Linear recumbent tyre advice

DIscuss anything relating to non-standard cycles and their equipment.
a.twiddler
Posts: 62
Joined: 4 Jun 2009, 12:17am

Re: Linear recumbent tyre advice

Postby a.twiddler » 8 Aug 2020, 2:54pm

Update on fitting a Schwalbe 20-438 on a 20-440 rim.

Well, it went on with not much more than thumb and heel of hand pressure as the wheel does have a well. Even so, I snapped a plastic tyre lever initially getting the old tyre off. It was as if it had been on so long that it had glued itself to the rim. Perhaps the legacy of someone using washing up liquid in the distant past? Nevertheless, it would make a useful spare if something terminal were to happen to the new one.

Feeling well chuffed, I replaced the original unpatched Schrader valve tube with a Presta valve one I had acquired in the meantime to match the rear. I packed the old tube away to use as a spare.
This is easy, I thought. No washing up liquid or talc required. However....

I pumped it up to recommended pressure and it looked lopsided. I pumped it up even further and it looked worse. 58psi max. Oh well, get the washing up liquid out. Then followed a couple of hours of sweating in the sweltering heat as despite all efforts with unfeasible amounts of washing up liquid, air pressure (I drew the line at 120psi!), assorted toe straps and a selection of stern words the tyre would not sit straight on the rim. I went off for a shower and my tea and returned to the fray a little later.

I removed the tyre and tube, pulled out the old rim tape which was actually plastic insulating tape (many layers), cleaned up the inner rim and well, then as I didn't have any spare rim tape, dug out some PVC tape from my electrical box. I checked the spoke ends for sharp edges, all smooth fortunately, then carefully wound the new tape tightly, seating it in the well. About 3 layers. Then followed another couple of hours of stern words, assorted toe straps, excess air pressure and judicious application of washing up liquid. The end result was not 100% to my eye, but the centre tread was central when spun. The reflective strip on the sidewalls emphasised any slight imperfections in the seating but as far as I could tell, it was OK.

I put the wheel back on, intending to test it the next day.

Next day dawned, and the tyre was fine. The centre tread is visible from the driving seat and it was perfectly central in its rotation. There is no unevenness in the feedback through the steering.

So, would I fit one of these again?

Points for :- it now matches the rear being black, with a reflective stripe, and having a kevlar belt. It is a Schwalbe, so ought to have a decent chance of longevity. It is easy to get on and off the rim. Availability "ought" to be OK in the future if it continues to be a Dutch standard size.
Points against:- Although it is easy to get on and off the rim, will it seat easily again now that it has been fitted, in the event of a puncture on the road? Will it matter that much, bearing in mind that it will at least get me home, where I can attack it with garage equipment.
Only time will tell.

a.twiddler
Posts: 62
Joined: 4 Jun 2009, 12:17am

Re: Linear recumbent tyre advice

Postby a.twiddler » 10 Aug 2020, 3:33pm

After a good run out yesterday I can confirm that the 438 tyre rolls fine and runs true. It looks fractionally narrower than the 440 it replaced and It may be my imagination but just feels a little more precise in steering feedback than the one that was in place before.

Now that I am becoming bolder and going further I am thinking more about the braking. I put a set of Fibrax blocks on the rear about 100 miles ago and initially they weren't too effective. Now they have bedded in they are still not too impressive, but they do stop predictably. There is no danger of leaving a skid mark when stopping (at least, not on the road). The caliper brake will never be as good as the discs on my tourer but I have considered Nigelnightmare's suggestion re ordering a set of Clarks MTB blocks. I have a set of dual compound ones ready to go on but I feel like giving the Fibrax ones a little longer just to give them every chance. I am all for conservation of momentum, and do my best not to turn my hard earned forward progress into hot wheel rims but sometimes you just have to be able to stop!

The front drum while not being massively powerful has more power than the light front end can apply to the road, and has loads of feel, so complements the bike well in my opinion.The extra weight of a drum is also in the right place in this instance.