Re-gearing a bike?? Know anything about it??

**ktee** · 24th December 2006, 12:02

I am looking at a Triumph Bonneville on Trademe Auction 82288692. To quote the owner ..... "Removed air injection system, and regeared to make a much better ride. Standard a T100 cruises at 100ks doing 4,200 rpm now its 3,300 rpm at 100ks in effect gives you another gear."

What does this mean and is it a good thing to do to a bike? How will it change it's performance? I have test ridden a standard version and am dubious about this one as I don't understand if the regearing is a good thing or not. Can someone explain it from an unbiased opinion? Cheers

**onearmedbandit** · 24th December 2006, 12:12

Just means he changed either the front or rear sprocket. Very easy to put back to standard with the right sprockets. Will affect your speedo if the speedo is driven by the gearbox, if it's driven by the front wheel it won't be an issue.

**Gremlin** · 24th December 2006, 13:43

OAB is correct on all points... and correct me if I am wrong, but he has either gone down at the back (in number of teeth) or up at front.

Effect would be lower revs at 100 (as he points out) which means less acceleration but if the bike can use it, higher top end.

**onearmedbandit** · 24th December 2006, 15:48

Yep, you're right.

**Bonez** · 24th December 2006, 15:58

The air injection system is to lean the bike out for emmisions control purposes. Removing it also make spark plug access easier. Shouldn't be a problem if the bike was tune after it's removal. Some owner reveiws here if that helps-

http://motorcycles.about.com/library...evbikes025.htm

**ktee** · 24th December 2006, 16:24

That helps.

**Ixion** · 24th December 2006, 17:21

Higher gearing makes for relaxed straight road touring. At the xpense of lousy traffic light acceleration, and more gearbox work on twisty roads.

All depends on what sort of riding you want. I'd think it was good. But that's me. Not good at all if you want to use the bike for commuting.

**Paul in NZ** · 24th December 2006, 17:33

Personally - that seems like quite a big jump he is quoting?? Doubt it would be required but I've never ridden one so WTFWIK

**Gremlin** · 24th December 2006, 18:09

I lost a tooth or two at the back, when I had to replace the sprockets on the 7, and didn't realise that it wasn't stock. 1 or 2 teeth (depending on which spec you seem to read, resulted in about 500rpm drop, at 100. People told me there shouldn't be much diff, but I'm pretty damn sure I noticed it wasn't as peppy... could have been my head tho.

Cheers OAB, was sorta checking for myself too, to make sure I had it correct

**release_the_bees** · 24th December 2006, 18:56

I've changed the gearing on every bike I've owned. Mainly due to the fact that I've pretty much only owned small capacity bikes, where gearing can make a MASSIVE difference in performance (Edit: use-ability)

Basically, the way I gear my bikes, is that if 6th gear is only used much over 100-120km/h then it is too high for basic road riding, so I lower the overall gearing, which give more acceleration out of the corners. Obviously the same consideration need to be taken into account for 1st gear too, or you may end up with a 1st gear that maxes out at around 15km/h.

Obviously the only way to figure out whether the gearing suits your needs is to take the bike for a spin and note how easily it takes off from a standstill, how fast it accelerates, and at what speed top gear becomes a useful asset. If you do feel that the gearing is too high (the bike is sluggish off the mark, and 6th gear is almost unusable below say 140 km/h) then don't discount the bike. It only costs $20-$40 to change the front sprocket, so it is not massively expensive to play with the gearing; hence the reason it is often changed..

Hope this helps. I've had a few pre Christmas wines and beers, so apologies for the long-windedness of the post.

**ktee** · 24th December 2006, 21:45

I have just brought the bike and can finally say goodbye to the GN250.

I appreciate all of your comments and they helped me to make this decision except I wont be riding it just yet as I broke a rib on Friday when a cager pulled out on me and I missed him but hit the curb and being my first off (on a test ride .... how embarassing) I held onto the bike which I know I shouldn't have done. I have lots of bruises but loved the bike. Cheers

**bluninja** · 24th December 2006, 22:05

Congrats on the new bike. Sorry to hear about the rib, hope nobody makes you laugh too much until it's healed.

**jafar** · 24th December 2006, 22:08

nice bike ktee.

**ktee** · 24th December 2006, 22:13

It is very nice and the best thing is I know how it responds in an emergency as it is the same type of bike I rode on the test ride, except that one is a little worse for wear. I felt really stink...but the guy in the car felt worse.