Welcome to the latest installment of our Questions page. (Previous pages can be accessed by clicking the button down the bottom). This is a page where people can write in with questions, which I will try to answer. By putting the question on this page, it allows other readers to offer their answers too. There's a lot of experience out there to draw on! How does this work? Well, what happens is you send an email by clicking the "email" button at the bottom of the page, (the address, if you want to just cut-and-paste it into your email program, is as follows: email@example.com). I then try to answer your question as best I can, but also publish it here for readers to look at and give their advice or opinions. So if you see a question you can offer some help with, or even just an opinion, then send me an email and I will publish your reply too. Robert wrote in with an interesting question; asking when, in terms of years, should tyres be replaced? Now, you might think that this isn’t a question you’d have to consider, as tyres on bikes usually wear out long before you’d have to consider replacing them on an age-basis. But if you have a bike that you don’t use often – which I know some readers do – then this will be an issue you need to think about. Robert explains what inspired him to think about this, and asks what we think. “On a recent ride one of the guys was remarking that his bike was slipping with only mild lean. He is riding a 4 year old Suzuki CT50 cruiser on original tyres, with only 5,000km on the clock. So a couple of us suggested that his tyres have ‘age hardened’. Indeed if you rub your finger on a clean area of the tyre and compare the friction it generates to a new tyre it did feel slippery by comparison. “So my question is, have you any knowledge regarding safe age of tyres? I did find this web-site, and it suggest 6 years. But I am thinking that’s too generous.”
The Old Bloke’s Reply:
Well Robert, as the article you found points out (and as I’ve mentioned above), this is not a question most of us have to consider, as bikes generally wear-out their tyres before they out-live any kind of use-by date. But tyres do deteriorate with age, so there comes a time, if you aren't doing high mileages each year, when you would replace the tyres on an age basis rather than a worn-out basis. But how long is that? Well, I’m sorry, but I really don't know. I read the article in the link you provided, and looked at a couple of forums too, but there doesn't seem to be any definite figure on it. Part of the reason for that is due to the variables. Rubber deteriorates faster if left exposed to harsh weather conditions. So if your bike was parked outside in scorching heat, pouring rain, and freezing cold, all year round, then the tyres would age a lot quicker than if the bike was tucked away in a nice sheltered garage. Tyres deteriorate in two ways – break-down of the rubber (and the glue that holds the different layers together), and hardening of the rubber compound. The first is easy to check – look for “crazing”, or tiny cracks, in the sidewalls of the tyre. If the rubber looks old and starting to develop these tiny cracks, or a perished look, then you know that the rubber has deteriorated badly and they are definitely in need of replacement. Secondly, as tyres age the rubber compound gets harder, thus reducing the level of grip – especially in the wet. This is the tricky issue, as there is no definite way to check this – without seeing if you fall over going around corners, or braking hard, in the wet. And that's not a recommended way to check! This is affected by weather too, so once again, this deterioration will tend to happen quicker if the tyre is sitting in extreme heat, rather than being under shelter in a shed or garage. Another issue is the type of tyre and type of riding you do. A sports-bike doing track days will need really fresh rubber: I wouldn't want to ride around a racing circuit on tyres that were a few years old. (But if you were doing track days they'd never last that long anyway, so the problem wouldn't arise!). More casual use could see tyres being satisfactorily left on for longer; but remember that regardless of how you ride, if you need to stop in a hurry the tyre needs to grip well, regardless of how gently you might have been riding it beforehand. To look at your example, in my opinion I doubt the compound would have hardened that much in 4 years. Although it could be a good idea to check the date of manufacture – as suggested in the article – to see how old they really are. If the tyres are older than the bike (which is quite possible – the tyres may have been on the shelf for a while before being originally fitted), then they may indeed have reached an age-hardened state. Now, to try to answer the question in general terms, the article you found, and forums I looked at, suggested a period of between 5 and 7 years, so the figure of 6 years suggested by that article sounds reasonable to me. My personal experience with aged tyres has mainly been with cars. I am involved in the classic car scene, and classic cars generally do low mileages, so the tyres tend not wear out quickly. Hence cars can often be seen with tyres that are very old – some showing those age-signs I mentioned above. I have an old (now classic) car that doesn’t get driven very much, and it has at times reached a stage where the tyres needed replacing because the compound had hardened. This became apparent in the wet especially, when the steering felt lighter – I could feel the reduced level of grip. I remember many years ago I had tyres on that were several years old – they’d have been on the car for over 10 years. They felt okay in the dry, but in the wet they were like driving on bald tyres! I did have a bike many years ago that I didn't ride much (or very far), and the tyres on that got to be several years old (not sure how old now, but probably 6 or 7 years). So I replaced them. I wasn't having any trouble with them, but just thought they'd been on the bike long enough to be replaced for safety’s sake. On another occasion I bought a bike that had been unregistered for a long time. The tyres looked a bit old (and, logically, would've been), so I replaced them straight away. Well, not straight away: I got it registered first (so the tyres were certainly legal), because I didn’t want to spend money on tyres only to find out there was some issue that stopped it being registered. But as soon as it had passed rego, the tyres were replaced. So, I’m sorry, but I’m not much help on this really. So I’ll put it to our readers for further consideration and opinion.
