Alan B
100 GW
HPA is not for everyone. I don't carry it on the bike, at least thus far. It is the best solution I have found for topping up truck/trailer tires. The small 13 cubic inch 3000 psi bottle is pretty small, but still more than I'd carry routinely on the bike. Any of these bottles could easily be carried in a support vehicle, but an 18V compressor is probably a better choice. More on that later. I presented the HPA here more as something interesting than proposing it as a solution for anyone.
I don't have any 25g CO2 cartridges, I'll have to get some. I haven't tried that size cartridge, I have used 12g non-threaded which are far cheaper here than any other size (per g). Best price I see for 25g is about five bucks each, and the 12g are about 25 cents, so 10 times the cost (per g). Also if you don't use all of a CO2 it is likely to leak out before you need it again, and with the 25g this could increase costs further, but if 25g was the right quantity it would be more convenient than using two 12g. I see the 20g may be cheaper than the 25g (per g). There are quite a few CO2 size choices. Best to choose one that fits your tires, which is hard to do if you are mostly helping others, or even yourself having several bikes.
One problem with any of the small CO2 cartridges is that about a quarter of the CO2 sublimes directly to solid when the cartridge is used to fill a tire quickly. Using the rest requires waiting for it to gain enough heat to convert back to gas or liquid. Most folks discard this if the tire needs more and puncture another cartridge.
Even the cheap 12g CO2 is quite expensive compared to bulk CO2. I pay about a dollar a pound for bulk CO2 (swapping refilled 20 pound bottles). That's about 3 cents for 12 grams or 5.5 cents for a 25 gram quantity of CO2. The smallest refillable paintball CO2 bottle I have holds 9 oz which is a lot of CO2 for bike tires. These tanks have good valves and don't tend to leak, at least not for some years. This might be good to carry on a group ride to keep the whole group going. The HPA tanks are about twice the bulk of the CO2 tanks for a similar amount of output volume. They are cheaper to fill and faster to use, and don't get as cold when using them. But CO2 wins for minimum bulk.
I have carried hand pumps, 12g and 16g CO2 cartridges on my ebikes and I never use them, at least for my tires. I have used them to help others on many occasions. When I get a flat it has been close enough to home or work that I just push the bike. I specifically chose tires for this bike (the GreyBorg of this thread) to avoid flats. When I was commuting and using this bike daily I was averaging one flat per year, and it was always a nail of some type, and it was always near home or work where the construction tends to be located. My path in between doesn't tend to have such hazards, though plenty of glass is present it doesn't threaten the thick moped rubber.
If I got a flat somewhere else on my ebike I would generally not fix it in situ, I would arrange to transport the bike back home for repair. At least on my non mid-drive ebikes, like the Borg of this thread, it is quite difficult to fix motor hub flats on the road (and it is always the motor wheel that gets the flat). The Borg's moped tires and rims require serious tools to support the heavy bike and to remove tires and to work on them. The hubmotor itself is about 30 pounds. I have the tools (purpose made steel tools over 12" in length) and did it a few times before I started taking them to a motorcycle shop for this work. That shop is gone now, next time I need to I'll have to decide to use my tools or just find another shop. But it is a struggle even with these tools. Shops use air powered tire machines rather than levers for this work.
Bicycle tires are another matter, generally not hard to work on. But hubmotors complicate things. If it is not too bad putting in more air might get one home or to some point where the bike can be transported. For that a hand pump might not be quick enough, and the CO2 supply might not last long enough to get home unless you brought a 12 oz paintball CO2 bottle.
I hear that tubeless is really the way to go and makes fixing flats much easier, and Stan's really works better than Slime, but I haven't gone there myself yet. Maybe carrying some Stan's for emergencies would be useful to try and hobble along.
For ebike tires here is the best setup I have found around the shop or to carry in the support vehicle:
I have a number of different compressors, CO2 and HPA solutions for pressurizing things, and this little battery powered pump is the one I go to the most for bike tires and similar needs. It is convenient and fast. It has a great quick connect schrader chuck, and there's a presta adapter and ball needle onboard. It has a large easy to read gauge. The smallest Ryobi 18 volt lithium battery runs it for a long time, no need to use a heavy one here. About $30 at Home Depot for the tool with no battery.
