nathanvgreene

I am currently 16 years old and would like to get into some actual road racing; however, after doing my homework, I realized that the Shimano 105 cassette on my new Trek Madone 4.5 will not allow me to qualify for races. The rollout for my 50-11t gearing will exceed the 26' restriction by 5 and a half feet. I've calculated that without changing the crank, my smallest cog will have to be 14t. This means blocking out my three smallest cogs...THREE!
I wanted to ask everyone's opinion on what path I should take: I could get an Ultegra junior cassette with gearing that would qualify, but I'm unsure of whether or not it will be compatible with my 105 STI shifting. I could also try to use limit-screw adjustments to block out the bottom three cogs, but that seems a little suspect and bad for the derrailleur. Finally, is there any way that I could just remove my 11,12,13t cogs and swap them out for other ones (16,18,20t maybe?) that would be compatible with the 105 cassette?

jsutkeepspining

just block out the gear. that's what i do.

tony2v

Simple, we just lock out the gears on our junior racers bikes.

chado445510

I started out with blocking the last three out. If you plan on racing seriously, buy the cassette. I bought the cassette 4 months into racing when i decided i would benefit from having the extra gears.

jsutkeepspining

yeah once you start going to nationals you need a jr specific cassette, but for a kid who is just getting into racing he'll do fine just riding a blocked out cassette.

nathanvgreene

So when you guys block/have blocked out the bottom three cogs, do you just use the limit screws? Will that affect my 10spd shifting to only be able to use 7 cogs?

mkadam68

+1 What chado said. No need to spend extra money unnecessarily.

Blocking out won't effect the shifting. The rear derailleur cable will be very slack if you shift all the way down (but the r.d. can't go there due to the limit screw). Shouldn't be a problem, though.

But, you may find the limit screws can only block out two gears. If that is the case, go to a hardware store and buy a (slightly) longer limit screw.

nathanvgreene

I like the idea of not spending any money, but I also feel like the new cassette would be good investment since I won't be able to ride my current one for four years in races

Homebrew01

Huh ?!?! The deraiileur doesn't care ... In fact it might be happy not having to work so much.

Do the gear restrictions change at different junior age groups ?

chado445510

Nope!

Best part is when you encounter a sprint with speeds about 35mph or so, the sprints in junior races sometimes end sitting down.

I understand the gearing restriction at my age, and I love the fact that there isn't any gaps in the cassette, but at 17 or 18 years old the kids are just about as developed as they're going to get and their knees would do just fine on the 11-25 cassette.

jsutkeepspining

i got gapped big time at the last training race, when the speed hit about 36 mph, i just couldn't spin fast enough. at 36 i was losing ground.

i've never been rolled out after a senior race, but I'm always afraid that the one time i don't have junior gears, they do a roll out after wards.

chado445510

Yeah i just did my first 1/2/3 race and the officials just waved me off because i placed about 35/100, so they didn't care either way. I can finish sprints, but like at killington where it was 43.5mph, there was a surge of people coming around me at the last 100m.

jsutkeepspining

yeah, i don't mind high speeds coming off of a downhill cuz there's little to know resistance or if i have to spin near 200 rpms i can just tuck, but on flats i always struggle to keep my rpms over 130.

nathanvgreene

Thanks for all the help guys, after discussing this with the other guys at the shop I work at, I decided to get the special cassette. I just wasn't willing to train and race on a 7spd bike when I paid for the full ten. It works awesome!