. I haven't lived in the netherlands but AFAIK, fixing flats on IGH bikes WITHOUT removing the rear wheel is a common method there, even in bike shops.

(Quote)You can also patch a flat tyre without removing the wheel and can do this by dismounting the tyre while it is still on the bike and patching the hole in the tube... only issue here is finding it.

I have a few Specialized MTB tubes that are not joined in a ring. I think they were made for DH bikes with a bolted axle. I just had to lift the tire next to the valve and pull the tube out.

I was thinking that one could take a standard tube and cut it so as it is just one long length and glue the ends. It would make it easier to change out a tube.

Unmount the tire. Cut the old tube off. Cut the new tube opposite the valve, thread it inside the frame, tie the two ends together with a square knot and remount the tire and inflate. You'll get used to the thumping.

I have a Nexus redband and found you don't even need the 2mm allen key. I shift to 1st (cable is then at it's slackest) and then pull the cable housing out of one of the cable stops. On my bike (and many others), the cable stops are slotted so you can easily get the inner cable in and out.

With the cable housing removed from one of the stops there is plenty enough slack in the cable so that the pinch bolt can rotate out of where it attaches to the hub.

I also have a roller brake and the reaction arm is bolted to the seat stay. I replaced the stock bolt with a hex head of similar size and replaced the stock nut with a wing nut. This makes it pretty easy to remove. Just have to be careful not to lose anything. Fietsbob's approach sounds even better.

Are you confusing this with the gear you ought to be in when calibrating the indexing?

You use to be able to buy inner tubes that were not circular, ie a long snake. These can be removed from the tyre without removing the wheel.

I've watched that first video 10 times now and he puts the Alfine in 4 to change it. I thought that's what you had to do to. Just watched this one:

http://www.youtube.com/watch?v=cxZXM4buaPI

He puts it in to 1st and also explains a bit about the coloured lock nuts.

I thought so too, until I re-read the instructions which came with the bike. (Alfine 8)