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Readers' Replies: Patrick reckons the 6 year period is about right. He wrote, “This is in line with industry thoughts and links with my practical experience of car and bike tyre life. An aspect of leaving tyres on a rim for excessive periods that is seldom commented on - until one has to do it - is the horror of removing a tyre solidly welded onto a rim by rust, rot, age, and other intergalactic adhesives peculiar to mechanical transport! Tyre technology also changes; what was good 6 years ago is likely to be average today. Another good reason for a fresh-up on the rubber.” Yes, good point on the difficult removal. He mentioned reading articles in Choice magazine on car tyres. One tested braking performance in the wet. “Best braking performance from 80kph in the wet for tyres under test was 36m, worst 48m - 12 metres difference! Tyre performance didn't appear to be intimately linked to price either. For example, their test had an $80 dollar tyre at position 2 (wet braking performance at 70%, equal to the number 1 tyre's performance), while at number 8 was a tyre retailing at $149 (wet braking performance 60%). Limping last in their test was an $85 tyre reporting a 35% wet braking performance. Pretty scary stuff. I'm asking Choice to consider a similar test of bike tyres.” A comparison like that on bike tyres would be interesting! I hope they take your suggestion. Thanks Patrick. Ivor couldn’t quote a number of years, but confirmed the deterioration with age that happens. “I remember many years ago having a bike that had really old tyres on it – tyres that were on it when I bought it. I rode it on those tyres it came with for a while, but I felt that they weren’t gripping as well as they should. They would’ve been pretty old, so I bought some new ones. It was surprising how different the bike felt. Yes, they were a different brand, and a better tyre, so that had a lot to do with the improved feel and pereformance, but a lot of the difference was probably also down to the age of the tyres too.” Another reader raised the issue of whether the tyre was being used or not. He said that if a tyre is stored out of the sun in a constant temperature, it would last for many years. “Once it is used then it comes down to how many heat cycles the rubber has had, the type of tyre it is and what the owner expects of it (eg on what bike, ridden in what way).” He also suggested that if a bike wasn’t being ridden often, then storing it with the wheels off the ground was a good idea. He further added, “Manufacturer comments about age / lifespan have more to do with limiting their period of accountability than being a reflection of the genuine useful life of a rubber tyre.” Looking more specifically at the situation described by the reader, he suggested that further issues to consider were, “Tyre pressure and, potentially, how hard the rider was holding onto the handlebars. They’d be the first two things I’d look at in that particular circumstance.” He added, “I’ve ridden a range of cruisers, across a range of surfaces (including dirt) and I’ve not experienced tyre slippage issues on any of them, no matter which bike - some were old, some had pretty average tyres.”
LAYING IT DOWN.
Malcolm wrote to ask about ABS in certain emergency situations. “The other day I was sitting contemplating life, the universe and everything, and for some unknown reason my thoughts turned to the couple of times when laying the bike down was the best option. The first was on my 250 Motosport when at about 80 kph I spotted barbed wire stretched across the lane to turn the cows into a paddock, and decided that going under the wire was the best option. The second time was first time out after dark on my brand new Waterbottle when I met a car and turned the headlight off instead of dipping it, and then couldn't find the on switch after the car passed. With an eight foot drop on my left and a bank on the right, when I felt the gravel edge under me, and had no idea whether it was the one on the left or right, I again decided the best thing was to lay down. So the other day I started to wonder, if the bike is ABS equipped, how do you quickly lay it down in an emergency, as the only way I know to do it is to lock the rear wheel?”
