first sprint triathlon bike advice

A road bike will be more than sufficient.  I'd advise buying used so you can upgrade once you really decide this is for you and what you want.  Don't be too concerned with the best or newest, if you're just learning how to ride then an aluminum/105 will do just fine! 

New or used, fancy or not, you need to find a bike that fits.  That is the single most important thing.  And there in lies the caveat with used bikes.  You shouldn't buy a used bike without being able to try it out first.  If you do go the used route then take some time and go to your LBS and try out a few different models of new bikes before hand to get a feel for how a properly sized bike should feel (every manufacturer and model will be a little bit different.  That should give you an idea of what geometry to be looking for.  If you decide to go the new bike route just about every manufacturer has an entry level road option that will be good enough to last you a couple years until you're ready to get something nicer.

thanks for the advice

I've also been into a bike shop and they recommended a hybrid as I will be training a lot on canal tow paths and they thought a road bike might not be robust enough. Any thoughts on doing a sprint triathlon on a road bike?

I would find another bike shop if they told you you need to get a hybrid because a road bike is not robust enough. What do you think the pros ride on the cobble stones in Europe. A road bike will be robust enough to handle most paths you are planning on riding. Besides a road bike will work better for TRIs and serve you well for many years. IMO hybrids are a compromise between a road bike and a mtb. You end up with a bike that isn't very good for either type of riding.

thanks again - road bike it is

A road bike would definitely be better than a hybrid for long term use.  However, I have to ask how rough the paths you plan on riding are.  A road bike may be able to withstand lots of abuse but that doesn't mean that riding it in rough condtions is going to be any fun.  Not to mention trying to keep the wheels true. 

IF  and I say IF,  your gonna ride paths alot and are not interested in road riding outside of triathlon races then there is another option which may not be the most popular but i think may serve your purpose. 

I have a trail (25mi) within a block of my house and I used to prefer trail rides to road rides so I know where your coming from.   A couple of road rides on a road bike and I got over it and now do 95 % of my training on the open road.   

I also agree a hybrid is a bad road bike and a bad mountian bike combined into 1 OK commuter bike.

If your convinced your gonna stay on the trail, a cyclocross bike is a better option.  Go to the LBS or look at bikesdirect.com
 

Just to add to that.

A cyclocross bike is similar to a road bike from a geometry stand point... there are differences but they're minor when compared to going road to hybrid.  The biggest difference you will see is the frame accomodates a wider tire size and most cyclocross bikes come stock with nobby tires.  Even though the tires are wider there still in most cases on 700c wheels.  Which means, again in most cases, you are riding the same size as a road bike.  For that reason you can put road tires on the bike.  If your so inclined you can get a set of race wheels / tires. 

When you put road tires on a hybrid you know your on a hybrid.  When you put a road wheelset on a cyclocross you will have a hard time telling the difference.  I have a number of friends that prefer the cyclocross bike because they can use the nobby or semi-nobby tires to train, ride, commute in bad weather or ride trails / paths when out with groups.  Then turn around and add road tires and race on the same bike 2,3,4 times a year.

I may get bashed for reccomending that as an option but think its far superior to the hybrid plan. 

thanks again - lots more useful information there

As well, if I may add, I was a beginner last year and did my first super sprint in September as a xcross training for a 1/2 mary. Well, did not have a bike so went to me LBS, they also recommended a hybrid. Loved the bike, loved the tri, now that I'm hooked, hate the choice of a hybrid over road bike. Now shopping for a road bike. Will keep the Hybrid as a great bike to ride with kids but should have bought a used hybrid and would have more money to put on the road bike. The one race was ok, you can do your first race on pretty much anything! I even saw MB. But, you will soon want to get the perfect bike for you! SO, I concur with the others...Road bike! Unless the path you will be training on is too rough, then the other option but unless you want to casually ride with the family more than training, Hybrid is a bad choice. Bad road bike and bad MB!

First: Don't blame the LBS! Once you say trail / unpaved and beginner, the most economical and likely best choice IS a hybrid / fitness bike. I know this is a tri board, but when a customer declares that as a primary use for the bike, a hybrid is likely going to be the best option. Besides, bikes like the Trek7.X series are well made, very good bikes for a large set of customers.

I completely agree with the OP that, for a triathlon / trail use, a cyclocross bike is a better option here. I sold one to a woman in this exact circumstance and she was VERY happy with her purchase.

Best value in cyclocross is likely Kona Jake or a Redline conquest. Both are very well made 6000series aluminum bikes, ready to race and/or ride almost anywhere. Mixed 105 / Tiagra components will give excellent performance and durability.

I would NOT argue for a road bike in this instance. A road bike should be ridden on asphalt. The limited tire choices and poor performance of slicks on soft pack will be a challenge. I've ridden gravel roads on a road bike and traction and mud clearance is an issue. Besides, entry-level components aren't quite durable enough for those conditions on a daily use.

Swap out the stock tires for a set of road dedicated slicks are you're ready for triathlon.

PITT83:
Sorry if I sounded negative about LBS. Did not mean to, Matter of fact, I'm going back to same LBS for my Road bike. I'm an adult, I did buy what I thought I needed. Like I said, I love the bike, just I regret settling for the Hybrid. The cost of Road bike was impressive for a first timer, so went with the Hybrid not knowing if I was going to stick with it! Now, I'm hooked to tris and need a new bike! I never said it was the LBS fault! Thanks for the 2 cents though!

Its not anyones fault... Its just the default position at a store when you say recreational riding and maybe a tri is the hybrid.  Had you been steered towards a cyclocross last year you'd be a seatpost, aero bars, and wheelset away from having a pretty decent tri set-up and could ride trails, paths, gravelroads, ect.  They're great multi-purpose bikes IMO.  Certainly nothing wrong with the hybrid option though, its just unfortunate that you made the investment and are already looking for something else.