A forum for owners of Yamaha TTR250 trail and enduro bikes!

peteBLUEttr · Super Guru

Who runs a rim lock on the FRONT??

alanwebbo · Veteran Member

The risk is that the tyre creeps on the rim and rips the valve out of the tube. Considering you can accelarate from 0 to 60 in say 15 seconds.. You can probabley stop from 60 to 0 on dry tarmac in less than half of that.. So the front brake is around twice as powerful as the engine. In my opinion you are more likely to loss grip off-road before you cause the tyre to creep, however if you have to do an emergency stop on the road between trails (assuming you havent pumped the tyre back up) there is a real possibility of tyre creep. I would rather run with one in just in case.

locky · Guru

Yes i have one on the front for the same reason as above.

peteBLUEttr · Super Guru

There is argument that you can get unbalance on the front if you run one.... Any experiences?

alanwebbo · Veteran Member

It is usually opposite the valve so would most likely need a little weight adding close to the valve. I have never bothered to balance knobbly tires and can't say it has ever bothered me. It would only be an issue at higher road speeds. If you were doing a lot of road work, more road biased tyres and road pressures would be sensible, in which case you wouldnt need a rim lock.

peteBLUEttr · Super Guru

I think its definitely sensible if you are going to have to possibly change a tube on the trail, because you cannot set the bead back on the rim (30psi plus)with a bicycle pump, and there's a much higher chance of the tyre spinning on the rim if the bead of the tyre isn't actually set on the rim properly, at least not until you get to the next petrol station anyhow. Maybe some people carry massive hefty compressor inflators with them on trail I dunno?!...

alanwebbo · Veteran Member

I have used these pages.ebay.com/link/ when stuck

-- Edited by alanwebbo on Monday 15th of June 2015 07:18:54 PM

peteBLUEttr · Super Guru

I have seen those before they seem pretty good idea, you would need somewhere between 4 and 8 of those 16g cartridges to set a bead on the rim...

alanwebbo · Veteran Member

Blimey.. How big are your wheels ??? I normally use a bicycle pump until my arm gets tired or i get bored...Whichever comes first.. Then use the canisters to finish the job off.. Never needed more than two.

-- Edited by alanwebbo on Monday 15th of June 2015 09:30:04 PM

pug · Guru

12V Pump get one like this take the plastic case off it's very small and will pop a tire out on to the rim. have had one in my tool kit for years they can be had for a fiver if you look hard and when it's out of the case it's smaller than a lot of the very expensive bike one's

Pug

www.ebay.co.uk/itm/NEW-12V-COMPACT-BALL-BIKE-AIR-COMPRESSOR-CAR-VAN-PUMP-TYRE-INFLATOR-BICYCLE-/161701782142

-- Edited by pug on Monday 15th of June 2015 09:12:53 PM

peteBLUEttr · Super Guru

Pug your toolkit must be massive! You seem to carry an awful lot!, dunno never seen those cartridges in use on a bike yet, the listing just says 4 for 30psi on a motorcycle, so it poss you would need to use up to 8 to get the tyre bead to pop out.

-- Edited by peteBLUEttr on Monday 15th of June 2015 09:48:26 PM

ttr steve · Super Guru

pug wrote:
12V Pump get one like this take the plastic case off it's very small and will pop a tire out on to the rim. have had one in my tool kit for years they can be had for a fiver if you look hard and when it's out of the case it's smaller than a lot of the very expensive bike one's

Pug

www.ebay.co.uk/itm/NEW-12V-COMPACT-BALL-BIKE-AIR-COMPRESSOR-CAR-VAN-PUMP-TYRE-INFLATOR-BICYCLE-/161701782142

-- Edited by pug on Monday 15th of June 2015 09:12:53 PM

That is the same as I have, used it loads and only takes up a tiny piece of space when stripped down of the casing. Have a mousse in the front now though and may run one in the back soon, so no need for all that stuff smile smile

peteBLUEttr · Super Guru

Hmm mousses are good but I like to be able to go over 50mph!... biggrin

ttr steve · Super Guru

peteBLUEttr wrote:
Hmm mousses are good but I like to be able to go over 50mph!...

