Author Topic: Rigida Chrina - BIG MISTAKE (Read 35859 times)

ran doner · « **Reply #50 on:** 19 September, 2012, 10:28:39 pm »

Just had my first experience of putting a tyre on a new chrina rim and thought of this thread...

And it went on OK. Struggled getting the first bead on but then twas OK. No levers required.

Tyre was a Conti GP 4 Season 25mm variety.

Viking · « **Reply #51 on:** 20 September, 2012, 08:21:54 am »

I have krylion carbon 25mm on my chrinas and have not had any problems fitting them. Mind you, I am not anal on insisting on not using tyre levers. I am not sure why anyone would be. I cannot envisage a time when I would not have them with the bike so why not use then?

Peter · « **Reply #52 on:** 20 September, 2012, 08:26:59 am »

I don't think it's anal to want to reduce the chances (which are there) of knicking the tube as you use the lever, is it? It's rare but it happens. Tyre levers are pretty handy for getting a tyre OFF, though!

vorsprung · « **Reply #53 on:** 20 September, 2012, 01:52:22 pm »

Quote from: Viking on 20 September, 2012, 08:21:54 am

I have krylion carbon 25mm on my chrinas and have not had any problems fitting them. Mind you, I am not anal on insisting on not using tyre levers. I am not sure why anyone would be. I cannot envisage a time when I would not have them with the bike so why not use then?

If you use the levers to fit a tyre there's a good chance of a pinch flat caused by the levers themselves

Viking · « **Reply #54 on:** 20 September, 2012, 03:13:12 pm »

OK, I understand the risk. I am very careful to avoid it and, so far, it hasn't happened to me.

mcshroom · « **Reply #55 on:** 20 September, 2012, 03:39:44 pm »

Same here. I very rarely if ever put tyres on the rims without using levers, but I've never had a pinch flat.

tom_e · « **Reply #56 on:** 20 September, 2012, 03:58:18 pm »

I virtually always use levers - just look carefully to avoid trapping the tube. I thought it was just a proving your manhood thing, trying to do it with just fingers.

Quote from: vorsprung on 20 September, 2012, 01:52:22 pm

If you use the levers to fit a tyre there's a good chance of a pinch flat caused by the levers themselves

Er, no. Checking my own understanding round the web, a pinch flat is when the tyre bottoms out due to a hitting a sudden hard edge or low pressure. How would a tyre lever cause that?

Peter · « **Reply #57 on:** 20 September, 2012, 05:14:16 pm »

I think it's just usage: I think a flat caused by hitting a hole or cattle-grid and pinching the rim on both sides is more usually referred to as a snake-bite, whereas with the tyre-lever kind you pinch the tube between the rim and the lever.

zigzag · « **Reply #58 on:** 20 September, 2012, 05:17:00 pm »

if it's possible to get away without using tyre levers, why complicate things? one more thing to carry, break, lose, forget, waste time..

Biggsy · « **Reply #59 on:** 20 September, 2012, 05:30:01 pm »

"Pinch flat" is American for snakebite puncture. We all know what Vorsprung meant anyway.

I think it's fair to say it's normal good practice to fit your tyre without levers when you can.

Blodwyn Pig · « **Reply #60 on:** 20 September, 2012, 07:04:27 pm »

I've had my chrina rims for years, and had no problem fitting gator skins 28c, spec nimbus 28c, spec nimbus all condition 25c, and marathon kevlar, almost fall off. guess i'm lucky. with regards to rim tape, I always use 3 x winds of insulating tape.

tom_e · « **Reply #61 on:** 20 September, 2012, 07:46:27 pm »

Quote from: zigzag on 20 September, 2012, 05:17:00 pm

if it's possible to get away without using tyre levers, why complicate things? one more thing to carry, break, lose, forget, waste time..