I don't have any 25g CO2 cartridges, I'll have to get some. I haven't tried that size cartridge, I have used 12g non-threaded which are far cheaper here than any other size (per g). Best price I see for 25g is about five bucks each, and the 12g are about 25 cents, so 10 times the cost (per g). Also if you don't use all of a CO2 it is likely to leak out before you need it again, and with the 25g this could increase costs further, but if 25g was the right quantity it would be more convenient than using two 12g. I see the 20g may be cheaper than the 25g (per g). There are quite a few CO2 size choices. Best to choose one that fits your tires, which is hard to do if you are mostly helping others, or even yourself having several bikes.
One problem with any of the small CO2 cartridges is that about a quarter of the CO2 sublimes directly to solid when the cartridge is used to fill a tire quickly. Using the rest requires waiting for it to gain enough heat to convert back to gas or liquid. Most folks discard this if the tire needs more and puncture another cartridge.
Even the cheap 12g CO2 is quite expensive compared to bulk CO2. I pay about a dollar a pound for bulk CO2 (swapping refilled 20 pound bottles). That's about 3 cents for 12 grams or 5.5 cents for a 25 gram quantity of CO2. The smallest refillable paintball CO2 bottle I have holds 9 oz which is a lot of CO2 for bike tires. These tanks have good valves and don't tend to leak, at least not for some years. This might be good to carry on a group ride to keep the whole group going. The HPA tanks are about twice the bulk of the CO2 tanks for a similar amount of output volume. They are cheaper to fill and faster to use, and don't get as cold when using them. But CO2 wins for minimum bulk.
I have carried hand pumps, 12g and 16g CO2 cartridges on my ebikes and I never use them, at least for my tires. I have used them to help others on many occasions. When I get a flat it has been close enough to home or work that I just push the bike. I specifically chose tires for this bike (the GreyBorg of this thread) to avoid flats. When I was commuting and using this bike daily I was averaging one flat per year, and it was always a nail of some type, and it was always near home or work where the construction tends to be located. My path in between doesn't tend to have such hazards, though plenty of glass is present it doesn't threaten the thick moped rubber.
If I got a flat somewhere else on my ebike I would generally not fix it in situ, I would arrange to transport the bike back home for repair. At least on my non mid-drive ebikes, like the Borg of this thread, it is quite difficult to fix motor hub flats on the road (and it is always the motor wheel that gets the flat). The Borg's moped tires and rims require serious tools to support the heavy bike and to remove tires and to work on them. The hubmotor itself is about 30 pounds. I have the tools (purpose made steel tools over 12" in length) and did it a few times before I started taking them to a motorcycle shop for this work. That shop is gone now, next time I need to I'll have to decide to use my tools or just find another shop. But it is a struggle even with these tools. Shops use air powered tire machines rather than levers for this work.
Bicycle tires are another matter, generally not hard to work on. But hubmotors complicate things. If it is not too bad putting in more air might get one home or to some point where the bike can be transported. For that a hand pump might not be quick enough, and the CO2 supply might not last long enough to get home unless you brought a 12 oz paintball CO2 bottle.
I hear that tubeless is really the way to go and makes fixing flats much easier, and Stan's really works better than Slime, but I haven't gone there myself yet. Maybe carrying some Stan's for emergencies would be useful to try and hobble along.
For ebike tires here is the best setup I have found around the shop or to carry in the support vehicle:
I have a number of different compressors, CO2 and HPA solutions for pressurizing things, and this little battery powered pump is the one I go to the most for bike tires and similar needs. It is convenient and fast. It has a great quick connect schrader chuck, and there's a presta adapter and ball needle onboard. It has a large easy to read gauge. The smallest Ryobi 18 volt lithium battery runs it for a long time, no need to use a heavy one here. About $30 at Home Depot for the tool with no battery.