Not a problem, done 65+ on mine. smile

peteBLUEttr · Super Guru

Is that because you put loads of lube on the mousse I guess? Bit of a pain changing it back to tube for the m.o.t?...

ttr steve · Super Guru

peteBLUEttr wrote:
Is that because you put loads of lube on the mousse I guess? Bit of a pain changing it back to tube for the m.o.t?...

Loads of lube pete, also rim lock, less movement and friction. and as for the mot.... cut an old valve off and put it in the hole in the rim and no one will know the difference wink wink

brindabella · Senior Member

regarding the original question - I wish I had installed a front rim lock (and appropriate balance weight) because last weekend I had to get the tyre levers out to re-position a front tyre which had pulled the valve to a dangerous looking angle - the reason for it was my negligence - with dunlop 606 tyres, they are such a hard compound that you barely notice the difference in ride as the pressure get near ZERO over time, but of course the tyre still creeps around the rim when ridden. However I wouldn't be too worried about getting the tyre perfectly seated with high pressure on a trail-side repair - it is just not that important in my opinion, and will likely fix itself after a bit of riding, without any tyre creep side effect as long as there was a moderate pressure in the tube.

TTRfan · Super Guru

Even the French have blackthorns cry

Caught a big one and the rear went flat very quickly. So much so that I didn't even try the aerosol puncture repair and assumed the valve had ripped or a big snake bite had occurred.

I carry a Slime compressor (much cheaper 12V inflators do the job just as well) in my headlight bag. I fitted a new tube and left the compressor running until the tyre had seated and then adjusted the pressure.

The compressor was also use on my bro's car as he has a slight leak on one - he thinks coz of the ally rims. Put it up to 40lbs no bother.

Brian

9 June 2015 010.jpg

peteBLUEttr · Super Guru

Mixed opinion then, but most people say use one. Quite a number of people via internet search do say no need to use one on the front if you don't run lower than 15 psi though. Different circumstances, different tyres etc I guess. I think those tyre inflators cartridges are worth buying, couple in your kit wont take up too much room and your likely not to use them too often. In my mind its pretty important to make sure the bead is popped out after changing/repairing a tube.. smile

TTRfan · Super Guru

Definitely recommend rim locks fore and aft!

A tip I was given was to file the valve holes in the rim slightly oval so that it is easier to see the valve start to move......

Regarding air cartridges, there are some disadvantages. If you have a puncture caused by a nail, wire or thorn then its useful to use a compressor to determine whether it's one hole or more. Also, if you are in a position of having too patch the tube then its useful to check that there is no air leak before replacing the tube. I could be wrong but I think the cartridges are all or nothing and, once started, totally discharge in which case you would need to carry a few. Is that the case?

Always happy to be put straight biggrin biggrin biggrin

Brian

alanwebbo · Veteran Member

You are right Brian, i carry the same kit on my old brit bike (which doesn't have a battery) and the TTR. i have a small bicycle pump which fits in the tail bag and a couple of cartriges. I use the pump to find the holes (as luck would have it i had a puncture in a stream on the isle of man last time i used it) and the cartridges to finish the job off if i struggle to get the tyre seated. I only carry a spare front tube which will go in the rear in an emergency.

-- Edited by alanwebbo on Tuesday 16th of June 2015 05:55:12 PM

peteBLUEttr · Super Guru

What is this Brit bike you speak of

brindabella · Senior Member

just effectively adding to my post above: I agree with Brian that filing the valve hole into an oval is useful - I did that, and I may have missed the "creep" if I had not done it. Regarding inflation methods, cartridges are nice, but bicycle pumps are pretty much fail safe, as long as you have a bit of time for the pumping chore (ie you are not competing in an enduro), and you can do it a second time if needed, and one pump will do for a group of riders. Since many bicycles run much higher pressures than dirt bikes, you could probably even pop the bead with a small bicycle pump, but it may be tedious. Often bicycle pumps have an adjustment which puts them into a high pressure pumping mode where each stroke delivers less air (making it easier but needing more strokes). I was definitely NOT saying don't bother about popping the bead in general - just saying that if you are out on a dirt track in a forest and have repaired/replaced a tube, there is no real need to obsess about it at that time, and it may just pop out by itself after a few bumps along the track, and if it doesn't you can fix it when you get back to civilization.