Ah, I thought people carried them for removing the tyre, but were avoiding using them to put it on. If you're saying you can avoid carrying them at all then I can at least see the point.

tom_e · « **Reply #62 on:** 20 September, 2012, 07:57:55 pm »

Quote from: Biggsy on 20 September, 2012, 05:30:01 pm

"Pinch flat" is American for snakebite puncture. We all know what Vorsprung meant anyway.

Well forgetting the confusion over the term, I'm not sure about that. He said "there's a good chance of a pinch flat caused by the levers themselves". That just doesn't fit the facts - several of us doing it and not getting flats. Sure there must be some chance, it could happen. But a good chance? - no, that would imply it would happen a significant percentage of the time. It doesn't.

Quote

I think it's fair to say it's normal good practice to fit your tyre without levers when you can.

Good call. Ignore the awkward facts and appeal to authority. It is normal good practice. Me silly boy.

mattc · « **Reply #63 on:** 20 September, 2012, 08:09:07 pm »

So what is a "significant percentage of the time"? And what %age of cyclists do you and your several compadres form? Surely both are undefined.

If we're having a vote, _I_ agree with Vorsprung's statement. And I have seen the same opinion expressed more than several times.

It's the sort of thing that - if it happened at Dark O'Clock in the rain, miles from habitation - would be significantly upsetting!

tom_e · « **Reply #64 on:** 20 September, 2012, 08:32:33 pm »

Quote from: mattc on 20 September, 2012, 08:09:07 pm

So what is a "significant percentage of the time"?

In the sense of a "good chance"? Well your guess is as good as mine really, but I would say reading a "good chance" of the pinch flat would imply to the reader that maybe somewhere 10-50% of fixes might fail in this manner? It's an english comprehension thing, so could vary. If by a "good chance" he meant a few percent then sure, that might be possible, but I would query that language as misleading.

Quote

And what %age of cyclists do you and your several compadres form?

Erm, three of us noted above, divide by however many cyclists you think there are, multiply by 100. Not sure what the relevance of that percentage is.

Quote

If we're having a vote, _I_ agree with Vorsprung's statement. And I have seen the same opinion expressed more than several times.

It's not a matter of opinion - this is not dark voodoo, it's a concrete discussion of changing a bike tyre. It could make some difference to the chance of a trapped tube and flat - the question is if so and how much, not what different guys' opinions are.

Quote

It's the sort of thing that - if it happened at Dark O'Clock in the rain, miles from habitation - would be significantly upsetting!

No shit sherlock. But equally picture the poor person at Dark O'Clock in the rain ... who is sitting there swearing and bruising their cold thumbs because the tyre won't go back on. But they think they can't use a lever because it'll just give them another flat.

Peter · « **Reply #65 on:** 20 September, 2012, 08:41:51 pm »

tom, I don't think anyone is really thinking like that. I have seriously arthritic thumbs but can still get Marathon tyres on my Chrina rims without using levers. It's not a macho thing (although I am unbelievably strong!). I do this to avoid whatever anybody wants to call holes on the tube, in the certain knowledge that a lever that hasn't been used can't cause trouble, whatever the figures. When it gets too hard for me to do that, I'll take my chance with a lever, which I'll have with me anyway to take the tyre off.

I'm getting a bit puzzled as to what this is all about. You seemed to wanting people's opinions and then when you get them you want to argue about them. If you want to use a tyre lever, use it! I'm sure no-one who doesn't will mind

aidan.f · « **Reply #66 on:** 20 September, 2012, 08:50:18 pm »

Has anyone speculated that rigida rims vary a good amount in bead diameter? thus explaining the last 5 pages of posts, some find it easy, some hard?

tom_e · « **Reply #67 on:** 20 September, 2012, 09:09:22 pm »

Quote from: Peter on 20 September, 2012, 08:41:51 pm

I'm getting a bit puzzled as to what this is all about. You seemed to wanting people's opinions and then when you get them you want to argue about them. If you want to use a tyre lever, use it! I'm sure no-one who doesn't will mind

Yer, I suppose I am being a bit grumpy. Just get a bit annoyed when somebody states something as a fact when it doesn't seem to be true. Somebody on the internet is _wrong_ and all that.

