Fitting new tyres - a couple of questions :-)

[john_roberts]

Hi

I'm finally fitting a couple of semi-slicks to my bike in the next few days, but have a couple of queries regarding this. The tyres are Continental Travel Contact MTB 26" x 1.75, and my questions are:

1) The tyres are marked: "Mount only on hooked rims." I have no idea what a hooked rim is...

2) Is there anything I should check whilst the wheels / tyres are off? I don't have any bike-specific tools but should be able to clean things up a bit and check for excessive play etc.

Thanks in anticipation - John

[natmat]

Hi John,

Here's my 2p. If everything else on the bike is OK, probably no need to touch it.

1) The tyres are marked: "Mount only on hooked rims." I have no idea what a hooked rim is...

If you feel the inside edge of the rim, your find a bulge (the 'hook' referred to above). The tyre beads (i.e. the two 'rigid' bands around the tyre) will sit below this when the tyre is fitted to keep it in place.

2) Is there anything I should check whilst the wheels / tyres are off? I don't have any bike-specific tools but should be able to clean things up a bit and check for excessive play etc.

1. I would check that the rim tape is centred in the rim, so that all spoke holes are fully covered.
2. Give that rim tape a light brush to remove any stuff that might later cause a puncture if not removed.
3. Dust the inner tube with chalk/talc before fitting (or is that 'old school' now?).

Nat.

[MLJ]

Most modern rims are 'hooked' ie they have an inside edge to the rim to grip the bead of the tyre. Apart from checking the bearings/hubs for correct adjustment you can either dismantle to regrease these or else (safer if not familiar with reassembling bearings) trickle some oil into the hub where the seal runs against the hub, while lying the wheel on its side. Also you can check the rim thickness at the braking surfaces for wear if you have a micrometer screw - CJ warns that 0.6mm is the breaking point where they become dangerous! To check the spoke tension, play a tune along them - they should all give the same note. Tighten or loosen the odd ones if required. Check that the rim tape is even before putting the tyre on.

[john_roberts]

Thanks Nat and MLJ

I don't think I'll have any problems with wear and tear on the bike, it's hardly covered any mileage in the 16 years of it's life (like sub 500 miles to my shame...) but I'll have a visual inspection and feel for excessive play.

What kind of oil would you recommend for the hub bearings? I have some chain oil though I think this is probably too 'thin' or some 3-in-1 general purpose oil. Or do you think it'll be OK to leave 'as-is' because of the low mileage?

[saudidave]

Thanks Nat and MLJ

I don't think I'll have any problems with wear and tear on the bike, it's hardly covered any mileage in the 16 years of it's life (like sub 500 miles to my shame...) but I'll have a visual inspection and feel for excessive play.

What kind of oil would you recommend for the hub bearings? I have some chain oil though I think this is probably too 'thin' or some 3-in-1 general purpose oil. Or do you think it'll be OK to leave 'as-is' because of the low mileage?

I wouldn't be putting oil in the hubs if I were you. They should be packed with grease. Ideally you should dismantle the hubs, clean them and the ball races then rebuild them with new grease and adjust them, but if the bike has done less than 500 miles and they are running smoothly, leave well alone for now

[john_roberts]

Yes, they seem to be running OK, with no play in them as far as I can ascertain. The front is ultra smooth, the rear slightly less so, not sure if this is normal. There's no 'roughness' just a slight awareness of moving parts which I don't get with the front. They are both Shimano Exage sealed mech.

Other than that all seems well, and it's giving me a good excuse to get the chrome polish out (I have an awful lot of chrome) in places that haven't been cleaned for years. Only surface cleaning, I'm not over cleaning any critical parts.

Shame the new inner tubes (free with the tyres) came with Presta valves - I've had to re-use my 16 year old Schrader tubes

[DaveP]

I would recommend giving some thought to your rimtape.
I fitted a pair of these (excellent IMO) tyres to some mtb wheels that had been supplied wearing knobblies. At first I ran them at 60 psi. They were Ok. Eventually I pumped them up to their max of 80 and went for a ride to see if it made any difference. I popped in a shop for 5 mins. When I came out one was completely flat. I discovered that the addiitional pressure had forced the original stretchy rubber rimtape to bulge through the spoke holes in the outer leaf of the box section rim, the tube had done likewise, and in one place it had split on the metal edge. There were signs of incipient failure all round both tubes. I was quite happy to replace both tubes, given that I hadnt been riding on them at the moment of decompression
Since then I swear by Velox cloth tape.

PS: According to my lbs you can use presta tubes on rims drilled for schraeder

[john_roberts]

Good thought Dave - I'm going to order some new inner tubes and I will have a look at rim tape too. The inner tubes and rim tape on the bike seem in very good order, but if I have problems (or more problems than before) then I'll refit the tyres and make necessary changes.

Are you running the same Conti's? If so - how did you find them compared to the knobblies? I had the utmost confidence in the old tyres and never thought twice about any terrain. What sort of limitations have you found with them?

[DaveP]

On the road, good, hard wearing, comfortable, reasonably puncture resistant. I'm also quite happy using them to travel over firm dirt. Just try to remember that they wont let you turn and stop as well as a knobbly would
And wet grass becomes highly entertaining!

[john_roberts]

I need some entertainment in my old age

I've been *so* used to the knobblies, now I've fitted these my MTB looks like a road bike

[Ambermile]

Keep your knobblies for "Winter" riding

I have a Winter set (with *huge* Tioga 2.5x2.3 beasties) and a Summer set (Schwalbe Road Cruisers) and I swear that when I swap them over I lose 2 inches! Not to mention the noise difference...

Arthur

[john_roberts]

Thanks Arthur - I intend to

All the bits and bobs I've recently updated on the bike are to be kept so I can restore it back to original if I need to. I'm also glad I bought a cycle computer with 'bike 1' and 'bike 2' settings as I've lost some height too. The tyre doesn't rest on the Black & Decker Workmate handle anymore when I put the bike in the garage

[squeaker]

PS: According to my lbs you can use presta tubes on rims drilled for schraeder

IME Schwalbe Presta tubes have a valve stem collar with a reduced diameter bit that locates inside the Schraeder sized rim hole: neat

[insanityideas]

Putting oil into the hub bearing is bad.. the oil will dilute or disolve the grease reducing its effectiveness, which will initially manifest itself as smoother faster running bearings (tho only very slightly so) as the grease is removed, then you will get excessive wear as the grease is no longer there to protect the bearings and the oil has long since moved out of the way (its not designed to lubricate bearings which carry that sort of load). The ball bearings will then proceed to destroy themselves and then the more expensive ball bearing races and axle. I wouldn't worry about this too much if it was just a squirt just the once, but don't keep doing it!! Unless you like dismantling your hubs changing the bearings and re-greasing them all the time.

[john_roberts]

Don't worry, I didn't touch the hubs at all as they run smooth and fine as they are.

I've been out a couple of times on the tyres and am very impressed with grip levels, though the ride is somewhat harsher on the more serious off road stuff (rough stone tracks etc) than the knobblies, but I can't have everything! On the road they are much superior, though I miss the 'whine' of the old tyres - I no longer sound like a worn out 1950's tube train

I only had a problem with handling once, along a 100 metre section of bridleway the bike completely lost control. I looked down to find I was riding on 2-3 inches of sand covered by dirt! I doubt even the knobblies would've coped with that, but I managed to get to the grass verge and could proceed with no problems albeit a lot slower!

Best top speed ever achieved on a certain short road section 22.2mph was shattered by 26.8mph on my first run on the tyres. Not bad for an old MTB and knackered rider