The Old Bloke’s Reply:
An interesting question! I have to say that I have never intentionally laid a bike down. While I know there are times when it is the best action to take, something inside me rejects the notion of, “Now I am going to intentionally hurt myself!”. Mostly, I think there are more attractive options. But the scenarios you describe are ones where laying the bike down was by far the best option. Although in the second situation, I'd still be worried about either sliding over the drop or into the bank. ABS might have stopped the progress of bike and rider quicker than laying down and sliding. Maybe. Anyway, it's true (as far as I can work out!) that you couldn't effectively lay the bike down with ABS engaged. So if you need to take that course of action, you can't. I suppose it's all a compromise – the advantages of ABS I think far outweigh the disadvantages; but I suppose there are always situations where the disadvantages will be a major issue. What do our readers think?
Not a lot of response to this one - suprisingly perhaps. But here are a coupel of opinions we got. Robert wrote, “Like yourself, I have never intentionally laid a bike down, nor do I know anyone who has. I do remember talking about it with friends back in the day, when it seemed like a good strategy under some circumstances, but in reality I doubt it ever was. I only know of one instance where this has happened, in a GP race where the bike lost his brakes (or partly lost them). There was no way he was going to stop before hitting the kitty litter so he laid it down and took a long slide.” Ivor didn’t subscribe to the laying-down approach either. He wrote, “‘Laying a bike down’ is mostly, I think, another term for ‘crashing’! I remember when I was younger people used to talk about this as a way of avoiding a collision, but you don’t hear of it much these days.” So there you are. In at least one of the situations mentioned by Malcolm, it would seem that laying the bike down was probably the best action to take. But in most normal situations .... maybe not.
YAMAHA XSR 700 V APRILIA SHIVER
Keith wrote in response to my test on the Yamaha XSR 700. He said, “It’s a pity the XSR 700 has the LAMS motor; it took 3 years to get the normal MT 07 here, then they don't put the good motor in the new model. Yamaha have dropped the ball again! I was going to go down this path but bought a KTM 690 instead and for me it's a great bike, especially with the 3 mapping modes. How did it stand up against the Aprillia Shiver?
The Old Bloke’s Reply:
Hi Keith. The thought of comparing these two bikes had occurred to me too. So I'm glad you asked the question. Firstly, yes, I too think Yamaha made a mistake by not getting the “normal” motor here quicker in the MT-07, and not at all for the XSR700. The Shiver Versus the XSR700. Yes, that’s an interesting comparison as they are similar bikes in a lot of ways. They're both fairly sporty in character (I commented on the foot-pegs being a bit higher than I'd prefer with both of them), but the Yamaha takes a kind of retro path while the Aprilia is pure modern. Ride and handling were pretty good on both, but the Yamaha had a slightly more comfortable seat. The Aprilia is not ham-strung by LAMS restrictions, so it goes a lot better. And it has different mapping modes for the engine too; as you’ve found on your KTM. The Aprilia costs a couple of grand more: but note that the Yamaha's price is +ORC, while the Aprilia is ready-to-ride, so the difference isn't as great as it would appear. For me, I think the Shiver would get the nod. In many respects they are pretty similar, but the Aprilia has the power it deserves.
OUT WITH INNER-TUBES?
Robert asked if inner tubes should, “Go the way of the dinosaur?” He explains. “In your General section, Puncture Repair, you mentioned that you used to carry a can of goo but had never used it. Well, just yesterday one of group got a flat (a tyre with inner tube), used the goo, which totally failed to work. It was a rear tyre on a standard spoked rim. This has been my experience also, the tyre inflates then goes flat almost immediately. This got me thinking and I asked around but could not get a single positive experience of using the goo. The best result that I personally witnessed was being able to ride about 15km with an intermediate fill up along the way, it just got him to town and that was it. So, should the inner tube be gotten rid of in favour of mag wheels or spoked wheels laced to the exterior of the rim?”
