Solé Bicycles leads with a 15% off code on bicycles, which works well for most shoppers buying a single bike at full price. That code cannot be combined with other promotions, so your choice comes down to comparing it against the public sale deals and the 10% options that might apply to your specific purchase.
Buying a bike at full price on your first order. The 10% off first order codes will beat the newsletter signup with a straightforward saving. If you are not a new customer and qualify for the main 15% off code, that gives you a larger discount than any of the 10% offers. On a $1,200 bike, for example, the 15% code saves you $180, leaving you $1,020 to pay.
Buying from the sale. The e-bike sale offers up to $650 off selected models, which may well beat 15% depending on the bike's price. The broader 15% off sale products deal also applies to any marked down item. Check the original sale price first: on a $2,000 e-bike marked down by $650, the sale discount leaves $1,350 to pay and beats a 15% code (which would save $300 from the full $2,000 price). On a smaller markdown, such as a $800 bike on sale for $700, the 15% off code delivers better value, saving you $120 from the full price to leave $680 to pay, against no additional saving from the sale discount alone.
Choosing between the codes. If you are eligible for both the 15% offer and a 10% option, take the 15% code, as it saves more money on any purchase. The 15% code cannot be combined with other promotions, so you cannot stack it with a sale or newsletter offer. If you are a first time buyer and the sale is not an option, the 10% first order codes and the general 10% offers deliver the same saving, so either one works; the 15% code is a better choice if you qualify.
Comparing to a public sale. If a bike is on sale and the public discount is larger than what the code would give you, take the sale price without a code. You can always test both the code and the checkout price and pay whichever is lower.