mattc · « **Reply #68 on:** 21 September, 2012, 08:25:50 am »

Quote from: tom_e on 20 September, 2012, 09:09:22 pm

Quote from: Peter on 20 September, 2012, 08:41:51 pm
I'm getting a bit puzzled as to what this is all about. You seemed to wanting people's opinions and then when you get them you want to argue about them. If you want to use a tyre lever, use it! I'm sure no-one who doesn't will mind

Yer, I suppose I am being a bit grumpy. Just get a bit annoyed when somebody states something as a fact when it doesn't seem to be true. Somebody on the internet is _wrong_ and all that.

Yup - and I think it's you!

Quote from: Sleepy on 20 September, 2012, 08:50:18 pm

Has anyone speculated that rigida rims vary a good amount in bead diameter? thus explaining the last 5 pages of posts, some find it easy, some hard?

This has indeed been covered on another thread. All rims vary across production runs, but there have been posts suggesting that Chrinas went through a "step-change" quite recently. Hence the 'problem' posts are mainly about new rims, compared with smug "I've never had a problem in 5 years of use" type posts!

Its only really a theory from what I've seen, but there you go ...

Blodwyn Pig · « **Reply #69 on:** 21 September, 2012, 09:53:11 am »

[/quote]
compared with smug "I've never had a problem in 5 years of use" type posts!

[/quote]

SMUG! I don't do smug

Fact is fact, like it or not. now if we were talking about fitting Spc armadillo nimbus 26x 1.5 on to Sun rims, now there is a knuckle buster. ( In my experience!

)

saturn · « **Reply #70 on:** 21 September, 2012, 08:13:42 pm »

The very different experiences of people on this and other threads on the same subject make me seriously wonder the diameter of these rims is subject to variation. I've never had much difficulty with any other tyre-rim combination but found it nearly impossible to fit exactly the same tyres that go on other rim types easily onto the Chrina that I have. Then other people come along and say they've never had a problem with Chrinas.

hulver · « **Reply #71 on:** 31 January, 2013, 11:27:34 am »

My new rear wheel has one of these rims.

I fought to get the tyre onto it in the first place.

Fitting the guards last night, the tyre was too high, so I went to swap it for a 23c instead.

I can't get it off again. I've broken 2 tyre levers already.

Good job it didn't happen at the side of the road.

interested · « **Reply #72 on:** 31 January, 2013, 03:32:31 pm »

Quote from: saturn on 21 September, 2012, 08:13:42 pm

The very different experiences of people on this and other threads on the same subject make me seriously wonder the diameter of these rims is subject to variation. I've never had much difficulty with any other tyre-rim combination but found it nearly impossible to fit exactly the same tyres that go on other rim types easily onto the Chrina that I have. Then other people come along and say they've never had a problem with Chrinas.

As I understand it, the extrusion die that shapes the rim, is worn slightly larger for each rim it makes, thereby increasing the diameter of the finished rims over time.

Since dies are cost money, it is tempting to use it beyond its lifetime. The result is rims that are slightly "too small" at the beginning of the manufacturing process, and "too large" when the extrusion die is finally taken out of production, in short, a frustrating variation of the same rim model.

Polar Bear · « **Reply #73 on:** 31 January, 2013, 03:34:47 pm »

hulver,

When you get the tyre off change your rim tape for the thinnest gossamer butterfly wing tape that you can find.

The rim that was the subject of the OP punctured on my first long ride out, coincidentally my first audax for over 6 years. The tyre had been pumped up to over 100 psi and this seemed to make a big difference in removal and replacement which was mysteriously much easier.

I will look to something different when these rims are worn though.

fred the great · « **Reply #74 on:** 31 January, 2013, 04:06:42 pm »

May I suggest that a smear of washing up liquid on the last part of a difficult to fit tyre bead will probably solve such a problem. And use strong levers carefully

.

I have used the liquid for various other problems like this and it has never failed