The Old Bloke’s Reply:
This is an interesting one. I think tubeless is certainly better, but I understand the problem with spoked wheels. Although they can get around this by lacing the spokes to the exterior of the rim, as you say. One benefit of tubeless tyres is that they have a tendency to seal around an object that penetrates the tread - like a nail or screw etc. So a puncture is not the hassle it is with tubed tyres that just go flat as soon as they get a puncture. There's also an issue of heat sometimes: if the tube moves against the tyre, causing heat build-up. So, I'm inclined to go with you - I reckon we should faze them out. Of-road bikes will probably be the exception though. Yes, as I mentioned, spokes can be laced to the outside of the rim, thus avoiding the protrusion of the end of the spoke onto the tube, but there could be situations with off-roaders where a tubed tyre is preferable. Other than that though, I think tubeless is definitely the way to go. Any comments?
YAMAHA XJR1300 MODS?
Evan wrote in to ask our opinions on whether he should carry out certain modifications to his Yamaha XJR1300. He wrote, “So, as you know, I love my XJR. It is now the only bike I own and the only reason that I would change it, is if I bought another one. I have questions for you (and maybe your readers). 1.Should I fit progressive fork springs or will getting the suspension professionally set up be enough? I weigh 90kgs and don't carry a pillion or any baggage 99% of the time. Any suggested suppliers? 2.Fork gators; good or bad? Any suggested supplier? 3.Foam grips to replace the standard to eliminate the typical UJM handlebar vibes? Any brand suggested? 4.I am getting the bike dyno-tuned in another 1000 kms as my bike is fitted with a Delkevic pipe and K&N filter. It seems to need smoothing out. Any suggestions and supplier of any particular product?
The Old Bloke’s Reply:
I'm glad to hear you are still enjoying the XJR. Suspension mods? Hmm, I don't know: one reason I bought the XJR is that it has fully adjustable suspension front and back, so you should be able to get it adjusted to suit your preference. Having said that, I suppose there is always room for improvement with a top-shelf make-over. Talk to suspension specialists, if you have some in your area. If not, email or phone some and get their advice. I'm not sure of the exact spring settings of the standard units, but I think the standard fork springs are progressive-rate. In 2007 they did an update on the suspension (including adding some of the adjustments it didn't have before) and one thing they did was improve the suspension, eliminating dive under brakes. There are some good suspension tuners around, but I'm not sure which ones they are now. I'm trying to remember one that was in Melbourne I think, who were very highly regarded. And one in Sydney? Sorry, I'm hazy on this. Perhaps some readers can recommend businesses they know of. (I know one reader had some suspension work done from one of the top-name places). Fork gaiters were good back in my trailbike days (helped keep all that mud and dirt out!) but I don't think are necessary today - unless you do a lot of dirt-road riding. Yes, foam grips, or softer grips, I think are a good idea. Something I've been intending to do for a while myself. There's one brand of grips - normal rubber ones, but softer than standard grips - I've seen called “Cush-Grip” that seem good. There’s another brand I can't remember. (I'm doing well aren't I! Ha ha). I did buy a pair of foam grips a few years ago, but gave up trying to get them on. I could get one on okay, but not the other. (Even after trying old tricks like a touch of vaseline, hairspry, etc). Something to watch for too: the grips on the XJR are shorter than on some other bikes. The foam grips I bought, for example, I had to cut shorter to fit. If you buy rubber ones (with the flange on the inner end), make sure youget the correct length. Dyno-tuning certainly can't hurt - especially with the different can and filters. I'm not sure if there is an after-market ECU, but personally I wouldn't bother - the standard one seems fine, and you never know what changes an after-market unit might bring. It may give more total power, but perhaps at the expense of smoothness off low revs. You never know, really. I'd be sticking with the original, as it seems to work well. With regard to handlebar vibes, it has to be said that the XJR engine is not a totally smooth unit. The basic design is fairly old, and being air-cooled means internal tolerances are greater than on a more modern air-cooled design. There is a well-known vibration or harshness that comes in around 4,500rpm when cruising. That's a characteristic of the motor, and there's not much you can do about that. (Strangely, I have encountered a similar harshness at the same sort of revs on a couple of other Yamahas with totally unrelated engines!). If the chain is not adjusted correctly (if it is too loose) that makes it a bit less smooth too. I hope this is of some help. Hopefully some of our readers might be able to offer more suggestions?